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[Display omitted] • Co-recycle of spent automotive catalysts and printed circuit boards was proposed. • Co-recycle can simultaneously achieve metal enrichment and detoxification. • Slag design, pollution suppression, metal distribution and settlement were analyzed. • Influence of copper size on platinum group metals recovery rate was discussed. The traditional pyrometallurgical recycling of nano-sized platinum group metals (PGMs) from spent automotive catalysts (SACs) is an energy-intensive process that requires the addition of large quantities of copper capture and slag-forming reagents. Similarly, pyro-recycling of valuable metals from waste printed circuit boards (WPCBs) is also an energy- and reagent-intensive process that and carries a risk of pollution emissions. Based on the complementarity of composition and similarity of recycling process, synergistic pyro-recycling of SACs and WPCBs allow copper in WPCBs to capture PGMs in SACs and oxides from two waste form slag jointly, which offers benefits of enhanced metal recovery, reduced reagent and energy consumption, and suppressed pollutant emissions. However, the mechanisms of PGMs capture and pollutant transformation in co-smelting remain unknown. Here, we investigated the sub-processes mechanisms of slag formation, brominates fixation, multi-metal distribution and kinetic settlement. Oxides in both wastes support SiO 2 -Al 2 O 3 -CaO slag formation with low melting point and viscosity, where CaO suppresses the emission of brominated pollutants. Copper (50–100 μm) from WPCBs facilitates nano-sized PGMs in SACs recovery through capture and settlement. The results of demonstration experiments indicated a recovery rate of 94.6 %, 96.8 %, 97.2 %, and 98.1 % for Cu, Pt, Pd, and Rh, respectively, with a debromination efficiency exceeding 98 %. The theoretical analysis provides support for the establishment of a synergistic pyro-recycling process for SACs and WPCBs and provides insights into the potential for a greener and more efficient co-recycling of multi urban mines. [ABSTRACT FROM AUTHOR]

Photocatalytic reaction shows great potential in environmental protection and energy conversion. However, it suffers from insufficient photocatalytic performance, which inhibits further application. The efficient separation of photogenerated charge carriers can contribute to the photocatalytic activity. Despite great progress in recent years, there is an absence of a systematic and solid understanding of the internal correlation between charge carriers' dynamics and photocatalytic performance. In this contribution, we focus on the photocatalytic mechanism and advanced modulation strategies of photogenerated charge carriers. In particular, the materials applied in photocatalysis are clarified and analyzed. Moreover, progressive techniques and theoretical calculations have been summarized to ascertain the transfer pathways of electrons and holes. Finally, the challenges and development tendencies in the future have been forecasted, which may be beneficial for the design of high-performance photocatalysts in solar energy conversion. • The latest regulation strategies of charge carriers have been summarized. • Correlations of photogenerated charge carriers and performance are explored. • Advanced characterization techniques have been reviewed. • The development of photocatalysis in the future has been forecasted. [ABSTRACT FROM AUTHOR]

Although numerous experimental studies on a hybrid thruster have been recently executed, a fuel port pressure was rarely measured because a gap between a fuel and a fuel case is complicated to be sealed due to a fuel port pressure sensor hole. Therefore, the hybrid thruster with an exposed solid fuel was applied to install a fuel port pressure sensor without the fuel case. An exposed solid fuel hydrogen peroxide catalytic decomposition hybrid thruster with PE (PolyEthylene) and PMMA (PolyMethyl MethAcrylate) as fuels, H 2 O 2 as an oxidizer, MnO 2 /Al 2 O 3 as a catalyst for the oxidizer, 20 bar as a combustion chamber pressure, and 5 s as a burning time was organized. Combustion tests without fuel port pressure sensors to discern an effect of them and with PMMA to visualize a combustion were performed. A fuel port pressure distribution was satisfactorily measured. Three phenomena of four fuel port pressures and a post-combustion chamber pressure in a steady state included an increase at the beginning, a maintenance at the middle, and a decrease at the end induced by a variable oxidizer mass flow rate, a flame generation, and a fuel regression respectively. • Application of exposed solid fuel to install fuel port pressure sensor on fuel. • Combustion visualization to explain occasional error solved by hydraulic fluid. • Increase of fuel port pressure at beginning due to variable oxidizer mass flow rate. • Maintenance of fuel port pressure at middle due to flame generation. • Decrease of fuel port pressure at end due to fuel regression. [ABSTRACT FROM AUTHOR]

Nafion, as a key component in the catalyst layer, plays a crucial role in the mass transport and electrochemical reactions within the catalyst layer. In this study, a numerical method is employed to reconstruct the three-dimensional nanoscale microstructure of the catalyst layer, including pores, Nafion, carbon particles, and Pt phases. A pore-scale model in which the Knudsen effect is taken into account is used to simulate the impact of Nafion contents on the interparticle transport and electrochemical reactions within the catalyst layer. The results show that the pore-scale simulation based on the reconstructed model can clearly reveal the mass transport process and highly uneven distribution of each physical quantity in the nanoscale particles and pores; When the Nafion content is relatively higher, the proton current distribution at the Pt/Nafion interface is relatively more uniform and the proton supply is sufficient. However, there is an inverse correlation between the oxygen mole concentration on the Pt surface and the Nafion content, which is the dominant factor affecting the electrochemical reactions on the Pt particle surface. When the Nafion content is lower, the proton supply becomes the dominant factor in the electrochemical reaction on the surface of Pt particles due to the weak connectivity of Nafion between the agglomerates. The combined effect of oxygen and proton transport result in the optimal Nafion volume fractions of 0.296 and 0.262 at voltages of 0.8 V and 0.7 V, respectively. The optimal Nafion volume fraction ranges between 0.224 and 0.262 at 0.6 V. As the voltage decreases, the effect of oxygen transport becomes more significant, and the optimal Nafion content decreases accordingly. [Display omitted] • A microstructure CL model consisted of nanoscale particles is reconstructed by stochastic numerical technology. • Nafion's effects on the transport among nanoscale particles are numerically observed directly. • The mass transport and multi-physics distribution characteristics among nanoscale Pt, C and Nafion particles are revealed. • The corresponding relationship between the working voltage and optimal Nafion content is obtained. [ABSTRACT FROM AUTHOR]

[Display omitted] • Automotive brake pad debris (BPD) can serve as effective Fenton catalysts. • BPD achieves 90% degradation of organic pollutants in 10 mins. • Oxidative treatment induces in-situ growth of Fe in BPD into Fe 2 O 3 nanocrystals. • Electronic interaction between Fe and Cu on BPD facilitates Fe(II)/Fe(III) cycling. • Triple Fe-C-Cu site of Cu/C-Fe 2 O 3 collaboratively activated H 2 O 2 to produce ·OH. The arbitrary disposal of used brake pads from motor vehicles has resulted in severe heavy metal pollution and resource wastage, highlighting the urgent need to explore the significant untapped potential of these discarded materials. In this study, The in-situ growth of highly dispersed Fe 2 O 3 nanocrystals was achieved by simple oxidation annealing of brake pad debris(BPD). Interestingly, Cu remained unoxidized and acted as a "valence state transformation bridge of Fe 2 O 3 " to construct the "triple Fe-C-Cu sites". The Fenton degradation experiment of pollutants was conducted under constant temperature conditions at 40 °C, a stirring rate of 1300 rpm, a pH value of 3, a catalyst dosage of 0.5 g/L, pollutant dosage ranging from 50 to 400 mg/L, and H 2 O 2 dosage of 0.25 g/L. Experimental results showed that BPD treated at 300 °C for 2 h exhibited optimal Fenton-like oxidation activity, achieving rapid degradation of over 90 % of refractory antibiotics, such as tetracycline and ciprofloxacin, in organic wastewater within 10 min. This remarkable performance was mainly attributed to the synergistic effect of "Fe-C-Cu triple sites", where the electron-donating role of C in the Fe-C and Cu-C interfaces facilitated the conversion of the Fe(III) to Fe(II) and Cu(II) to Cu(I). In addition, the ability of Cu2+ to accept electrons at the Fe-Cu interface promoted the transition from Fe (II) to Fe (III). This "balance of electron gain and loss" accelerated the interfacial electron transfer and the recycle of dual Fenton sites, Fe(II)/Fe(III) and Cu(I)/Cu(II), to generate more ·OH from H 2 O 2. Therefore, this strategy of functionalizing BPD as Fenton-like catalysts without the addition of external Fe provides intriguing prospects for understanding the construction of Fe-based Fenton catalysts and resource utilization of Fe-containing solid waste materials. [ABSTRACT FROM AUTHOR]

Efficient delafossite CuCoO 2 photo(electro)catalysts necessitate effective separation and transport of photogenerated carriers to enable the production of solar fuel. Addressing this requirement, the current study employed facet engineering to induce the surface polarization effect. Hydrothermal conditions were utilized to prepare CuCoO 2 photo(electro)catalysts with diverse morphologies and sizes. Specifically, CuCoO 2 hexagonal nanosheets, predominantly exposing the (001) facet and possessing a thickness of 120 nm, exhibited optimal performance, as evidenced by a photocurrent density of 40 μA/cm2 under zero-bias conditions and 90 % degradation of tetracycline hydrochloride within 150 min. To overcome the limitations associated with hydrothermal preparation, Ca substitutional doping was employed. This doping strategy caused disruption of the O–Cu–O dumbbell-like structural motif, transforming CuCoO 2 into an open-layered structure while simultaneously reducing the thickness of CuCoO 2 hexagonal nanosheets to 30 nm. Consequently, an enhancement in the photo(electro)catalytic performance was achieved. By striking a balance between the surface polarization effect and the doping effect, CuCoO 2 hexagonal nanosheets with 0.5 % Ca doping content and a thickness of 80 nm exhibited the most significant photo(electro)catalytic performance. This study presents a feasible strategy and concept for optimizing the morphology and hydrothermal preparation conditions of CuCoO 2 nanomaterials, leading to improved photo(electro)catalytic performance. [Display omitted] • Surface polarization enhances carrier separation and transport in CuCoO 2 photoelectrodes. • CuCoO 2 hexagonal nanosheets exhibit superior photo(electro)catalytic activity. • Ca doping overcomes limitations in hydrothermal synthesis for preparation thinner CuCoO 2 nanosheets. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) materials have driven great interest due to a large specific surface area to volume ratio and adjustable surface behaviors, which show huge potentials for enhancing the activity of energy conversion and property optimization. In order to regulate the physicochemical properties of photocatalyst for water splitting reaction, defect engineering on 2D materials have drawn great attention. Meanwhile, a widely used strategy to improve the H 2 evolution rate kinetics has been achieved. In this paper, we prepared AgBr/g-C 3 N 4 catalyst by chemical precipitation. The obtained photocatalyst shows a unique charge transfer pathway. In addition, a deep understanding of the proton shuttle during H 2 evolution reactions can offer profound opinion into heterostructure construction and property optimization. It is found that the enhanced performance is correlated to the superiority of the S-scheme heterojunction and defect engineering on graphitic carbon nitride 2D materials. This work offers a novel method for improving efficiency in terms of energy conversion and property optimization. [Display omitted] • Surface nitrogen vacancy is instrumental in the chemisorption and activation of H 2 O. • S-scheme band of AgBr/g-C 3 N 4 is conjectured by the experiments and DFT calculations. • The prolonged photocarrier lifetime has increased H 2 production. • The results of XPS are consistent with the mechanism of S-scheme heterojunction. [ABSTRACT FROM AUTHOR]

The CO 2 electrochemical reduction reaction (CO 2 ERR) offers an effective way to solve the problems of energy storage fluctuation and CO 2 over-emission at the same time. However, the mass transfer limitation during CO 2 ERR owing to the gaseous property of CO 2 greatly restricts the efficiency and selectivity of CO 2 reduction. Here, we report, for the first time, the design of a copper-zinc (CuZn) bimetal decorated superstructure catalyst (CuZn@KCA) via capitalizing on porous N-doped konjac glucomannan (KGM) aerogel and CuZn metal organic frameworks (CuZn-MOF), based on multiphysics infinite elemental simulations. The CuZn@KCA catalysts show high performance for CO 2 ERR (faradaic efficiency for HCOOH reaches 75% at −1.0 V vs. RHE). As demonstrated by infinite elemental simulations and detailed characterizations, the improved CO 2 ERR is attributed to the mass transfer enhancement effect of the superstructure catalyst on the reaction process (The mass transfer with CuZn@KCA is 16 times higher than that with CuZn-MOF). As such, the strategy for crafting a hierarchical superstructure might open up an avenue to improve the reaction activity of CO 2 ERR. • CuZn@KCA superstructure catalyst is designed and fabricated through finite element simulations and ice-templated method. • CuZn@KCA exhibits prominent CO 2 ERR performance and excellent stability for long time operation. • Fast charge and mass transfer rates attributed to hierarchical superstructure lead to higher CO 2 conversion FE. [ABSTRACT FROM AUTHOR]

Solar-hydrogen energy systems for spacecraft reliably provide energy for carrying out various kinds of unscheduled work on board and for eliminating emergency situations. Surplus energy is constantly accumulated on board in the form of the chemical energy of cryogenic hydrogen. The article presents too the result of the development of a solar-hydrogen power supply system for spacecraft, the onboard network of which provides slow and fast processes. The paper presents too pulsed and continuous models of voltage converters of the electrical power system of automatic spacecraft. It is proved on the simulation basis that the deviation of frequency characteristics of continuous models from pulse ones is insignificant (not more than 2%), while the use of continuous models to study both frequency and time characteristics of the converter allows us to reduce the simulation time tenfold. [ABSTRACT FROM AUTHOR]

The interactions between metals and oxide supports, so-called metal-support interactions (MSI), are of great importance in heterogeneous catalysis. Pd-based automotive exhaust control catalysts, especially Pd-based three-way catalysts (TWCs), have received considerable research attention owing to its prominent oxidation activity of HCs/CO, as well as excellent thermal stability. For Pd-based TWCs, the dispersion, chemical state and thermal stability of Pd species, which are crucial to the catalytic performance, are closely associated with interactions between metal nanoparticles and their supporting matrix. Progress on the research about MSI and utilization of MSI in advanced Pd-based three-way catalysts are reviewed here. Along with the development of advanced synthesis approaches and engine control technology, the study on MSI would play a notable role in further development of catalysts for automobile exhaust control. [Display omitted]. [ABSTRACT FROM AUTHOR]

[Display omitted] • A large area of centimeter-scale PtSe 2 /MoS 2 heterostructure photodetector is fabricated on SiO 2 /Si substrate. • PtSe 2 /MoS 2 photodetector shows better device performance than PtSe 2 in terms of lower dark current and high detectivity. • PtSe 2 /MoS 2 exhibits high responsivity of 17.9 AW-1 and specific detectivity of 9.8×1012 Jones under 900 nm illumination. • A broadband 400-1200 nm and ultra-fast response with rise/ fall time of 103 μs /117 μs is obtained for PtSe 2 /MoS 2 device. • A detailed carrier transport mechanism is explained at the heterointerface for the working of PtSe 2 /MoS 2 photodetector. Group-10 transitional metal dichalcogenide, in particular Platinum selenide (PtSe 2), have attracted substantial attention owing to its fascinating properties such as high carrier mobility, narrow bandgap, and high stability in contrast to other low bandgap 2D materials. However, in bare PtSe 2 , high dark current and lower sensitivity restrict to make high-performance broadband photodetector. Herein, a large area and stable PtSe 2 /MoS 2 heterostructure based photodetector is fabricated which exhibits suppressed dark current and high-performance with broad 400-1200 nm detection, covering visible to near-infrared region (NIR). The PtSe 2 /MoS 2 heterostructure device exhibits ∼103 order reduction in the dark current, high detectivity, and better stable response as compared to its bare PtSe 2 device. Moreover, under NIR (900 nm) illumination, the PtSe 2 /MoS 2 device demonstrates high responsivity of 17.9 AW−1 and high specific detectivity of 9.8 × 1012 Jones at a moderate bias of −5V. It exhibits ultra-fast response with rise/ fall time of 103 μs/117 μs corroborating its high performance. To understand the working of PtSe 2 /MoS 2 photodetector, a detailed carrier transport mechanism is investigated based on the interface. This work provides a facile strategy to fabricate large area, fast response and high-performance broadband photodetector to build future optoelectronic devices. [ABSTRACT FROM AUTHOR]

Internal combustion engines emit harmful gasses that affect the environment adversely. The study aims to reduce harmful emissions from CNG-fueled spark ignition engines by using a three-way catalytic converter. This present work investigates the effect of different parameters on CNG-fueled spark ignition engine before and after the catalytic converter. The experiment was conducted to investigate the effects of hydrogen ratios (0%–20%), EGR ratios (0%–20%), spark timing (8o–59o CA bTDC), load (25%–75%), and speed (900 rpm–1500 rpm) under stoichiometric conditions. Emissions (CO, HC & NOx) and conversion efficiency of laboratory-based CNG SI engine before and after catalytic converter is investigated. CO emissions are 8.78 g/kWh, 8.62 g/kWh and 6.97 g/kWh at 16o CA bTDC before the catalytic converter, at same ignition timing by using the catalytic converter, CO emissions are 3.41 g/kWh, 3.34 g/kWh and 3.22 g/kWh with HCNG0, HCNG10 and HCNG20 respectively. Conversion efficiency of the HC emissions is increased by increasing the (900 rpm–1500 rpm) speed. The NOx emissions increased by increasing the load are present in the amount of 0.0551 g/kWh, 0.0557 g/kWh and 0.160 g/kWh approximately for loads 25%, 50% and 75% respectively at 25o CA bTDC and reduced after the catalytic converter. Additionally, an improved particle swarm optimization combined with back propagation neural network (IMPSO-BPNN) predicts emissions, achieving a higher correlation coefficient (R = 0.9970) and minimum MSE of 0.0057 for CO, (R = 0.9993) and minimum MSE of 0.0037 for HC, and (R = 0.9995) and minimum MSE of 0.0020 for NOx. The findings may enhance training for electronic control units and the development of HCNG-fueled engines. • Experiments were performed on the HCNG engine under different operating conditions with & without a catalytic converter. • CO, CO 2 and HC emissions are considered for analysis. • IMPSO-BPNN algorithm applied to predict the emissions before and after the catalytic converter. [ABSTRACT FROM AUTHOR]

[Display omitted] • The factors influencing PMs distribution behavior were summarized. • Distribution coefficients of Au, Ag were discussed for recycling e-waste. • Distribution coefficients of PGMs were discussed for recycling spent catalysts. • The development directions of pyrometallurgical processes were put forward. Precious metals (PMs), particularly platinum group metals (PGMs), are of strategic importance due to their high supply–demand imbalance, scarcity, and functionality in high-tech fields. The global supply of PMs is constrained due to the rising demand in clean energy applications. Therefore, the recycling of PMs from secondary resources can effectively alleviate the risk of supply shortages. Pyrometallurgical technologies have attracted considerable interest because of their high recovery efficiency, extensive processing capacity, and minimal wastewater production. To enhance the recovery efficiency of PMs and promote the development of the underlying theories and technologies for pyrometallurgical enrichment, this review provides a comprehensive overview of the distribution behavior of PMs between slag and metal, with a particular focus on gold, silver, platinum, palladium, rhodium, and ruthenium. The factors, including gas partial pressure, temperature, slag composition, matte grade, and halogen elements, which have an influence on PMs distribution coefficients, are considered when designing slag types and setting smelting conditions. The characteristics of e-waste and spent catalysts differ significantly from those of ores. The distribution behaviors of PMs determine the recycling of PMs from spent catalysts and e-waste. Finally, the prospects of pyrometallurgical PMs recycling technologies are presented. [ABSTRACT FROM AUTHOR]

The automobile catalytic converter (ACC) contains a huge number of precious metals as catalysts. When an ACC fails to meet standards, it is removed from the exhaust of an automobile but retains some catalytic activity. However, the recovery and/or activation of this waste is a high-cost process and includes several chemical treatments. Catalytic wet air oxidation (CWAO) has been reported as an effective wastewater treatment method. The most important disadvantage of CWAO is cost-nonefficiency. Herein, to overcome these problems, the simple recovery of catalysts from waste ACC for reuse in CWAO was investigated. The optimum conditions of reaction were investigated through response surface methodology (RSM). The optimum removal efficiency was 88% when the reaction conditions were set on the 20 bar of pressure at 111.5 °C over 77 min and using 0.41 g of recovered catalyst. In addition, toxicity testing was performed on a model of malathion-contaminated wastewater before and after CWAO treatment. Final product identification was performed which showed that CWAO eliminated the toxicity of wastewater and was determined to be malaoxon, present at acceptable concentrations, and tributyl phosphate. In conclusion, there may be important potential for the use of recovered ACC catalyst in the treatment of toxic wastewater. [Display omitted] • A UACC was used as catalyst in wet air oxidation. • Catalyst was simply recovered through a simple grounding and washing. • The WACC is able to remove malathion from aqueous solution through the CWAO. • Malathion completely was degraded and non-toxic intermediates were generated. [ABSTRACT FROM AUTHOR]

A series of MnO 2 /g-C 3 N 4 composites with different exposed crystal plane were successfully prepared by different synthesized method. UV–Vis, PL, ESR and electrochemical results suggest that the visible-light absorbance, photoexcited electron-separation efficiency and oxygen defects are greatly dependent on the exposed crystal-faceted MnO 2 supported on g-C 3 N 4. The experimental results display that the exposed crystal plane of MnO 2 have great influences on the photocatalytic hydrogen evolution performance, and the m-MnOCN composite with exposed (111) crystal plane exhibits superior photocatalytic performance for the release of H 2 under visible light irradiation, followed by the order of b-MnOCN [002]> p-MnOCN [110]. Moreover, Mechanism studies have shown that the possible mechanism of photocatalytic hydrogen evolution reaction is Z-scheme mechanism. • Photocatalytic hydrogen evolution performance of MnO 2 /g-C 3 N 4 is enhanced with different exposed crystal plane. • The m-MnOCN composite with exposed (111) crystal plane exhibits superior photocatalytic performance. • The Z scheme mechanism is proposed for the photocatalytic hydrogen evolution mechanism of MnO 2 /g-C 3 N 4 composite. [ABSTRACT FROM AUTHOR]

• Membrane technology enables sustainable recovery of aqueous valuable resource. • It is crucial to develop innovative hybrid membrane technology for resource recovery. • Membrane fouling and instability are bottlenecks that deteriorate the performance. • It is challenging to achieve large-scale engineering application of resource recovery. Considering the circular economy and environmental protection, sustainable recovery of high-value metals from wastewater has become a prominent concern. Unlike conventional methods featuring extensive chemicals or energy consumption, membrane separation technology plays a crucial role in facilitating the sustainable and efficient recovery of valuable metals from wastewater due to its attractive features. In this review, we first briefly summarize the sustainable supply chain and significance of sustainable recovery of aqueous high-value metals. Then, we review the most recent advances and application potential in promising state-of-the-art membrane-based technologies for recovery of high-value metals (silver, gold, rhenium, platinum, ruthenium, palladium, iridium, osmium, and rhodium) from wastewater effluents. In particular, pressure-based membranes, liquid membranes, membrane distillation, forward osmosis, electrodialysis and membrane-based hybrid technologies and their mechanism of high-value metal recovery is thoroughly discussed. Then, engineering application and economic sustainability are also discussed for membrane-based high-value metal recovery. The review finally concludes with a critical and insightful overview of the techno-economic viability and future research direction of membrane technologies for efficient high-value metal recovery from wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]

Platinum group metals (PGMs) are regarded as strategic metals due to high melting point, corrosion resistance and catalytic activity. They are widely employed in renewable energy, petrochemical industry, vehicles and pharmaceutical engineering. However, the supply and demand of PGMs are facing challenges stemming from rarity and unequal distribution across the globe. This review aims to delve into the supply-demand of PGMs to elucidate primary applications and pinpoint current or projected shortfalls in the supply chain. The future demand for PGMs indicates a significant increase, particularly within the hydrogen sector. It is anticipated that Pt and Ir consumption in fuel cell vehicles and proton exchange membrane electrolysis will reach 143 tons and 38 tons by 2050, respectively. Production of PGMs is far from meeting demand. Sustainable development strategies, including recycling, substitution and innovative technologies, are proposed to address this contradiction. Recycling serves as a strategy to increase PGMs supply. Nevertheless, recycled PGMs accounted for approximately 26 %. Substitution represents a pathway to decrease the PGMs contents in products. The Pt load in fuel cells declined from 1.0 g kW−1 in the 1990s to 0.3 g kW−1 nowadays. Innovative technologies can mitigate the PGMs demand. Electric vehicles, solid oxide fuel cells and electrolysis cells provide promising alternatives for PGMs intensive industry. Ultimately, key future development directions for PGMs are outlined. The emphasis should lie on enhancing PGMs recovery efficiencies and intensifying research into catalytic mechanisms. Notably, ensuring the secure supply of PGMs will facilitate the advancement of renewable and sustainable energy. [Display omitted] • The supply and demand for PGMs is serious imbalance. • The demand for PGMs is forecasted, especially hydrogen industry. • PGMs sustainable strategies include recycle, substitution, innovative technologies. • Challenges and suggestions for PGMs sustainable development are raised. [ABSTRACT FROM AUTHOR]

In this work, the effects of structure parameters on the conversion performance of the dual-carrier catalytic converter for heavy-duty natural gas engines are investigated. A three-dimensional numerical model adopting an empirical global reaction mechanism for the Pd–Rh dual-carrier catalytic converter is established. The results show that the conversion efficiency slightly increase with the increase of the carrier cell density ratio, the maximum conversion efficiency differences of CH 4 , CO and NO are 5.7 %, 8.3 % and 7.9 %, respectively. When the carrier wall thickness decreases from 0.24 mm to 0.10 mm, the conversion efficiencies of CH 4 , CO and NO slightly increase, and the maximum differences are 5.5 %, 8.0 % and 8.0 %, respectively. Additionally, the fuzzy grey relational analysis (FGRA) is employed to make a comprehensive evaluation. For the conversion efficiencies of CH 4 and NO, the primary and secondary relationships of the influence factors are carrier diameter > carrier length > carrier cell density ratio > carrier wall thickness. The orthogonal experiment analysis indicates that case 7 shows the best total conversion performance (CH 4 : 91.9 %; CO: 99.7 %; NO: 83.9 %) at 673K. Compared with the baseline case 2, the conversion efficiencies of CH 4 and NO are increased by 14 % and 19.9 %, while the volume increased by 36.1 %. • A dual-carrier catalytic converter for heavy-duty natural gas engines is developed. • Effects of structure parameters on the conversion performance of the dual-carrier catalytic converter are studied. • Enhancing the carrier cell density ratio is useful for improving the conversion efficiency. [ABSTRACT FROM AUTHOR]

[Display omitted] • Resin 3D printing can produce a wide set of structured catalyst supports. • Assessment of their transport properties is necessary for engineering purposes. • 3D printed resin supports are coated with Pd/CeO 2 layers. • Rich H 2 oxidation is used to study the fluid-solid mass transfer properties. • The experimental protocol is validated for open-cell foams and TKKD POCS. In this work, we propose a novel methodology for the evaluation of the external mass transfer properties of 3D printed catalyst supports. This protocol relies on the use of a lab scale SLA 3D printer with a resin characterized by a high heat deflection temperature (HDT) for the manufacturing of samples at a lower price and with higher accuracy than equivalent metallic 3D printed structures. Periodic open cellular structure (POCS) samples with Tetrakaidecahedron unit cells (TKKD) were 3D printed and catalytically activated by depositing a 3% Pd/CeO 2 washcoat by spin-coating. The washcoat was then consolidated with a two-step heat treatment composed by in-situ calcination in N 2 and reduction in N 2 /H 2 stream. Catalytic tests of rich H 2 combustion showed the possibility to reach the external mass transfer control at temperatures below the resin HDT. Sherwood numbers were eventually estimated from the oxygen conversions under full external mass transfer control assuming a PFR behaviour. To validate the methodology, 3D printed replicas of open cell foams were also tested, and the results were successfully compared against a well-established literature correlation. Moreover, a one-to-one comparison was performed between the Sherwood numbers of a resin 3D printed structure, tested with the proposed methodology, and a metallic 3D printed structure, tested with the conventional CO oxidation approach. The two methods lead to superimposed results, thus providing the experimental evidence of the equivalence of the two methodologies for the evaluation of the external mass transport properties of complex catalyst substrates. [ABSTRACT FROM AUTHOR]

1 Amorphous carbon was facilely obtained via the treatment of waste papers with sulfuric acid. 2 The combination of amorphous carbon with graphitic carbon nitride leads to an increased photo-catalytic H 2 generation. 3 The enhancement in H 2 generation is resultant from the efficient separation of electrons and holes owing to the excellent electrical conductivity of amorphous carbon. Up-cycling of waste papers to value-added carbon products has significant environmental and economic benefits in real life. This work aims to recycle the waste papers to construct amorphous carbon modified graphitic carbon nitride composite photocatalysts for efficient photocatalytic hydrogen generation from water under visible light. Amorphous carbon (labeled as a-C) was yielded from the office waste papers by simple sulphuric-acid treatment and then combined with graphitic carbon nitride (g-CN) to form the g-CN/a-C composite photocatalysts by the thermolysis of a-C and melamine mixture. The addition of a-C enlarges the surface area of g-CN from 11.52 m2 g−1 of pristine g-CN to 28.12 m2 g−1 of g-CN/a-C-100. In addition, the a-C incorporation can significantly separate the electrons from the photoexcited g-CN owing to the excellent conductivity of a-C. As a result, an increased photocatalytic H 2 generation was realized under visible light exposure. The g-CN/a-C-100 sample with optimized a-C contents offers the highest photocatalytic H 2 generation rate of up to 17.1 μ mol h−1, which is ∼12 times higher than that of pristine g-CN under the same condition. The present study manifests the great potential of the recycling of office waste papers for increased photocatalytic H 2 generation. Graphical Abstract [Display omitted]. [ABSTRACT FROM AUTHOR]

Photocatalysts can be used both for air cleaning and solar energy harvesting through water splitting. However, pure TiO 2 photocatalysts are often inefficient and therefore co-catalysts are needed to improve the yield. To achieve this goal, we prepared TiO 2 and deposited Pt, Ir and Ru co-catalysts on its surface. Two base TiO 2 nanoparticles were used: P25 and rutile TiO 2 synthesized via hydrothermal method. Co-catalysts were deposited by wet impregnation technique using single element and a combination of two elements (Pt and Ir or Pt and Ru), followed by annealing in either air or H 2 /Ar. Annealing in reducing atmosphere increased the photocatalytic activity of oxidation of isopropanol compared to annealing in air. We demonstrated a clear influence of the co-catalysts on the photocatalytic degradation of isopropanol and on electrochemical water-splitting reaction. The platinum-containing samples showed the best HER activity. • TiO 2 deposited with single co-catalysts (Pt, Ir, Ru) and their pairs (Pt/Ir, Pt/Ru). • Rutile with co-catalyst annealed in H 2 /Ar shows remarkably increased activity. • Rutile with Pt shows the highest activity in hydrogen evolution reaction (HER). • The deposited co-catalysts for all metals were in the 2–4 nm size range. [ABSTRACT FROM AUTHOR]

[Display omitted] • 94% ACE degradation was achieved within 5 min in the W 18 O 49 /Fe3+/H 2 O 2 system. • Accelerated Fe2+/Fe3+ cycling controlled by variational W4+/W6+ and intermediate •OH stabilization by oxygen vacancy was the dual driving force in the W 18 O 49 /Fe3+/H 2 O 2 system. • 1O 2 was the major pathway for ACE degradation, followed by •OH and O 2 •−. • The degradation rate of ACE in the W 18 O 49 /Fe3+/H 2 O 2 system was 4.3 times faster than that in the Fe3+/H 2 O 2 system. • The W 18 O 49 /Fe3+/H 2 O 2 system could withstand a wide range of pH changes and the impact of multiple co-existing substances. The traditional Fenton reaction always encounters the restriction that the solution pH needs to be strictly regulated, and Fe2+ is easy to self-decompose but not easy to regenerate. Fe3+ is relatively stable but its reaction with H 2 O 2 is super-restricted. A novel strategy for the co-catalytic effect of W 18 O 49 on the enhancement of Fe3+/H 2 O 2 reaction activity was presented in this study. The W 18 O 49 /Fe3+/H 2 O 2 system achieved a 94% acetaminophen (ACE) degradation rate within 5 min, which was much higher than the Fe3+/H 2 O 2 system (48%), and W 18 O 49 also showed excellent repeatability. Quenching experiment and ESR proved that the removal of ACE mainly depended on 1O 2 (leading role) and •OH, which was different from the previously reported Fenton/Fenton-like system dominated by •OH. Accelerated Fe2+/Fe3+ cycling controlled by variational W4+/W6+ and intermediate •OH stabilization by oxygen vacancy for enhancing the breaking of O-O bond in H 2 O 2 to produce more radicals was the dual driving force in the W 18 O 49 /Fe3+/H 2 O 2 system for enhanced oxidation activity. The W 18 O 49 /Fe3+/H 2 O 2 system has favorable tolerance to a wide range of pH and anions, which provides a feasible strategy for the practical application of the Fenton-like system. [ABSTRACT FROM AUTHOR]

• Ni/CeO 2 catalysts with tunable Ni crystal faces and oxygen vacancies were prepared. • Ni crystal plane and oxygen vacancy concentration affect H 2 and CO 2 activation. • Ni crystal planes and oxygen vacancies synergize to enhance catalytic activity. • The activity of Ni/CeO 2 -SG catalyst is 2 times than Ni/CeO 2 -CP catalyst. • Ni/CeO 2 -SG catalyst involves a direct formate hydrogenation pathway. It is challenging to boost CO 2 methanation activity over Ni-based catalysts, and new findings that decipher the relationship between the essential laws of catalysts and their catalytic performance will be transformative. Herein, three kinds of Ni/CeO 2 catalysts with different Ni crystal facets and oxygen vacancy are developed by varied preparation methods, which show significant differences in catalytic performance for CO 2 methanation, and these catalysts are taken as a case study for the investigation of the crystal plane and oxygen vacancy effects in CO 2 methanation as well. It is observed that the activity of Ni/CeO 2 -SG catalyst with abundant oxygen vacancies and principally exposed Ni (1 1 1) crystal facet is highly active for CO 2 methanation reaction, which is 1–3 times than that of Ni/CeO 2 catalysts with poor oxygen vacancy and/or Ni (1 1 1) crystal face. In addition, the former one cannot suffer from deactivation even in operation 130 h at 300 °C. Both structural investigations and catalytic evaluations indicate that the adsorption and activating ability of H 2 and CO 2 can be controlled by adjusting the Ni-exposed crystal face and oxygen vacancy concentration, respectively. It is also verified that the synergistic contribution of the Ni crystal facets and the oxygen vacancy play a crucial role in boosting the catalytic activity of the Ni/CeO 2 catalysts by affecting the adsorption and activation of reactants. The Ni/CeO 2 catalysts exposed Ni (1 1 1) crystal plane facilitate the catalytic activity by strengthing the H 2 adsorption/dissociation capacity, while the abundantly available oxygen vacancies maximize the activity via acting as CO 2 activation sites. Furthermore, the in situ DRIFT experiments reveal that the direct formate hydrogenation pathway is involved in the CO 2 methanation process over the Ni/CeO 2 -SG catalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] • The freestanding BiOBr/CCFs composites photocatalyst has been constructed. • The BiOBr/CCFs exhibits the highest photogenerated carrier separation efficiency. • The BiOBr/CCFs shows excellent photocatalytic degradation RhB performance. The recycling efficiency of the photocatalyst is an important factor in practical application, which is one of the problems that most powder catalysts need to solve urgently. Herein, the freestanding photocatalyst that BiOBr nanosheets anchored on coal-based carbon fibers (CCFs) has been prepared. Integrating BiOBr to CCFs nanosheets can enlarge the specific surface area of materials, broaden the light absorption range, and increase the carrier transport rate. The optimum BiOBr/CCFs-2 sample exhibits excellent photocatalytic degrade Rhodamine B (RhB) efficiency of 92 % within 20 min under visible light, and the kinetic constant is 2.6 times higher than that of BiOBr. The photogenerated carriers generated by BiOBr nanosheets transfer to CCFs with excellent electrical conductivity and then synergistically improving the photocatalytic performance of BiOBr/CCFs-2. The BiOBr/CCFs-2 still remain excellent photocatalytic activity and cycling stability after five cycles, and the composite will be expected to be widely applied in other fields. [ABSTRACT FROM AUTHOR]

[Display omitted] • Co@WS 2 /Co@MoS 2 heterostructure with double-layer Co doping was designed and synthesized. • Interfacial doping engineering adjusts the surface electronic structure and further optimizes the catalytic performance. • The optimized d-band state and the formation of hybrid interface account for its good HER activity. • The Co@WS 2 /Co@MoS 2 exhibits excellent HER catalytic performance and stability in alkaline environment. Activating inert basal planes of transition metal composites through interfacial engineering and electronic modulation shows great potential on electrocatalytic hydrogen evolution reaction (HER). However, rational design of heterojunction structures through interfacial doping engineering still remains a costly and complicated challenge. Foreign atom doping can change the local electronic structure of the catalyst and adjust its catalytic performance. In this paper, the HER catalytic performance of WS 2 /MoS 2 heterostructure is strongly boosted for the first time by double-layer Co doping, which could not only induces the formation of Co@WS 2 /Co@MoS 2 hybrid interface but also regulates its d-band state. Additionally, activating the inert basal planes of the transition metal complex provides excellent electrocatalytic HER activity. Under the guidance of density functional theory (DFT) theory, a series of cobalt doped WS 2 /MoS 2 -based catalysts were systematically synthesized using a hydrothermal method. The prepared Co@WS 2 /Co@MoS 2 catalyst exhibited remarkable electrochemical activity and durability in alkaline environment, with an extra-low overpotential of 117 mV for HER to deliver a current density of 10 mA·cm−2. The experimental results clearly prove the prediction of DFT simulations. This work provides new insights of interface structure construction for high-performance hydrogen evolution catalysts by adjusting the electron distribution. [ABSTRACT FROM AUTHOR]

• Magnetic domain evolution of FeRh alloy in AFM-FM phase transition process is directly observed. • Magnetic domain evolution differences under temperature cycles for FeRh alloy are revealed. • The remnant magnetic domain at 300 K after temperature cycles are quite different. • The effect of M and A on magnetic domain evolution under temperature cycles are studied. The magnetocaloric effect of CsCl-type ordered FeRh alloy (space group Pm-3m, No. 221, cP2) almost cut in half with temperature cycling, limiting their application in magnetic refrigeration. This behavior is related to its phase transition dynamics that remain unveil. In this work, the phase transition dynamic process of FeRh alloy with entropy change of 10 J/kgK (0–3 T) were studied by directly observing the temperature-dependent magnetic domain evolution using in-situ LTEM. Significant differences of magnetic domain evolution behavior under temperature cycles occur in FeRh alloys. Specially, a virgin effect appears for the remnant magnetic domain at 300 K, where the number of magnetic vortexes reach 5 and remain stable at 300 K after the first temperature cycle instead of the original large irregular domains. Combined with micromagnetic simulation, we demonstrated that the domain wall motion induced change of magnetization M and exchange stiffness A should be responsible for the reduction of magnetic refrigeration performance under temperature cycles. These results help to understand the physical origin of the cyclability performance of magnetocaloric effect and antiferromagnetic to ferromagnetic phase transition in FeRh alloy. [ABSTRACT FROM AUTHOR]

[Display omitted] • H 2 O inhibits NO adsorption on both hydrophilic and hydrophobic Pd/SSZ-13, while the latter can be less affected by H 2 O. • In the presence of H 2 O, NO adsorbed on Z 2 Pd2+ and Z[Pd2+(OH)] to form hydrated Pd2+–NO and Pd+–NO, respectively. • CO increases NO adsorption on Z 2 Pd2+ and Z[Pd2+(OH)] sites following different pathways. • NO adsorption on Z[Pd2+(OH)] involves the reduction of Pd2+ to Pd+, which can be greatly inhibited by H 2 O and activated by CO. Pd-based zeolites are attractive candidates for passive NOx adsorbers to reduce NOx emission from vehicle exhausts at low temperature. However, it is not well understood the NO adsorption/desorption mechanism in the presence of H 2 O and CO, which are constant components in diesel exhaust. In this study, an initial Pd/SSZ-13 sample was treated by reduction in H 2 and then oxidation in NO to obtain a hydrophilic Pd/SSZ-13 with mostly Z[Pd2+(OH)] sites, or by thermal aging at 750 °C to prepare a hydrophobic Pd/SSZ-13 dominated by Z 2 Pd2+ and Z[Pd2+(OH)] sites. The two distinct Pd/SSZ-13 catalysts were characterized by XRD, H 2 -TPR, 27Al MAS NMR, and in situ DRIFTS spectra of CO adsorption, etc. Furthermore, the NOx adsorption/desorption reaction experiments and in situ DRIFTS studies were carried out on the two Pd/SSZ-13 catalysts under various conditions to explore the role of Z 2 Pd2+ and Z[Pd2+(OH)] sites in NO adsorption in the presence of H 2 O or co-existence of H 2 O and CO. Additionally, the recovery of active Pd sites after NO desorption was studied. [ABSTRACT FROM AUTHOR]

[Display omitted] • Understand phase transitions and mass transport in a key industrial catalyst system. • Demonstration of the utility of the 'sifting' strategy for pore structure characterisation. • Demonstration of the power and capabilities of a minimalist modelling approach. • Identify key aspects of pellet forming process that control mass transport properties. Diffusion-limited, heterogeneously-catalysed processes mean choices influencing pore structure-transport relationships, made during pellet fabrication, affect product performance. This work shows how the 'sifting strategy' can identify the critical aspects of a highly complex catalyst pellet pore structure that control mass transport to construct an idiosyncratic, minimalist model. This is implemented using fully-integrated gas overcondensation, mercury porosimetry and X-ray tomography experiments. It showed high temperature shift (HTS) catalyst pellets had a trimodal pore structure. The second mode, consisting of macropores within the roll-compacted feed particles, controlled mass transport. Knudsen-regime mass transport was shown to be critically-controlled by an incipiently-percolating cluster of these intermediate-sized macropores, as its rate could be drastically reduced via introduction of very few blockages via mercury entrapment. This incipiently percolating network could be represented by a lattice-based, random cluster model. X-ray tomographic images, analysed with an AI segmentation algorithm, validated the proposed model of interpretation for the indirect characterization data. [ABSTRACT FROM AUTHOR]

[Display omitted] • Innovative double-layer adsorptive membrane consists of a PDA layer and a PDMC layer. • Palladium was adsorbed via the dual mechanism of ion exchange and chelation. • The designed membrane has superior selectivity to Pd(II) in coexisting metal cations. • The membrane can be an alternative to adsorbents for palladium selective separation. Palladium (Pd) recovery from secondary resources is urgently needed to meet the rising demands for precious metals for sustainable development and environmental protection. To achieve the goal of simple, efficient, and selective recovery of precious metal Pd, we reported an innovative strategy that utilized a double-layer adsorptive membrane based on polydopamine (PDA) modification and polymethacryloxyethyltrimethyl ammonium chloride (PDMC) grafting. The adsorption results suggested that the adsorptive membrane exhibited an excellent adsorption capacity of 61.5 mg g−1 towards Pd(II) at pH 2.0 and the adsorption capacity remained stable after six cycles. Moreover, the adsorption processes of Pd(II) were fitted to pseudo second-order kinetic models and the Langmuir isotherm models. Density functional theory (DFT) simulation, and FTIR, XPS analysis indicated the adsorption mechanisms were ion exchange from the PDMC layer and chelation and ion exchange from the PDA layer. In the presence of other metal ions (Ni(II), Cu(II), Zn(II), Ca(II), Mg(II), K(I) and Na(I)), the separation factor of adsorptive membrane for Pd(II) was in the range of 50–529. The remarkable selectivity was due to the mechanism of the combination of electrostatic attraction and coordination interaction to Pd(II) while the electrostatic repulsion to other metal cations. Furthermore, membrane filtration results suggested that Pd(II) was effectively adsorbed and rejected and the leakage risk could be reduced by dual adsorption from the double-layer membrane. This study not only offers an innovative strategy to precisely and effectively recover Pd(II) and other platinum group metals, but also provides valuable insights for the future implementation of adsorptive membranes in recycling low-concentration wastewater in an efficient and friendly way. [ABSTRACT FROM AUTHOR]

• Three-way catalysts (TWC) are used in spark-ignition engines to meet exhaust regulations. • NH 3 emissions are generated in TWCs during the NO x reduction. • In Euro 7, NH 3 has been designated as a new regulated substance. • NH 3 formation is greatly influenced by catalyst activation. Emission regulations have been made more strengthened both regulated (NO x) and unregulated emissions (NH 3 , N 2 O, and CH 4) from internal combustion engines. Delays in supply of batteries and semiconductors has slowed the commercialization of electric and hydrogen electric vehicles, necessitating further research on internal combustion engines for the time being. Gasoline and liquefied petroleum gas (LPG) vehicles equipped with spark-ignition (SI) engines use three-way catalysts (TWC) to meet exhaust regulations; however, recent studies have shown that TWC can cause NH 3 emissions. This study analyzed the NOx and NH3 emission characteristics of LPG engines owing to catalyst activation, aging and capacity. A basic study of TWC was conducted using engine experiments, and real vehicle characteristics were analyzed using a worldwide harmonized light vehicle test procedure (WLTP) and real driving emissions (RDE). As a result, it was confirmed that there is a trade-off relationship between NOx reduction and the generation of NH 3 in the three-way catalyst system. a decrease in ambient temperature delays catalyst activation, resulting in reduced NH 3 emissions. Aged catalysts exhibit an increase in NH 3 due to accumulated ammonia within the catalyst. Moreover, higher catalyst capacity is associated with a more substantial reduction in NOx, contributing to an increase in NH 3 generation. [ABSTRACT FROM AUTHOR]

• The regulator retained in the metal node can improve the MOF conductivity. • The porphyrin-centered Pd as an electron bridge to accelerate carrier separation and transfer. • The role of Pd as an electron bridge was further confirmed by DFT calculations. • The MOF prepared by alkyl monocarboxylic acid has excellent photocatalytic activity and stability. The technology of photolysis water hydrogen evolution driven by solar energy is considered promising to alleviate the energy crisis. However, the low separation and transfer efficiency of photogenerated charge carriers is still one of the challenges leading to the inferior efficiency of photocatalysis. In this paper, alkyl n-hexanoic acid (HA) and aryl benzoic acid (BA) were used as modulators to synthesize HA-PCN-224 and BA-PCN-224 by solvothermal method, in which TCPP linker was coordinated with Zr-O clusters in accompany with part of reserved modulators, respectively. The photocatalytic hydrogen evolution activity of HA-PCN-224 (225.29 μmol·g−1·h−1) was 2.86 times as that of BA-PCN-224 (78.78 μmol·g−1·h−1), which should be ascribed to the higher conductivity confirmed by the electrochemical impedance spectroscopy (EIS). Subsequently, the sample HA-PCN-224(Pd) was synthesized by introducing PdⅡ into the porphyrin center. The Photoluminescence (PL), photocurrent response (i-t), Mott-Schottky characterization, and density functional theory (DFT) calculations show that HA-PCN-224(Pd) has excellent electrical conductivity and unique PdⅡ electron bridge, which can significantly accelerate the carrier separation and transfer efficiency. Surprisingly, with the help of PdⅡ as an electron bridge, the photocatalytic hydrogen production activity of HA-PCN-224(Pd) is as high as 20411.32 μmol·g−1·h−1, which is about 90.60 times as that of the original HA-PCN-224. This work provides us with a novel avenue to modulate the conductivity of MOFs via adjusting monocarboxylic acid regulators and introduce unique PdⅡ as the effective electron bridge to promote excellent separation and transfer efficiency of charge carriers for the application in solar energy-related fields. [ABSTRACT FROM AUTHOR]

• Co, Cu, and Ag - doped Ce-Tb nanofibres were developed using electrospinning. • From FE-SEM analysis, the fibers were porous and had a 100 to 600 nm diameter. • XRD studies displayed a similar trend for cubic fluorite structure. • Raman spectra revealed the presence of a secondary phase in CeTbCo nanofibers. • CeTbCo nanofibers showed better T 50 (347 ℃) than the other nanofibers. Ceria-based materials have an excellent potential to be catalysts for catalytic three-way converters in the automobile industry. Developing Ceria-based nanofiber catalysts can be a significant approach for further exploring the application of these materials in automobile industries. In this study, Ag, Cu, or Co doped Ceria–Terbium nanofibers were synthesized using the electrospinning technique. The obtained nanofiber catalysts were characterized using FE-SEM, XRD, FT-Raman Spectroscopy, and BET-BJH analysis and tested for soot oxidation activity and its kinetics. FE-SEM examination reveals that the obtained nanofibers have a diameter ranging from around 100 to 600 nm. CeTbCo nanofibers exhibited a reduced particle size and enhanced pore formation. The XRD investigation revealed that all the nanofibers displayed a face-centered fluorite structure of CeO 2. In Raman spectroscopy analysis, CeTbCo nanofibes showed the emergence of a secondary Co 3 O 4 phase. The CeTbCo nanofiber catalyst showed better S BET (specific surface area) (66 m2/g) and average pore size (12.08 nm) and total pore volume (0.223 cc/g)), better soot oxidation activity (T 50 = 347 ℃) than other nanofiber catalysts. The CeTbCo nanofiber catalyst exhibited an activation energy of 132 kJ mol−1 and a pre-exponential factor (ln (A)) of 25.63 min−1. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, ammonia emissions characteristics of typical light-duty gasoline vehicles were obtained through laboratory vehicle bench test and combined with New European Driving Cycle (NEDC) condition and Worldwide Harmonized Light Vehicles Test Cycle (WLTC) condition. The influence of ambient temperature on ammonia emissions is mainly concentrated in the cold start stage. The influence of ambient temperature on ammonia emission is shown that the ammonia emissions of light-duty gasoline vehicles under ambient temperature conditions (14 and 23°C) are lower than those under low ambient temperature conditions (−7°C) and high ambient temperature conditions (35 and 40°C). The influence of TWC on ammonia emission is shown that ammonia is a by-product of the catalytic reduction reaction of conventional gas pollutants in the exhaust gas in the TWC. Under NEDC operating conditions and WLTC operating conditions, ammonia emissions after the catalyst are 45 times and 72 times that before the catalyst, respectively. In terms of ammonia emissions control strategy research, Pd/Rh combination can reduce NH 3 formation more effectively than catalyst with a single Pd formula. Precise control of the engine's air-fuel ratio and combination with the optimized matched precious metal ratio TWC can effectively reduce ammonia emissions. [Display omitted] [ABSTRACT FROM AUTHOR]

Bioethanol has been considered a potential alternative to the conventional fossil fuels in transportation sector as well as a hydrogen carrier. This study proposes a thermochemical recovery pathway to extend the use of bioethanol in compression ignition engines through catalytic exhaust gas reforming of ethanol-biodiesel-diesel blends into hydrogen. The aim is to improve the heat recovery of the engine exhaust gas and increase the on-board production of hydrogen which can potentially partially replace the diesel fuel in the engine. Results indicate that the effectiveness of the reforming process mainly depends on the blend composition, reforming temperature, and oxygen to carbon ratio (O/C). It is deduced that ethanol content in the fuel blend has a key role in sustaining catalyst activity and hydrogen production. Overall, the study highlights the positive impact and practicality of recovering exhaust heat using the ethanol-biodiesel-diesel blends. This implementation can result in noticeable improvements in emission reduction of diesel powertrains once the reformate is fed back into the engine. • Ethanol-diesel-biodiesel blends are effectively applied for producing H 2 on-board. • Reforming the fuel blends is proven to be an effective thermochemical exhaust recovery method. • H 2 from reforming is strongly dependent on fuel composition and injection conditions. • Ethanol fraction in fuel blend has a dominant effect in reformer catalyst performance. • Blends with higher ethanol and lower biodiesel fractions show a better recovery performance. [ABSTRACT FROM AUTHOR]

Monolith reactors (MR) have structured packing of catalyst and are commonly used for catalytic converters in automobile applications. Compared to a randomly packed bed reactor (PBR), MR has advantages like lower pressure drop, enhanced mass transfer, etc. Recent investigations have revealed that MR performs better than PBR for certain applications including highly exothermic reactions, mainly because of better conduction in the former. Hence, the use of MR for the process of unmixed combustion (UMC)/chemical looping combustion (CLC) which is typically carried out in PBR and involves oxidation of copper (Cu), an exothermic gas–solid reaction, was investigated using modeling and simulation studies. A Pseudo-homogeneous model was developed and two cases were considered, viz. Case I: insulated wall, and Case II: convective heat transfer from the wall to coolant air. COMSOL Multiphysics™ 5.4 was used for this purpose. The heat transfer behavior of MR was compared with PBR based systems having spherical particles. The simulation results showed that for Case I, it is possible to achieve a high temperature outlet stream (>1200 K) for a longer duration of time in MR as compared to that obtained in the existing CLC based PBR. In Case II, the MR system showed a better rate of radial heat transfer, while maintaining the bed temperatures within the desired range, than that in the PBR system for similar operating conditions. Moreover, in the MR system, there is scope for increasing the heat transfer rate, whereas PBR has process limitations to do so. Effects of inlet concentration and inlet velocity on the performance of reactors have also been investigated. MR was found to have a feasible operation at relatively higher concentrations and velocities. Thus MR proves to be a potential alternative to PBR, for the oxidation of Cu in UMC/CLC processes. [ABSTRACT FROM AUTHOR]

[Display omitted] • The photodeposition method was very effective for obtaining the platinized catalysts. • Fluoridation and platinization of commercial oxides made it possible to obtain materials for the production of H 2. • Pt-F-Nb 2 O 5 material, showing this as the best material evaluated for the industrial effluents studied. • Catalyst Pt-F-Nb 2 O 5 had the highest H 2 production equal to 66 μmol/min/g. Different Pt-TiO 2 -Nb 2 O 5 systems were synthesized and studied in the photocatalytic reforming of glucose for the generation of H 2. The physicochemical properties of the synthesized photocatalysts were analyzed using different characterization techniques from which it was found that fluoridation and sulphation have different effects on the oxides under study such as a protective effect on the crystalline phase in anatase, and greater response in the visible region of the electromagnetic spectrum. The addition of fluorine or sulfates favors the reduction of platinum species on the surface of the semiconductor oxides and a better homogeneity of size and distribution of the particles of this metal. Studies were carried out in the gas phase that allowed the monitoring and quantification of the hydrogen produced from aqueous glucose solutions and it was determined that Pt-F-Nb 2 O 5 and Pt-F-TiO 2 are the most efficient materials for the production of hydrogen from this substrate. Similarly, liquid phase studies were carried out with a real sample from a confectionery industry where it was determined that with the material Pt-F-Nb 2 O 5 the highest transformation of glucose is obtained, without the formation of any other sugar or intermediate compound, indicating the preferential production of hydrogen during the photocatalytic reaction. The foregoing demonstrates the potential of the evaluated process in obtaining this gas from the recovery of polluting residues derived from the samples under study. [ABSTRACT FROM AUTHOR]

This paper examines the impact of three modes of transport infrastructure, namely high-speed rail, highway, and aviation on population density and economic growth in China using a fixed effects model based on a panel data of 2847 counties from 2008 to 2019. The results indicate that transport infrastructure can contribute to regional agglomeration and productivity enhancement, with high-speed rail having a distinct effect from the other two modes. High-speed rail has the most significant positive effect on population density while the other two modes aren't significant enough. Regarding per capita GDP, highway and aviation can both stimulate the development over different types of counties, while high-speed rail enhances the economic growth only in more developed regions. The findings highlight the need for a targeted planning strategy for regions with different development levels to harness the catalytic effect of transport on promoting reasonable distribution of resources. [ABSTRACT FROM AUTHOR]

The conveniently recoverable photocatalyst with self-floating and photothermal performance has attracted considerable attention. Herein, AgI/UiO-66-NH 2 was anchored on carbonized wood (CW) via a facile solvothermal and ion exchange deposition process. The catalytic properties and performance of the fabricated heterojunction were systematically characterized. The high-resolution transmission electron microscopy confirmed AgI/UiO-66-NH 2 was anchored on CW surface. The X-ray photoelectron spectroscopy revealed the shift of Zr 3d and Ag 3d, proving the heterojunction formation of samples. The heterojunction exhibited the strong UV adsorption peaks between 400 and 800 nm. The infrared photothermal analysis showed the heterojunction (41.2 °C) can adsorb more heat than AgI/UiO-66-NH 2 (31.2 °C) within 15 min visible light irradiation. As the floating carrier, CW enhanced the adsorption and utilization of sunlight. More than 96% of Rh B were degraded within 150 min with irradiation when the heterojunction was applied, and above 85% degradation rate were preserved after 6 cycling recycles, confirming its outstanding stability. Conclusively, this study paved a new pathway for fabricating the potential of easy recyclability and high stability of AgI/UiO-66-NH 2 @CW from biomass for wastewater treatment. [Display omitted] • AgI/UiO-66-NH 2 @CW was synthesized via a facile two-step procedure. • Carbonized wood solved the aggregating disadvantages of powder catalyst. • AgI/UiO-66-NH 2 @CW has good photocatalytic performance and recyclability. • The active species during the degradation process were identified as h+ and ∙O 2 −. [ABSTRACT FROM AUTHOR]

Spent automobile catalysts (SACs) and waste-printed circuit boards (WPCBs) are key secondary resources because of the presence of the platinum group metals (PGMs), copper (Cu), aurum (Au), and argentum (Ag). To recover these resources simultaneously and efficiently, a resource-saving process for co-smelting SACs and WPCBs was proposed using Cu from WPCBs to collect PGMs, Au, and Ag. Mechanical activation was found to enhance PGMs recovery by 5-10% by disrupting the cordierite encapsulation structure, thus exposing the PGMs. Additionally, gases generated during co-smelting efficiently reduced PGMs oxides and sulfides. Under optimized conditions, recovery rates reached up to 96.31% for Pt, 97.42% for Pd, 85.28% for Rh, 86.74% for Cu, 90.06% for Au, and 83.54% for Ag, respectively. The co-smelting process facilitated the transformation of organic matter, achieving the lightning and dehalogenation of the liquid phase products with a calorific value of 23.42 MJ/kg. Vitrification of residues effectively immobilized heavy metals within the glass matrix, surpassing the standards outlined in "Technical Requirements for Solid Waste Vitrification Product" (GB/T 41015-2021). Analysis confirmed the formation of a Cu-PGMs solid solution through charge transfer from PGMs to Cu, validated by SEM-EDS and XPS. [Display omitted] • The optimal conditions for recovering PGMs, Cu, Au, and Ag through SACs and WPCBs co-smelting were investigated. • Heavy metals (e.g., Pb, As, and Cr) were solidified. • The mechanism of solid solution formation between PGMs and Cu was deduced. • The decomposition pathway of organic matter was discussed in detail. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) can induce oxidative damage to biomolecules within tumor cells, making them suitable for tumor therapy. However, the effectiveness of these ROS in treating tumor cells is restricted due to their short half-life or short diffusion distance. Sulfate radicals (SO 4 •–), with a longer half-life and higher oxidation potential, provide a compelling alternative. Herein, we propose an efficient strategy to activate peroxymonosulfate (PMS) and produce SO 4 •– and •OH by using ultrasound-mediated Cu2+/Cu+ redox cycling, enabling oxygen-independent synergistic tumor therapy. Notably, this redox cycle ensures the continuity of effective Cu+ catalytic sites and prevents adverse effects on healthy tissues. The density functional theory results demonstrate that the decisive copper valence-conversion step is derived from the ultrasound-induced excitations of electrons in spin-down bands of Cu 2 (OH)PO 4. This ultrasound-controlled transition metal valence alteration enables in-situ activation of a nontoxic drug to produce toxic reactive X (X = O/S) species in an O 2 -independent manner, offering an efficient, adaptable and universal methodology for treating hypoxic tumors in living systems. [Display omitted] • Ultrasound-mediated Cu2+/Cu+ redox cycling for the reversible activation of peroxymonosulfate. • SO 4 •– with long half-life and high oxidation potential for oxygen-independent antitumor therapy. • Ultrasound-induced excitations of electrons in spin-down bands of Cu 2 (OH)PO 4 plays a decisive role in copper valence-conversion mechanistically. [ABSTRACT FROM AUTHOR]

The properties of polymer electrolyte membrane fuel cells (PEMFCs) are highly affected by the catalyst layer (CL). However, the cyclic swelling and shrinking of the ionomer caused by the change of temperature and relative humidity (RH) combined with external random mechanical loads may lead to electrochemical activity degradation through cyclic plasticity accumulation. In this study, a theoretical model to assess the ratcheting limit of the CL for PEFMCs subjected to thermal-mechanical-humidity cycling is developed based on linear matching method (LMM). The influences of embedded depth of Pt/C particle, cyclic temperature or RH modes, as well as the random reaction force are considered by the proposed method. The ratcheting limits of CL are achieved under various thermal-mechanical-humidity cycling and verified by step-by-step simulation. Moreover, a simplified prediction model is established to evaluate the ratcheting limits under the combined temperature and RH cycling. It is of interest that the ratcheting limit under the pure normal force is almost 3 time of that under the pure tangential force under the same thermal-humidity cycling. Furthermore, the accumulated plastic strain occurs near the junction area causing the debonding of Pt/C particle from the ionomer under thermal-mechanical-humidity cycling, which agrees well with the microscopic observation. Based on ratcheting assessment results obtained by the proposed method, the reliability and durability of PEMFCs can be improved by increasing the affinity between Pt/C and ionomer, decreasing the size of gas pore and inhibiting the tangential force in the CL. • A theoretical model to assess the ratcheting limit of the CL under thermal-mechanical-humidity cycling is established. • The effects of embedded depth of Pt/C, cyclic temperature or RH modes, and random reaction forces are considered. • A simplified prediction method is proposed to evaluate the ratcheting limits under thermal-mechanical-humidity cycling. [ABSTRACT FROM AUTHOR]

With tightening emission regulations and the advent of Zero-Carbon targets, curbing emissions from engines has become imperative. To enhance the emissions reduction of engines, a diesel oxidation catalyst (DOC) inserted within a three-layer porous media is proposed. Effects of Pd/Pt blended ratios, porous media settings, and boundary conditions on pollutant conversion are simulated and analyzed. The results indicate that increasing the Pd/Pt blended ratio and reducing the porosity favor the conversion of CO and C 3 H 6 but hinder the generation of NO 2 , and there exists a balancing effect of porosity and multi-layer porous media on emission conversion. With mean porosity augment from 0.4 to 0.6, NO conversion rate is improved by 2.1 % in the DOC with incremental porous media setting at V in = 10 m/s, T in = 550 K, and 100 % Pt. Moreover, the differences in conversion rates are enlarged with an increased Pd catalyst content, by 3.2 %, 5.9 %, 9.6 %, and 10.6 % respectively. Besides, 50 sets of DOCs are simulated, using orthogonal experiment analysis to optimize the boundary conditions and DOC setting. The maximum conversion rate is achieved when V in = 10 m/s, T in = 600 K, m O2 = 0.04, and Pd/Pt catalyst blended ratio and porosity is 100%Pt+1/4 + 1/4 and 0.5 + 0.4+0.4 in porous media. • A diesel oxidation catalyst inserted multi-layer porous media is proposed. • Coupling effects of Pd/Pt ratio and porous media settings are investigated. • Comprehensive analysis is conducted to obtain optimized setup of diesel oxidation catalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] • Silver catalyzes NO formation from plasma-derived N radicals with high selectivity. • Rates of N conversion to NO on the surface are determined by rates of mass transfer processes. • Consumption of N in the gas phase limits the ability of N to diffuse to the surface and react to form NO. Pathways and timescales relevant to facilitate plasma-assisted N 2 -O 2 reactions are assessed by measuring the consumption of plasma-derived N and the formation of NO in the gas phase and over Ag catalytic surfaces. These measurements are enabled by a setup that enables N 2 activation in an atmospheric pressure RF plasma jet, enables O 2 addition in the plasma afterglow, facilitates reactions over an Ag wire catalyst, and allows species density quantification by molecular beam mass spectrometry. Gas-phase reactions consume N but do not form NO with high selectivity. The presence of the non-porous Ag wire catalyst increases the rate of N conversion to NO, though mass transfer processes, not surface reactions, dictate the rate of N consumption. When O 2 concentrations and the ratio of the surface area of the catalyst to the void volume of the reactor are high (3–5 mol% O 2 , 10900 m−1), N conversion to NO reaches 100 % selectivity. When both N 2 and O 2 are fed through the plasma jet, gas-phase NO production increases 10×, although plasma and gas-phase processes do not exclusively produce NO. Above a threshold NO density, N cannot diffuse to the catalyst surface faster than it is consumed in the gas phase by reactions with NO. Thus, the use of heterogeneous catalysts to enhance plasma-driven N x O y formation and control N x O y product selectivity is limited to cases where diffusive transport of N from the gas phase to the catalyst surface is faster than consumption of N from gas-phase reactions with NO. [ABSTRACT FROM AUTHOR]

[Display omitted] • NH 3 -SCR with Cu/BEA catalyst investigated without DOC and DPF on actual engine exhaust. • Weak and moderate acid sites aid in NH 3 coverage up to 350 °C – Maximum NOx reduction of 63.5 % obtained. • Kinetic model developed by using genetic algorithm for optimizing kinetic parameters. • Investigated parametrically for variations in reaction temperature and concentrations of NH 3 , NO, and O 2. Selective catalytic reduction (SCR) technology using NH 3 has shown to be the most promising method in the curbing of NOx and zeolite catalysts impregnated with copper has shown excellent SCR activity below 350 °C. However, most of the investigations are carried out with the artificial mixing combination of exhaust gases. The effect of real-time engine-out exhaust gas on NH 3 -SCR activity has been scantily reported. In this paper, Cu/BEA zeolite with varying copper loading from 0.83 to 4.31 wt% has been used and the effect of engine-out exhaust emissions has been investigated. The catalysts were prepared using ion-exchange method and characterized using SEM, XRD, and BET analyses. The highest NOx reduction efficiency of 62.5 % was observed for 1.77 wt% Cu for which the Cu/Al ratio was close to unity. The kinetic modeling of the SCR activity was also carried out to validate the experimental results with an average error of 3.85 %. [ABSTRACT FROM AUTHOR]

This work further investigates the heterogeneous alloyed PdPtCu nanoflower clusters (PdPtCu NVFs) mediated photo-Fenton and photothermal synergistic catalysis for dye elimination. [Display omitted] • Synthesized heterogeneous alloyed PdPtCu nanoflower clusters (PdPtCu NVFs) mediated photothermal and photo-Fenton synergistic catalysis for dye elimination. • Increased dye degradation by PdPtCu NVFs under NIR laser irradiation. • Reusable nano-catalyst has great potential for organic sewage treatment. This study primarily employed a one-step reduction method to synthesize palladium-platinum-copper nanovelvet flowers (PdPtCu NVFs). PdPtCu NVFs are multi-branched nanomaterials composed of nanosynapses that radiate in different directions. Their unique structure and incorporation of three metallic elements contribute to their outstanding Fenton catalytic vitality and photothermal performance. Characterizations for PdPtCu NVFs were conducted by using transmission electron microscope (TEM), electron paramagnetic resonance (ESR), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) techniques. Under near-infrared light, PdPtCu NVFs rapidly reached a temperature of 50 °C. In comparison with conventional photocatalysts, PdPtCu NVFs demonstrated significantly enhanced degradation of organic dyes (methylene blue, MB) degrading due to their superior Fenton catalytic activity. Even after multiple reuse, PdPtCu NVFs still exhibited distinct nanosynapses, along with excellent photothermal stability and Fenton catalytic activity. These results indicate that PdPtCu NVFs possess excellent purifying capabilities for organic wastewater. [ABSTRACT FROM AUTHOR]

Excessive phosphorus content can aggravate the formation and emission of particulate matter (PM) during biodiesel combustion, which can lead to the performance degradation of automobile exhaust catalytic converters and make it difficult to control pollutant emissions. However, the influential mechanism of phosphorus in biodiesel on PM formation is not clear yet. Therefore, thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy are used to study the formation, oxidation characteristics, and nanostructures of soot particles produced from Jatropha biodiesel (JB100) combustion under different phospholipid (PE:phosphatidylethanolamine, main phospholipid type in JB100) contents. The results show that with increasing PE content in JB100, the amount of soot particles first increases and then decreases. When the PE content is 400 ppm, the amount of soot particles is the largest, almost 13.40% higher than that produced from neat JB100. Further, the activation energy (AE) of soot oxidation first increases and then decreases with increasing PE content. The apparent AE is the largest (131.40 kJ/mol) at 400 ppm. Furthermore, when the PE content is 400 ppm, the strength of oxygen-containing functional groups in the soot particles is the weakest, and the ratio of nanocrystal height to polycyclic aromatic hydrocarbons (PAHs) interlayer spacing (L c /d 002) (4.396), the average lattice spacing of PAHs (0.367 nm), and the ratio of D 1 and G peaks integral intensity (I D1 /I G) (2.566) are minimum. This verifies that the PE content in JB100 can affect the strength of active oxygen-containing functional groups and the size and structure of PAHs in the soot particles and that the oxidative reactivity of soot particles is lowest at 400 ppm. • PE content can affect the generation amount of soot particles. • PE addition changed the strength of oxygen functional groups in soot particles. • PE content can affect the size and structure of PAHs in soot particles. • When PE is 400 ppm, the oxidation activity of soot particles is the weakest. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fabrication of cryogel via rapid UV-irradiation grafting cryopolymerization. • The designed chitosan based-cryogel is flexible and antibacterial in nature. • Better selectivity for Pd(II) ions in the presence of coexisting metal ions. • Maximum adsorption capacity for Pd(II) was 184.93 mg g−1. • The cryogels have a better thermal stability and shelf life. • Promising adsorption performance for Pd(II) in waste electronic materials. Retrieving valuable metals like palladium, gold, and platinum from electronic waste poses significant challenges. In this study, we developed highly macroporous and flexible antibacterial chitosan-based cryogel through rapid cryopolymerization induced by ultraviolet exposure. This designed cryogel exhibited exceptional palladium adsorption capabilities within an acidic environment, demonstrating swift and efficient adsorption. Remarkably, the chitosan-based cryogel showed an impressive palladium adsorption capacity, reaching 184.93 mg g−1 as Langmuir isotherm model, thus highlighting its promising potential for palladium recovery. The adsorption efficiency and concentration examination was conducted using an Inductively Coupled Plasma Optical Emission Spectrometer in the presence of multiple coexisting ions. Various factors and parameters, including pH, contact time, temperature, concentration, and selectivity, were investigated to assess the effectiveness of the biopolymeric cryogel in palladium adsorption. Additionally, the thermal stability of the developed cryogel was explored within the temperature range of 25-100˚C, revealing a commendable palladium adsorption capacity even at 100˚C. This finding underscores the material's potential for application under challenging conditions. The cryogel that was synthesized exhibits an extended shelf-life of up to six months and can be reused without any discernible alteration in its adsorption efficiency. Furthermore, the palladium adsorption capacity was evaluated in a real-world sample, demonstrating commendable adsorption capabilities. Remarkably, the biosorbent displayed a higher selectivity of 91% for palladium, even in the competing ions presence. In summary, biosorbent offers superior adsorption performance and remarkable stability, making it a valuable contribution to polymer chemistry and environmental science. Its potential for recovering precious metals from wastewater is indeed noteworthy. [ABSTRACT FROM AUTHOR]

Developing confined heterogeneous catalytic systems with diverse and evenly dispersed active sites is a hot research topic for various applications. However, the issues related to the agglomeration of active nanoparticles, spatial distribution uniformity of active nanoparticles, and coverage of active sites with the participation of surfactant or organic ligand restrict the activity or selectivity. In this work, a confined catalyst Pd(PPh 3) 4 @MOF-808-150 was successfully prepared through a host-guest assembling strategy followed by thermal activation to enhance the rigidity of the catalyst. The synthesized catalyst is employed to generate β-ketoenamines in the cascade reaction involving nitro-reduction and sequential condensation. This catalyst effectively resolves the electronic preference conflict of the two catalytic steps by isolating the different active sites, demonstrating excellent activity and high chemoselectivity. It is generally applicable to the synthesis of many β-ketoenamines, with up to 16 kinds of products that have been successfully prepared with conversion and selectivity up to 99%. The extended synthesis method holds significant potential for developing the nanoconfined catalyst without surfactant encapsulation. Constructing a synergistic catalyst by confining Pd within a MOF using an extended "bottle-around-ship" protocol for catalytic cascade reaction with conflicting electronic requirements. [Display omitted] • Pd(PPh 3) 4 @MOF-808 prepared by the extended "bottle-around-ship" protocol. • Highly dispersed palladium is successfully confined in the channel of MOF-808. • Thermal activation effectively improves activity and stability. [ABSTRACT FROM AUTHOR]