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Copyright of Nonferrous Metals (Extractive Metallurgy) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nachrichten aus der Chemie is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nonferrous Metals (Mineral Processing Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Three-way catalyst (TWC) stands as the state-of-the-art technology for controlling emissions in natural gas vehicles, but its utilization can generate NH3 by-product. This study proposed a novel strategy for reducing NH3 emissions during three-way catalytic reaction process of Pd-based catalysts by adding Ru. Catalysts Pd/LA + Si, Pd/LA + Ru/CZLN, and Pd/LA + CZLN were fabricated through incipient wetness impregnation and mechanical ball-milling methods. Testing under simulated exhaust conditions showed that Pd/LA + Si produced high NH3 levels, while Ru/CZLN addition significantly reduced NH3 emissions from 330 to 20 ppm. Conversely, the addition of CZLN facilitated steam reforming and water–gas shift reactions, generating more H2 for NO reduction, which led to an increase in NH3 emissions. Experimental evidence confirmed that Ru/CZLN could effectively decompose NH3, which was produced over Pd/LA, into N2 and H2, thereby significantly reducing NH3 emissions. This study provides a promising approach for developing TWC with low NH3 emissions for natural gas vehicles. [ABSTRACT FROM AUTHOR]

Limited research exists on catalytic converter theft despite it being a persistent issue for years. This study relies on police data for catalytic converter thefts (n = 414) in a medium-sized city for 18 months in 2021–2022. The study also uses vehicle registrations in the county, and Census data. Negative binomial regression models use Census Block Groups (n = 92) and consider neighborhood and environmental characteristics. The most likely vehicles to have catalytic converters stolen are the Honda Element, Toyota Prius, and Ford E-Series van. More than half of thefts occurred in parking garages and parking lots. Regression models find that the most consistent predictor of catalytic converter theft is adjacency to arterial roadways. Results suggest police departments should target efforts at parking garages and lots near highways, close to downtown, in areas that experience other kinds of crime. The situation changes when considering additional neighborhood characteristics, though highways are still a significant predictor. [ABSTRACT FROM AUTHOR]

Rhodium and iridium, both belonging to the platinum group metals, are critical metals due to their scarcity and broad industrial applications, particularly in automotive catalysts. With increasing global demand for PGMs and the depletion of primary resources, recycling spent catalysts has become essential for sustainable resource management and reducing environmental impact. This review focuses on recent advancements in the dissolution of Rh and Ir from spent catalysts, highlighting various hydrometallurgical leaching methods. Aqua regia, while commonly used, shows limited efficiency for both Rh and Ir due to their chemical inertness. More advanced techniques such as HCl-based systems with oxidizing agents like NaClO or NaClO3, microwave-assisted leaching, and dry aqua regia have demonstrated improved dissolution efficiency. There is some difference in the dissolution behavior between Rh and Ir metal by the reported leaching systems. Owing to the stronger chemical inertness of iridium metal, its dissolution requires different approaches from the dissolution of Rh. Microwave-assisted leaching offers superior Rh recovery rates, while Ir dissolution benefits from dry aqua regia, which reduces energy consumption by generating chlorine in situ at lower temperatures. Additionally, alloy fragmentation has proven effective for Ir dissolution by increasing surface area and enhancing chemical reactivity. The environmental and operational advantages of dry aqua regia are highlighted, presenting them as viable options for industrial recycling. This review would contribute to the development of sustainable processes for the recovery of these critical metals from secondary resources. [ABSTRACT FROM AUTHOR]

[Display omitted] In this study, leveraging the tunable surface groups of MXene, the two-dimensional (2D) Nb 2 C T x with OH terminal (NC) was synthesized. 2D ZnIn 2 S 4 (ZIS) nanosheets were prepared with the aid of sodium citrate, enhancing the exposure ratio of active (1 1 0) facet. On this basis, 2D/2D ZnIn 2 S 4 /Nb 2 C T x heterojunctions were fabricated to improve photocatalytic hydrogen evolution reaction (HER) performance. The optimized 6 wt%Nb 2 C T x /ZnIn 2 S 4 -450 (6NC/ZIS-450) photocatalyt exhibits a remarkable HER rate of 3603 μmol g−1h−1, which is 10 times superior to that of the original ZnIn 2 S 4. Its apparent quantum efficiency (AQE) at 380 nm reaches 14.9 %. Meanwhile, even after 5 rounds of HER, the activity of 2D/2D ZnIn 2 S 4 /Nb 2 C T x heterojunction remained at 90 %, far superior to that of pure ZnIn 2 S 4 (34 % and 31 %). Energy band structure analysis and density functional theory (DFT) calculation indicate that Nb 2 C T x adsorbed with OH exhibit a low work function. By serving as a hole cocatalyst, it effectively boosts the photocatalytic HER rate of ZnIn 2 S 4 /Nb 2 C T x heterojunction and inhibits the photocorrosion of ZnIn 2 S 4. This unique insight, via hole transport highways and increased exposure of active facets, effectively enhances the activity and stability of sulfides photocatalysts. [ABSTRACT FROM AUTHOR]

The actual ionomer distribution in the catalyst layer is revealed by integrating multiple electrochemical methods. Different catalyst layer interfaces are formed with varying ionomer contents. Uneven distribution of ionomers will lead to a low ECSA, causing high local oxygen transport resistance. Though the uniformity of ionomer distribution can be improved by increasing ionomer contents, it will enlarge the oxygen transport distance from the bulk of the catalyst layer to active sites, thereby increasing the local oxygen transport resistance. The former has a more obvious impact on PEMFC performance. [Display omitted] In view of a catalyst layer (CL) with low-Pt causing higher local transport resistance of O 2 (R local), we propose a multi-study methodology that combines CO poisoning, the limiting current density method, and electrochemical impedance spectroscopy to reveal how real CL interfaces dominate R local. Experimental results indicate that the ionomer is not evenly distributed on the catalyst surface, and the uniformity of ionomer distribution does not show a positive correlation with the ionomer content. When the ionomer coverage on the supported catalyst surface is below 20 %, the ECSA is only 10 m2·g−1, and the ionomer coverage on the supported catalyst surface reaches 60 %, the ECSA is close to 40 m2·g−1. The ECSA has a positive correlation with ionomer coverage. Because the ECSA is measured by CO poisoning, it can be inferred that the platinum contacted with ionomer can generate effective active sites. Furthermore, a more uniform distribution of ionomer can create additional proton transport channels and reduce the distance for oxygen transport from the catalyst layer bulk to the active sites. A higher ECSA and a shorter distance for oxygen transport will reduce the R local , leading to better performance. [ABSTRACT FROM AUTHOR]

[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]

The use of fossil fuels in transportation equipment, especially motorized vehicles, will have an extraordinary effect on air pollution. The percentage of air pollution from transportation sources in Indonesia is 70.5 % CO, 18.34 % HC, 8.89 % NOx, 0.88 % SOx, and 1.33 % particulate matter. Given the danger of exhaust emissions, especially carbon monoxide, which can cause death for humans who inhale it, efforts are needed to control air pollution from motorized vehicles. There are several methods that can be applied, one of which is to use adsorbents. Activated carbon can be used as an adsorbent. In this experimental research, briquettes with a diameter of 20 mm and a length of 30 mm were made. A mixture of coconut shell charcoal briquettes and wood charcoal briquettes 65–25 % (Model 1), 55–35 % (Model 2), and 45–45 % (Model 3) was used. The microwave method and sulfuric acid activation for 1 hour were applied. Testing with the object of the study was performed on a 4-stroke motor vehicle (Honda Supra 125) 2012 with an engine speed of 2,000 rpm. Emission tests were carried out using a gas analyzer. The performance test of a motorbike engine where adsorbents are installed in the exhaust gas was conducted using a dyno test. The results show that this briquette mixture can reduce carbon monoxide (CO) gas emissions by 71.6 % compared to without a catalytic converter. In addition, gas emissions of hydrocarbons (HC) were seen to be reduced by 88.8 % in comparison with an engine without a catalytic converter. Engine performance tests showed no significant impact on torque and power due to the use of this adsorbent. In conclusion, a mixture of coconut shell charcoal briquettes and wood charcoal briquettes activated with sulfuric acid, which is used to reduce exhaust gas emissions in motor vehicles can be applied. [ABSTRACT FROM AUTHOR]

Although oxygen vacancies (Ovs) have been intensively studied in single semiconductor photocatalysts, exploration of intrinsic mechanisms and in‐depth understanding of Ovs in S‐scheme heterojunction photocatalysts are still limited. Herein, a novel S‐scheme photocatalyst made from WO3‐Ov/In2S3 with Ovs at the heterointerface is rationally designed. The microscopic environment and local electronic structure of the S‐scheme heterointerface are well optimized by Ovs. Femtosecond transient absorption spectroscopy (fs‐TAS) reveals that Ovs trigger additional charge movement routes and therefore increase charge separation efficiency. In addition, Ovs have a synergistic effect on the thermodynamic and kinetic parameters of S‐scheme photocatalysts. As a result, the optimal photocatalytic performance is significantly improved, surpassing that of single component WO3‐Ov and In2S3 (by 35.5 and 3.9 times, respectively), as well as WO3/In2S3 heterojunction. This work provides new insight into regulating the photogenerated carrier dynamics at the heterointerface and also helps design highly efficient S‐scheme photocatalysts. [ABSTRACT FROM AUTHOR]

This experimental study investigates the palladium/rhodium based three-way catalyst (TWC) in a hydrogen-gasoline dual-fuel spark ignition (SI) engine under stoichiometric and lean conditions. The work focused on lean-burn engine operating conditions with the aim of reducing nitrogen oxides (NOx) emissions during the combustion process, where the TWC is not effective, while improving the thermal efficiency of the engine. Under these leanburn engine conditions, the combustion promoting properties of hydrogen allowed for maintained engine combustion stability as determined by the cycle-to-cycle variation (COVimep) values even up to ultra lean conditions (λ= 2.0). It was found that by reducing the combustion temperature through the application of lean conditions, engine-out NOx emissions could be reduced or even eliminated, while under these conditions the TWC was effective in reducing engine-out carbon-based gaseous emissions. [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]

The integration of machine learning (ML) methods into chemical catalysis is evolving as a new paradigm for cost and time economic reaction development in recent times. Although there have been several successful applications of ML in catalysis, the prediction of enantioselectivity (ee) remains challenging. Herein, we describe a ML workflow to predict ee of an important class of catalytic asymmetric transformation, namely, the relay Heck (RH) reaction. A random forest ML model, built using quantum chemically derived mechanistically relevant physical organic descriptors as features, is found to predict the ee remarkably well with a low root mean square error of 8.0 ± 1.3. Importantly, the model is effective in predicting the unseen variants of an asymmetric RH reaction. Furthermore, we predicted the ee for thousands of unexplored complementary reactions, including those leading to a good number of bioactive frameworks, by engaging different combinations of catalysts and substrates drawn from the original dataset. Our ML model developed on the available examples would be able to assist in exploiting the fuller potential of asymmetric RH reactions through a priori predictions before the actual experimentation, which would thus help surpass the trial and error loop to a larger degree. [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]

The results of diagnostic tests under steady-state speed conditions of an unloaded engine do not fully reflect the emissivity of vehicles adapted to run on natural gas. Therefore, it is reasonable to pay attention to the emissions performance of these vehicles under dynamic conditions. In this regard, the tests were carried out on a chassis dynamometer with the engine fueled by gasoline and natural gas. Due to the area of operation of natural gas vehicles being usually limited to urban areas, the urban phases of the NEDC (New European Driving Cycle) and WLTC (Worldwide harmonized Light-duty vehicles Test Cycle) were adapted. While CO2 emissions are lower when fueled by natural gas, CH4 emissions can be high, which is related to momentary changes in the composition of the combustible mixture. Although CH4 emissions are higher when the engine runs on natural gas, the CO2eq value is, depending on the driving cycle, about 15–25% lower than when running on petrol. Additionally, studies have shown that in engines adapted to run on CNG (compressed natural gas), it is advisable to consider the use of catalytic converters optimized to run on natural gas, as is the case with vehicles which are factory–adapted to run on CNG. [ABSTRACT FROM AUTHOR]

Metallic catalytic converter (MCC) is one of the technologies widely applied to motorcycle exhausts which aims to improve exhaust emission to be more environmentally friendly. However, even though many studies have been conducted, optimal design has not been achieved compared to other designs. Through this research, the Taguchi method is proposed as an alternative method to find the optimum parameters of MCC. The Taguchi method was chosen because of its ability to find a robust combination of parameters. There are four MCC parameters used as inputs while each parameter consists of three levels, thus the design used is the L18 Orthogonal Array (OA) which each combination is tested on three types of motorcycles, namely Moped, Automatic, and Sports. The signal-to-noise ratio (S/N) was adopted as one of the quality indicators of each combination. The optimization results showed that the best MCC design to reduce CO emissions is STD PGM. However, the optimum CO design can be used as an alternative because the difference in the S/N ratio is only -0.372. Meanwhile, the optimum CO design has another advantage over the STD PGM, namely the S/N value of the power ratio which tends to be higher with a difference of 5.037 compared to the STD PGM. Then, the best MCC design capable of increasing power is the optimum power design. The optimum power design has a superior S/N ratio with a difference of 5.404. In terms of emission, the optimum power design tends to be lower by a difference of -1.875 compared to the STD PGM. [ABSTRACT FROM AUTHOR]

Solid‐state lithium metal batteries (LMBs), constructed through the in situ fabrication of polymer electrolytes, are considered a critical strategy for the next‐generation battery systems with high energy density and enhanced safety. However, the constrained oxidation stability of polymers, such as the extensively utilized polyethers, limits their applications in high‐voltage batteries and further energy density improvements. Herein, an in situ fabricated fluorinated and crosslinked polyether‐based gel polymer electrolyte, FGPE, is presented, exhibiting a high oxidation potential (5.1 V). The fluorinated polyether significantly improves compatibility with both lithium metal and high‐voltage cathode, attributed to the electron‐withdrawing −CF3 group and the generated LiF‐rich electrolyte/electrode interphase. Consequently, the solid‐state Li||LiNi0.6Co0.2Mn0.2O2 batteries employing FGPE demonstrate exceptional cycling performances of 1000 cycles with 78 % retention, representing one of the best results ever reported for polymer electrolytes. Moreover, FGPE enables batteries to operate at 4.7 V, realizing the highest operating voltage of polyether‐based batteries to date. Notably, our designed in situ FGPE provides the solid‐state batteries with exceptional cycling stability even at practical conditions, including high cathode loading (21 mg cm−2) and industry‐level 18650‐type cylindrical cells (1.3 Ah, 500 cycles). This work provides critical insights into the development of oxidation‐stable polymer electrolytes and the advancement of practical high‐voltage LMBs. [ABSTRACT FROM AUTHOR]

Introducing continuous mesochannels into covalent organic frameworks (COFs) to increase the accessibility of their inner active sites has remained a major challenge. Here, we report the synthesis of COFs with an ordered bicontinuous mesostructure, via a block copolymer self‐assembly‐guided nanocasting strategy. Three different mesostructured COFs are synthesized, including two covalent triazine frameworks and one vinylene‐linked COF. The new materials are endowed with a hierarchical meso/microporous architecture, in which the mesochannels exhibit an ordered shifted double diamond (SDD) topology. The hierarchically porous structure can enable efficient hole‐electron separation and smooth mass transport to the deep internal of the COFs and consequently high accessibility of their active catalytic sites. Benefiting from this hierarchical structure, these COFs exhibit excellent performance in visible‐light‐driven catalytic NO removal with a high conversion percentage of up to 51.4 %, placing them one of the top reported NO‐elimination photocatalysts. This study represents the first case of introducing a bicontinuous structure into COFs, which opens a new avenue for the synthesis of hierarchically porous COFs and for increasing the utilization degree of their internal active sites. [ABSTRACT FROM AUTHOR]

Platinum group element levels have increased in natural aquatic environments in the last few decades, in particular as a consequence of the use of automobile catalytic converters on a global scale. Concentrations of Pt over tens of μg L−1 have been observed in rivers and effluents. This raises questions regarding its possible impacts on aquatic ecosystems, as Pt natural background concentrations are extremely low to undetectable. Primary producers, such as microalgae, are of great ecological importance, as they are at the base of the food web. The purpose of this work was to better understand the impact of Pt on a cellular level for freshwater unicellular algae. Two species with different characteristics, a green alga C. reinhardtii and a diatom N. palea, were studied. The bioaccumulation of Pt as well as its effect on growth were quantified. Moreover, the induction or repression factors of 16 specific genes were determined and allowed for the determination of possible intracellular effects and pathways of Pt. Both species seemed to be experiencing copper deficiency as suggested by inductions of genes linked to copper transporters. This is an indication that Pt might be internalized through the Cu(I) metabolic pathway. Moreover, Pt could possibly be excreted using an efflux pump. Other highlights include a concentration-dependent negative impact of Pt on mitochondrial metabolism for C. reinhardtii which is not observed for N. palea. These findings allowed for a better understanding of some of the possible impacts of Pt on freshwater primary producers, and also lay the foundations for the investigation of pathways for Pt entry at the base of the aquatic food web. [ABSTRACT FROM AUTHOR]

The paper discusses the characteristics of an oxidising catalytic converter for a diesel engine's particulate filter system, analyzed through simulation and empirical studies. Constructed from a metal monolith, the converter has a 1.4 dm3 volume, 400 cpsi channel density, and a 2.5 g/dm3 platinum coating. Its chemical composition was examined using a scanning electron microscope, revealing platinum crystallites on a highly porous surface. Simulation tests in the AVL Boost program, utilizing real exhaust gas concentration data, assessed the converter's efficiency in converting CO, HC, and NO2 in NOX at various engine speeds and channel conditions. An experiment on an engine dynamometer paralleled these simulations, verifying their accuracy. The study indicates that the simulation algorithm can predict the converter's performance, potentially reducing the need for extensive empirical testing and aiding in preliminary evaluations. [ABSTRACT FROM AUTHOR]

In the combined electrolysis and catalytic exchange (CECE) process, the electrolyzer produces both hydrogen and oxygen streams. Hydrogen is typically fed to the bottom of the liquid-phase catalytic exchange column. The oxygen stream, however, is processed and afterward is either fed back to the trickle bed recombiner in heavy water detritiation or released to the exhaust stack in light water detritiation. This paper discusses the handling of the oxygen stream both in heavy and light water detritiation CECE processes. Oxygen leaving the electrolyzer has a trace amount of tritium gas in it as well as water vapor (due to diffusion across the membrane). Trace tritium is converted to vapor using a catalytic converter and then either scrubbed using an oxygen vapor scrubber or captured in a dryer bed. This study analyzes and compares the different options for handling the oxygen stream in a CECE process. [ABSTRACT FROM AUTHOR]

In this study, EC process using an aluminum anode, and EC-EO process using aluminum and mixed metal oxide, i.e., platinum-ruthenium dioxide-coated onto titanium (Al-Ti/Pt-RuO2) anode was used to understand the remove of phenolic syntan (PS) from synthetic tannery wastewaters. The operational conditions of the abovementioned electrochemical processes were optimized using Taguchi L16 method in terms of maximum removal of total organic carbon (TOC) and PS. At the optimum operating condition (current density = 14.25 mA/cm2, initial pH = 4, rotational speed = 70 rpm and initial PS amount = 0.25 g/L), the incomplete removal of TOC (83.93%) and PS (81.19%) was obtained in the EC process with the energy consumption of 0.135 kWh/g TOC remove and 0.056 kWh/g PS remove. In contrast, almost (≈100%) complete removal of the dissolved organic pollutant was observed in the EC-EO process with the energy consumption of 0.113 kWh/g TOC remove and 0.0453 kWh/g PS remove. The energy consumption per g TOC and PS removed was 0.135 and 0.056 kWh for the EC process, whereas 0.113 and 0.0453 kWh for the EC-EO process. The operating cost of the EC-EO process was estimated to be 1.39 USD/m3, which was lesser (-19.65%) than the operating cost of the EC process. Signal-to-noise ratio and ANOVA results showed that current density was the most influential parameter with the highest delta value and contribution ratio for TOC and PS removal in both the EC and EC-EO process. The UV/Vis and FT-IR analyses indicate that the highest removal of aromatic compounds was obtained in the EC-EO process compared to the EC process. FT-IR analyses confirmed that the PS was first degraded into a quinone functional group, which was further oxidized into carboxylic acid. [ABSTRACT FROM AUTHOR]

This study focuses on the detailed analysis of exhaust emissions from multi-point fuel injection (MPFI) engines by manipulating the injection parameters through a programmable electronic control unit. In addition, tests are carried out using different generations of catalytic converters and checking that their working temperature is correct using a thermographic camera, verifying operation, to evaluate their effect on emission reduction. Detailed comparisons of the results between these configurations will allow the identification of the combination that reduces emissions the most without compromising engine efficiency and performance. This research aims to promote a more sustainable approach in the automotive sector by properly configuring systems, but also by demonstrating the technical robustness of their application in vehicles. It has also helped to verify that varying injection and ignition parameters help to fine-tune fuel injection, resulting in efficient combustion. Combining this variation with catalytic converters has further reduced exhaust pollutants. [ABSTRACT FROM AUTHOR]

Rhenium is utilized as an additive to improve the high-temperature strength and stability of materials, such as nickel-based superalloys, which are employed in jet engine turbine blades, alloys for ultrahigh-temperature thermocouples, and platinum catalysts, which are used in oil refining. Currently, around 80% of rhenium demand is for superalloy production, and this demand has been increasing with the increase in demand for aircrafts. The abundance of rhenium in the earth's crust is only 1 ppb (10−9), which is less than those of platinum and gold. Owing to the rare and unevenly distributed nature of rhenium, there is the risk of supply disruption and rapid increases in its price. In this article, the recent situation of rhenium and its compounds are reviewed, especially with respect to their demand, distribution characteristics, smelting, and recycling. Some of the technologies recently developed for smelting and recycling rhenium are also introduced. [ABSTRACT FROM AUTHOR]

A novel and selective method has been developed for high-accuracy determination of Pd, Pt and Rh in complex autocatalyst matrices using isotope dilution (ID) analysis (for Pt and Pd) and internal standard (IS) matching (for Rh) with ICP-time-of-flight mass spectrometry (ICP-TOFMS). By using a desolvating inlet interface and He collision gas, spectral interferences on selected isotopes (e.g., 105Pd, 195Pt, 196Pt) were successfully removed. Calibration is performed by exact-matching ID analysis for Pd (104Pd/105Pd) and Pt (196Pt/195Pt) and IS matching with 101Ru for monoisotopic 103Rh. Due to the quasi-simultaneous determination of all the isotopes of interest by ICP-TOFMS, isotope ratio precision was improved in comparison with that of sequential instrumentation, thus leading to reduced measurement uncertainties of <1% (k = 2), as required by autocatalyst manufacturers. This represents an approximately 2–3-fold improvement for Rh and Pd and 6-fold improvement for Pt in comparison to the uncertainties achieved using the same measurement strategy for sequential ICP-MS instrumentation. The method has been applied to the characterisation of a candidate CRM LGC3101 (unused automobile catalyst) containing high levels of Zr and Hf and validated by the analysis of similar matrix CRMs and by participation in an interlaboratory exercise. [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]

Recycling precious metals with high-efficiency is undoubtedly beneficial to optimize resource utilization for environmental remediation and sustainable development. Herein, we report an efficient route to recycle the palladium (Pd) and platinum (Pt) electrocatalysts using a phase transfer method. This strategy involves acidic dissolution of deactivated precious metal (Pd/Pt) electrocatalysts from their loading substrates, mixing with an ethanolic solution of dodecylamine (DDA), subsequent extraction of metal ions into a non-polar organic phase, and final reduction by sodium borohydride to reproduce high-performance electrocatalysts towards typical electrochemical reactions, e.g., oxygen reduction reaction (ORR) and ethanol oxidation reaction (EOR). In specific, the transfer efficiencies are up to 98% and the final recovery rate is over 85% for Pd and Pt electrocatalysts in each cycle. This approach symbolizes a facile and efficient way to recover precious metals, which might be applied to recycling a wide range of metals in various realms after appropriate modifications. [ABSTRACT FROM AUTHOR]

The Electrostatic Precipitator (ESP) is a widely employed device in boilers to mitigate the release of particulate matter. This study proposes the design and fabrication of a similar device tailored for reducing emissions from automobiles, particularly targeting older versions of BS vehicles lacking dedicated emission control mechanisms. Despite the catalytic converters equipped in BS-6 vehicles, there exists a need for an efficient emission reduction solution for their predecessors. This research aims to analyse various ESP designs through Computational Fluid Dynamics (CFD) simulations using ANSYS software. The design optimization will be conducted based on fluid flow analysis, leading to the fabrication of the most optimal prototype. The final step involves testing the fabricated prototype to ensure compliance with Pollution Under Control (PUC) standards, contributing to environmental sustainability. [ABSTRACT FROM AUTHOR]

In heterogeneous catalysis, reactivity and selectivity are not only influenced by chemical processes occurring on catalytic surfaces but also by physical transport phenomena in the bulk fluid and fluid near the reactive surfaces. Because these processes take place at a large range of time and length scales, it is a challenge to model catalytic reactors, especially when dealing with complex surface reactions that cannot be reduced to simple mean-field boundary conditions. As a particle-based mesoscale method, Stochastic Rotation Dynamics (SRD) is well suited for studying problems that include both microscale effects on surfaces and transport phenomena in fluids. In this work, we demonstrate how to simulate heterogeneous catalytic reactors by coupling an SRD fluid with a catalytic surface on which complex surface reactions are explicitly modeled. We provide a theoretical background for modeling different stages of heterogeneous surface reactions. After validating the simulation method for surface reactions with mean-field assumptions, we apply the method to non-mean-field reactions in which surface species interact with each other through a Monte Carlo scheme, leading to island formation on the catalytic surface. We show the potential of the method by simulating a more complex three-step reaction mechanism with reactant dissociation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hollow structure favors active site exposure and mass transport of S-NiCo 2 O 4 -6. • S2− doping reduces the oxidation potential of Ni cations during the OER process. • The reduced oxidation potential promotes the formation of γ-NiOOH active sites. • S2− doping enhances the conductivity of NiCo 2 O 4. Inducing the surface reconstruction of spinels is critical for improving the electrocatalytic oxygen evolution reaction (OER) activity. Herein, S-doped NiCo 2 O 4 hollow cubic nanocage was synthesized by anion etching Metal-Organic Frameworks (MOFs) template and air annealing strategies. The hollow structure possesses a large specific surface area and pore size, facilitating active site exposure and mass transport. S2− doping regulates the electronic structure, reducing the oxidation potential of Ni sites during the OER process, thus promoting the surface reconstruction into γ-NiOOH active species. Meanwhile, S2− doping enhances conductivity, accelerating interfacial charge transfer. As a result, S-NiCo 2 O 4 -6 exhibits superior OER activity (262 mV overpotential @ 10 mA cm−2) and stability in 1.0 M KOH solution. Furthermore, 20 % Pt/C‖S-NiCo 2 O 4 -6 only needs 1.832 V to achieve 50 mA (the electrochemical active area is 4 cm2) in a homemade anion exchange membrane (AEM) electrolyzer. This work proposes a novel approach for preparing efficient anion-doped spinel-based OER electrocatalysts. [ABSTRACT FROM AUTHOR]

The efficiency of incorporating deuterium into 4-aminobutanoic acid (GABA) has been studied. The use of D2O at 200°C makes it possible to introduce into GABA an average of about 0.5 deuterium atoms, D2O with trifluoroacetic acid (1 : 1) at 250°C, an average 1.49 deuterium atoms with a yield of 15%. The solid-phase method permits introducing about 3 deuterium atoms per GABA molecule. During isotopic exchange with D2O, the use of a palladium–rhodium mixture pretreated with deuterium gas made it possible to produce [D]GABA with the deuterium content of 4.5–4.6 atoms. But in both cases, the yields of [D]GABA were low. Preparative amounts of [D]GABA were produced engaging additional supports. The best result was obtained when applying GABA to zeolite. Using D2O with 5% Pd/BaSO4–GABA–zeolite pretreated with deuterium gas, allows producing [D]GABA with an average content of 1.5–2.0 deuterium atoms and a yield of about 30%. [ABSTRACT FROM AUTHOR]

In this paper, numerical simulation methods are adopted to explore the influencing factors of a Ceramic Catalytic Turbine (CCT) for reduced exhaust pollution from vehicles during the warm-up stage. Also, an analysis is conducted regarding the potential effects of turbulence on the catalytic reaction mechanism and the sensitivity of relevant parameters to the Arrhenius equation. It is found out that the air-fuel ratio inside the engine has a considerable effect on the reactions of CCT, with the conversion efficiency of each emission species sharply reduced under fuel-rich conditions. At 600K, the conversion efficiency declines by 11.3% for C3H6, 12.26% for CO, and 3.64% for NO. At 700K, the conversion efficiency is reduced by 6.7% for C3H6, 11.56% for CO, and 6.44% for NO. Despite increasing the concentration of reaction gas components, a high flow rate makes little difference to the reaction itself. At the same rotational speed of the turbine, the conversion rate of harmful components drops with an increase in flow rate due to the increase in space velocity. When the flow rate is constant and the temperature is kept in the control zone of chemical kinetics, the conversion efficiency of the catalytic reaction is enhanced at a higher rotational speed. Differently, when the temperature is in the control zone of mass transport and the flow rate is constant, the conversion efficiency decreases as the turbine accelerates. In practical terms, reducing activation energy within a controllable range is equivalent to further reducing the light-off temperature of the catalyst. Meanwhile, this may disrupt the convergence of numerical calculations because the catalytic reactions could occur at around the light-off temperature. [ABSTRACT FROM AUTHOR]

New solvent systems for selective separation of palladium from nuclear wastes represent a prospective way to reduce the total waste volume and induce this metal's extraction. For this purpose, the potential of modern green solvent room-temperature ionic liquid was assessed with diamide-type extractants based on N-heterocycles and S-donating thiodiglicolic acid. The N-donating heterocyclic extractants demonstrate structure-dependent high selectivity toward palladium in the presence of various impurity metals (such as Zr, Cs, Sr, Mo, Ce, Fe, and Cr) from spent nuclear fuel. Palladium is extracted into the organic phase quite selectively with a separation factor greater than a thousand for all extractants. Ionic liquid media are capable of selective palladium separation from platinum group metals and synergetically increase the selectivity of the extractants. [ABSTRACT FROM AUTHOR]