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Composition-varied Au/PtTe hetero-junction-abundant nanostructures are fabricated by combining interfacial self-assembly and interface-confined transformation strategy, and can be directly used as electrocatalysts of boosting ethanol electrooxidation. [Display omitted] Pt-based multi-metallic electrocatalysts containing hetero-junctions are found to have superior catalytic performance to composition-equivalent counterparts. However, in bulk solution, controllable preparation of Pt-based hetero-junction electrocatalyst is an extremely random work owing to the complexity of solution reactions. Herein, we develop an interface-confined transformation strategy, subtly achieving Au/PtTe hetero-junction-abundant nanostructures by employing interfacial Te nanowires as sacrificing templates. By controlling the reaction conditions, composition-varied Au/PtTe can be easily obtained, such as Au 75 /Pt 20 Te 5 , Au 55 /Pt 34 Te 11 , and Au 5 /Pt 69 Te 26. Moreover, each Au/PtTe hetero-junction nanostructure appears to be an array consisting of side-by-side Au/PtTe nanotrough units and can be directly used as a catalyst layer without further post-treatment. All Au/PtTe hetero-junction nanostructures show better catalytic activity towards ethanol electrooxidation than commercial Pt/C because of the combining contributions of Au/Pt hetero-junctions and the collective effects of multi-metallic elements, where Au 75 /Pt 20 Te 5 exhibits the best electrocatalytic performance among three Au/PtTe nanostructures owing to its optimal composition. This study may provide technically feasible guidance for further maximizing the catalytic activity of Pt-based hybrid catalysts. [ABSTRACT FROM AUTHOR]

Fe-SiO 2 interaction is a critical issue in the study of Fischer-Tropsch Fe/SiO 2 catalyst. It has been advanced that the formation of Fe-O-Si bond is related to Fe-SiO 2 interaction and responsible for dispersing iron particles and stabilizing active phases. This work formulates studying the relationship and interconversion between Fe-O-Si bond and Fe 2 SiO 4 phase, and further concludes that Fe 2 SiO 4 is another form of Fe-SiO 2 interaction. A well mixing of Fe-O and Si-O domains in the catalyst precursor benefits the distribution of extensive Fe-O-Si bond, which in turn facilitates the formation of Fe 2 SiO 4 during the catalyst reduction process. High ramp rate and diluted H 2 favor the transition of discrete Fe-O-Si to Fe 2 SiO 4 kinetically and thermodynamically, respectively. During the transition, amorphous Fe 2 SiO 4 initially forms before undergoing a rapid crystallization process, at ca. 560 ± 10 °C, to transform to large crystals detectable by XRD. In addition, the amorphous nature of Fe 2 SiO 4 requires the combination of characterization techniques capable of detecting short-range ordered structures, e.g., XAFS, MES, and magnetometer. [Display omitted] • Fe 2 SiO 4 is another form of Fe-SiO 2 interaction for Fischer-Tropsch Fe/SiO 2 catalyst. • Well distributed Fe-O-Si bond can transform to amorphous Fe 2 SiO 4. • High ramp rate and diluted H 2 kinetically favor the transition of Fe-O-Si to Fe 2 SiO 4. • Amorphous Fe 2 SiO 4 undergoes rapid crystallization process to form large particles at 560 ± 10 °C. • The dehydration of Si-OH facilitates the crystallization of Fe 2 SiO 4. [ABSTRACT FROM AUTHOR]

Novel 3D P-doped poly(triazine imide) (PTI) nanotubes were prepared in situ by molten salt method with melamine and hexachlorotriphosphazene as starting precursors. The as-prepared composite showed superior photocatalytic properties under visible-light irradiation due to the integrated merits of 1D tubular structure, 1D nanorods, and P doping. The improved utilization of visible light and the enhanced separation of photo-induced charge carriers resulted in the maximum degradation rate constant of P-doped PTI at 2.86 min−1, which was approximately 6.3 and 2.6 folds those of bulk graphite-like carbon nitride and pristine PTI material, respectively, during tetracycline hydrochloride photodegradation. Moreover, the novel catalyst has an excellent stability and thus is a promising candidate for photocatalysis. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Pd-Pt nanocrystals were synthesized using a high-temperature solution-phase reduction method. • PdO x or PtO x nanoparticles (2 nm) dispersed homogeneously on γ-Al 2 O 3. • CeO 2 can improve the dispersion of PdO x and PtO x nanoparticles. • 0.2%Pd-Pt(1:1)/10%Ce/γ-Al 2 O 3 had good stability and the highest activity for benzene oxidation. Abstract In this investigation, a mesoporous γ-Al 2 O 3 with large surface area and good thermal stability was synthesized and employed as the support for preparing a series of Pd-Pt nanocrystalline catalysts by using a high-temperature solution-phase reduction method. The PdO x (x = 0, 1) and PtO x (x = 0, 2) nanoparticles were found to have a small diameter (about 2 nm) and were highly dispersed on the surface of the mesoporous γ-Al 2 O 3. The results show that catalysts with the appropriate ceria greatly improved the physical adsorption/chemisorption of benzene to Pd-Pt nanocrystals, which greatly enhanced the activity to achieve the complete oxidation of benzene. The high activity of the catalyst was mainly due to the nano-effects of Pd-Pt nanocrystals and the interactions among the active components. 0.2%Pd-Pt(1:1)/10%Ce/γ-Al 2 O 3 demonstrated the best activity for the complete oxidation of benzene at 200 °C. Furthermore, this catalyst maintained 95% benzene conversion for 1000 h at 190 °C and displayed good resistance to water and Cl-poisoning, which indicated that the Pd-Pt nanocrystalline catalysts have promise for adoption by the industry. [ABSTRACT FROM AUTHOR]

Microwave based technology is an alternative heating method and has already been successfully used in biomass pyrolysis for biochar and biofuel production thanks to its fast, volumetric, selective and efficient heating. Previous review mainly focused on production and analysis of bio-oil and gas instead of biochar. The current paper provides a review of microwave-assisted pyrolysis (MWP) of biomass and its biochar characteristics, including product distribution and biochar yield, biochar properties, microwave absorbers (MWAs) and catalysts commonly used in MWP, as well as comparison of biochar derived from MWP and conventional pyrolysis (CP). MWAs not only absorb microwave energy, they also act as catalysts to interact with gas, vapor and solids in the reactor, adjusting the product distribution and quality of products. It was reported for MWP that the highest biochar yield was >60 wt% and the maximum BET surface area was about 450–800 m 2 /g. Technology status and economics of MWP of biomass in China were briefly introduced. The Optimization of yield and quality of biochar strongly depends on feedstock properties, reactor types, operating parameters, MWAs and catalysts added to the system. [ABSTRACT FROM AUTHOR]

We synthesized Fe 3 O 4 /LDO/BiOBr composites (Fe 3 O 4 /ZnAl-layered double oxide/bismuth oxybromide) by hydrothermal self-assembly and calcination treatment. The UV–visible diffuse reflectance spectra showed that Fe 3 O 4 /LDO/BiOBr had a significant redshift and enhanced visible-light absorption ability. Fe 3 O 4 /LDO/BiOBr demonstrated excellent photoreduction activity in response to Cr(VI), and the photocatalytic efficiency for 50 mg/L Cr(VI) was 98% within 30 min by Fe 3 O 4 /LDO/BiOBr-1.5. The improved behavior of Fe 3 O 4 /LDO/BiOBr for Cr(VI) was attributed to the construction of electron transfer path and efficient separation of photogenerated carriers. Fe 3 O 4 acted as the electron-bridge between LDO and BiOBr, which accelerated the carrier transfer speed and reduced the interface resistance. The transient photocurrent response and electron transfer rate of Fe 3 O 4 /LDO/BiOBr-1.5 were 5.3 and 2.2 times greater than those of BiOBr, respectively. Fe 3 O 4 /LDO/BiOBr-1.5 also exhibited favorable durability and reusability, potential application in real Cr(VI) wastewater, and easy recovery ability from solutions under an external magnetic field. This study provided a ternary assembled Fe 3 O 4 /LDO/BiOBr for efficient photoreduction of high concentrations of Cr(VI) by effective solar light harvesting, which expanded the application of LDO-based catalysts in future wastewater treatment devices. [Display omitted] • Fe 3 O 4 /LDO/BiOBr-1.5 removed 98% of 50 mg/L Cr(VI) in 30 min. • Fe 3 O 4 /LDO/BiOBr-1.5 maximized visible light harvesting. • The electron bridge facilitated photoexcited carrier separation and transfer. • Fe 3 O 4 /LDO/BiOBr-1.5 displayed preferable stability and activity in wastewater systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • hs-CoFe catalyst with "plate reactor" structure was facilely synthesized. • Hetero-porous structure was constructed by selective etching and rGO supporting. • The OER/ORR was lowered to 0.608 V due to this smooth mass transfer channel. • ZAB performance and stability were significantly boosted. Large-scale application of zinc air batteries (ZABs) is impeded by the lack of efficient and cost-effective bifunctional oxygen catalysts. In this work, hetero-porous is rationally engineered for the carbon encapsulated CoFe catalyst, which is highly active toward both oxygen evolution reaction (OER) and oxygen evolution reaction (ORR). The hs-CoFe catalyst with "plate reactor" structure is facilely synthesized by combining the selective etching and reduced graphene oxide supporting to construct pores with size of 10–100 nm and 100–1000 nm, respectively, for smooth mass transfer. OER/ORR activities are significantly boosted, and difference between the potential to deliver 10 mA/cm2 OER and half wave potential of ORR is therefore lowered to 0.608 V while this potential difference of Pt/C-IrO 2 is 0.732 V. The corresponding ZAB exhibits a maximum power density of 232 mW/cm2, which sheds light on providing a novel strategy for oxygen reaction catalyst designation. [ABSTRACT FROM AUTHOR]

Abstract: In this research, the catalytic activity of a rhodium-based (Rh) catalyst with imidazolium-based ionic liquids (IBILs) as solvents for ethylene hydroformylation was studied. The structures of IBILs had an important influence on the activity and stability of the Rh catalyst. The IBILs with longer cation side chains, which were the strong steric hindrances around the Rh catalyst, were more unfavorable for the catalytic activity. The turnover frequency (TOF) of the Rh catalyst was 10627h−1 when [Bmim][BF4] was used as solvent. The activity of the Rh complexes in the ionic liquid is better than they do in toluene. We used electrospray ionization mass spectrometry to characterize the catalyst after the reaction and found that [Bmim]+ acts as a ligand of the Rh catalyst to form a new active catalytic site [Rh(CO)(PPh3)2(Bmim)(BF4)]+ through the coordination of the Rh atom with the imidazole-2-C group of [Bmim][BF4], and it was essential for the stabilization of the Rh catalyst and prevented the formation of low-active Rh clusters. In addition, the catalyst recycling test showed that the Rh catalyst could be reused with [Bmim][BF4] as solvent without obvious loss of catalytic activity. [Copyright &y& Elsevier]

Abstract: A series of silica-supported 12-silicotungstic acid catalysts (H4SiW12O40, abbreviated as HSiW), modified with various loadings of Teflon (HSiW/SiO2-Teflon), were prepared by an impregnation method. The surface properties of the catalysts were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), BET, infrared (IR) spectroscopy, NH3-TPD and the Drop Shape Analysis (DSA). SEM results combined with energy-dispersive X-ray (EDX) measurements of HSiW/SiO2-Teflon revealed that F-compound (Teflon) is effectively coated on the catalyst surface. The contact angles for water and oil of 50wt% HSiW/SiO2 and HSiW/SiO2-Teflon indicate that HSiW/SiO2-Teflon catalyst enhances not only the surface hydrophobicity but also the surface lipophobicity by means of the addition of Teflon. Silica-supported 12-silicotungstic acid modified with Teflon exhibits higher selectivity and longer lifetime than that of silica-supported 12-silicotungstic acid in isobutene oligomerization. Thus, surface-appropriate lipophobicity of catalysts may be effective for decreasing the interaction between coke precursors and the catalyst surface and for removing deposited coke more easily. [Copyright &y& Elsevier]

Abstract: Oxidation of alcohols (including C2–C6 alkyl alcohols, cyclohexanol, benzyl alcohol, 1-octanol and allyl alcohol) to corresponding aldehydes or ketones has been performed over silver catalyst; the silver catalyst is highly active and selective to the reaction. The mechanism of oxidations of alcohols is inclined to oxidative dehydrogenation at low temperature region (<550K). The facets of silver are ideal versatile facets to activate molecular oxygen and generate oxidative, strong basic oxygen species (O δ−), and weak acidic sites (Ag δ+) which can stabilize the organic intermediates, quickly. The facets of silver containing oxygen integrate several active catalytic sites existing in liquid-phase catalytic oxidation of alcohols and make catalytic reaction more effective. [Copyright &y& Elsevier]

This article explores a supported catalyst of Fe(bpy)32+ on a cationic exchange resin (Amberlite IRA 200) as a photocatalyst for the degradation of organic pollutants by activating molecular oxygen under visible irradiation (λ>420 nm) in water. Different from Fe(bpy)32+ which is not photoactive in solution, the supported catalyst exhibits a very efficient photoactivity for the degradation of N,N-dimethylaniline and the cationic dyes of Rhodamine B (RhB) and Malachite Green (MG) in an aerated aqueous medium. TOC removal yield was 75, 60 and 58%, respectively, after 700 min of visible light irradiation. The photocatalytic activity of the supported Fe(bpy)32+ remained unchanged after 22 cycles of over 100 h. The photocatalyst was characterized by UV-Vis diffuse reflectance, and X-ray photoelectron spectroscopies (XPS). EPR studies suggest that the active superoxide species {Fe(bpy)33+O2⋅−} are involved in the light-activated reaction. A reaction mechanism is proposed in the text. [Copyright &y& Elsevier]

Lignin is an attractive renewable source of aromatics with a low effective hydrogen to carbon ratio (H/Ceff). The catalytic hydrodeoxygenation (HDO) of lignin-derived model compounds is a key strategy for lignin upgrading. In this work, the HDO of guaiacol, a typical lignin-derived compound, was carried out over metal–organic framework (MOF)-derived Ni-based catalysts. A monometallic Ni-MOF catalyst and different ratios of bimetallic NiMo-MOF catalysts were synthesized by a hydrothermal process, followed by a carbonization process. Among these catalysts, Ni3Mo1@C exhibited an excellent catalytic performance, affording a guaiacol conversion of 98.8% and a cyclohexanol selectivity of 66.8% at 240 °C and 2 MPa H2 for 4 h. The addition of Mo decreased the particle size of the spherical structure and improved the dispersion of metal particles. The synergistic effect between Ni and Mo was confirmed by various means, including ICP, XRD, SEM, TEM, and NH3-TPD analyses. In addition, the effect of the reaction temperature, time, and H2 pressure during the HDO process is discussed in detail. [ABSTRACT FROM AUTHOR]

Cu/ZnO/Al 2 O 3 catalysts have been widely applied as industrial catalysts for methanol synthesis from syngas, but suffers low activity for CO 2 hydrogenation to methanol. This study establishes highly active Cu catalysts through modulation of the composite of Al 2 O 3 and ZrO 2 in Cu/ZnO-based catalysts. The composition of Al 2 O 3 and ZrO 2 impacts the Cu dispersion, exposed surface area of Cu, the Cu0/(Cu0+Cu+) ratio and surface basicity. An appropriate content of Al 2 O 3 and ZrO 2 presents the higher Cu surface area, desirable ratio of Cu0/(Cu0+Cu+) and moderate-strong basic sites for effective CO 2 adsorption/activation, giving rise to higher space-time yield of methanol (up to 648 g CH3OH ·kg cat −1·h−1) than the commercial Cu catalyst. STY of methanol can be correlated with Cu surface area and Cu0/(Cu0+Cu+) ratio under the investigated conditions. The mechanistic analysis demonstrates that surface formate and methoxy species are the major intermediates. The methanol formation principally follows the formate-methoxy intermediate pathway. [Display omitted] • An appropriate amount of Al 2 O 3 and ZrO 2 favors the production of methanol. • The conversion rate of CO 2 is positively correlated with S Cu. • The relatively high content of Cu0 showed higher activity. • The increase of the number of moderate basic sites contributes to the improvement of CO 2 conversion rate. • The CO 2 hydrogenation to methanol followed the formate intermediate pathway. [ABSTRACT FROM AUTHOR]

Abstract: Polyaniline was used as a nonmetal catalyst in the oxidative dehydrogenation of ethylbenzene and yield of 22.9% at 573K and ∼40% at 673K were obtained, respectively. An indirect oxidative dehydrogenation mechanism was proposed based on the results of pulse reactions. [Copyright &y& Elsevier]

A selected number of tetradentate N2Py2 ligand-supported ReO2+ complexes and a monodentate pyridine-supported ReO2+ complex have been investigated as catalysts for the deoxydehydration (DODH) of diols and polyols. In situ 1H NMR experiments showed that these N-donor ligand-supported ReO2+ complexes are only the pre-catalyst of the DODH reaction. Treatment of (N2Py2) ReO2+ with an excess amount of water generates an active species for DODH catalysis; use of the Re-product of this reaction shows a much shorter induction period compared to the pristine complex. No ligand is coordinated to the "water-treated" complex indicating that the real catalyst is formed after ligand dissociation. IR analysis suggested this catalyst to be a rhenium-oxide/hydroxide oligomer. The monodentate pyridine ligand is much easier to dissociate from the metal center than a tetradentate N2Py2 ligand, which makes the Py4ReO2+-initiated DODH reaction more efficient. For the Py4ReO2+-initiated DODH of diols and biomass-based polyols, both PPh3 and 3-pentanol could be used as a reductant. Excellent olefin yields are achieved. [ABSTRACT FROM AUTHOR]

In this work, single-atom Ag anchored on nitrogen-doped carbon catalysts are designed to investigate the effect of different N -coordination environments on the ECO 2 RR products pathway. The combination of experiments and theory calculations reveal that the Ag-N 4 -C (pyrrolic N) site facilitates the adsorption of CO 2 to produce CO, whereas Ag-N 3 -C (pyridine N) exhibits the highest binding energy (-4.73 eV) to hold *CO intermediates for dimerization, consequently steering the pathway to ethanol (C 2 H 5 OH) formation with a FE of 42% at −0.97 V vs. RHE. [Display omitted] • Ag N C catalysts with controllable N species and content were prepared. • ECO 2 RR products from CO to C 2 H 5 OH can be regulated. • Ag-N-rGO 0.025 M with pyrrolic N promotes the production of CO. • Ag-N-C 0.05 M with pyridine N facilitates a FE C2H5OH of 42 % at −0.97 V RHE. • Experiments and DFT calculations reveal the structure–activity relationship. The rational modulation of the coordination environment of the active center of single-atom catalysts (SACs) is a potential strategy to improve the activity and selectivity of electrocatalytic CO 2 reduction. We developed a series of single-atom Ag-anchored on N -doped carbon catalysts with different N -coordination environments by regulating the carbon source (glucose/graphene oxide, GO). Results demonstrated that the CO 2 -to-CO/C 2 H 5 OH pathway can be converted through reasonable regulation of the content of pyrrolic N and pyridine N. At a highly dominant pyrrolic N content of 40.0 %, the electrocatalyst of Ag-N-rGO 0.025 M facilitates the formation of CO with a Faradaic efficiency (FE) of 69.7 %. By contrast, when the pyridine N content is 70.5 %, the best Ag-N-C 0.05 M catalyst in the H-cell shows an FE of 42 % for C 2 H 5 OH at −0.97 V vs. RHE; moreover, the FE is stable at 40 % within 31 h. Density functional theory calculations further confirm that the pyrrolic N site is conducive to the conversion of CO 2 to intermediate *CO, whereas pyridine N exhibits the highest binding energy (ΔG = -4.73 eV) to hold *CO intermediates for dimerization, consequently steering the pathway to the formation of C 2 H 5 OH. The results of this study provide novel insights into the rational design of carbon-based SACs based on efficient electrochemical CO 2 reduction reaction and the regulation of CO 2 selectivity and activity for C 2 H 5 OH production. [ABSTRACT FROM AUTHOR]

The lateral size of graphene nanosheets plays a critical role in the properties and microstructure of 3D graphene as well as their application as supports of electrocatalysts for CO2 reduction reactions (CRRs). Here, graphene oxide (GO) nanosheets with different lateral sizes (1.5, 5, and 14 µm) were utilized as building blocks for 3D graphene aerogel (GA) to research the size effects of GO on the CRR performances of 3D Au/GA catalysts. It was found that GO-L (14 µm) led to the formation of GA with large pores and a low surface area and that GO-S (1.5 µm) induced the formation of GA with a thicker wall and isolated pores, which were not conducive to the mass transfer of CO2 or its interaction with catalysts. Au/GA constructed with a suitable-sized GO (5 µm) exhibited a hierarchical porous network and the highest surface area and conductivity. As a result, Au/GA-M exhibited the highest Faradaic efficiency (FE) of CO (FECO = 81%) and CO/H2 ratio at −0.82 V (vs. a Reversible Hydrogen Electrode (RHE)). This study indicates that for 3D GA-supported catalysts, there is a balance between the improvement of conductivity, the adsorption capacity of CO2, and the inhibition of the hydrogen evolution reaction (HER) during the CRR, which is related to the lateral size of GO. [ABSTRACT FROM AUTHOR]

The effects of Fe, Ni, and Mo active components loaded with HZSM-5 on the composition of hydrothermal liquefaction bio-oil from microcrystalline cellulose were investigated. All three supported catalysts resulted in the cyclization of microcrystalline cellulose into aromatic compounds. Additionally, Fe/HZSM-5 underwent oxidation, producing ketones, aldehydes and carboxylic acids, which accounted for 44.5% of the total composition of bio-oil. On the other hand, Ni/HZSM-5 and Mo/ZHSM-5 caused ring-opening of microcrystalline cellulose, leading to the production of alcohols and hydrocarbons, constituting 23.05% and 36.46% of the total composition, respectively. These findings indicate that the catalysts not only facilitated the ring-opening of polycyclic rings in microcrystalline cellulose but also underwent reactions with the hydroxyl groups present. To further understand the impact of these catalysts on hydroxyl groups similar to microcrystalline cellulose, glycerol was used as a model compound for liquefaction. The results revealed that 40.72% of Fe/HZSM-5 bio-oils consisted of cyclic ketones, while Ni/HZSM-5 predominantly produced straight-chain alkanes, straight-chain lipids, and straight-chain carboxylic acids. In contrast, Mo/HZSM-5 primarily yielded six-membered cyclic carboxylic acids, accounting for 72.48% of the composition. [Display omitted] • The composition of bio-oil was adjusted by loading different metal active components. • Fe/HZSM-5 is mainly used to oxidize hydroxyl groups on microcrystalline cellulose to form ketones, aldehydes and carboxylic acids. • Ni/HZSM-5 and Mo/HZSM-5 are mainly ring-opening of microcrystalline cellulose to supply hydrogen to form hydrocarbons and alcohols. • Glycerol was used as the model compound. Fe/HZSM-5 and Mo/HZSM-5 oxidized and cyclized hydroxyl groups, and Ni/HZSM-5 mainly oxidized the hydroxyl group. • The HHV of bio-oil(Fe/HZSM-5), bio-oil(Ni/HZSM-5) and bio-oil(Mo/HZSM-5) were 27.70MJ / kg, 31.44MJ / kg and 33.02MJ / kg, respectively. [ABSTRACT FROM AUTHOR]

• Different organic ligands had great effects on the catalyst properties. • Phosphotungstic acid had positive impact on catalysts acidity. • Phosphotungstic acid modified Co-based catalyst showed best catalytic activity. Catalytic transfer hydrogenation (CTH) was recognized as a promising technique for converting various lignin derivatives to fuels and high-value compounds in heterogeneous systems. Herein, Co@C catalysts with diverse organic ligands, Keggin-type heteropolyacids, acid addition quantities, and metal/organic ligand molar ratios were synthesized via one-pot hydrothermal processes and carbonization methods. The optimized catalyst demonstrated highly efficient active hydrogen generation from isopropanol and the best conversion (100 %) for vanillin (VAN) hydrodeoxygenation (HDO) with 90 % 2-methoxy-4-methylphenol (MMP) yield at 180 °C for one hour under mild conditions of 0 MPa N 2 (hydrogen-free circumstance), which were strongly connected to the higher specific surface area (154.45 m2/g), acidic site density (4.67 mmol/g), and stronger metal-P interactions of the Co(H 4)@C-HPW 0.25 catalyst. The findings in this work provided an advanced thinking for designing high-performance non-noble-metal catalysts that could be applied in the catalytic HDO transformation of various biomass derivatives into green fuel and chemicals under mild circumstances. [ABSTRACT FROM AUTHOR]

• The active oxygen on Pd/Sn 1−x Ce x O 2 (Ce-rich) is mainly lattice oxygen. • The active oxygen on Pd/Sn 1−x Ce x O 2 (Sn-rich) is mainly chemisorbed oxygen. • The active oxygen on Sn-rich oxide has better mobility than that on Ce-rich oxide. The properties of Sn-Ce solid solution have a significant effect on the CO oxidation performance of the Pd/Sn 1-x Ce x O 2 catalyst. Herein, we compared the effects of Sn-rich and Ce-rich supports on the catalytic performance of the Pd/Sn 1-x Ce x O 2 catalysts. Our results show that the active oxygen species on the Ce-rich and Sn-rich supports are mainly the lattice oxygen species and the chemisorbed oxygen species, respectively. Although the active oxygen species on the Ce-rich supports have higher intrinsic activity, the active oxygen species on the Sn-rich supports have better mobility. It leads to an interesting phenomenon that the change trend of the activity of the Pd/Sn 1-x Ce x O 2 catalysts with temperature is consistent with that of their supports. Compared with the Ce-rich supports and the corresponding supported Pd catalysts, the catalytic activity of the Sn-rich supports and the corresponding supported Pd catalysts increased faster with the increase of temperature. [ABSTRACT FROM AUTHOR]

For medium and low matured shale oil exploration, in situ upgrading could promote the oil recovery. There are two main disadvantages herein, high exploration temperature and large energy consumption. The new approach has been proposed to apply porous aluminosilicate catalysts for shale oil highly efficient upgrading at 350°C, H‐clin and Ni‐clin catalysts were prepared with natural clinoptilolite. Al‐SBA‐15 catalysts were synthesized by following one‐step crystallization procedure, and firstly employed for shale oil in situ upgrading. Kinetic studies of pyrolysis showed that the activation energy of organic matter conversion in shale was reduced from 113.80 kJ mol−1 to 37.28 kJ mol−1. After the catalyst addition, shale oil conversion temperature was declined, the reaction rate was increased, and the energy consumption of in situ upgrading was reduced. In Sinopec patented testing instrument, hydrocarbon generation and hydrocarbon expulsion unit, shale oil catalytic conversion showed increased hydrocarbon generation by 2%‐16%. Under the same reaction conditions, the Al‐SBA‐15 (Si/Al = 5) revealed the best activity for hydrocarbon generation, and the efficiency was elevated to 32.67%, twice as that of thermal conversion. The quality of catalytically produced oil was promoted, by improving the further cracking of bitumen to light oil and gas. The results have a breakthrough significance for intensifying the high‐efficiency hydrocarbon generation and expulsion process of low and medium matured shale oil. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) is an important chemical with a diverse array of applications. However, the existing scenario of centralized high-concentration production is in contrast with the demand for low-concentration decentralized production. In this context, the on-site green and efficient two-electron oxygen reduction reaction (ORR) for H2O2 production has developed into a promising synthetic approach. The development of low-cost, highly active, and durable advanced catalysts is the core requirement for realizing this approach. In recent years, single-atom catalysts (SACs) have become a research hotspot owing to their maximum atom utilization efficiency, tunable electronic structure, and exceptional catalytic performance. The coordination engineering of SACs is one of the key strategies to unlock their full potential for electrocatalytic H2O2 synthesis and holds significant research value. Despite considerable efforts, precisely controlling the electronic structure of active sites in SACs remains challenging. Therefore, this review summarizes the latest progress in coordination engineering strategies for SACs, aiming to elucidate the relevance between structure and performance. Our goal is to provide valuable guidance and insights to aid in the design and development of high-performance SACs for electrocatalytic H2O2 synthesis. [ABSTRACT FROM AUTHOR]

Binary single‐atom catalysts (BSACs) have demonstrated fascinating activities compared to single atom catalysts (SACs) for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Notably, Fe SACs is one of the most promising ORR electrocatalysts, and further revealing the synergistic effects between Fe and other 3d transition metals (M) for FeM BSACs are very important to enhance bifunctional performance. Herein, density functional theory (DFT) calculations are first adapted to demonstrate the role of various transition metals on the bifunctional activity of Fe sites, and a notable volcano relationship is established through the generally accepted adsorption free energy that ΔG*OH for ORR, and ΔG*O−ΔG*OH for OER, respectively. Further, ten of the atomically dispersed FeM anchored on nitrogen‐carbon support (FeM‐NC) are successfully synthesized with typical atomic dispersion by a facile movable type printing method. The experimental data confirms the bifunctional activity diversity of FeM‐NC between the early‐ and late‐ transition metals, agrees very well with the DFT results. More importantly, the optimal FeCu‐NC shows the expected performance with high ORR and OER activity, thereby, the assembled rechargeable zinc–air battery delivers a high power density of 231 mW cm−2, and an impressive stability that can be stably operated over 300 h. [ABSTRACT FROM AUTHOR]

CO2 hydrogenation to methanol was conducted using a set of activated carbon-supported Cu/ZnO/Al2O3 catalysts (CCZA) prepared by an incipient wetness impregnation approach. The effect of the Cu/Al ratio on the physicochemical properties of the catalysts, as well as their catalytic performance, were investigated. As Cu/Al ratio increased, the metallic Cu surface area displayed a reducing trend from 6.88 to 4.18 m2∙gcat−1, while the CO2 adsorption capacity exhibited an increasing trend. Meanwhile, aluminum content will have an important effect on the catalysts' reducibility and, thus, on their catalytic performance. The CCZA-2.7-de catalyst demonstrated the highest selectivity to methanol at 83.75% due to the excellent distribution and synergistic effect of copper and zinc. Although the CO2 conversion of CCZA-2.2-de and CCZA-3.5-de exceeded 10%, the CH3OH selectivity was less than 60%, which may be attributed to the larger particle sizes of ZnO and poor interactions in Cu–Zn. The present study offers a novel approach to increase the number of active sites, optimize the activated carbon-aided Cu/ZnO/Al2O3 catalyst's composition, and finally elucidate the mechanism for CO2 hydrogenation to methanol. [ABSTRACT FROM AUTHOR]

[Display omitted] • One-step redox precipitation method for the preparation of trace Co-doped Ce-Mn-based catalysts with multiple applications. • A dual redox cycle was constructed (Mn4+ + Ce3+ ↔ Mn3+ + Ce4+ and Mn3+ + Co3+ ↔ Mn4+ + Co2+). • C1M3C-3% exhibited superior NH 3 -SCR performance and was capable of catalytic combustion of VOCs. • C1M3C-3 % demonstrated excellent resistance to moisture and sulfur and can be recirculated by simple calcination (350 °C, 4 h). • The NH 3 -SCR mechanism of C1M3C-3% was revealed by in-situ DRIFTS. Trace amounts of Co-doped Ce-Mn-based metal oxide catalysts with various applications were synthesized by a simple redox method. When the molar fraction of doped Co was 3 %, the catalyst possessed comparatively high contents of adsorbed oxygen species (O ads), Mn4+, Ce3+, and Co3+, and exhibited promising catalytic performance. C1M3C-3 % had a wide denitrification temperature window, achieving 80 % NO removal at 87–277 °C and 90 % catalytic combustion of toluene at 171 °C (T 90% = 171 °C). Furthermore, the catalyst exhibited satisfactory moisture and sulfur resistance activity and can be regenerated by simple calcination (350 °C, 4 h). The reason for the high sulfur resistance of C1M3C-3 % was investigated in detail and a schematic diagram was provided. The NH 3 -SCR process was revealed to satisfy the L-H mechanism with the assistance of in situ DRIFTS. This work demonstrated that the Co-doped Ce-Mn-based catalyst had the potential for downstream of soot treatment equipment. [ABSTRACT FROM AUTHOR]

Ru-modified monolayer-dispersed WO x /CeO 2 hybrid composites were prepared by co-impregnation (CI) and step impregnation (SI) methods, and the effects of active site distribution on the catalytic oxidation of 1,2-dichloroethane (DCE) were investigated. Ru species tends to be deposited on the monolayer-dispersed WO x (m-WO x) by SI method, which can increase the oxygen vacancies (O V,m-WOx) at m-WO x /CeO 2 interfaces. Abundant O V,m-WOx can promote the formation of more active W–OH and accelerate the dechloridation and oxydehydrogenation of DCE. Oppositely, for CI method, Ru species exists mainly in the form of Ru−O−Ce bonds, increasing the oxygen vacancies (O V,RuCe) into CeO 2 surface lattices and promoting the deep oxidation of intermediate products. The closer contact between the two hetero-interfacial oxygen vacancies (O V,RuCe and O V,m-WOx) on Ru-modified m-WO x /CeO 2 produces a stronger synergistic effect on DCE activation and oxidation, and meanwhile advantageously inhibits the adsorption of chlorine species as well as the formation of polychlorinated by-products. [Display omitted] • Impregnation sequence affects active site distribution on Ru-modified m-WO x /CeO 2 catalysts. • Ru species on m-WO x surfaces increases O V,m-WOx and W–OH by SI method. • CI method generates more Ru−O−Ce and O V,RuCe. • Synergies of hetero-interfacial O V promote DCE activation/oxidation and inhibit Cl species absorption. [ABSTRACT FROM AUTHOR]

Note: The source of the background picture is from website. [Display omitted] • K 3 PO 4 could adjust Cu+/(Cu0 + Cu+) and promote catalytic performance greatly. • By regression analysis, Fe2+, Cu0, and medium base site show linear relation to C 2+ OH STY. • Significance level of above three factors follows Cu0＞Fe2+＞medium base sequence. • Conversion of Fe0 to Fe 3 C or Fe 3 O 4 leads to activity decrease. CO 2 hydrogenation to C 2+ OH is an effective way to diminish CO 2 emissions. Although challenges still exist in large-scale applications, CuFeZn catalysts attract extensive attention due to their low-cost. Herein, CuFeZn catalysts are modified by different amounts of K 3 PO 4 , (KP) 0.1 CuFeZn exhibits an excellent catalytic performance (total alcohols selectivity of 15.76 % at CO 2 conversion of 38.10 %, C 2+ OH/ROH fraction of 94.23 %, and C 2+ alcohols space–time-yield (STY) of 53.81 mg·mL−1·h−1). Combined with a series of characterization results, it is found that the effect of K 3 PO 4 is complex, and the proportion of Fe2+, Cu0 and medium base shows perfect linear relation to STY of C 2+ OH. The significance level of the above three factors is in the following sequence: Cu0＞Fe2+＞medium base. The introduction of K 3 PO 4 decreases the proportion of Fe2+ (active site for RWGS, the competitive reaction for C–C coupling) and increases the proportion of Cu+/(Cu++Cu0) (Cu+ is the active site for C–C coupling) due to the synergistic effect of Cu0 and Cu+, thereby improving the synthesis of C 2+ OH. Moreover, conversion of Fe0 to Fe 3 C or Fe 3 O 4 plays negative roles in the stability of the catalysts. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DESs), which were prepared by using AlCl 3 and acetamide or urea, show excellent catalytic performance for the olefin alkylation thiophenic sulfur (OATS) in 3-methylthiophene (3-MT) model oil and real gasoline within 40 min at 50 °C. The addition of toluene and benzene increases the conversion of thiophenic compounds and decreases the conversion of olefin. Then the mechanism of OATS with modified catalyst was discussed. [ABSTRACT FROM AUTHOR]

An emerging organic structure with excellent 2e- oxygen-reduction activity in the photosynthesis of H 2 O 2 has been developed, of which the photocatalytic performance was significantly improved after anchoring the active moiety into extending conjugated covalent organic frameworks. The resulting materials rendered high H 2 O 2 productivity in pure water. [Display omitted] • An emerging organic photocatalytic structure for the photosynthesis of H 2 O 2 from oxygen and water has been developed. • Extending conjugated COFs promotes H 2 O 2 productivity in pure water. • The suitable distance of active moiety generates the highest efficiency. • An alternative strategy for constructing 2e- oxygen reduction photocatalyst. Direct synthesis of hydrogen peroxide (H 2 O 2) using oxygen and water through the photocatalytic route is a prospective approach for the on-site production of H 2 O 2. However, the limited varieties of photocatalytic sites and ambiguous structure-active relationship impede the development of environmentally friendly technology. Herein, we report a active compound (benzotrithiophene, BTT) for the photosynthesis of H 2 O 2 using oxygen and water, and design four benzotrithiophene-based 2D covalent organic frameworks (BTT-COFs) linked with aromatic amines linkers. Significant enhancement in photocatalytic activity has been observed via the introduction of BTT struct into 2D COFs. The high crystallinity of COFs increases the visible light absorption ability and photostability of BTT. The suitable distance of BTT struct in COFs and the construction of donor–acceptor (D-A) structure further promote the carrier generation and transfer. The COF-BTT-TAPT exhibited the highest H 2 O 2 production rate of 620 μmol g−1 h−1. Mechanism investigation experiments have given the validation that BTT-COFs efficiently reduce oxygen in pure water to form H 2 O 2 under visible-light irradiation. This work paves a revolutionary way for designing and fabricating high-performance metal-free photocatalysts for visible-light-driven H 2 O 2 production. [ABSTRACT FROM AUTHOR]

Self-confinement synthesized Ni@Mo 2 C/CN can stalely achieve 10 mA/cm2 overall urea oxidation with 1.51 V applied voltage due to the mutual promotion effect of Ni and Mo 2 C on UOR activity and HER activity. [Display omitted] • Ni@Mo 2 C/CN catalyst was synthesized via an in situ self-confinement strategy. • A mutual promotion effect of Ni and Mo 2 C on UOR activity and HER activity exists. • An applied voltage of 1.51 V can achieve 10 m A/cm2 stable overall urea oxidation. Efficient hydrogen production from water splitting is crucial for sustainable energy and yet impeded by sluggish anodic water oxidation. Urea oxidation had been considered as an alternative reaction due to its much lower oxidation potential. Rational design of highly efficient cost-effective electrocatalysts for urea oxidation is therefore urgent for hydrogen production from overall urea oxidation. Here, the Ni/Mo 2 C@CN catalyst consisting of a porous carbon shell and a heterojunction Ni/Mo 2 C core was constructed by an in situ self-confinement synthesis strategy. The mutual promotion effect of Ni and Mo 2 C can boost the urea oxidation and hydrogen evolution reactions at the same time. Only 1.51 V applied potential was needed to achieve stable 10 mA/cm2 overall urea oxidation on the Ni/Mo 2 C@CN catalyst. By considering the great stability resulting from the protective effect of the carbon shell, a practical application potential of Ni/Mo 2 C@CN in overall urea oxidation was achieved. [ABSTRACT FROM AUTHOR]

The emission of toluene into the atmosphere can seriously affect the environmental quality and endanger human health. A dielectric barrier discharge reactor filled with a small amount of Au nanocatalysts was used to decompose toluene in He and O 2 gases mixtures at room temperature and atmospheric pressure. Normally, the oxidation of toluene using Au nanocatalysts suffers from low reaction activity and facile catalyst deactivation. Herein, the effects of Au loading, calcination time and calcination temperature were systematically investigated. It was found that 0.1 wt%Au/γ-Al 2 O 3 calcined at 300 °C for 5 h can keep an average size around 6 nm with good dispersion on γ-Al 2 O 3 surface and display the best catalytic performance. Moreover, the influences of energy density, gas flow rate, toluene concentration and O 2 concentration on toluene degradation using 0.1 wt%Au/γ-Al 2 O 3 were evaluated. It showed the best catalytic performance of near 100% conversion for toluene degradation under the reaction conditions of the energy density was 20 J/L, the gas flow rate was 300 mL/min, the concentration of toluene was 376 mg/m3 and the oxygen content was 10%. Combining experimental results and theoretical calculations, the values of reaction constant k were 8.6 × 10−5, 3.53 × 10−5 and 3.09 × 10−5 m6/(mol*J), when O 2 concentration, power or flow rate changed, respectively. Therefore, O 2 concentration has the greatest effect on toluene decomposition compared to other factors in the presence of Au/γ-Al 2 O 3. [Display omitted] • Nano-sized Au catalyst was coupled in a DBD reactor for toluene degradation. • 0.1 wt%Au/γ-Al 2 O 3 showed the best toluene degradation near 100%. • Au/γ-Al 2 O 3 calcined at 300 °C for 5 h has small average size with good dispersion. • Reaction constants for plasma degradation of toluene were calculated. • Oxygen concentration has a great effect on toluene decomposition. [ABSTRACT FROM AUTHOR]

Rhenium disulfide (ReS2) as a catalyst is promising in water splitting for hydrogen evolution reaction (HER) owing to its unique structure and physiochemical property. Chemical vapor deposition (CVD) is one of effective means for the fabrication of high-crystallinity ReS2. At present, conductivities of typical substrates used for the CVD growth are mostly poor. The transfer to a conductive support or other engineering for improving the conductivity is necessarily required for the application of HER electrode. However, the damage to original structure and the introduction of impurities are highly possible in the process. The cost of time and material is also increased. In this work, we propose that a wood-derived carbon framework is used as a working electrode supporting CVD-grown ReS2 nanosheets in electrocatalytic HER. The optimal HER electrode with unique pore-through structure exhibits effective electrochemical surface area of 521 cmECSA2 and outstanding stability over 11 h. Such a carbon framework derived from natural wood is earth-abundant, ecofriendly and renewable, which can be potentially applied in the green energy industry. [ABSTRACT FROM AUTHOR]

Alkynone and enolized angelica lactone (or its anion) coordinated to Sc(III) center, forming a hexaccoordinate-Sc(III) active species. Chiral N , N '-dioxide-Sc(III) catalyst exerted asymmetric induction by bulky ortho - i Pr group and chiral backbone. • Counterion CF 3 SO 3 -accelerated the isomerization of α-angelica lactone and the construction of C H bond as proton-shuttle. • Alkynone and enolized angelica lactone (or its anion) coordinated to Sc(III) center, forming an active species. • Catalyst exerted asymmetric induction by bulky ortho - i Pr group and chiral backbone. The reaction mechanism and enantioselectivity of asymmetric Michael addition reaction between alkynone (R1) with α-angelica lactone (R2) catalyzed by chiral N , N '-dioxide-Sc(III) complex were investigated at the M06/6-31G(d,p) (acetonitrile, SMD) level. The α-angelica lactone substrate could isomerize to the active enolized form in the presence of Sc(OTf) 3 reagent, assisted by the counter trifluoromethanesulfonate anion OTf-. The alkynone substrate and enolized angelica lactone (or its anion) coordinated to Sc(III) center of N , N '-dioxide-Sc(III) complex catalyst simultaneously, forming a high active hexacoordinate-Sc(III) complex. The catalytic reaction occurred via a two-step mechanism, in which C 2 C γ bond formation was predicted to be the chirality-controlling step as well as the rate-determining step (RDS), affording predominant S -enantiomer. The counterion OTf- facilitated C H construction as a proton-shuttle, producing mainly E -configuration product observed in experiment. The steric repulsion from the ortho -substituent of amide moiety as well as the chiral backbone of N , N '-dioxide-Sc(III) catalyst played the key role for chiral induction in the asymmetric reaction. The less destabilizing Pauli repulsion and more stabilizing attractive interaction, especially the orbital interaction, along the si -face attack pathway enhanced the enantiodifference of the two competing pathways for high enantioselectivity. The energy barriers for E / Z isomerization of S or R -enantiomer assisted by HOTf was as high as 34.6–35.0 kcal mol−1, indicating that the product with Z -conformation was difficult to be obtained. These results were in good agreement with experimental observations. [ABSTRACT FROM AUTHOR]

Single-atom catalysts are of great interest because they can maximize the atom-utilization efficiency and generate unique catalytic properties; however, much attention has been paid to single-site active components, rarely to catalyst promoters. Promoters can significantly affect the activity and selectivity of a catalyst, even at their low concentrations in catalysts. In this work, we designed and synthesized CuO catalysts with atomically dispersed co-promoters of Sn and Zn. When used as the catalyst in the Rochow reaction for the synthesis of dimethyldichlorosilane, this catalyst exhibited much-enhanced activity, selectivity and stability compared with the conventional CuO catalysts with promoters in the form of nanoparticles. Density functional theory calculations demonstrate that single-atomic Sn substitution in the CuO surface can enrich surface Cu vacancies and promote dispersion of Zn to its atomic levels. Sn and Zn single sites as the co-promoters cooperatively generate electronic interaction with the CuO support, which further facilitates the adsorption of the reactant molecules on the surface, thereby leading to the superior catalytic performance. [ABSTRACT FROM AUTHOR]

This work designs and constructs a porous surface with multi-defense against various organic foulants in water purification, where hydrophilic, underwater superoleophobic, and anti-bacterial double Fe-based Fenton catalysts of β -FeOOH nanorods and CuFeO 2 nanoparticles were coated on PVDF membrane via a facile metal-ion-induced in situ deposition process. [Display omitted] • Multi-defense is designed and constructed on the porous membrane. • Double Fe-based Fenton nano-catalysts were in situ deposited on PVDF membrane. • M FeOOH/CF has ultra-stable underwater superoleophobicity and ultra-low oil adhesion. • M FeOOH/CF can degrade various foulants under the solar-driven photo-Fenton process. Membrane separation technology has been widely employed in wastewater separation, although, it is restricted by terrible membrane fouling. The acceptable "single defense" is insufficient to generate a desirable antifouling surface against various organic foulants in complex wastewater. Therefore, this work designs and constructs a porous surface with "multi-defense" by integrating hydrophilic, underwater superoleophobic, and anti-bacterial nano Fe-based Fenton catalysts of β -FeOOH nanorods and CuFeO 2 nanoparticles on the polyvinylidene difluoride membrane via metal-ion-induced deposition process. The obtained composite membrane (M FeOOH/CF) has ultra-stable underwater superoleophobicity and ultra-low oil adhesion, which prevent oils from adhering to the membrane and benefit to separate various surfactant-stabilized oil-in-water emulsions with high water flux and separation efficiency of 99%. M FeOOH/CF also exhibits nearly 100% bactericidal activity against Escherichia coli. Moreover, the various foulants (such as bovine serum albumin, methylene blue, and crude oil) adhered to the membrane after filtration can be successfully degraded by M FeOOH/CF under the solar-driven Fenton process, leading to ultrahigh flux recovery ratio (FRRV) of 98.2 ± 0.3% and a low irreversible fouling ratio (RirV) of 2.0 ± 0.1%. The apparent degradation rate constant (k) of M FeOOH/CF is 2.5 times the β -FeOOH coated membrane (M FeOOH) because the introduction of CuFeO 2 nanoparticles provides more reactive sites and lowers the Fe3+/Fe2+ redox potential. This study is working to bring about a highly efficient "multi-defense" on the porous membrane, which will realize membrane regeneration and boost wastewater purification. [ABSTRACT FROM AUTHOR]

• A novel biomass-based catalyst for catalytic upgrading and viscosity reduction process of heavy oil was prepared. • The mechanism analysis of catalyst on catalytic upgrading of heavy oil was explained in detail. • Non-acidic components in the catalyst could upgrade the chemical structure of heavy compositions. A biomass-based catalyst for catalytic upgrading and viscosity reduction process of heavy oil was prepared. The experimental results showed the viscosity of oil sample reduced from 508800 mPa.s to 22230 mPa.s (50 ℃) with 0.2wt% biomass-based catalyst at 320 ℃ for 30 min, and the viscosity reduction was up to 95.63%. The content of resin was significantly reduced by 10.1% after reaction under the optimal conditions. Furthermore, composition analysis, FT-IR analysis, thermogravimetric analysis and elemental analysis of the biomass-based catalyst were characterized in detail. In addition, FT-IR analysis, elemental analysis and SEM analysis were employed to evaluate the properties of oil sample. Further, influence mechanism of biomass-based catalyst on catalytic upgrading process of heavy oil was expounded through viscosity change, SARA analysis, 1H-NMR analysis, weight average molecular weight and average particle sizes analysis, and the above analysis results revealed that under the catalytic action of organic nickel salt, the presence of non-acidic components in the catalyst could improve the chemical structures of heavy compositions of oil sample. Finally, a possible schematic diagram of catalytic upgrading process was simply depicted in this work. [ABSTRACT FROM AUTHOR]

[Display omitted] • A general strategy is developed to prepare ternary single-atom catalysts. • The ternary single-atom catalyst shows high bifunctional activity. • Theatrical calculations provide insights into enhanced bifunctional performance. Synergistic effects have been demonstrated for binary single-atom catalysts (SACs), while it is still challenging to investigate the activity and performance of ternary SACs due to the lack of robust method to synthesize these materials. Herein, we provide a general approach for the preparation of ternary SACs, and the features of single atoms highly dispersed on the support have been identified and verified. As an illustration, trace platinum decorated iron-cobalt ternary single atom catalysts (PtFeCo/NC) possess an obviously enhanced bifunctional activity of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), as well as high stability. The density functional theory calculations reveal that the synergistic effects induced by the introduction of Pt enable modulating the adsorption strength of reaction intermediates both on the Fe-N 4 and Co-N 4 sites, thus enhancing the ORR and OER activity, respectively. In addition, the PtFeCo/NC-based Zn-air battery delivers a higher power density than that of commercial Pt/C-RuO 2 , and can be steadily operated over 188 h. [ABSTRACT FROM AUTHOR]

[Display omitted] • A silver decorated amorphous cobalt hydr(oxy)oxide is fabricated through a pre-oxidation process. • The catalyst exhibits outstanding OER performance and excellent stability. • The catalyst ranks amongst the highest OER activity for cobalt-based catalysts of recent studies. • Ag decoration induced greater Co3+ content, higher electrochemically active specific surface area, and better electron conductivity synergistically enhance the catalytic performance. "Soft" and "flexible" amorphous materials have gained traction recently due to their self-adjustability toward environmental changes. Unfortunately, poor conductivity and limited stability seriously hamper their commercial applications. In this work, we develop an Ag-decorated amorphous and efficient oxygen evolution reaction (OER) catalyst, requiring overpotentials of only 170 and 250 mV to yield current densities of 10 and 100 mA cm−2 in a 1.0 M KOH solution, respectively. The catalyst also exhibits outstanding stability, maintaining 93.1% of its initial performance after 27 h of continuous testing. When used as an air-electrode catalyst in a zinc-air battery, it recorded a charge–discharge cycle life of 330 h at a current density of 5 mA cm−2, with a voltage gap of 0.87 V. And the Ag decoration induced better electrical conductivity, more active specific surface, and higher Co3+ content are found to be the proper reasons for the catalyst's outstanding OER performance and stability. [ABSTRACT FROM AUTHOR]

The design and synthesis of highly efficient and low-temperature NO x reduction catalysts with long-term stability and good water resistance still remain a challenge in the field of gas catalysis. In this work, we demonstrated the integration of MnO x -Fe 2 O 3 /TiO 2 /Ti monolithic catalysts on flexible Ti mesh through plasma electrolytic oxidation technology, associated with hydrothermal reaction, and chemical bath deposition methods. The in-situ grown TiO 2 nanosheet supports hold a very strong substrate adhesion with Ti mesh, and provide ideal nucleation sites for the following deposition of high density of MnO x -Fe 2 O 3 active components. The brush-like nanostructure morphology of active MnO x -Fe 2 O 3 catalysts enables the complete adsorption and reaction of gas molecules on the catalyst surface. The selective catalytic reduction of NO x with NH 3 tests indicate that MnO x -Fe 2 O 3 /TiO 2 /Ti monolithic catalysts exhibit excellent low-temperature catalytic performance with 100% of NO x conversion at 137 °C, good stability and water resistance, showing great potential and broad application prospects in comparison with powder catalysts and honeycomb ceramic catalysts. The strategy of depositing multi-components active catalysts on in-situ grown ultra-thin TiO 2 nanosheet supports on flexible Ti mesh paves a solid way toward the practical applications of novel low-temperature selective catalytic reduction catalysts in diverse fields. [Display omitted] • TiO 2 nanosheet array in-situ grown on the Ti mesh serves as ideal substrate for Mn-Fe active component deposition. • Needle-like MnO x -Fe 2 O 3 heterostructure nanowires have large surface area and strong synergistic effect. • MnO x -Fe 2 O 3 /TiO 2 /Ti monolithic catalysts exhibit excellent low-temperature catalytic performance and good stability. [ABSTRACT FROM AUTHOR]

Multi-stage porous structure engineering has been proposed via dual-template strategy to overcome the mass transfer issue in the electrochemical devices, effectively promoting the performances of practical zinc-air batteries and direct methanol fuel cells. [Display omitted] • A dual-template strategy was developed for carbon-based catalyst synthesis. • Multi-scale porous structure can boost the ORR activity in electrochemical devices. • Great DMFC and ZAB performances were achieved. The oxygen reduction reaction (ORR), as a key semi-reaction in various electrochemical conversions, was widely studied. The FeNC catalyst showed great potential to replace precious Pt as the ORR catalyst. The multi-scale porous structure was crucial for the catalytic activity of the FeNC catalyst due to the discrete distribution of active sites. Therefore, a dual-template strategy was developed using solid NaCl as the hard template and self-polymerized resin as the soft template to construct a smooth multi-scale porous FeNC (FeNC-DT) catalyst with embedded metallic Fe. The as-prepared catalyst exhibited a half-wave potential of 0.954 V vs. a reversible hydrogen electrode under alkaline conditions. The corresponding zinc-air battery and direct methanol fuel cell (DMFC) using FeNC-DT as the catalyst performed superior to the precious-metal-based catalysts in power density. Especially, the self-breathing DMFC achieved a maximum power of 23 mW/cm2, indicating a great application prospect of the FeNC-DT catalyst in actual electrochemical devices. [ABSTRACT FROM AUTHOR]

The direct methane (CH 4) oxidation to high value-added C1 chemicals is a great promising strategy to explore the CH 4 resource utilization. However, the low activity and selectivity of catalytic performance remains a great conundrum due to the difficulty to activate the C H bond and the unmanageable over oxidation. Herein, Pd x Au y nanowires (NWs) with various Pd/Au atomic ratios are presented as ideal models to explore the atomic-level effect of PdAu atoms for the direct CH 4 oxidation. The influence of reaction parameters are systematically investigated, and Pd 9 Au 1 NWs display a maximum yield of 2890.3 μmol g−1 h−1 with 99% selectivity for the liquid C1 oxygenated products. This enhanced performance is attributed to the combination of one-dimensional structure and the synergistic effect from the suitable portion of Au on Pd sites, which regulates bond strength between adsorbed radicals (•OH, •OOH, •CH 3) and PdAu atoms, confirmed by the density function theory calculations. [Display omitted] • High quality Pd x Au y NWs with different Pd/Au atomic ratios are prepared by galvanic replacement reaction. • The Pd 9 Au 1 NWs show a maximum yield of 2890.3 μmol g-1 h-1 and a 99% selectivity for liquid C1 products. • The incorporation of Au moderates binding strength of intermediates, facilitating the C-H activation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Internal voltage losses in PEM water electrolysis cell can be deconvoluted. • The electrical resistance of catalyst layers in PEMWE cells is in-situ measured. • The electrical resistances of the anode catalyst layers changed dynamically during operation. • The sensing methodology could be applied to other energy storage/conversion systems. Proton exchange membrane water electrolysis (PEMWE) technology has been regarded as one of the most promising ways to fulfill a sustainable energy system when coupled with renewable energies. Understanding the working mechanisms and losses in PEMWE devices is critical for achieving the desired performance and durability that targets wide commercial applications. This work demonstrates a novel four-wire sensing technique for acquiring the internal voltage losses in an operating PEMWE cell, which deconvolutes the total cell voltage into five parts. Most importantly, the ohmic resistances on anode and cathode catalyst layers are in-situ and operando measured. The two catalyst layer resistances show completely different values and trends under the same operating conditions, which is mainly due to the electrical conductivity difference between the two layers. The ohmic resistance of the anode catalyst shows an exponential decay with current density, which is in accordance with previously published visualization results, and shows a dependency on temperature; while the ohmic resistance of the cathode catalyst layer is a constant and not related to operating conditions. With the adoption of the technique, a phenomenon in which the ohmic resistance of the anode catalyst changes dynamically during the cell testing is captured and recorded for the first time. These findings provide very valuable data and results for understanding the catalyst layer working mechanisms, and also help to optimize the future catalyst layer. The four-wire sensing technique developed in this study is a promising tool for diagnosis, analysis, and optimization not only for PEMWE devices, but also potentially for other energy storage and conversion devices. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two-bubble class model was employed for the gas–liquid mass transfer. [•] Axial dispersions of liquid and solid phases are incorporated in above model. [•] Bench-scale experiment was carried out in a 2L stainless steel tube of 2m long. [•] Scale-up simulations at a capacity of 1.0Mt/a for VR processing were conducted. [•] Due to the non-uniform distribution of catalyst, axial dispersion model is required. [ABSTRACT FROM AUTHOR]

Integrating high-efficiency oxygen evolution catalysts from the waste printed circuit board leachates is achieved via a one-step boriding recycling strategy. [Display omitted] • Mixed metal borides (FeNiCuSnBs) were obtained from waste printed circuit boards via a facile boriding process. • High metal ion recovery rates (over 99.40 %) are achieved for Fe, Ni, Cu and Sn via the boriding process. • The optimal metal boride exhibits a record‐high activity (η 10 = 199 mV) among waste-derived OER electrocatalysts. • The metal borides features accelerated surface self-reconstruction via B and Sn co-etching under OER conditions. • The in-situ generated metal (oxy)hydroxides act as the catalytic active sites. Converting electronic wastes into high-efficiency energy conversion catalysts is a win-win strategy in addressing the metal resources shortage and sustainable energy challenges. Herein, a facile boriding strategy is developed to directly convert the leachates of waste printed circuit boards into magnetic mixed metal borides (FeNiCuSnBs) for oxygen evolution reaction (OER) catalysts. Via the boriding process, a metal cation recovery rate of 99.78 %, 99.98 %, 99.96 %, and 99.49 % has been attained for Fe, Ni, Cu, and Sn, respectively. The obtained catalysts with a higher ratio of Ni and Fe show better OER performance. The optimal FNCSB-4 attains 10 mA cm−2 at a low overpotential of 199 mV, as well as good stability in alkaline solution. Remarkably, FNCSB-4 represents a record‐high activity among waste-derived OER electrocatalysts. In-depth study suggests that the superior OER performance is mainly owing to accelerated surface self-reconstruction by B/Sn co-etching under OER potential region, and the newly formed multimetal (oxy)hydroxides act as the active species for OER. Additionally, the efficient mass/charge transfer, the amorphous feature, and hierarchical structure also benefit OER. Apart from providing an insight into the correlation between surface self-reconstruction and OER activity of multimetal boride-based catalysts, this study also offers a general strategy for the high-efficiency recovery and advanced energy-driven applications of critical metals from other urban mines in a sustainable and environment-friendly approach. [ABSTRACT FROM AUTHOR]

Abstract: In this review article, the extracellular enzymes production, their properties and cloning of the genes encoding the enzymes from marine yeasts are overviewed. Several yeast strains which could produce different kinds of extracellular enzymes were selected from the culture collection of marine yeasts available in this laboratory. The strains selected belong to different genera such as Yarrowia, Aureobasidium, Pichia, Metschnikowia and Cryptococcus. The extracellular enzymes include cellulase, alkaline protease, aspartic protease, amylase, inulinase, lipase and phytase, as well as killer toxin. The conditions and media for the enzyme production by the marine yeasts have been optimized and the enzymes have been purified and characterized. Some genes encoding the extracellular enzymes from the marine yeast strains have been cloned, sequenced and expressed. It was found that some properties of the enzymes from the marine yeasts are unique compared to those of the homologous enzymes from terrestrial yeasts and the genes encoding the enzymes in marine yeasts are different from those in terrestrial yeasts. Therefore, it is of very importance to further study the enzymes and their genes from the marine yeasts. This is the first review on the extracellular enzymes and their genes from the marine yeasts. [Copyright &y& Elsevier]

Abstract: Catalytic reduction of NO by CO was studied over perovskite-like La2−x Sr x CuO4 (x =0.0, 0.5, 1.0) catalysts prepared by citrate method and calcined at 900°C. The catalysts were characterized by O2-TPD, H2-TPR and cyclic voltammetry (CV) measurements. Results obtained from CV were in well agreement with those obtained from O2-TPD and H2-TPR, suggesting that CV is also a powerful means in the study of heterogeneous catalytic reaction carried out at high temperatures. In O2-TPD experiment, the desorption area of β oxygen, which was contributed by the oxygen adsorbed on the oxygen vacancy, increased with the increase of Sr content and was in the same order as the activity, indicating that the activity depended largely on the oxygen vacancy resulted by Sr addition. In H2-TPR measurements, the increasing area of the first reduction peak indicating that the oxygen vacancy resulted by Sr addition plays important role in this peak, since the Cu3+ content in La1.5Sro.5CuO4 and LaSrCuO4 is the same. And in the CV curves, the area of redox peak, which represents the amount of oxygen vacancy participating in the reaction, has close correlations with the activity of NO+CO reaction, while the symmetry of redox potentials does not contribute much to the activity. Overall, with the link of oxygen vacancy, CV was introduced and has obtained great success in explaining reaction in heterogeneous catalysis. Besides, from the result that none reductive peak was observed in the first CV curves of LaSrCuO4, it suggested that the first step of a catalytic reaction is reduction, corresponding to the oxidation of catalyst i.e., M n+(Cu2+)→M(n+1)+(Cu3+). [Copyright &y& Elsevier]

• Cross-linked multi-atom Pt anchored on a Zn, Fe and N co-doped carbon catalyst is prepared. • The MAC-Pt/ZnFe -N- C catalyst shows 100 % exposure of surface Pt atoms. • The MAC-Pt/ZnFe -N- C catalyst exhibits remarkable catalytic activity and stability for the oxygen reduction reaction. • A fuel cell assembled by this catalyst delivers a maximal power output of 1.02 W cm−2 at 0.035 mg Pt cm−2 at the cathode. Although single-atom catalysts (SACs) are drawing wide attention because they offer properties that differ from those of conventional nanoparticle (NP)-based catalysts, the lack of neighboring metal centers to cooperate in catalysis limits their actual application in many important chemical processes. Here, we report the synthesis of multi-atom Pt catalyst that consists of cross-linked Pt-Pt metal centers stabilized by atomically dispersed ZnFe -N- C support through Pt-N bonds. XAFS analysis reveals that each Pt atom in the multi-atom Pt catalyst coordinates with ∼2.6 N atoms and ∼4.3 Pt atoms. This novel catalyst combines the merits of SACs and NPs, resulting in 100 % exposure of surface Pt atoms and excellent stability and fuel cell performance. With an ultralow Pt loading of 0.035 mg cm−2 at the cathode, the fuel cell delivers a 1.02 W cm-2 maximal power output. DFT calculations revealed that the strongly coupled Pt-N bond is critical for stabilizing the cross-linked Pt. [ABSTRACT FROM AUTHOR]

Transition metal oxide catalysts have attracted considerable attention for their promising potential as an alternative to replace noble metal catalysts in the application of various catalytic reactions. Herein, we report the design of monolithic Mn 3 O 4 /TiO 2 catalysts in-situ grown on Ti mesh substrate for efficient and stable CO oxidation. Porous TiO 2 film which is fabricated from the oxidation of Ti mesh using conventional plasma electrolytic oxide process plays an important role in the in-situ nucleation of TiO 2 nanosheets with strong adhesion to maintain the long-term stable CO oxidation, as well as providing Ti precursors for the formation of TiO 2 nanosheets. The decoration of Mn 3 O 4 co-catalysts on TiO 2 nanosheet support could significantly enhance the catalytic property of monolithic Mn 3 O 4 /TiO 2 catalysts due to the synergetic effect. Thus, a complete CO oxidation can be achieved as low as 160 °C without the involvement of any noble metal catalyst. The novel synthesis strategy of Mn 3 O 4 /TiO 2 heterogeneous catalysts shows overwhelming advantages of outstanding catalytic performance and superior stability in comparison with other traditional methods of powder-based catalysts. More importantly, it can be extended to the rational design of a variety of TiO 2 -based transition metal oxide catalysts which can be used for diverse applications including CO oxidation, de-NO x , CH x decomposition etc. Image 1 • In-situ grown TiO 2 seeding layer with strong adhesion is fabricated on Ti mesh by PEO method. • Mn 3 O 4 cocatalyst is uniformly supported on TiO 2 nanosheets grown on TiO 2 film. • Mn 3 O 4 /TiO 2 monolithic catalysts show low-temperature and stable CO oxidation performance. • Mn 3 O 4 /TiO 2 monolithic catalysts on flexible Ti mesh is promising for a variety of catalytic applications. [ABSTRACT FROM AUTHOR]

• Preparing catalyst with a novel unsaturated-impregnation-precipitation method. • uip-γ-Al 2 O 3 -CeO 2 -500 °C continuously get 97 % yield of imine in a fixed bed reactor. • The isolated yield of imine and TON BA reached up to 81 % and 16838 after 20 days. • uip-γ-Al 2 O 3 -CeO 2 -500 °C could be reactivated in situ in the fixed reactor. • Abundant acid sites of γ-Al 2 O 3 and the synergistic effect between CeO 2 and γ-Al 2 O 3. One-pot synthesis of imines from benzyl alcohols and anilines by heterogeneous catalysis in batch reactor has already been widely studied, but its high cost and low production efficiency limit its application in the fine chemicals industry. In this work, γ-Al 2 O 3 balls supported CeO 2 catalyst (uip-γ-Al 2 O 3 -CeO 2) was prepared by a novel unsaturated-impregnation-precipitation method, and was employed as a catalyst for continuous solvent-free synthesis of imines in a fixed bed reactor. Under the optimal technological parameter of fixed bed reactor and reaction condition, uip-γ-Al 2 O 3 -CeO 2 -500 °C obtained remarkable 97 % yield of imine. After 20 days' continuous operation, the total isolated yield of imine and TON BA/CeO2 reached up to 81 % and 16838, respectively. Importantly, the catalyst could be reactivated in situ in the fixed reactor. Through detailed characterization, the extraordinary catalytic performance of uip-γ-Al 2 O 3 -CeO 2 -500 °C can be attributed to the abundant acid sites of γ-Al 2 O 3 as well as the synergistic effect between CeO 2 and γ-Al 2 O 3. [ABSTRACT FROM AUTHOR]

• La modified Si pillared clays (SPC) with a house-of-cards structure were prepared. • S BET and V p values of Pt/LaSPC (0.5:1) was 544 m2/g and 1.33 cm3/g, respectively. • The particle size of PtO x was 3–5 nm for Pt/LaSPC (0.5:1) versus 5–7 nm for Pt/SPC. • The temperature of benzene combustion using 0.2% Pt/LaSPC (0.5:1) was about 200 °C. • 0.2% Pt/LaSPC (0.5:1) exhibited high stability at 195 °C in 100 h ongoing tests. La 2 O 3 modified silica-pillared clays (SPC) was synthesized by a soft template method. Both the basal spacing and the specific surface area increased after pillaring and modification, and the thermal stability was also improved, all of which could reduce the mass transfer resistance and improve the adsorption capacity of benzene. PtO x nanocrystalline catalysts were prepared by a high-temperature liquid reduction method. Among them, the catalyst with 0.2 wt% Pt loading and a La/KSF molar ratio of 0.5:1 (0.2% Pt/LaSPC (0.5:1)) showed the highest catalytic combustion activity and higher CO 2 selectivity, and the reaction temperature for benzene combustion was about 200 °C. Besides, the Pt0, Pt2+ and Pt4+ with particle sizes of about 3–5 nm coexisted on the surface of LaSPC (0.5:1). And this catalyst also exhibited good stability during the 100 h continuous reactions at 195 °C. The high dispersion of Pt particles, active oxygen species and strong redox property are responsible for the high activity of 0.2% Pt/LaSPC (0.5:1) for benzene combustion. [ABSTRACT FROM AUTHOR]