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Herein, atomically dispersed Ni–N 3 –C materials are facilely synthesized by the pyrolysis of Ni-doped ZIF-8. Each single Ni atom is proved to be bonded with three N atoms to form Ni–N 3 sites by X-ray absorption spectroscopy. During the pyrolysis at high temperature, the increasing of relative contents and blue-shift binding energy of pyrrolic N can be observed, indicating the Ni might be bonded with pyrrolic N. Moreover, the formation energy (E f) of NiN 3 -pyrrolic structure is smaller than that of NiN 3 -pyridinic calculated by density functional theory (DFT), thus confirming the dominated bonding structure of NiN 3 -pyrrolic further. The optimum material can achieve an ultra-high CO Faradaic efficiency of 99.37% at −0.75 V vs. RHE with a turnover frequency (TOF) of 3498 h−1 and a high CO partial current density of 80 mA cm−2 at −1.15 V vs. RHE, which is among the best Ni catalysts. Based on DFT results, the NiN 3 -pyrrolic sites can facilitate both the formation of COOH* intermediate and desorption of CO, which can also suppress the competitive hydrogen evolution reaction (HER) simultaneously, thus resulting in high catalytic activity and selectivity from CO 2 to CO. Electroreduction from CO 2 to CO with high activity and selectivity are achieved on the single-atom Ni–N–C catalyst due to the dominated Ni coordination structure by three pyrrolic N atoms. [Display omitted] • Single Ni atom catalysts were synthesized with Ni-doped ZIF-8 as precursor. • NiN 3 -pyrrolic coordination structure was identified as the dominated active sites. • Ultra-high activity and selectivity for CO 2 reduction towards CO was achieved. • NiN 3 -pyrrolic sites can promote the formation of *COOH intermediate by DFT. [ABSTRACT FROM AUTHOR]

Amorphous catalysts have a large number of catalytic active sites. Here, we report a magnesium composite trace lanthanum catalyst (La@Mg), in which La and Mg layers form amorphous Mg–La compound on the surface of layered Mg. The test shows this La@Mg has hydrogen storage capacity of about 7.6 wt% and hydrogen desorption of 7.2 wt%, higher than that of crystalline La@Mg and sole Mg, rapid absorption/desorption kinetic and stable reversible absorption/desorption cycles. La@Mg exhibits an optimistic hydrogen storage performance than Mg-based materials previously reported in the literature. Combined with theoretical calculations, it is shown that the amorphous Mg–La has an catalysis on hydrogen storage performance of La@Mg system, which contributing to the dispersion of Mg and providing channels for hydrogen diffusion, facilitating hydrogenation by accelerating H atoms diffuse between the subsurface and the surface. This work provides experiment and mechanism guidance for the development of efficient hydrogen storage materials. • The amorphous La@Mg catalyst was rationally synthesized. • The La@Mg has a hydrogen storage capacity of 7.6 wt% and reversible hydrogen absorption/desorption. • The content of amorphous LaMg was increased and it was conducive to the hydrogen absorption. [ABSTRACT FROM AUTHOR]

Developing readily scalable synthesis techniques for electrocatalysts is highly desirable for large-scale high-efficiency energy storage by water electrolysis. In this work, a coupled procedure of direct electrodeposition and in situ chemical transformation is presented to synthesize a nickel-iron-sulfur (Ni–Fe–S) composite catalyst. A polythiophene (PTh) coating with abundant micro/nano holes is directly deposited on graphite electrode at a constant potential. Two precursor solutions were injected onto and completely absorbed by the porous PTh coating, within which they spontaneously combine to form active species for catalysis. The PTh coating functions as a monolithic conductive matrix that well captures and disperses the catalyst species and thus decreases the contact resistance across the phase interfaces. The prepared catalyst shows a high catalytic performance for both hydrogen and oxygen evolution reactions. It requires a full cell voltage of about 2.0 V to afford a current density of 100 mA cm−2 in 1.0 M KOH, with no activity degradation at least for 24 h. The active species for the cathodic and anodic catalysis are different and discussed separately. This work indicates that in situ chemical synthesis within a porous conductive polymer coating is a promising approach for preparing high efficiency electrocatalysts. [Display omitted] • Abundant micro/nano holes inside polythiophene coating working as microreactors. • Rapid formation of catalyst active species within microreactors. • Monolithic conducting matrix well capturing and dispersing active species. • A single catalyst but different active species for HER and OER catalysis. [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]

The development of Ni-based catalysts with outstanding anti-coking ability is necessary for realizing the industrial application of dry reforming of CH 4 (DRM) to syngas. Here, a facile combustion method with unique characteristic was employed to prepare the Ni/SiO 2 catalyst with different promoters (ZrO 2 or Ru). The effects of Ni particle size and promoter (ZrO 2 or Ru) on the anti-coking ability of Ni/SiO 2 catalyst were examined. The XRD and TEM results showed that improved Ni dispersion can be obtained via the facile combustion method, accompanying with enhanced metal-support interaction and CO 2 adsorption capacity confirmed by H 2 -TPR and CO 2 -TPD, respectively. In comparison with Ni-IMP catalyst (prepared via the traditional impregnation method), the carbon deposition over Ni–C catalyst (prepared via the combustion method) decreased by 67% (from 2.7 to 0.9 mg carbon deposition ·g−1 CH4) as a result of the small Ni particles. The H 2 -TPR and XPS results revealed the interaction between promoter (ZrO 2 and Ru) and Ni. The addition of ZrO 2 can enhanced the CO 2 activation ability of catalyst and the formed oxygen species can facilitate the elimination of carbon species, further decreasing the carbon deposition compared with Ni–C catalyst. The best catalytic performance with least carbon deposition (only 0.4 mg carbon deposition ·g−1 CH4) is achieved on the NiRu–C catalyst. The slower CH 4 dissociation rate and the improved CO 2 activation benefited from Ru can bring in the better balance between the carbon formation and elimination, leading to the best anti-coking ability of catalyst. [Display omitted] • Highly dispersed Ni particles are obtained by a combustion method with low cost. • Excellent catalytic stability is achieved on the catalyst with small Ni particles. • ZrO 2 can enhance the CO 2 activation and facilitate the elimination of carbon species. • NiRu/SiO 2 catalyst can balance CH 4 and CO 2 activation, minimizing the coke formation. [ABSTRACT FROM AUTHOR]

• Providing a new strategy for preparation of dual/ multivariate single-atoms electrocatalyst. • Designing a dual single-atoms electrocatalyst TaCo-N-C. • The photovoltaic performanceof TaCo-N-C-based DSSC exceeds that of Pt-based DSSC. • Presenting an theoretical understanding of synergistic effect between dual single-atom. This study aims to design a dual single-atom electrocatalyst (DSAC) and elucidate the synergistic effect mechanism between DSAs. A novel synthetic strategy, combining ZIF pyrolysis and ionexchange, is employed for fabricating DSA electrocatalyst. A new type of electrocatalyst of TaCo-N-C containing dual atomically dispersed activity sitesis first obtained. Its intrinsic activity is investigated experimentally and rivals that of Pt. The adsorption energies of activity moieties are computated by first-principle density functional theory (DFT) to give synergistic effect description. Co-adsorption enhances catalytic activity by decreasing adsorption energy. This work provides an ideal alternative to Pt and a new idea for the preparation of dual/multivariate single-atom electrocatalysts and presents an atomic scale mechanism understanding of synergistic effect, which is a predictive guideline for the rational design of new types of electrocatalysts. [ABSTRACT FROM AUTHOR]

This study reports on the development of highly-efficient Pt/CuO-Fe 2 O 3 /TiO 2 monolithic catalysts for the low-temperature conversion of NO to N 2 via CO-SCR. In this case, ultrathin TiO 2 nanosheet arrays are designed to in situ grow on flexible Ti mesh to provide more spaces/areas for the loading of highly-dispersed Fe 2 O 3 and CuO active components. Furthermore, Pt nanoparticles with an average size of 1.30 nm are effectively decorated on the surface of CuO-Fe 2 O 3 /TiO 2. The H 2 -TPR and NO-TPD results demonstrate that the excellent synergistic effect between TiO 2 , CuO, Fe 2 O 3 and trace amounts of Pt is conducive to enhance the adsorption of NO and finally promote the CO-SCR. The obtained Pt/CuO-Fe 2 O 3 /TiO 2 catalysts exhibit excellent CO-SCR performance with 100 % NO conversion, and 100 % N 2 selectivity at 250 °C, showing great potential of de-NO x application by using toxic CO as reductant in industry. [Display omitted] • Pt/CuO-Fe 2 O 3 /TiO 2 monolithic catalysts were in-situ grown on a Ti mesh. • Ultrathin TiO 2 nanosheet array facilitates the high loading of Fe 2 O 3 and CuO. • The decorated Pt nanoparticles facilitate the adsorption and reduction of NO. [ABSTRACT FROM AUTHOR]

Highlights • An advanced class of hierarchical CoNi nanobundles catalysts are constructed. • The hierarchical nanobundle structure can help expose more active sites. • The Co 1 Ni 0.3 nanobundles are featured with rich oxygen vacancies. • The Co 1 Ni 0.3 nanobundles possess excellent oxygen evolution reaction activity. Abstract Electrochemical water splitting is a promising approach for the production of H 2 fuel while greatly limited by the sluggish anodic oxygen evolution reaction (OER). In this regard, searching for a highly efficient and durable OER catalyst with low cost, abundant active sites, and excellent durability is increasingly demanded. Herein, a facile one-pot hydrothermal method that using urea as pH regulator is demonstrated to engineer nanobundle-like CoNi layered double hydroxides (CoNi LDHs) with high surface areas and rich oxygen vacancies. As a result, by virtue of the nanobundle-like structure, abundant oxygen vacancies, as well as the modified electronic structures, the optimized Co 1 Ni 0.3 LDHs can deliver the current density of 10 mA/cm2 with the overpotentials of only 266 mV, much superior than those of Ir/C, Co(OH) 2 , and Ni(OH) 2 catalysts. More importantly, the resultant Co 1 Ni 0.3 LDHs also possesses excellent stability catalytic activity without negligible activity decay for at least 22 h. Our work not only establishes a potential OER electrocatalyst, but also open up a new avenue for the design and development of highly active electrocatalysts with controlled shapes. Graphical abstract Image, graphical abstract [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]

In this study, a novel route was proposed for microalgae biofuel production by catalytic upgrading of Chlorella hydrothermal liquefaction (HTL) derived biocrude. Al-SBA-15, CuO/Al-SBA-15, ZuO/Al-SBA-15, and CuO-ZnO/Al-SBA-15 catalysts were synthesized in a facile, one-pot way, and tested for methyl palmitate decarboxylation and biocrude upgrading without H 2 addition. These modified SBA-15 catalysts enhanced alkane selectivity of methyl palmitate decarboxylation from 7.6 wt% up to 79.6 wt% at 340–350 °C. FT-IR, TG and GC–MS characterizations were employed to identify the composition and properties of the upgraded bio-oils. Compared with thermal upgrading, modified SBA-15 catalysts enriched the yield of low boiling point compounds, and the content of heavy bio-oil (>400 °C) declined from 9.57 wt% to 1.89 wt%. Hydrocarbon yield was greatly enriched on the catalysts, and aromatics predominant on Al-SBA-15 while aliphatics abundant on metal oxide(s) supported catalysts. The hydrocarbon yield was increased from 25.1 wt% (thermal) to 65.7 wt% on the CuO/Al-SBA-15. [ABSTRACT FROM AUTHOR]

[Display omitted] • Different nanozyme-based electrochemical sensors separated by signal reporting forms. • Traditional electrochemistry, electrochemiluminescence and photoelectrochemistry. • Nanozymes acted as catalytic tags or target catalysts. • Promising prospects and challenges facing in the future. Nanozymes, as emerging artificial enzymes with superior catalytical properties and high stability, have attracted broad attention in the sensing field. As an important branch, nanozyme-based electrochemical sensing experienced fast growth in the last few years in combination with the intrinsic enzyme-mimic activity and unique physicochemical features owing to the high sensitivity, excellent selectivity, ease for miniaturization and versatile signal reporting modes. Generally, the electrochemical sensing can be achieved using nanozymes as signal tags for amplification or as the advanced catalysts for generating/influencing the electroactive probes. To highlight the achievement in this field, the representative works based on different signal reporting manners including traditional electrochemical assays and the evolutionary modes of electrochemiluminescent and photoelectrochemical sensing are discussed in details in the present work. Finally, the current challenges and perspectives facing are given. [ABSTRACT FROM AUTHOR]

The Pt-based alloys with Pt-skin or Pt-rich surface own significant structural advantages for a range of electrocatalytic reactions. Herein, we give a minireview for such catalysts, which covers a brief background introduction, the mechanisms for the activity enhancements derived from the special Pt-skin structures, the very recent advances on the preparation routes and applications of the catalysts in various electrochemical reactions, and a future perspective. Indeed the Pt-skin structured catalysts have shown great promising which in the future, may provide more opportunities for enhancing electrocatalytic performance at the molecular level. [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]

CO 2 methanation is conducive to the storage of renewable electricity and the utilization of CO 2. Exploiting highly efficient Ni-based catalysts with a simple method is of significance for this reaction. To achieve an excellent low-temperature activity, the attention is focused on the small Ni particles and ZrO 2 promoter in this work, which can increase the amounts of H 2 and CO 2 active sites. Firstly, the simple combustion-impregnation method was employed, forming small Ni particles (about 6 nm). More metal-support interface and increased basicity could be generated in the meantime. Hence, the higher H 2 dissociation and CO 2 adsorption ability were attained. Secondly, ZrO 2 serving as a promoter was beneficial to the formation of oxygen vacancies, which played an important role in CO 2 activation and CH 4 formation. These oxygen vacancies could weaken the C O bonds, improving the CO 2 activation. In addition, they might serve as the H reservoir, increasing the H 2 adsorption capacity. Because of the H spillover effect from Ni to ZrO 2 , the activated H atoms on Ni could react with activated CO 2 to generate CH 4. Therefore, with more active sites for H 2 and CO 2 activation, the Ni/ZrO 2 -COM catalyst exhibited the excellent catalytic performance at 300 °C. This work is of great significance in developing highly efficient Ni-based catalysts at low temperatures for CO 2 methanation with a facile method. [Display omitted] • Highly dispersion Ni particles are achieved by the combustion-impregnation method. • Oxygen vacancies benefiting to CO 2 activation are created by ZrO 2 promoter. • The best catalytic activity is obtained on the Ni/ZrO 2 -COM catalyst. • The simultaneously increased active sites for H 2 and CO 2 play an important role. [ABSTRACT FROM AUTHOR]

• The NO removal efficiencies of β, SAPO-34 and ZSM-5 under optimal conditions were 92%, 83% and 67%, respectively. • NO+ was determined as the key species for NO oxidation with H 2 O 2 by In-situ DRIFTS spectroscopy study. • Adsorbed NO+ is in equilibrium with gas-phase NO and desorbs to yield an oxidized acid site (Si-O•-Al). In this study, by comparing the NO removal experiments with H 2 O 2 over of β, SAPO-34 and ZSM-5 in a fixed-bed reactor, in which β zeolite showed 91% NO removal efficiency under the optimal experimental conditions (2 mol/L H 2 O 2 , 0.3 g catalyst, reaction temperature=140 °C). Through characterization analysis and comparison, the ESR test illustrated ZSM-5 and SAPO-34 produce hydroxyl radicals more efficiently than β, but NO removal efficiency of these two zeolites was lower than β, indicating that the removal of NO was not due to the hydroxyl radicals. NH 3 -TPD and Py-FTIR analysis revealed that the zeolite catalyzes the oxidation of NO by H 2 O 2 because of the presence of Brønsted acid sites. The highest content of Brønsted acid in β zeolite was the main reason for its highest removal efficiency. Furthermore, through in-situ FTIR analysis, the coordinated N O + in the framework (S i − O · (N O +) − A l) of zeolites played an important role in catalysis, and a possible reaction path was proposed. Finally, the removal test was carried out for 6 h, and the changes of the catalyst before and after the reaction were studied through XRD and FTIR tests, which showed strong stability. Graphical Abstract [Display omitted]. [ABSTRACT FROM AUTHOR]

Herein, we converted spent LiFePO 4 battery to the sea urchin-like material (SULM) with a highly efficient and environment-friendly method, which can contribute to building a zero-waste city. With SULM as a Fenton-like catalyst, a highly-efficient degradation process was realized for organic pollutants with interface and solution synergistic effect. In our SULM+NH 2 OH+H 2 O 2 Fenton-like system, NH 2 OH can effectively promote the interface iron (Fe(Ⅲ)/ Fe(Ⅱ)) and solution iron (Fe(Ⅲ)/Fe(Ⅱ)) redox cycle, thus promoting the generation of reactive oxygen species (ROS). However, the ROS generation process and organic pollutants degradation pathway with the presence of NH 2 OH remains a puzzle. Here the detailed ROS generation mechanism and pollutants degradation pathway have been illustrated carefully based on experimental exploration and characterization. Therein, hydroxyl radicals (·OH) and singlet oxygen (1O 2) are the main ROS for oxidizing and degrading organic pollutants. Notably, 1O 2 can be converted from superoxide radicals (·O 2 ) in SULM+NH 2 OH+H 2 O 2 system. This study not only demonstrates the strategy of "trash-to-treasure" and "waste-to-control-waste" to simultaneously reduce the hazardous release from industrial solid waste and organic wastewater, it also provides new mechanistic insights for NH 2 OH mediated Fenton-like redox system. [Display omitted] • Spent LiFePO 4 battery was converted to SULM catalyst based on "trash to treasure". • The degradation of organic pollution shows the "waste-to-control-waste" strategy. • A synergistic Fenton-like reaction of interface and solution iron was observed. • ·OH and 1O 2 are main reactive oxygen species for oxidizing and degrading pathway. • 1O 2 can be converted from superoxide radicals (O 2 ) in SULM+NH 2 OH+H 2 O 2 system. [ABSTRACT FROM AUTHOR]

Plasma catalysis technology is suitable for the emission control of low concentration volatile organic compounds (VOCs), but the energy cost and complete oxidation are the bottleneck for its application. Herein, MnOx/γ-Al 2 O 3 catalysts incorporated with small amounts of Pt nano particles were designed for plasma catalytic oxidation of o-xylene which is one typical kind of VOCs from paint industry. A dielectric barrier discharge reactor installed with Pt 0.1 Mn 6 /γ-Al 2 O 3 catalyst can decompose 90% o-xylene oxidation with 90% CO 2 selectivity at an energy density of 211 J/L and a reaction temperature of 150 °C, while only 29% o-xylene conversion and 5% CO 2 selectivity were obtained without discharges under the same reaction condition. The energy cost is as high as 12.3 g/kWh which is reached top level at the same VOCs concentration. The excellent performance of Pt@MnOx/γ-Al 2 O 3 catalyst is due to the synergistic effect of Pt nano particles and MnOx, which promoted the activation of O 2 and the complete oxidation to CO 2 of by-products. [Display omitted] • High performance of plasma catalytic oxidation of o-xylene was obtained. • Pt-MnOx bimetallic interface played a dominant role in o-xylene oxidation. • Pt 0.1 Mn 6 /γ-Al 2 O 3 had highest ratios of Pt0/(Pt0 + Pt2+), Mn4+/(Total Mn) and O ads /O latt. • Pt 0.1 Mn 6 /γ-Al 2 O 3 enhanced the generation of surface reactive oxygen species. • Pt 0.1 Mn 6 /γ-Al 2 O 3 promoted the gasification of surface carbonates to gaseous CO 2. [ABSTRACT FROM AUTHOR]

• Spent biochar-based adsorbents are converted into magnetic metal borides/biochar heterostructures by a facile boriding process. • The efficiency of spent adsorbents conversion into electrocatalysts near 100%. • The pore confinement effect of biochar facilitates the formation of well-dispersed nano-sized metallic borides. • The optimal catalyst exhibits an excellent activity toward oxygen evolution reaction. Heavy metal contaminated spent adsorbents are of great environmental concern due to their hazardous effects and large-scale accumulation in the natural environment. Converting massive spent adsorbents into efficient electrocatalysts with a facile strategy can address the challenge of growing energy demand and achieving carbon neutral goal. Herein, we demonstrated a "spent adsorbents to heterostructured electrocatalysts" conversion strategy based on the "waste-to-wealth" principle. Via a facile boriding process, the metal ions laden biochar-based spent adsorbents (SA) have been totally transformed into magnetic metal borides/biochar heterostructures, which exhibit excellent activities towards oxygen evolution reaction. The optimized NiCuFeB/SA catalyst takes a low overpotential of 251 mV to drive a current density of 10 mA cm−2, outperforming many Ni/Fe-based catalysts synthesized from commercial material resources. Comprehensive analyses suggest the high catalytic efficiency mainly attributes to the porous biochar confined well-dispersed nano-sized metallic borides, the in-situ evolved active metal (oxy)hydroxides, favourable charge-transfer kinetics, as well as the heterostructure and amorphous feature. This work offers a general strategy to efficiently reutilize the spent metal-bearing biochar-based adsorbents, which can be extended to advanced energy applications-oriented reutilization of other metal-contaminated solid wastes in an economically and environmental-benign manner. [Display omitted] [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]

[Display omitted] • Highest selectivity of CPL (up to 90%) under moderate reaction conditions (140 °C, 2 MPa, 2 h) in aqueous medium. • Materials fabricated with cheap metal. • Broadened scope of the FFA-derived substrates hydrogentreatment. Metal-organic frameworks (MOFs) as an emerging class of porous materials exhibit some unique advantages, including controllable composition, a large surface area, high porosity, and so on. In this work, the spherical NiMo bimetal catalysts supported on porous carbon matrix were prepared using a simple wet impregnation method and studied for selective hydrogenation of furfural (FFA). Three different catalysts were investigated including Ni/C-Mo-BTC, Ni/C-Mo-DHTA and Ni/C-Mo-PTA. Of the catalysts studied the Ni/C-Mo-BTC catalyst could achieve the highest selectivity of CPL (up to 90%) under moderate reaction conditions (140 °C, 2 MPa, 2 h) in aqueous medium. In addition, other Ni-based catalysts (Ni/C-Fe, Ni/C-Zn, Ni/C-Cu, Ni/C-Ce) were also investigated to achieve yields of 20–70% under the same reaction conditions. The influence of temperature, H 2 pressure, time and solvent were investigated for the best performing catalyst. Based on the optimal reaction condition, various of furfural derivatives could also be effectively transferred to produce corresponding products. The detailed physicochemical characterization was carried out by means of XRD, SEM, TEM, XPS, NH 3 -TPD and Raman analysis. In the end, the optimal Ni/C-Mo0.4 catalyst could be recycled magnetically and efficiently applied in the next run for five consecutive recycling tests in the FFA hydrogenation to CPL. The results suggested Ni/C-Mo0.4 catalyst occurred to increasingly favor the formation of Ni-Mo alloys and suggested a metallic active site in FFA hydrogenation with the addition of element Mo. Mechanism study indicated that water was a key factor contributing to the formation of different desired products, which was responsible for the arrangement of furan compound. [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: Lipases are important catalysts in the production of biodiesel and they are widely available in natural world,including aminal, plant, microorganism.The cost of biodiesel production is the resources cost, which is the key determinant of biodiesel prices and the bottleneck factor restricting profit of biodiesel producers.This article addresses the sources of lipases, renewable sources of biodiesel, and the production of biodiesel with lipases. [Copyright &y& Elsevier]

H1−x LaNb2−x Mo x O7 was prepared by solid-state reaction followed by an ion-exchange reaction. Pt was incorporated in the interlayer of H1−x LaNb2−x Mo x O7 by the stepwise intercalation reaction. The H1−x LaNb2−x Mo x O7 showed hydrogen production activity and the activities were greatly enhanced by Pt co-incorporating. The x value in H1−x LaNb2−x Mo x O7 had an important effect on the photocatalytic activity of the catalyst. When the x =0.05, the H1−x LaNb2−x Mo x O7/Pt showed a photocatalytic activity of 80cm3 h−1 g−1 hydrogen evolution rate in 10vol.% methanol solution under irradiation from a 100W mercury lamp at 333K. [Copyright &y& Elsevier]

Abstract: A series of novel air-stable carbene adducts of cyclopalladated ferrocenylimines have been synthesized and characterized. The structures of these complexes were determined by single-crystal X-ray analysis. These adducts have been successfully applied to the Suzuki–Miyaura coupling reaction under aerobic conditions. Good to excellent yields were obtained in short reaction times with a lower loading of the catalyst. [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]

• Mn/Al-MCM-41 is feasible for NH 3 -SCR reaction. • MnOx/3Al-MCM-41 achieves above 90% NOx conversion and good SO 2 - and H 2 O-resistance. • Al doped MnOx/MCM-41 can obtain about 90% N 2 selectivity at 120–400 °C. • The doping of Al can produce different reaction paths between NOx and NH 3. • The bridge nitrates are more stable at high temperature. The MCM-41 molecular sieve was synthesized by hydrothermal method and Al was used to modify MCM-41. A series of MnOx/xAl-MCM-41 for NH 3 -SCR were prepared by impregnating Mn(NO 3) 2 onto xAl-MCMM-41 and characterized by XRD, SEM, HRTEM, H 2 -TPR, NH 3 -TPD, XPS and in situ DRTFTS. The results showed that Al doping can significantly change NOx removal ability of MnOx/MCM-41 and achieves above 90% NOx removal efficiency at 200–400 °C and about 90% N 2 selectivity at 120–400 °C. Introducing of Al into MCM-41 enhances the H 2 O and SO 2 resistance of catalysts and inhibits the non-selective reduction of NO to N 2 O, but short-range ordered structures of MCM-41 appear distortions because of Al doping. Al doping into MCM-41 cannot change the Mn species (Mn2+, Mn3+ and Mn4+) on the catalyst but it changes redox properties of catalysts. Mn/MCM-41 samples have only Lewis acid sites while Mn/xAl-MCM-41 samples have both Lewis acid sites and Brönsted acid sites. The bridge nitrates are very stable and exist in the entire testing temperature range and mainly adsorbed on Lewis and Brönsted acid sites, while the monodentate nitrates only exist at low temperatures (200 °C) and adsorbed on Lewis acid sites, resulting in different reaction paths between NOx and NH 3. [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]

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]

Mn-promoted NiMgAl mixed-oxide (NiMnx-LDO, x = 0, 5, 10, 15) catalysts derived from hydrotalcite were synthesized using co-precipitation for CO 2 hydrogenation to synthetic natural gas. By regulating Mn contents, NiMn5-LDO delivered the most excellent catalytic performance, being about 2 times higher than that of undoped NiMn0-LDO catalyst (TOF of NiMn5-LDO and NiMn0-LDO: 0.61 s−1 vs 0.31 s−1 @ 240 °C). Through extensive characterization, it was found that Mn dopants promoted the reduction of bulk NiO through tuning the interaction between Ni and Mg(Mn)AlOx support. A high surface ratio of Ni0/Ni2+ was achieved over NiMn5-LDO. Furthermore, the surface basicity strength was tailored by Mn dopants. With 5 wt% of Mn, NiMn5-LDO catalyst showed a stronger medium-strength basicity and higher capacity of CO 2 adsorption than others. Particularly, TOF indicates a good correlation with medium-strength basicity over NiMnx-LDO catalysts. The strong metal-support interaction originated from the hydrotalcite structure kept nickel uniformly dispersed, endowing to the improved catalytic performance. [Display omitted] • Mn-promoted NiMnx-LDO catalysts were derived from quaternary hydrotalcite. • Mn dopants regulated the interaction between Ni and Mg(Mn)AlOx, increasing the surface Ni0/Ni2+ ratio. • The doubled TOF was correlated to the tailored surface Ni0 species and medium-strength basic sites. [ABSTRACT FROM AUTHOR]

Exploiting Ni-based catalysts with excellent low-temperature activity is significant for CO 2 methanation, which is a promising route to CO 2 utilization. In this work, a facile combustion-impregnation method was developed to prepare the SiO 2 supported Ni catalysts. Small Ni particles (around 6 nm) and massive Ni–SiO 2 interface could be obtained due to the "combustion" process. The H 2 -temperature programmed desorption (H 2 -TPD) revealed the existence of Ni–SiO 2 interface and confirmed the high Ni dispersion obtained by this method, which were vital for the activation of reactant. Moreover, more medium basic sites which were beneficial for the CO 2 activation could also be created. In comparison with the reference Ni/SiO 2 catalyst prepared by the conventional impregnation method, much higher CO 2 conversion (66.9%) and more superior selectivity to CH 4 (94.1%) were achieved with the Ni/SiO 2 -Gly catalyst at 350 °C. Additionally, it was also found that glucose, citric acid and glycine were all effective fuels for this combustion-impregnation method, and the as-prepared catalysts all exhibited greatly improved low-temperature activity. Therefore, this work represents an important step toward developing Ni-based catalysts for CO 2 methanation by a promising wide-used method. [Display omitted] • A novel combustion-impregnation method is developed to prepare Ni-based catalysts. • High Ni dispersion and massive Ni–SiO 2 interface are obtained by this novel method. • An improved low-temperature activity with high CH 4 selectivity can be obtained. • Glucose, citric acid and glycine are all effective for the "combustion" process. [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]

[Display omitted] • a facile approach involving ball milling and calcination to prepare Mn/HZSM-5 catalysts in this study. The raw materials utilized for synthesizing are cost-effective which enhances their practicality. • The increasing ratio of Mn4+ improved the electron transfer efficiency, and enhance the concentration of surface hydroxyls, while the surface hydroxyls can makes the catalyst easier to adsorb formaldehyde and oxidize formaldehyde. The synergistic effect between Mn4+ and hydroxyls of Mn/HZSM-5 is demonstrated. Catalytic oxidation of gaseous formaldehyde at room temperature over non-noble metal catalysts has wide application prospect. Regulation of catalyst surface active species such as surface hydroxyls, valence state of active metal, oxygen vacancies, etc., is effective in promoting catalytic performance. Herein, we prepared a series of Mn/HZSM-5 catalysts with a facile ball mill strategy. The optimal catalyst 0.4%Mn/HZSM-5 exhibited superior activity of nearly 100% HCHO conversion at 30 °C under 100 ppm gaseous HCHO condition. The characterization results revealed that the catalyst with high specific surface area has a large number of Mn4+ ions and hydroxyls on surface, which facilitates providing more active sites for formaldehyde oxidation. Combining XPS and chemisorption experiments, it was clear that the interaction between Mn4+ and the carriers provided more surface reactive oxygen species. In addition, in situ DRIFTS results revealed that Mn4+ and hydroxyls could jointly activate formaldehyde, and Mn4+ could further activate oxygen to oxidize the reaction intermediate to CO 2 and H 2 O. [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]

Guaiacol, a typical lignin-derived phenolic compound, can be converted to high value-added cyclohexanol through hydrodeoxygenation (HDO). In this work, a series of core-shell Co x @C@Ni catalysts were prepared via two-step hydrothermal and calcination treatments, and applied to catalyze guaiacol to cyclohexanol. Compared with Co@C catalyst, core-shell Co x @C@Ni catalysts exhibited much better catalytic performance. Almost 100% guaiacol conversion and 90% cyclohexanol selectivity were achieved over Co 1.2 @C@Ni catalyst at 220 °C, 0 MPa N 2 for 2 h using isopropanol as H-donor solvent, which was carried out under much milder conditions compared with previous research. The structure feature of core-shell Co x @C@Ni catalysts were analyzed by BET, XRD, SEM, TEM, HRTEM, etc. The catalyst compositions and acidities played a significant role on hydrodeoxygenation of guaiacol via ICP and NH 3 -TPD analysis. The influences of reaction temperature, reaction time and initial nitrogen pressure were also investigated to explore the optimal reaction condition. Moreover, the possible reaction pathways and reaction mechanism was deduced based on the product distributions and physicochemical properties. Core-shell Cox@C@Ni catalysts were synthesized for catalytic hydrodeoxygenation of guaiacol to generate cyclohexanol under mild condition. [Display omitted] • Guaiacol can be effectively converted into cyclohexanol over core-shell Cox@C@Ni catalysts. • The highest 90% cyclohexanol yield was obtained over Co1.2@C@Ni at 220 ℃, 0 MPa N2 for 2 h. • The synergetic effect of Co and Ni and the acidity of catalysts play an important role in the HDO of guaiacol. • A possible reaction mechanism of hydrogenation process was studied. [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]

[Display omitted] • The new NiMgAl-LDO catalysts were synthesized via sequenced precipitation for CO 2 -to-SNG process. • The optimized Ni-LDO-A70 catalyst gave 7 times higher value of per mole nickel activity than that of traditional sample (Ni-LDO-A0) at 573 K. • Ni particle size had been tuned by sequenced precipitation, evidenced by characterizations. • The ratio increasement of medium-strong basic sites and the promoted nickel reducibility were observed. In this work, hydrotalcite-derived new Ni-LDO catalysts were synthesized via sequenced precipitation, for CO 2 catalytic reduction to synthetic natural gas (SNG) with high performances, while the traditional sample via coprecipitation was prepared and measured as the comparison. By regulating precipitation procedure, a significant performance enhancement was attained, in which the CO 2 conversion rate per gram nickel was 7-times higher than that of the conventional comparison, at the temperature of 573 K and atmospheric pressure. In addition, the desired product selectivity is up to 99%. Structural characterizations proved that the as-synthesized catalysts showed layered meso -porous properties. An increasing Ni particle size and higher coverage of medium-strong basic sites was observed over the optimized catalyst sample prepared when part of Mg2+ and Al3+ were precipitated at first step. Catalyst surface nickel enrichment and promoted reducibility were also achieved when using sequenced precipitation. This work achievements provided a new route for surface nickel enrichment of much more active hydrotalcite-derived Ni-LDO layered catalysts for enhanced performances. [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]

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]

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]

[Display omitted] • A novel EF system for producing bioproducts from acetate was developed. • The broadest products spectrum was obtained at 0.6 V. • High applied voltage may accelerate acetate heterotrophic consumption. • Interspecies H 2 transfer may be a bridge between biofilm and cathode. Acetate is the main component in the anaerobic digestion broth of organic waste, which is difficult to be extracted and further recovered because of its completely miscibility. A novel technology convert acetate to bioproducts (like ethanol, butyrate, and caproate) in electro-fermentation system by chain elongation microbiome has recently attracted attention. This work focused on the fate of acetate as substrate and sole electron acceptor under different applied voltage regulation. Products spectrum analysis showed that acetate was effectively converted and accumulated to a maximum concentration of 4.26 g L−1 ethanol firstly at 0.6 V, then butyrate (2.40 g L−1) and caproate (0.12 g L−1) were synthesized respectively. With the increase in voltage intensity, the bioconversion performance of acetate gradually deteriorated. The monitoring results of cathode chamber indicated an appropriate applied voltage creating a more favorable conversion environment for chain elongation microbiome, and a biocathode with better redox capability could act as an effective catalyst, contributing to the hydrogen-mediated electron transfer for chain elongation process. The correlation analysis between cathode multi-parameters and bioproduct performance at 0.6 V showed that the chain elongation process may be more dependent on the fermentation environment than the reduction of acetate to ethanol, especially for pH and redox potential. This study provides a sustainable and energy-saving platform for producing bioproducts from readily available acetate under the regulation of applied voltage. [ABSTRACT FROM AUTHOR]

[Display omitted] • The CO-SCR performance of spinel-type CuM 2 O 4 (M = Co, Mn, Fe, Ni, and Cr) oxides was studied. • CuCo 2 O 4 catalyst exhibited the highest de-NO x activity, surpassing 90 % between 143 and 381 °C. • The presence of Cu2+–O v –Mδ+ sites was the key to promoting CO-SCR performance. • Two possible CO-SCR mechanisms were observed over the CuM 2 O 4 catalysts. The influence of the chemical state of Cu species in spinel-type catalysts on the selective catalytic reduction (SCR) of NO with CO has not been well understood. A series of CuM 2 O 4 (M = Co, Mn, Fe, Ni, and Cr) were synthesized and studied in this work. Notably, CuCo 2 O 4 demonstrated the best CO-SCR performance, exhibiting the de-NO x activity exceeding 90 % in a broad temperature window of 143–381 °C. Furthermore, CO conversion surpassed 90 % above 225 °C. Characterizations revealed that the synergy between Cu2+ and surface oxygen vacancy in the Cu2+–O v –Mδ+ sites (δ represents the M cations in the lower valence states) played a vital role in enhancing the CO-SCR performance of the CuM 2 O 4 catalysts. The superior CO-SCR performance of CuCo 2 O 4 was also attributed to the optimal interplay between Cu and Co cations, resulting in superior Cu2+/Cu+ redox cycle and improved lattice oxygen mobility. In situ DRIFTS verified that Cu2+ was the primary site during the CO-SCR reaction, and two possible mechanisms (oxygen vacancy-assisted and lattice oxygen-assisted routes) over CuM 2 O 4 were carefully proposed. This study unravels the nature of the CO-SCR activity of the CuM 2 O 4 catalysts and provides novel perspectives on the development of Cu-based catalysts for CO-SCR applications. [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]

The design and development of robust and efficient non-Fe doped transition metal-nitrogen doped carbon (TM-N/C) catalysts for oxygen reduction reaction is significant for promoting the applications of TM-N/C based catalysts in sustainable energy devices such as metal-air batteries and fuel cells. In this study, exclusive Cu-N x moieties implanted in metal-organic framework (MOF) polyhedrons are successfully fabricated by an adsorption-calcination approach. The optimal electrocatalyst (CuNC-1100) exhibits much higher stability and satisfactory catalytic activity with a half-wave potential (E 1/2) of 0.885 V, which is 40 mV higher than commercial Pt/C in 0.1 M KOH solution, and exhibits a dominant 4-electron direct reaction path. The comprehensive characterization data reveals that the high activity of the catalyst originates from the porosity and high surface area, high dispersion of Cu atoms, and high density of graphitic nitrogen content and Cu-N x species. [Display omitted] • Porous carbon polyhedrons catalyst is prepared by an adsorption-calcination approach. • High density of Cu-N x species and graphitic nitrogen efficiently catalyzed oxygen reduction reaction (ORR). • The optimal CuNC-1100 catalyst exhibited an excellent ORR performance in 0.1 M KOH. [ABSTRACT FROM AUTHOR]

A close correlation between M2 selectivity and the quantities of oxygen vacancies of catalysts is observed that the appropriate concentration of oxygen vacancies on its surface can not only promote the adsorption of gaseous CH 3 Cl molecules, but also optimizes the electronic structure of surface CuO thereby optimizing the adsorption strength of CH 3 Cl, and its porous structure can accelerate the subsequent diffusion of generated Cu atoms, thus contributing to the formation of more Cu x Si active intermediate and ultimately leading to the best M2 selectivity. [Display omitted] • The effect of oxygen vacancies (O V) in the CuO-ZnO catalysts on catalytic performance in Rochow reaction is investigated. • An optimized O V concentration of the catalyst can lead to the highest dimethyldichlorosilane selectivity. • The enhanced selectivity is attributed to the more CH 3 Cl adsorption sites and an optimized surface CuO electronic structure. In metal oxides, oxygen vacancies (O V) are ubiquitous and intrinsic defects that can pronouncedly impact the physicochemical properties of the catalysts. In this work, we investigated the effect of the O V concentration in CuO-based catalysts on the performance of the Rochow reaction. A series of foamed CuO-ZnO composite catalysts with a highly porous structure were synthesized by a facile co-precipitation method, followed by hydrogen reduction at different times. When used in the Rochow reaction to synthesize dimethyldichlorosilane (M2), the CuO-ZnO-20 catalyst with an appropriate O V concentration exhibited the highest M2 selectivity at a similar Si conversion level of the other CuO-ZnO catalysts with different O V concentrations. By correlating the structure and performance of the catalysts, we found that the O V at an appropriate concentration in CuO-ZnO-20 acted as the adsorption sites for the reactant CH 3 Cl molecules, and generated an optimized electronic structure for surface CuO as confirmed by the X-ray photoelectron spectroscopy analysis (XPS), thereby optimizing the adsorption strength of CH 3 Cl and ultimately promoting the formation of alloyed CuxSi active phase. This work provides an effective strategy for designing heterogeneous catalysts with high selectivity by controlling the O V concentration in the catalysts. [ABSTRACT FROM AUTHOR]