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The Cu‐glutathione (GSH) redox system, essential in biology, is designed here as a supramacromolecular assembly in which the tetrahedral 18e Cu(I) center loses a thiol ligand upon adsorption onto ZIF‐8, as shown by EXAFS and DFT calculation, to generate a very robust 16e planar trigonal single‐atom Cu(I) catalyst. Synergy between Cu(I) and ZIF‐8, revealed by catalytic experiments and DFT calculation, affords CO2 conversion into high‐value‐added chemicals with a wide scope of substrates by reaction with terminal alkynes or propargyl amines in excellent yields under mild conditions and reuse at least 10 times without significant decrease in catalytic efficiency. [ABSTRACT FROM AUTHOR]

With the advancement of scientific research, the introduction of external physical methods not only adds extra freedom to the design of electro‐catalytical processes for green technologies but also effectively improves the reactivity of materials. Physical methods can adjust the intrinsic activity of materials and modulate the local environment at the solid‐liquid interface. In particular, this approach holds great promise in the field of electrocatalysis. Among them, the ultrasonic waves have shown reasonable control over the preparation of materials and the electrocatalytic process. However, the research on coupling ultrasonic waves and electrocatalysis is still early. The understanding of their mechanisms needs to be more comprehensive and deep enough. Firstly, this article extensively discusses the adhibition of the ultrasonic‐assisted preparation of metal‐based catalysts and their catalytic performance as electrocatalysts. The obtained metal‐based catalysts exhibit improved electrocatalytic performances due to their high surface area and more exposed active sites. Additionally, this article also points out some urgent unresolved issues in the synthesis of materials using ultrasonic waves and the regulation of electrocatalytic performance. Lastly, the challenges and opportunities in this field are discussed, providing new insights for improving the catalytic performance of transition metal‐based electrocatalysts. [ABSTRACT FROM AUTHOR]

Single atom catalysts had been widely used in oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). However, the relationship between local coordination environment and catalytic activity were unclear. In this work, the effect of N‐defect and axial halogen atoms on electrocatalytic OER/ORR activity of FeN4 catalysts were investigated by density functional theory calculations (DFT). When the overpotential was the only criterion, FeN3Br was the optimal candidates for OER, followed by FeN3F, FeN4I, FeN4Cl and FeN4Br; FeN4I, FeN4Br and FeN4Cl were also the promising candidates for ORR. FeN4I, FeN4Br and FeN4Cl may be excellent ORR catalysts in an acidic media because of the low overpotential and reaction barrier of kinetics rate limiting step. In summary, N‐defect and axial halogen atoms can effectively balance kinetics, thermodynamics and catalytic activity. [ABSTRACT FROM AUTHOR]

The Ni/γ‐Al2O3, Nix‐Fey/γ‐Al2O3 and Fe/γ‐Al2O3 catalysts are prepared by impregnation method, and the influence of nNi/nFe on the performances of the prepared catalysts for the methyl laurate hydrodeoxidation (HDO) was evaluated. The prepared catalysts and precursors were characterized by BET, H2‐TPR, XRD, and H2‐TPD, which confirmed the existence of NiFe alloy is advantageous to improve the catalytic activity, and the synergistic effect between Ni and Fe was elucidated. The catalytic properties of the studied Nix‐Fey/γ‐Al2O3 catalysts with low Fe content was significantly worse than that of monocomponent Ni/γ‐Al2O3 catalyst, due to the migration and agglomeration of highly dispersed Ni0 species on the corresponding catalyst surface. The introduction of Fe species had significant influence on the HDO performances and product selectivity of the Ni‐based catalyst. The higher Fe content can promote the main reaction path from hydrodecarbonylation/hydrodecarboxylation to hydrodeoxygenation, which results in the high C12 alkane selectivity on the corresponding catalysts and inhibits the cracking reaction. The bimetallic Ni3‐Fe7/γ‐Al2O3 catalyst had the best methyl laurate hydrogenation performances. The conversion of methyl laurate was 93.3 % and the selectivity of alkane compounds could reach 90 % on the Ni3‐Fe7/γ‐Al2O3 catalyst at the reaction temperature of 340 °C. [ABSTRACT FROM AUTHOR]

Understanding the structure-activity relationship of Mn-based oxide catalysts is of great importance for the rational development of highly performance catalysts for VOCs catalytic oxidation. However, the knowledge of the electronic structure-catalytic oxidation activity relationship over Mn-based oxide catalysts is still limited. Herein, we investigated the typical Mn x O y (Mn 3 O 4 , MnO 2 , and Mn 2 O 3) with different valence electronic structures by using various characterizations and DFT calculations. The MnO 2 exhibits superior intrinsic activities (R S , 1.14×10−9 mol·m−2·s−1) when compared with Mn 3 O 4 (0.54×10−9 mol·m−2·s−1) and Mn 2 O 3 (0.45×10−9 mol·m−2·s−1) for toluene catalytic oxidation. The solid experimental and DFT calculation results show that the d -band center of Mn determines the intrinsic activity. The superior catalytic oxidation activity of MnO 2 can be attributed to its higher d -band center (-1.03 eV) in comparison with that of Mn 3 O 4 (-1.25 eV) and Mn 2 O 3 (-1.59 eV). The higher d -band center can weaken the surface Mn-O bonds strength (k = 290.9 N/m) and strengthen the gaseous O 2 adsorption simultaneously, then enhancing the mobility of surface lattice oxygen and the amount of adsorbed oxygen species. This work firstly reveals the intrinsic relationship between catalytic oxidation activity and d electronic structure over Mn-based oxide catalysts and provides knowledge that will advance the design of high-performance catalysts for catalytic oxidation. [Display omitted] • The Mn x O y with different valence electron has been prepared by precipitation method. • The hybridization between Mn 3 d orbital and O 2 p orbital tune the Mn-O bond strength. • The Mn 3 d electronic structure state modulates the O 2 adsorption and activation. • The MnO 2 with higher d- band center shows the superior toluene oxidation activity. [ABSTRACT FROM AUTHOR]

The deep utilization of green and renewable chemicals has laid the foundation for sustainable development. Recombining and modifying the long carbon chain structure and oxygen-containing functional groups in fats and oils can prepare important chemical products, such as high-quality second-generation biodiesel and oxygen-containing compounds (fatty alcohols, fatty acids, and esters). To improve the hydrodeoxygenation (HDO) performances of Ni-based catalysts, the effect of surface composition was studied in detail. Acid-base centers of Ni/γ-Al 2 O 3 catalysts were finely regulated by adding metal oxides (ZrO 2 , CeO 2 , La 2 O 3 , and MgO). It was found that enhancing the basicity of the studied catalyst was conducive to the methyl laurate conversion, but was not conducive to the HDO of oxygen-containing intermediates. In other words, the strong basicity would promote the condensation reaction of oxygen-containing intermediates over Ni-based catalyst. Among the studied catalysts, Ni/La 2 O 3 /γ-Al 2 O 3 catalyst showed the highest methyl laurate conversion (73%) and oxygen-containing product selectivity (64%) at 400 °C, LHSV = 1.5 h−1, H 2 /oil = 500 Nm3/m3, and P H2 = 2.0 MPa over the Ni/La 2 O 3 /γ-Al 2 O 3 catalyst. The acidity was favorable to improve the conversion of oils and the yield of alkane products, and the basicity was favorable to obtain oxygen-containing compounds over the corresponding catalysts. [Display omitted] • Acidic sites are favorable to improve the yield of alkane products. • Alkaline sites are favorable to obtain oxygen-containing compounds. • Highly dispersed Ni sites are conducive to activating H 2. • HDO products distribution can be adjusted by the acidity and alkaline. [ABSTRACT FROM AUTHOR]

The adsorbed CO 2 molecules can be easily activated to CO 2 * species by accepting electrons, which subsequently react with the activated H* species to generate the formate or CO intermediate species. Then, the generated intermediate species can be deeply hydrogenated to produce CH 4. The Co0 species and oxygen vacancies on the xCo/MnO catalysts surface both act as the active centers to catalyze the CO 2 hydrogenation reaction. The Co loading can deeply affect the CO 2 hydrogenation reaction by affecting the concentration of oxygen vacancies, metal-support interaction and the basic site numbers on the prepared xCo/MnO catalysts, which are critical to the formation of active centers and the CO 2 adsorption ability of the xCo/MnO catalysts. [Display omitted] • xCo/MnO catalysts with high CO 2 hydrogenation performances can be prepared. • The Mn 1-y Co y O solid solution can be formed in the prepared xCo/MnO catalysts. • Co0 species are the main active centers for CO 2 hydrogenation. • The basic and hydrogenation active sites can be regulated by Co loading. CO 2 hydrogenation technology has great potential for mitigating the greenhouse effect and creating a green economy. The development of catalysts plays a key role in the progress of CO 2 hydrogenation technology. In this study, the xCo/MnO catalysts for CO 2 hydrogenation reaction were prepared by the impregnation method using MnO x as the catalyst support. And the effects of the Co loading on the CO 2 hydrogenation performances of the prepared xCo/MnO catalysts were investigated. The active Co0 species on the xCo/MnO catalysts surface are the main active centers for the CO 2 hydrogenation reaction, and the medium basic sites on the xCo/MnO catalysts are the main CO 2 adsorption sites. The MnO x support possesses a large number of medium basic sites, which can enhance the CO 2 molecules adsorption ability of the xCo/MnO catalysts. An effective regulation of the basic and hydrogenation active site numbers on the xCo/MnO catalysts surface can be achieved by changing the Co loading amount, which in turn can affect the CO 2 molecules adsorption, activation and hydrogenation abilities of the xCo/MnO catalysts. Moreover, the Mn 1-y Co y O solid solution was found to be formed in the prepared xCo/MnO catalysts, which is conducive to the dispersion of metal Co nanoparticles on the MnO surface and the generation of oxygen-deficient sites. The CO 2 desorption amount on the 12Co/MnO catalyst reached 1.76 mmol/g, which provided the catalyst with strong CO 2 adsorption and activation abilities, enabling it to exhibit great CO 2 hydrogenation performance. Under the conditions of atmosphere and 420 °C, the CO 2 conversion and CH 4 selectivity on the prepared 12Co/MnO catalyst reached 57.5 % and 78.8 %, separately. Furthermore, the CO 2 conversion was able to consistently remain at the initial 57.5 %, and the CH 4 selectivity was maintained above 70.0 % in the 10 times CO 2 hydrogenation cycle tests on the 12Co/MnO catalyst. Our study highlights the potential of using MnO x as catalyst support in the CO 2 hydrogenation reaction, and the findings will provide convenient for the future studies. [ABSTRACT FROM AUTHOR]

[Display omitted] • CoN 3 -pyrrole displayed highly bifunctional OER/ORR catalytic activity. • Overpotential was not the only evaluation criteria of catalytic performance. • Energy barrier of kinetics rate limiting step was another evaluation criteria. • N-defect and pyrrole can balance the effects of thermodynamics and kinetics. • CoN 3 -pyridine exhibited superior OER catalytic activity than IrO 2. The development of bifunctional electrocatalysts for fuel cells and rechargeable metal-air cells was very urgent, but it still faced enormous challenges. Single atom catalysts had achieved satisfactory performance in these research fields, however, the coordination environment and catalytic mechanism of the active center were still unclear. Herein, density functional theory (DFT) calculations were used to systematically investigated the effects of heterolateral pyridine or pyrrole ligand and/or N-defect on oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) of CoN 4 catalysts both in acidic and alkaline media. Compared with CoN 4 , the N-defect and axial pyrrole or pyridine ligand jointly modified CoN 4 catalysts had improve activities for OER, the N-defect and heterolateral pyrrole ligand modified CoN 4 catalysts had improve activities for ORR. Additionally, CoN 3 -pyrrole also exhibited moderate intrinsic barriers for the kinetics rate-limiting step (KRLS) in both acidic and alkaline media for OER and ORR. In conclusion, CoN 3 -pyrrole was considered as the optimal candidate for bifunctional catalysts due to its relatively superior bifunctional theoretical overpotential and reaction barrier of KRLS in acidic and alkaline media. The theoretical overpotential was not the only evaluation criteria, the intrinsic barrier of KRLS must be considered as another evaluation criteria of electrocatalytic performance. [ABSTRACT FROM AUTHOR]

Sulfur-free Ni/γ-Al 2 O 3 and Ni-based bimetallic Ni 5 X 5 /γ-Al 2 O 3 (X = Cu, Fe, Zn, Co, and Mn) catalysts prepared by impregnation method were characterized by H 2 -TPR, XRD, BET, NH 3 -TPD, Py-IR, TEM, ESEM, XPS, and H 2 -TPD. The effects of transition metal on the physicochemical properties and methyl laurate hydrodeoxygenation (HDO) performance of the studied Ni-based catalysts were also investigated. The results showed that all the prepared Ni-based catalysts have mesoporous structure and large specific surface area (>130 m2 g−1), the Ni, Cu, Fe, Zn, Mn, and Co species were dispersed highly over the Ni 5 X 5 /γ-Al 2 O 3 catalysts. The introduction of transition metal has a remarkable influence on the reducibility of Ni species and obviously improve the low temperature "absorption-desorption" performance of the studied Ni-based catalysts to H 2 molecules. All the studied Ni-based catalysts can preferentially catalyze the methyl laurate to occur decarbonylation/carboxyl (DCO) reaction to produce C 11 alkanes, because of the synergy effects between metal centers and acid sites. The carbonyl and/or bridge oxygen atoms in methyl laurate can be activated by electrophilic acidic sites, the intermediate products can be attacked by the reactive H atoms formed on the metal centers. The selectivity of the hydrogenation products including C 11 , C 12 , and oxygenated compounds are obviously affected by transition metal additives. Methyl laurate conversion and C 11 alkanes selectivity can reach 99.8 and 87.3 % at 400°Ϲ, respectively. In addition, the Ni 5 Cu 5 /γ-Al 2 O 3 catalyst possesses acceptable cycle and regeneration performances. The introduction of transition metal X into the Ni based catalyst can significantly improve the electronic and structural effects of the catalyst. The dispersion of the Ni species is also enormously improved. Meanwhile, the reducibility of Ni species and the low-temperature "absorption-desorption" performance of Ni-based catalysts to H 2 are promoted. All the prepared Ni 5 X 5 /γ-Al 2 O 3 catalysts show superior hydrogenation DCO performance and the main deoxygenation products are C 11 alkanes. [Display omitted] • Electronic and structural effects can be significantly improved by additive metal. • Formed NiX alloy can effectively promote the electronic effect between Ni and X. • Highly dispersed Ni, X, and NiX species are beneficial for hydrodeoxygenation. • The main deoxygenation pathway of methyl laurate is DCO on the Ni-based catalyst. [ABSTRACT FROM AUTHOR]

The greenhouse gases CH 4 and CO 2 can be use as feedstock to prepare syngas (CO + H 2) by CH 4 /CO 2 reforming reaction, and the syngas can be used to produce high value-added chemicals through Fischer-Tropsch reaction. That is, the CH 4 /CO 2 reforming reaction can provide an effective way to rationally use CO 2 and CH 4. The CoCe catalysts were prepared by impregnation method and grinding method, respectively, and the physicochemical properties were characterized by H 2 -TPR, XRD, BET, Quasi in-situ XPS and CO 2 -TPD. The synergistic effects between Co and Ce species can promote the CH 4 and CO 2 molecules to be continuously and rapidly activated, so that the CoCe catalysts exhibited good catalytic activity for the CH 4 /CO 2 reforming reaction. The preparation methods can affect the dispersion of the Co species and the thermal stability of the oxygen vacancies on the CoCe catalysts to affect catalytic activity. The impregnation method is conducive to the Co species dissolving into the CeO 2 lattice to form oxygen vacancies with high thermal stability, and the Co species on the CeO 2 surface were in a highly dispersed state, which can provide more stable catalytic activity centers. Thus, the catalysts prepared by impregnation method displayed superior catalytic performances for CH 4 /CO 2 reforming reaction. And the CH 4 and CO 2 conversions can reach 43.4% and 29.0% at the reaction temperature of 600 °C, respectively. For the CoCe composite catalyst prepared by impregnation method, a large number of Co species can dissolved into the CeO 2 lattice to form Co-O-Ce solid solutions and oxygen vacancies with high thermal stability, and the Co species on the CeO 2 surface were in a highly dispersed state, so the CoCe catalyst prepared by impregnation method exhibits good CH 4 /CO 2 reforming reaction catalytic performance. [Display omitted] • Synergistic effects between Co and Ce species can be effectively regulated by the preparation method. • The synergistic effects between Co and Ce species can promote the CH 4 /CO 2 reforming performances. • External defects can promote the formation of oxygen vacancies to enhance CH 4 /CO 2 reforming activity. [ABSTRACT FROM AUTHOR]

Abstract Green and renewable bio-diesel prepared from oils catalytic hydrodeoxygenation (HDO) will have a great impact on clean energy structure and industrial application. The core issue of catalytic oils HDO research is still the development of catalysts with high performance, and it has become the research focus of researchers in recent years. The bio-diesel after deoxygenationis similar to petroleum fuel in composition, which has better fuelproperties because of its higher cetane number, higher energy density, and very low sulfur content. Therefore, the prepared bio-diesel can be employed directly in fuel industry. In order to ensure that the catalyst has superior deoxidization performances, it should have good "H-H" dissociation ability, "C-O" and "C=O" adsorption and activation abilities. To obtain the expected products, feasible production processes, and suitable catalyst systems are needed. In this paper, the status and reaction system of oil HDO conversion in recent years are reviewed, and the catalytic performances of the corresponding catalyst in the oil HDO reaction is described in detail. In addition, this review also involed the effects of support, promoters, interaction between active components and support on the HDO activity and selectivity, and detailed information about the reaction mechanism. The HDO performances of the corresponding catalyst can be effectively improved by optimizing the active components and controlling the properties of the support. The catalyst used into the HDO reaction is mainly concentrated on the supported catalyst. In addition, the choice of the support is based on the prepared catalyst with the best physical and chemical properties. What's more, ensuring the prepared catalyst has simple deoxidation route, suitable acid strength, high "C-O" hydrogenolysis activity and low carbon deposition performances. The selection of the metal active component mainly depends on the model compound, owing to the deoxidization pathway of the model compound is mainly determined by the active center. The reaction pathway mainly contains hydrolysis, HDO, cracking, hydrogenation, decarbonylation, and decarboxylation reaction. In addition, several outlooks on the development of catalyst with high performance, the future research, and the development direction of bio-diesel produced by oils HDO reaction are also addressed in this paper. Highlights • Green and renewable bio-diesel can be prepared from oils catalytic hydrodeoxygenation (HDO). • Noble metal catalysts and non noble metal catalysts each have advantages in oil hydrodeoxygenation. • The development of new catalyst is beneficial to hydrodeoxygenation of oils to produce bio-diesel. • Deep excavation of hydrodeoxygenation mechanism is conducive to prepare catalysts with superior performance. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Developed mesoporous structure and highly dispersed Ni are more favorable for hydrodeoxygenation. • Sulfur-free Ni/γ-Al 2 O 3 catalyst has superior methyl laurate hydrodeoxygenation performance. • The methyl laurate is mainly decarbonylation/decarboxylation to produce C 11 alkane with high selectivity. • The used Ni/γ-Al 2 O 3 catalyst retains good regeneration properties. Abstract A series of sulfur-free Ni/γ-Al 2 O 3 catalysts with different metal Ni loading amount were prepared by impregnation method. The prepared catalysts and corresponding precursors were investigated through XRD, BET, H 2 -TPD, and H 2 -TPR analysis methods. The effect of Ni loading on catalytic performance of Ni/γ-Al 2 O 3 catalysts was evaluated by methyl laurate catalytic hydrodeoxygenation (HDO). Results indicate that the catalytic HDO performance of the prepared Ni/γ-Al 2 O 3 catalysts was directly related to hydrogen storage properties, hydrogen desorption properties, dispersion of the active component Ni, and so on. The 10 wt.% Ni/γ-Al 2 O 3 catalyst exhibits the best HDO performance, and the methyl laurate conversion can reach 91.1% when the reaction temperature is 400 °C and pressure is 2 MPa. The HDO products are alkanes, such as C <10 , C 10 , C 11 , C 12 alkane, C 12 alcohol, and C 12 acid, especially. The main product C 11 alkane with one carbon less is formed by decarbonylation/decarboxylation, and selectivity can reach 68.6%. The effects of reaction conditions on HDO reaction of oils were studied, for example, reaction pressure and H 2 /Oil ratio. The catalyst retains comparable activity upon regeneration through calcinations and H 2 reduction. [ABSTRACT FROM AUTHOR]

Electrochemical nitrogen reduction (NRR) to synthesize NH 3 is limited by low Faraday efficiency (FE). Developing electrocatalysts that can efficiently adsorb/activate N 2 and suppress hydrogen evolution reaction (HER) to enhance FE is needed. In this work, x-ZrO 2 /CQDs-T series catalysts were successfully prepared. The results demonstrate that: (I) The appropriate introduction of carbon quantum dots (CQDs) effectively enhances the surface adsorption capacity of ZrO 2 /CQDs for N 2. (II) By high-temperature calcination eliminates the alkaline functional group (-NH 2) of CQDs, which reduces the basicity of ZrO 2 /CQDs catalyst and inhibits the adsorption of protons on the catalyst surface. (III) Due to the semiconductor properties of ZrO 2 , the charge transfer efficiency of ZrO 2 /CQDs catalyst is significantly reduced, thereby weakening the binding of electrons to the adsorbed protons. As a result, 1-ZrO 2 /CQDs-750 catalyst appropriately and effectually restricts the accessibility of protons/electrons and promotes more N 2 molecules to occupy active sites, thus achieving up to 66.62 % FE, which is superior to most reported NRR catalysts so far. Meanwhile, electrochemical in situ ATR-SEIRAS technique reveals that 1-ZrO 2 /CQDs-750 catalyst surface occurs in associative alternating reactions. The introduction of CQDs not only effectively affects the adsorption of N 2 and N-related intermediates on ZrO 2 /CQDs catalyst and limits the proton/electron accessibility to improve FE of NRR, but also promotes the exposure of active sites to increase NH 3 yield. [Display omitted] • 1-ZrO 2 /CQDs-750 effectively limits proton/electron accessibility, reduces HER and enhances FE of NRR. • Suitable introduction of CQDs enhanced the adsorption capacity of 1-ZrO 2 /CQDs-750 for N 2. • More exposure to active sites has a positive effect on increasing NH 3 yield. • 1-ZrO 2 /CQDs-750 has a high Faraday efficiency of 66.62 %. [ABSTRACT FROM AUTHOR]

[Display omitted] • The catalytic properties of noble metal@@MoS 2 /WS 2 heterojunction are studied. • The Pt@MoS 2 /Pt@WS 2 has better catalytic properties compared to MoS 2 /WS 2 heterojunction. • The high catalytic activity of Pt@MoS 2 /Pt@WS 2 is attributed to the inherent electrical conductivity of Pt doping. • The doped elements narrow the band gap, which further promotes the electron transport of the catalyst. • The Pd-doped MoS 2 /WS 2 heterojunctions have better conductivity. Transition metal disulfides (MoS 2 and WS 2) are regarded as the potential candidates for efficient hydrogen evolution reaction. However, their practical application is hindered due to the inert basic plane, the few active sites and the low electrical conductivity. The specially coupled interface with strong electronic interaction and low interface impedance in heterostructure helps to improve the catalytic hydrogen evolution performance of the catalyst. Therefore, we construct MoS 2 /WS 2 heterojunction to investigate it's catalytic hydrogen evolution behavior. The transition metal elements (Pt and Pd) are doped for further enhancing the catalytic hydrogen evolution performance of the heterojunction. Our results show that the Pt-doped heterojunction (Pt@MoS 2 /Pt@WS 2) has a ΔG H of 0.008 eV as well as Volmer/Heyrovsky reaction energy barrier of 0.293 eV/0.702 eV, which can be used as a high-efficiency hydrogen evolution catalyst.Naturally, the high catalytic activity of Pt@MoS 2 /Pt@WS 2 is attributed to four important factors. Firstly, the unique heterostructure improves the inherent electrical conductivity and catalytic activity. Secondly, the doped elements narrow the band gap, which further promotes the electron transport of the catalyst. Thirdly, the new impurity levels produced by doping make the catalysts easy to bond hydrogen protons. Fourthly, the unique charge distribution of electron depletion-accumulation-depletion regions on the basic plane invites the competitive effect between adsorption enhancement and adsorption weakening, thereby inducing the best Gibbs free energy change of adsorbed hydrogen and the low hydrogen evolution reaction energy barrier. [ABSTRACT FROM AUTHOR]

The synthesis and application of bifunctional mesoporous Al-P-V-O catalysts with both acidic and redox sites for selective oxidation of methanol to dimethoxymethane (DMM) is described. The catalysts were characterized by N2 adsorption/desorption, X-ray diffraction, temperature-programmed desorption, X-ray photoelectron spectroscopy, and infrared spectroscopy. It is shown that porosity; redox property and surface acidity of the catalysts were greatly influenced by the Al/V/P ratio. The synergistic effect of phosphorus and vanadium was investigated. Al-P-V-O catalysts exhibited good catalytic activity because of the controlled reducibility and the acidic sites. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2587-2593, 2013 [ABSTRACT FROM AUTHOR]

Exploring efficient, cost-effectiveness and stable bifunctional electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is critical for rechargeable metal-air batteries. Herein, CoFe alloyed nanocrystals encapsulated in N, P-codoped carbon nanovesicles assembled hollow spheres (CoFe@NP-CHS) are prepared by pyrolyzing the homogenous mixture of vitamin B12 (VB12), melamine and Fe 2 O 3 at 700 °C. The resultant CoFe@NP-CHS demonstrates distinct activity for ORR and OER in the alkaline media. More impressively, the as-developed Zn-air battery displays excellent performance with enhanced open-circuit voltage of 1.516 V, enlarged peak power density of 123.1 mW cm−2, and remarkable cycling stability at 10 mA cm−2 (40 h), outperforming the mixture of commercial Pt/C + RuO 2 catalysts. This work provides a promising avenue to fabricate efficient, low cost and stable electrocatalyst for practical viability in electrochemical energy devices. Image 1 • Hollow spheres were assembled with CoFe in N, P-doped carbon nanovesicles. • The hollow structures provided extra active sites and enlarged active area. • The catalyst showed excellent catalytic activity and stability for ORR and OER. • The as-assembled Zn-air battery had high power density and long-term durability. [ABSTRACT FROM AUTHOR]

This communication describes the design of bifunctional VOx/TS-1 catalysts with enhanced redox and acidic character viadoping SO42−and PO43−for selective oxidation of methanol to dimethoxymethane. Redox sites enable the production of formaldehyde, while acidic sites favor the condensation of formaldehyde to DMM. [ABSTRACT FROM AUTHOR]

A series of Ni/KIT6 catalyst precursors with 25 wt.% Ni loading amount were reduced in H2 at 400, 450, 500, and 550 °C, respectively. The studied catalysts were investigated by XRD, Quasi in-situ XPS, BET, TEM, and H2-TPD/Ranalysis methods. It was found that reduction temperature is an important factor affecting the hydrodeoxygenation (HDO) performance of the studied catalysts because of the Strong Metal Support Interaction Effect (SMSI). The reduction temperature influences mainly the content of active components, crystal size, and the abilityfor adsorbing and activating H2. The developed pore structure and large specific surface area of the KIT-6 support favored the Ni dispersion. The RT450 catalyst, which was prepared in H2 atmosphere at 450 °C, has the best HDO performance. Ethyl acetate can be completely transformed and maintain 96.8% ethane selectivity and 3.2% methane selectivity at 300 °C. The calculated apparent activation energies of the prepared catalysts increased in the following order: RT550 > RT400 > RT500 > RT450. [ABSTRACT FROM AUTHOR]

Cu was introduced into Ni/γ-Al 2 O 3 to prepare mesoporous Ni x Cu y /γ-Al 2 O 3 catalysts with different Ni and Cu contents. H 2 -TPR, XRD, BET, H 2 -TPD, and in-situ XPS were used to study the physicochemical properties of the prepared Ni x Cu y /γ-Al 2 O 3 catalysts. The catalytic performances of Ni x Cu y /γ-Al 2 O 3 catalysts were evaluated by methyl laurate catalytic hydrodeoxygenation (HDO) reaction. The Ni x Cu y O/γ-Al 2 O 3 precursors can be reduced to Ni0, Cu0, and NiCu alloy active species by H 2 at 420°C. Formed NiCu alloy can effectively promote the electronic effect between Ni and Cu, and enhance the adsorption and activation abilities of the corresponding catalyst for the reactant molecules. The Ni active sites preferentially catalyzes the decarbonylation/carboxyl (DCO) reaction in the deoxygenation of methyl laurate, while the HDO pathway is predominant on the Cu active sites. The deoxygenation pathway obviously changes from DCO to HDO at the mole ratio of Ni/Cu lower than 3/7, and the main deoxygenation products change from C 11 to C 12 alkane. At the H 2 /Oil ratio of 500N, the space velocity (SV) of 1.5 h−1, H 2 pressure(P) of 2 M Pa, and the reaction temperature of 380°C, the Ni 3 Cu 7 /γ-Al 2 O 3 catalyst shows the best methyl laurate DCO properties. And methyl laurate conversion and the main deoxygenation products C 11 alkane selectivity can reach 98.3 and 87.4%, respectively. Moreover, Ni 3 Cu 7 /γ-Al 2 O 3 catalyst also exhibits good stability. The introduction of Cu into the Ni based catalyst can enormously improve the dispersion of Ni0, Cu0, and NiCu alloy active components. Meanwhile, formed NiCu alloy can also effectively promote the electronic effect between Ni and Cu. The main deoxygenation pathway of methyl laurate and the product selectivity can be directly affected by the content of Ni and Cu active components in the prepared catalysts. The prepared Ni x Cu y /γ-Al 2 O 3 catalysts present superior catalytic hydrodeoxygenation performance and good use stability. Image 1 • The deoxygenation pathway of methyl laurate can be affected by the content of Ni and Cu active components. • Formed NiCu alloy can effectively promote the electronic effect between Ni and Cu. • Developed mesoporous structure and highly dispersed Ni, Cu, and NiCu alloy are beneficial for hydrodeoxygenation. • Ni x Cu y /γ-Al 2 O 3 catalysts present superior methyl laurate hydrodeoxygenation performance and good stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • CoCe catalysts can be prepared by glucose-assisted method. • Glucose can promote oxygen vacancies and active Co0 species to be formed. • The interactions between Co and Ce species can be affected by Co/Ce mole ratio. • The electronic effect between Co and CeO 2 can be effectively enhanced by glucose. In this paper, the CoCe catalysts, which were prepared using a glucose-assisted in-situ reduction method, used to the CO 2 /CH 4 dry reforming (DRM). The physicochemical properties of the prepared catalysts were investigated by H 2 -TPR, XRD, BET, Quasi in-situ XPS and CO 2 -TPD. The findings revealed that the metal Co was the primary active species in the DRM reaction. The good interaction between Ce and Co species can effectively promote the precursors to be reduced to form the active Co0 species and oxygen vacancies, which can also effectively inhibit the Co0 species to be sintered. The metal Co crystallinity and crystal size, active Co0 centers and oxygen vacancies can be successfully constructed by the glucose-assisted method. With the introduction of the glucose promoter, the crystal size of the corresponding catalyst metal Co decreased from 23.21 nm to 18.67 nm, the active Co0 species content on the catalyst surface increased from 41.3 % to 45.7 %, and the adsorbed oxygen content on the surface increased from 20.0 % to 23.0 %. Besides, the glucose promoter can affect the electronic effects of Co-Ce species to promote the DRM reaction. The CoCe3-G catalyst with a Co/Ce mole ratio of 3.0 exhibited the best reforming catalytic performances, and the CH 4 and CO 2 conversion was 87.2 % and 54.0 % at atmospheric pressure and 700 °C, respectively. Meanwhile, the CoCe3-G catalyst exhibited excellent reforming catalytic stability. [ABSTRACT FROM AUTHOR]

The surface active centers, which include metal Co, surface oxygen vacancies, and Co0–CeO 2-δ interface structures, can be constructed on the mesoporous Co/CeO 2-δ catalysts by wet impregnation method. And the surface active centers can be regulated by the Co species dosage. The interaction between the metal Co and CeO 2-δ can promote surface oxygen vacancies and Co0–CeO 2-δ interface structures to be formed and be conducive to inhibit the aggregation and sintering of Co species in high temperature environment. The prepared Co/CeO 2-δ catalysts have better catalytic performances for CO 2 hydrogenation than the single component Co and CeO 2-δ catalysts, which can be attributed to the synergistic effect between Co0 active centers, surface oxygen vacancies, and Co0–CeO 2-δ interface structures. Therefore, the Co/CeO 2-δ catalysts have strong adsorption and activation ability for reactant CO 2 and H 2 molecules to improve the CO 2 hydrogenation activity. At atmospheric pressure and 400 °C, the CO 2 conversion and CH 4 selectivity on the Co/CeO 2-δ catalyst with Co loading of 12% could reach 59.7% and 95.7%, respectively, and maintained good stability in 9 cycles for CO 2 hydrogenation reaction. • Co0–CeO 2-δ interface structure can be constructed by impregnation method. • Interaction between Co and Ce species promote oxygen vacancy and Co0 to form. • Co0 and oxygen vacancy are mainly active centers in CO 2 hydrogenation. • There is synergy effect among Co0–CeO 2-δ , pore structure, oxygen vacancy, and Co0. [ABSTRACT FROM AUTHOR]

[Display omitted] • Porous CoCex catalyst can be prepared by hydrothermal assisted soft template method. • Co0 species are the active centers for CH 4 /CO 2 dry reforming. • Ce species can produce strong electronic effects with Co species. • Oxygen vacancies can promote the oxidative elimination of carbon deposition. The CoCex composite catalysts prepared by hydrothermal assisted template agent CTAB, have superior catalytic performances for CH 4 /CO 2 dry reforming (DRM). The physicochemical properties of the catalysts were investigated in depth with the help of XRD, H 2 -TPR, CO 2 -TPD, ICP, Quasi in-situ XPS and N 2 adsorption–desorption measurements. The transition metal Co is the main active center in the DRM reaction, which can easily release the outer electrons in the reaction to activate the reactant molecules. The introduction of Ce species can promote the highly dispersed metal Co species and catalytic active centers to be formed, as well as the adsorption and activation of CO 2 molecules by the catalyst. Ce species can produce strong electronic effects with Co species, which can promote the electron-deficient CeO 2-δ and electron-rich Coδ- species to be formed. The formation of CeO 2-δ species facilitates the adsorption and activation of CO 2 molecules, and the active oxygen species on the CeO 2-δ surface facilitates the oxidative activation for CH 4 molecules. The CH 4 and CO 2 reactant molecules can be adsorbed and activated by the formed Coδ- species to form CH 4-x (x = 0–4) and CO 2 δ- reactive species, which can promote the DRM reaction. The Co/Ce molar ratio has an important effect on the physicochemical properties and CO 2 adsorption performance of CoCex catalysts. And the CoCe2 catalyst prepared at a 2.0 Co/Ce molar ratio exhibited superior catalytic performance and high stability for the DRM reaction. The CH 4 and CO 2 conversion of the CoCe2 catalyst reached 88.6%, and 52.1% at 700 °C, respectively. In addition, the CoCe2 catalyst can maintain high cycle stability for CH 4 /CO 2 dry reforming. [ABSTRACT FROM AUTHOR]

Abstract Au nanoparticles on ZnO nanorods is a sustainable catalyst for oxygen-promoted, base-free, complete formaldehyde reforming into H 2 and CO 2 at low temperatures. The strong metal-support interaction (SMSI) between Au and ZnO is suggested to be responsible for this catalytic feature partially due to the presence of surface cationic Au+ species formed during high temperature treatment in air. in-situ EPR and resonance Raman analysis show that a two-electron reduction pathway is involved to produce hydrogen peroxide as the active species and C H bond cleavage is the rate-determining step. Graphical abstract Unlabelled Image Highlights • Au/ZnONRs is promising for oxygen-promoted complete formaldehyde reforming. • Strong metal-support interaction (SMSI) is present between Au and ZnO. • Surface cationic Au+ species reduces molecular oxygen into hydrogen peroxide. • Hydrogen peroxide is the active species for formaldehyde reforming. [ABSTRACT FROM AUTHOR]

Highlights: [•] Multimetallic catalysts with hydrophobic supports were prepared. [•] They efficiently catalyzed oxidative esterification of MAL with CH3OH and O2 to MMA. [•] High MAL conversion and MMA selectivity were obtained in mild reaction condition. [•] These catalysts proved to be stable and recyclable. [ABSTRACT FROM AUTHOR]

• Highly efficient photocatalytic water splitting is facilitated by a new O 2 -mediated reaction pathway. • O 2 acts both as an oxidant and a homogeneous catalyst during the partial water splitting. • The oxidation of methanol to formaldehyde is the rate limiting step. • The formation of photoactivated reactive oxygen species is the key to H 2 evolution. • S and P co-doped g-C 3 N 4 shows higher visible-light-driven H 2 evolution efficiency. We report a visible-light-driven, photocatalytic partial water splitting process that proceeds via an oxygen-mediated, sequential single-electron transfer mechanism over heterogeneous photocatalysts. In the absence of any cocatalyst, hydrogen evolution efficiency of 78.9 and 643.0 μmol h−1 g catalyst −1 were achieved over a simple carbon nitride catalyst from methanol and formaldehyde solutions, respectively, in 1.0 bar O 2 atmosphere at room temperature. On the carbon nitride catalyst, molecular O 2 is photocatalytically transformed into reactive oxygen species, which acted both as an oxidant and as a homogeneous catalyst for the partial photocatalytic water splitting reaction, resulting in the two-step oxidation of methanol to formaldehyde and subsequently formic acid. DFT calculations reveal that the new oxygen mediated photocatalytic hydrogen evolution pathway proceeds with virtually zero activation energy. Further improvement in hydrogen evolution efficiency was attained by doping the carbon nitride catalyst with phosphorous and sulfur, which promoted the transport of photogenerated charge carriers. [ABSTRACT FROM AUTHOR]