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The hydrodeoxygenation of furfural (FF) over Mo carbides in liquid phase at 200 °C, 30 bar of H2 for 4 h in 2‐butanol was investigated. Unsupported and SiO2‐supported Mo carbide with different crystallographic phases (β‐Mo2C/SiO2 and α‐MoC/SiO2), and in the presence of Cu and Ni as promoters were studied. The reactivation treatment under H2 atmosphere of the passivated Mo carbides was investigated by XAS. The results show that Mo is present in different states of oxidation in the passivated catalysts, with more severe oxidation in the bimetallic systems, in which the original carbides are not restored after reactivation. Finally, the product distribution in the HDO of furfural is modified as a function of catalyst oxidation degree. Using the less oxidized Mo carbide (β‐Mo2C), a higher yield to 2‐methylfuran is obtained, while C10 condensation products are formed for the more oxidized catalysts. [ABSTRACT FROM AUTHOR]

The hydrogen and oxygen evolution reactions (HER and OER) are two steps in electrochemical water splitting for conversion of electric power to chemical energy. The main challenge remains the development of efficient, stable and cheap electrocatalysts able to perform both reactions under alkaline conditions. Single atom Ru stabilized by nitrogen-doped carbon and RuO2 are currently the materials of choice for the HER and OER, respectively. Here, we propose a strategy for the preparation of Ru embedded in a carbon nitride matrix for efficient HER and OER in KOH solution. It is based on the preparation of a covalent organic framework 2D CIN-1 structure with coordinated RuII, producing Ru oxide nanoparticles with low valence Ru sites arranged in the form of nanowires between layers of graphitic carbon nitride after pyrolysis. The material demonstrates smaller overpotentials for the HER and OER in comparison with benchmark Pt and RuO2 catalysts, and high catalytic stability. [ABSTRACT FROM AUTHOR]

This study explores the performances of nickel‐based materials for the dry reforming of methane (DRM), an important process for hydrogen and syngas productions. Ni nanoparticles are issued from porous phyllosilicate phase exolution under reducing conditions (in situ or ex situ). Phyllosilicate precursors were obtained by deposition/precipitation with urea onto SBA‐15 porous silica, with metal loading up to 40 wt.%. Reaction was performed at 600–700 °C. The successful formation and stabilization of highly dispersed nanoparticles (2–6 nm) is revealed, even for highly loaded formulations (20 wt.% and 40 wt.%). In DRM‐700 (CH4/CO2=1, 20 % CH4, 480,000 mL gcat−1 h−1) the formulation at 20 wt.% metal loading (Ni_20 %) activated during reaction affords 50 % and 65 % of CH4 and CO2 conversions respectively at 700 °C. Ni_20 % is showing excellent resistance toward sintering after DRM stability test of 80 h. Characterizations made for spent catalyst show high resistance toward sintering and limited carbon formation. [ABSTRACT FROM AUTHOR]

The synthesis of methanol and dimethyl ether (DME) from carbon dioxide (CO2) and green hydrogen (H2) offers a sustainable pathway to convert CO2 emissions into value-added products. This heterogeneous catalytic reaction often uses copper (Cu) catalysts due to their low cost compared with their noble metal analogs. Nevertheless, improving the activity and selectivity of these Cu catalysts for these products is highly desirable. In the present study, a new architecture of Cu- and Cu/Zn-based catalysts supported on electrospun alumina nanofibers were synthesized. The catalysts were tested under various reaction conditions using high-throughput equipment to highlight the role of the hierarchical fibrous structure on the reaction activity and selectivity. The Cu or Cu/ZnO formed a unique structure of nanosheets, covering the alumina fiber surface. This exceptional morphology provides a large surface area, up to ~300 m2/g, accessible for reaction. Maximal production of methanol (~1106 gmethanolKgCu−1∙h−1) and DME (760 gDMEKgCu−1∙h−1) were obtained for catalysts containing 7% wt. Cu/Zn with a weight ratio of 2.3 Zn to Cu (at 300 °C, 50 bar). The promising results in CO2 hydrogenation to methanol and DME obtained here point out the significant advantage of nanofiber-based catalysts in heterogeneous catalysis. [ABSTRACT FROM AUTHOR]

The catalytic performance of the Ag/TiO2 catalyst was evaluated in the oxidation of furfural (FF) to furoic acid (FA) in an alkaline aqueous solution under 15 bar of air in a batch reactor. The catalytic activity, yield, and stability of the catalyst were compared as a function of different reaction parameters including temperature (25–110 °C), nature of the atmosphere, base equivalent (nbase/nFF = 0.25–3), and nature of the inorganic bases used (NaOH, NaHCO3, and Na2CO3). Under optimum conditions, the yield of FA (96%) was achieved at room temperature, with an excellent carbon balance (>98%). The recyclability of the catalyst was also studied and the catalytic activity of the Ag/TiO2 catalyst slightly declined due to an increase in particle size as confirmed by TEM studies. [ABSTRACT FROM AUTHOR]

The direct synthesis of dimethyl carbonate (DMC) from CO2 and methanol has recently attracted much attention because such a process would allow the application of green chemistry principles. However, its major drawbacks lie in the high stability of CO2 and in the thermodynamic equilibrium of the reaction. The present review aims to discuss strategies that have been explored by researchers recently to improve the yield of DMC. Elaborate catalysts for the activation of CO2 and methanol, such as organometallic catalysts, ionic liquids, alkali metal catalysts, heteropolyacid catalysts, metal-supported catalysts, metal organic frameworks (MOFs) and metal oxide catalysts, are summarized and discussed in this review paper. Moreover, the significance of using a dehydrating agent for in situ water trapping during the reaction (and concomitant thermodynamic equilibrium shift), such as molecular sieves, ionic liquids, acetals, esters and nitriles, is also considered and the detailed roles of dehydrating agents in the formation of DMC are analyzed in this review. [ABSTRACT FROM AUTHOR]