Beta zeolite supported on silicon carbide for Friedel-Crafts fixed-bed reactions

Beta zeolite supported on silicon carbide, with high thermal conductivity and high mechanical strength, was successfully used as an active and stable catalyst for Friedel-Crafts reactions in a fixed bed configuration.     

Quantitative measurement of the Brönsted acid sites in solid acids: toward a single-site design of Mo-modified ZSM-5 zeolite

On the basis of our previous H/D exchange studies devoted to the quantification of the number of Br?nsted acid sites in solid acids, we report here an innovative approach to determine both the amount and the localization of Mo atoms inside the Mo/ZSM-5 catalyst, commonly used for the methane dehydroaromatization reaction. The influence of Mo introduction in the MFI framework was studied by means of BET, X-ray diffraction, 27Al magic angle spinning NMR, NH3 temperature-programmed desorption, and H/D isotopic exchange techniques. A dependence was found between the decrease of acidic OH groups and the Mo content. Depending on the Si/Al ratio of the zeolite, i.e., the proximity of two Br?nsted acid sites, the Mo atoms substitute a different number of OH groups. Consequently, a chemical structure was proposed to describe the geometry of the Mo complex in the channels of the ZSM-5 zeolite.     

Combining Metabolic Engineering and Electrocatalysis: Application to the Production of Polyamides from Sugar

Biorefineries aim to convert biomass into a spectrum of products ranging from biofuels to specialty chemicals. To achieve economically sustainable conversion, it is crucial to streamline the catalytic and downstream processing steps. In this work, a route that combines bio‐ and electrocatalysis to convert glucose into bio‐based unsaturated nylon‐6,6 is reported. An engineered strain of Saccharomyces cerevisiae was used as the initial biocatalyst for the conversion of glucose into muconic acid, with the highest reported muconic acid titer of 559.5 mg L^?1 in yeast. Without any separation, muconic acid was further electrocatalytically hydrogenated to 3‐hexenedioic acid in 94 % yield despite the presence of biogenic impurities. Bio‐based unsaturated nylon‐6,6 (unsaturated polyamide‐6,6) was finally obtained by polymerization of 3‐hexenedioic acid with hexamethylenediamine.     

Beta zeolite supported on a macroscopic pre-shaped SiC as a high performance catalyst for liquid-phase benzoylation

Preparation and characterisation of a highly active and stable beta zeolite supported on a pre-shaped silicon carbide catalyst for the benzoylation reaction in liquid phase.     

凝结相中功能性碳材料和碳纳米复合物催化转化生物质制备可再生化学品(英文)

The production of chemicals from lignocellulosic biomass provides opportunities to synthesize chemicals with new functionalities and grow a more sustainable chemical industry. However, new challenges emerge as research transitions from petrochemistry to biorenewable chemistry. Compared to petrochemisty, the selective conversion of biomass-derived carbohydrates requires most catalytic reactions to take place at low temperatures ( 300 °C) and in the condensed phase to prevent reactants and products from degrading. The stability of heterogeneous catalysts in liquid water above the normal boiling point represents one of the major challenges to overcome. Herein, we review some of the latest advances in the field with an emphasis on the role of carbon materials and carbon nanohybrids in addressing this challenge.