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Cu-Co bimetallic nanoparticles coated with carbon layers have been developed through direct heating treatment of bimetallic oxide precursors incipiently deposited with polyethene glycol. The as-synthesized nanocatalyst performs excellently in chemoselective hydrogenolysis of 5-hydroxymethylfurfural to 2,5-dimethylfuran. The Co-based catalysts exhibit higher performance than Cu-based catalysts. Cu-Co@C (Cu: Co = 1:3) shows the highest yield of 2,5-dimethylfuran (99.4%). Bimetallic nanocatalysts are detailedly characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The bimetallic nanoparticles are entrapped by carbon shells that can protect them from oxidation and deactivation. The catalytic activity and selectivity are kept constant in a six-run recycling test. The synergistic effect between two metal components is helpful to enhance catalytic performance. [ABSTRACT FROM AUTHOR]

Bimetallic catalysts supported over TiO 2 –ZrO 2 binary oxides were prepared by co-impregnation methods and used for catalyzing liquid-phase hydrogenation of furfural. Highly selective hydrogenation catalysts can be developed based on bimetallic synergistic effect. The coexistence of small proportion of palladium with supported nickel species greatly improves the catalytic performance and transfer the reaction selectivity from partial hydrogenation to total hydrogenation. The catalyst with Ni–Pd mole ratio of 5:1 shows the best performance. The yield of tetrahydrofurfuryl alcohol (THFA) reaches 93.4%. Ni–Pd synergistic effect is interpreted through XPS measurement and a hydrogen-transfer mechanism is proposed. Pt–Re bimetallic catalyst is an excellent partial hydrogenation catalyst for furfural conversion. Furfural can be totally converted and the selectivity of partial hydrogenation product (FA) reaches 95.7%. When rhenium oxide species are located on the Pt surface, the hydrogen species on Pt are transferred to adsorbed C O bond to achieve selective hydrogenation. [ABSTRACT FROM AUTHOR]

Abstract: Glycerol was converted to liquid fuels through a one-pot process catalyzed by mesostructured Ir–Re–W/SiO2. The reaction was performed over 0.4g of catalyst suspended in an aqueous solution of glycerol (4.72mmol/ml) at 553K under a hydrogen pressure of 6.0MPa for 50h. A hydrocarbon-enriched organic phase was self-separated from the aqueous solution after the reaction. The total yield of oil products was greater than 40%, and the selectivity toward hydrocarbons was approximately 90%. The conversion proceeds through a complicated mechanism that involves a Cg reaction and hydrodeoxygenation. Doped tungsten oxide species in a silica matrix are active acidic sites for acid-catalyzed dehydration. Supported iridium species are catalytic active sites for hydrodeoxygenation and Cg reactions. The evolution of their chemical states during the catalytic process was detected by X-ray photoelectron spectroscopy. Rhenium species are important co-catalysts for iridium species. These active catalytic species work together to achieve the direct conversion of glycerol in aqueous solution to liquid fuels under a hydrogen atmosphere. [Copyright &y& Elsevier]