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Cellulose is converted into sorbitol and related sugar compounds over water-tolerant and durable carbon-supported Pt catalysts under aqueous hydrogenation conditions. Pre-treatment of cellulose with ball-milling effectively reduces the crystallinity and particle size of cellulose, which results in high conversion of cellulose to sorbitol and mannitol. The selectivity of sorbitol increases by using Cl-free metal precursors in the catalyst preparation as residual Cl on the catalysts promotes the side-reactions. The transformation of cellulose to sorbitol consists of the hydrolysis of cellulose to glucose viawater-soluble oligosaccharides and the successive hydrogenation of glucose to sorbitol. The hydrolysis of cellulose is the rate-determining step, and the Pt catalysts promote both the hydrolysis and the hydrogenation steps. [ABSTRACT FROM AUTHOR]

Abstract: A manganese oxides supported on cerium(IV) oxide MnO x /CeO2 precatalyst by wetness impregnation with manganese(II) acetate and cerium(IV) oxide. A Ru/MnO x /CeO2 catalyst was prepared by wetness impregnation of MnO x /CeO2 precatalyst with aqueous solution of ruthenium(III) chloride. The Ru/MnO x /CeO2 catalyst has high catalytic activities for the oxidation of alcohols to the corresponding carbonyl compounds. Especially, the advantage of the present catalyst is the smooth oxidation of alcohols at 300K under molecular oxygen atmosphere. [Copyright &y& Elsevier]

Ru/C catalysts are active for the conversion of cellulose using 2-propanol or H2of 0.8 MPa as sources of hydrogen, whereas the Ru/Al2O3catalyst is inactive in both reactions, indicating that the Ru/C catalysts are remarkably effective for the cellulose conversion. [ABSTRACT FROM AUTHOR]