title: Hydrogenolysis of cellulose over Cu-based catalysts-analysis of the reaction network.
abstract: A series of polyols, carbohydrates, and cellulose were tested in the aqueous, CuO/ZnO/Al2O3-catalyzed hydrogenolysis reaction at 245 °C and 50 bar H2. The compositions of liquid-phase products were analyzed; based on these results a unified reaction mechanism is proposed that accounts for the observed product distribution. Elementary transformations such as dehydration, dehydrogenation/hydrogenation, Lobry de Bruyn-van Ekenstein isomerization and retro-aldol cleavage were identified as most important for controlling the selectivity of simple polyols and carbohydrates. For cellulose the product distribution is considerably different than for glucose or sorbitol, indicating a change in the reaction pathway. Therefore, next to the traditional hydrolysis of the glycosidic bond, an additional depolymerization mechanism involving only the reducing ends of cellulose oligomers is proposed to account for this observation.
authors.affiliation: Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim a. d. Ruhr (Germany).
authors.forename: Kameh
authors.initials: K
authors.lastname: Tajvidi
authors.forename: Peter J C
authors.initials: PJ
authors.lastname: Hausoul
authors.forename: Regina
authors.initials: R
authors.lastname: Palkovits
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D056804:Biofuels; D002384:Catalysis; D002482:Cellulose / Q000737:chemistry*; D003246:Conservation of Energy Resources; D003300:Copper / Q000737:chemistry*; D006358:Hot Temperature; D015034:Zinc Oxide / Q000737:chemistry
chemical_list: D056804:Biofuels; D003300:Copper; D002482:Cellulose; D000537:Aluminum Oxide; D015034:Zinc Oxide; C030973:cupric oxide
keywords: biomass; cellulose; copper; hydrogenolysis; mechanism