Hydrogen Production by Aqueous-Phase Reforming of Biomass over Supported Pt Catalysts

Pt catalysts supported on Al(2)O(3), activated carbon (AC), HUSY, and SiO(2) were prepared and characterized by N(2) physisorption, inductively coupled plasma atomic emission spectrometry, and H(2) chemisorption. The catalytic performance of these catalysts for H(2) production by aqueous-phase reforming (APR) of glycerol was studied. In addition, the reforming of different reactants such as polyols, glucose, and other soluble saccharides was also investigated. It was found that the activity of the supported Pt catalysts for the reforming of glycerol increased in the order Pt/AC < Pt/HUSY < Pt/SiO(2) < Pt/Al(2)O(3) at 503 K; however, the activity increased in another order Pt/SiO(2) < Pt/HUSY < Pt/AC < Pt/Al(2)O(3) at higher temperature (538 K). Pt catalysts supported on acidic supports such as Al(2)O(3) and HUSY tended to increase hydrocarbon formation. The H(2) selectivity and production rate for the reforming of polyols decreased with increasing carbon number. The H(2) selectivity and yield for the reforming of glucose decreased when the glucose concentration increased, while selectivity for hydrocarbon showed a maximum at glucose concentration of 4.6%, which was ascribed to the condensation and degradation reactions. Fructose is less readily reformed to H(2) than glucose. Higher H(2) Selectivity and yield were obtained by reforming of polysaccharide starch compared with those obtained by reforming of disaccharide maltose and monosaccharide glucose.