Photocatalytic Reforming of Sucrose and Dextrose for Hydrogen Production on Pd/TiO₂

Photocatalytic reforming of sucrose and dextrose was performed on TiO₂ supported Pd (0.25, 0.5, 1.0, 1.5, and 2.0 wt%) catalysts under UV light irradiation. Hydrogen production increases with increasing the sucrose concentration. Semiconductor TiO₂ has shown benefit from palladium additions up to about 0.5–1.0 wt%; however, the further metal increase has no benefits. Kinetics study reveals that the apparent reaction rate for hydrogen evolution follows the Langmuir-Hinshelwood (LH) mechanism. The equilibrium constant (K) determined was 1.078 for 1 %Pd/TiO_2, while 2 %Pd/TiO₂ exhibited 0.122, which is an order of magnitude less than the former catalyst. Hydrogen yield from dextrose is higher than sucrose under similar reaction conditions. Furthermore, the catalyst pretreated by sodium borohydride displayed higher activity for dextrose reforming than untreated, implying that metallic Pd enhanced hydrogen production.