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/TiO2, 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.

Automated summary

The optimal loading of Pd/TiO2 catalyst for photocatalytic reforming of sucrose and dextrose is around 0.5-1.0 wt%, with higher or lower Pd content not beneficial for hydrogen production. Kinetic studies conducted under the Langmuir-Hinshelwood (LH) mechanism show that metallic Pd enhances the rate of hydrogen evolution.