Efficient production of hydrogen by photo-induced reforming of glycerol at ambient conditions

Photocatalytic reforming of aqueous Solutions of glycerol at ambient conditions has been investigated with the use of Pt/TiO2 photocatalysts and a solar light-simulating source. The effects of platinum loading, photocatalyst content in suspension, glycerol concentration, solution pH and temperature on the reaction rate have been studied in detail. Results obtained show that the reaction proceeds with intermediate production of methanol and acetic acid and eventually results in complete conversion of glycerol to H-2 and CO2. Optimal results are obtained for TiO2 photocatalyst loaded with 0.1-0.5 wt.% Pt, whereas further increase of platinum content has a detrimental effect on photocatalytic performance. The reaction is favored over neutral and basic solutions, compared to acidic solutions, and the reaction rate increases substantially with increasing temperature from 40 to 60-80 degrees C. For high glycerol concentrations (similar to 1 mol L-1) the rate of hydrogen evolution is about two orders of magnitude higher, compared to that obtained for pure water, rendering the process suitable for application. It is concluded that glycerol photoreforming at ambient conditions may provide an efficient and low cost method for the production of renewable hydrogen. (C) 2008 Elsevier B.V. All rights reserved.