Photocatalytic water-gas shift reaction at ambient temperature

Present environmental concerns indicate that hydrogen would be suitable as a future fuel. Photocatalytic production of hydrogen is a valuable technology as a clean method of hydrogen production which can use sunlight as the energy input. The role of the photocatalyst is to absorb sunlight which can then be used to produce hydrogen. In the work reported here, catalysts of palladium on titania have been used for hydrogen production by the ambient temperature reforming of methanol, or by using CO in the water-gas shift reaction. Photocatalysis enables both to take place at ambient temperature, Water is the oxidant under these anaerobic conditions. The reaction appears to take place at the boundary between metal nanoparticles and the support, TiO2. A complete mechanism for the reaction is proposed. (C) 2002 Elsevier Science B.V. All rights reserved.