CO Oxidation over Au/TiO2-Carbon Catalysts: The Effect of Thermal Treatment, Stability and TiO2 Support Structure

The effect of thermal treatment on the catalyst structure and the CO oxidation performance of a Au/TiO2 catalyst supported on a carbon composite material has been studied. X-ray absorption spectroscopy shows that the carbon composite stabilises the TiO2 and prevent agglomeration of the particles. The activity measurements show that both Au and TiO2 need to be present in order to obtain catalytic activity. The catalytic performance was found to be strongly affected by thermal treatments of the active phase prior to the reaction. The thermal treatments have an effect on the ordering of the TiO2 structure, and on the CO oxidation activity. Heat treatment after Au deposition has a positive effect on the CO oxidation performance. This is attributed to the introduction of a stronger interaction between the oxide and Au which improves the catalytic activity. This also indicates that the TiO2 support and the Au-TiO2 interface play important roles in the CO oxidation reaction.