Properties of TiO2 support and the performance of Au/TiO2 catalyst for CO oxidation reaction

Gold catalysts were prepared on TiO2 supports of different phase structures (i.e., anatase, rutile and biphasic), TiO2 crystal size (i.e., 9-23 nm), surface and textural properties (i.e., hydration and surface area). The CO oxidation on the gold catalysts was carried out in an operando-DRIFTS set-up equipped with DRIFTS reactor cell connected on-line to CO gas analyser and gas chromatograph enabling real time monitoring of surface reaction and simultaneous reaction rate measurements. Gold catalysts supported on pure anatase TiO2 were more resistant to sintering compared to catalysts supported on rutile and bi-phasic TiO2. Besides catalyst sintering, deposition of surface carbonates is an important cause of catalyst deactivation. The best gold catalyst was prepared on 13 nm anatase TiO2 It displays both increased activity and stability for CO oxidation reaction at room temperature. Surface and textural properties of TiO2 also play a role on the performance of the Au/TiO2 catalyst