In-situ Fourier transform infrared spectroscopy study on CO oxidation over Au/titanate and Au/titania nanocatalysts

Surface charge state and surface hydroxyl coverage of the catalyst support were reported to have great impact on the CO catalytic oxidation activity. Protonic layered titanate nanotubes are featured with cation-vacancy defects and full surface Ti-OH group coverage, whereas titania nanoparticles are featured with anion-vacancy defects and partly Ti-OH surface group coverage. In order to explore the influence on the activity from these differences, Fourier transform infrared spectra study of CO adsorption and oxidation over the Au/titanate and Au/titania catalysts is performed and the results indicate that (i) both Au/titanate and Au/titania have strong adsorption for CO molecules, and (ii) the Au/titania sample has a higher reactive activity for CO oxidation than the Au/titanate sample. This phenomenon is reasonably explained combining with a traditional strong metal-support interaction theory known in CO catalytic oxidation reactions.