Surface reaction network of CO oxidation on CeO₂/Au(110) inverse model catalysts

Abstract

CeO₂/Au(110) inverse model catalysts were prepared and their activity toward the adsorption and co-adsorption of O₂, CO, CO₂ and water was studied by means of X-ray photoelectron spectroscopy, low energy electron diffraction, thermal desorption spectra and temperature-programmed reaction spectra. The Au surface of CeO₂/Au(110) inverse model catalysts molecularly adsorbs CO, CO₂ and water, and the polycrystalline CeO₂ surface of CeO₂/Au(110) inverse model catalysts molecularly adsorbs O₂, and molecularly and reactively adsorbs CO, CO₂ and water. By controllably preparing co-adsorbed surface species on CeO₂/Au(110) inverse model catalysts, we successfully identified various surface reaction pathways of CO oxidation to produce CO₂ with different barriers both on the CeO₂ surface and at the Au-CeO₂ interface, including CO oxidation by various oxygen species, and water/hydroxyl group-involved CO oxidation. These results establish a surface reaction network of CO oxidation catalyzed by Au/CeO₂ catalysts, greatly advancing the fundamental understandings of catalytic CO oxidation reactions.