Pt-Au/MO x -CeO₂ (M = Mn, Fe, Ti) Catalysts for the Co-Oxidation of CO and H₂ at Room Temperature.

A series of nanostructured Pt-Au/MO _x -CeO₂ (M = Mn, Fe, Ti) catalysts were prepared and their catalytic performance for the co-oxidation of carbon monoxide (CO) and hydrogen (H₂) were evaluated at room temperature. The results showed that MO _x promoted the CO oxidation of Pt-Au/CeO₂, but only the TiO₂ could enhance co-oxidation of CO and H₂ over Pt-Au/CeO₂. Related characterizations were conducted to clarify the promoting effect of MO _x . Temperature-programmed reduction of hydrogen (H₂-TPR) and X-ray photoelectron spectroscopy (XPS) results suggested that MO _x could improve the charge transfer from Au sites to CeO₂, resulting in a high concentration of Ce ³⁺ and cationic Au species which benefits for the CO oxidation. In-situ diffuse reflectance infrared Fourier transform spectroscopy (In-situ DRIFTS) results indicated that TiO₂ could facilitate the oxidation of H₂ over the Pt-Au/TiO₂-CeO₂ catalyst.