Pt-Au/MO_x -CeO₂ (M = Mn, Fe, Ti) catalysts for the co-oxidation of co and H₂at 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 MOx 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 MOx could improve the charge transfer from Au sites to CeO₂ , resulting in a high concentration of Ce³⁺ 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.