Abstract
Herein, a series of metal oxide/CeO2 (M/CeO2) nanocomposites derived from Ce-benzene tricarboxylate (Ce-BTC) adsorbing with different metal acetylacetonate complexes were prepared for CO oxidation under four different CO gas atmospheres. It was demonstrated that Cu/CeO2 exhibited the highest catalytic activity and stability in CO oxidation. Remarkably, both O2 selectivity and CO selectivity to CO2 are 100% in most of the investigated conditions. Several analytical tools such as N2 adsorption-desorption and powder X-ray diffraction, were employed to characterize the prepared catalysts. In addition, the excellent catalytic performance of Cu/CeO2 in CO oxidation was revealed by H2 temperature-program reduction experiment, X-ray photoelectron spectroscopy, and in situ diffuse reflectance infrared Fourier transform spectroscopy. The result showed that high oxygen vacancy and high CO adsorption capacity (Cu+-CO) caused by the electron exchanges of Cu2+/Cu+ and Ce3+/Ce4+ pairs (Ce4+ + Cu+ ⇆ Ce3+ + Cu2+) are two key factors contributing to the high oxidation performance of Cu/CeO2 catalyst.