Activity and deactivation behavior of Au/LaMnO3 catalysts for CO oxidation

Perovskite oxide LaMnO3 was prepared by sol-gel method and the nanosize Au/LaMnO3 catalyst was prepared by deposition-precipitation (DP) method in the paper. Characterization of the catalyst sample was made by X-ray diffractometer (XRD), atom absorption spectra (AAS) and X-ray photoelectron spectroscopy (XPS) instrumental methods. The activity, long-term stability and the reasons for deactivation of the gold catalyst in CO oxidation were investigated. The experiment results demonstrated that the Au/LaMnO3 catalyst exhibited high stability in the ambient storage process. However, the gradual decrease in initial activity during 100 h reaction was still observed, which could be ascribed to the aggregation of gold particles and the transfer from gold ion to the metal gold.