a Research Institute of Chemical Defence, Beijing 100083, China
b Research Center for Eco-Environmental Sciences, Chinese Academy Sciences, Beijing 100085, China
Abstract:
Composite oxide MOx/Al2O3 supported gold catalysts for low-temperature CO oxidation were prepared and investigated. The presence of transition metal oxide was proved to be beneficial to the improvement of catalytic performance of Au/Al2O3 catalysts for low-temperature CO oxidation. Furthermore, the influence of various pretreatment conditions on Au/MOx/Al2O3 catalysts was studied carefully. The image of TEM showed that gold catalyst with small gold particles only in the form of a fine dispersion exhibited highly catalytic activity. The XPS, Fourier transform infrared (FTIR) spectroscopy characterization results of Au/FeOx/Al2O3 catalyst showed that gold catalysts having partially oxidized gold species have the best catalytic performance. One possible pathway for CO oxidation on Au/FeOx/Al2O3 catalyst is that the CO adsorbed on gold particles reacts with adsorbed oxygen, which is possible to occur on oxygen vacancies on the support or at the metal–support interface.