文摘
In order to correlate the physico-chemical properties of CexZr1-xO2 catalysts with their catalytic activities for direct carboxylation of methanol to dimethyl carbonate (DMC), ceria-zirconia mixed oxides with the same nominal composition (Ce0.5Zr0.5O2), which were prepared by different methods, were applied. The catalysts were characterized by means of XRD, N2 adsorption, ICP-MS, NH3-TPD, CO2-TPD, Raman spectroscopy and XPS. Significant variations in their physico-chemical properties were observed by varying the preparation conditions. The results showed that the catalytic activity of the ceria-zirconia mixed oxides increased with improving the proportion of Ce4+, acidity and basicity of the catalyst surface. And the number of surface Ce4+ content is the most important factor.