The proportion of Ce4+ in surface of CexZr1-xO2 catalysts: The key parameter for direct carboxylation of methanol to dimethyl carbonate

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.

We reported that different preparation methods of Ce0.5Zr0.5O2 catalysts have great influences on their surface and bulk properties and catalytic activities of synthesis of DMC from methanol and CO2.163