Abstract: Microwave heating for a mixture of CuCl and SiO2-TiO2 support was used to prepare a CuCl/SiO2-TiO2 catalyst with high dispersion of CuCl on the support surface in a short time. X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption, thermal gravimetric analysis, H2 temperature-programmed reduction, and CO temperature-programmed desorption were carried out to examine the bulk and surface properties of the CuCl/SiO2-TiO2 catalyst. The characterization results showed that in the CuCl/SiO2-TiO2 catalyst prepared by microwave heating, a great amount of CuCl particles strongly attached to the SiO2-TiO2 support as compared with that prepared by con-ventional heating, resulting in a lower reduction temperature of copper species and a stronger adsorption to CO. Microwave heating also caused that the mass loss temperature of part CuCl was higher than 1 200 oC, which could be attributed to the formation of a strong Cu–O coordinate bond between CuCl and the SiO2-TiO2 support. Catalytic test results showed that the CuCl/SiO2-TiO2 catalyst prepared by mi-crowave heating exhibited methanol conversion of 11.7% and dimethyl carbonate selectivity of 96.5%, higher than that prepared by conven-tional heating in liquid-phase oxidative carbonylation of methanol.

Key words: microwave irradiation, cuprous chloride, silicon dioxide, titanium dioxide, supported catalyst, methanol, oxidative carbonylation, dimethyl carbonate