Influence of preparation methods on the structure and performance of CaO–ZrO 2 catalyst for the synthesis of dimethyl carbonate via transesterification

Abstract

CaO–ZrO 2 catalysts, which were prepared by physical mixing, impregnation and coprecipitation methods, were developed for the synthesis of dimethyl carbonate from propylene carbonate and methanol. It was found that the CaO–ZrO 2 catalyst prepared by the coprecipitation method showed high performance for the reaction, which was greatly dependent on the calcination temperature. The XRD and CO 2-TPD measurement of the catalysts revealed that both catalytic activity and stability were strongly influenced by the structure of CaO–ZrO 2. The aggregated CaO on the support as well as highly dispersed CaO showed poor catalytic stability, but Ca 2+ ion substituted for Zr 4+ ions in the host lattice to form homogeneous CaO–ZrO 2 solid solution, which led to the strong interaction between CaO and ZrO 2 and then high stability.