One-pot template-free preparation of mesoporous MgO-ZrO2 catalyst for the synthesis of dipropyl carbonate

A series of mesoporous nano-MgO-ZrO2 with various Mg:Zr atomic ratios were prepared via simple co-precipitation process without addition of a template. It was demonstrated by XRD, Na adsorption-desorption and TEM that these samples still kept well mesoporous structure even after calcination at 600 degrees C. During the preparation process, divalent Mg2+ ions could be incorporated into tetragonal ZrO2 lattice to form a solid solution. More important, the surface basic density of these catalysts closely depended on their Mg content. Then, the resulting MgO-ZrO2 catalysts were used as basic catalysts for the dipropyl carbonate (DPC) synthesis via transesterification of n-propanol and dimethyl carbonate. The relationship between the basic property of solid base and their catalytic performance was clarified in detail. Among all the materials, the catalyst with Mg:Zr atomic ratio = 0.5 showed the best catalytic performance. Under the suitable reaction conditions, the yield of DPC could reach 98.5% with 100% selectivity. In addition, based on the reusability test and catalyst characterization, this catalyst exhibited extraordinary structure stability and it could be reused at least four times without obvious loss of reactivity.