Condensation of methyl propionate with formaldehyde to methyl methacrylate over Cs-Zr-Mg/SiO_2 catalysts

摘要

Cs-Zr-Mg/SiO_2 can be effective catalysts for the product of methyl methacrylate (MMA) by the condensation of methyl propionate (MP) and formaldehyde (FA). The catalysts with different magnesium loading were prepared by incipient wetness impregnation. The number and strength of surface acid and base sites of catalysts were determined by stepwise temperature-programmed desorption (TPD) of NH_3 and CO_2, respectively. It was found that the catalyst with a magnesium loading of 1.0 g/100molSiO_2 had the modest acidity and basicity and showed the excellent performance. Furthermore, it was also observed that the activity of the catalyst decreased with reaction time, and coke formed on the catalyst was characterized by DTA/TG technique after reaction.