Catalysts, kinetics and process optimization for the synthesis of methyl acrylate over Cs-P/gamma-Al2O3

Bifunctional catalysts Cs-P/gamma-Al2O3 were developed and firstly applied in a one-step synthesis of methyl acrylate using methyl acetate (Ma) and formaldehyde (FA). The catalysts were prepared using impregnation and characterized with X-ray diffraction, transmission electron microscopy, thermogravimetry and differential thermal analysis, nitrogen adsorption-desorption, ammonia-and carbon dioxide-temperature programmed desorption methods. The catalytic performance was evaluated using a fixed-bed microreactor. Experimental results indicated that the P loading had significant influence on the catalytic activity by modifying the acid-base surface properties of the catalyst. The process optimization using response surface methodology was performed and the interactions of operational variables including the Ma/FA molar ratio, reaction time and temperature were elucidated. Then the kinetics of the aldol condensation reaction was studied using a pseudo-homogeneous kinetic model. In addition, the lifetime of optimum Cs10%-P5%/gamma-Al2O3 catalyst was evaluated over a continuous period of 400 h, and did not exhibit an obvious decrease in efficiency.