Effect of Pore Structure of SiO2 on Catalytic Performance of Pd-SiW12/SiO2 for Direct Oxidation of Ethylene to Acetic Acid

The Pd-SiW12/SiO2 catalysts with different pore structure of SiO2 were prepared for direct oxidation of ethylene to acetic acid. The catalysts were characterized by X-ray diffraction, N, physical adsorption, infrared spectroscopy of adsorbed pyridine, and H-2-pulse chemical adsorption. The results showed that the pore structure of SiO2 had an important influence on the catalytic performance of the catalysts. The Pd-SiW12/SiO2 catalyst prepared by the SiO2 support with larger pore size and pore distribution exhibited the highest catalytic activity, on which 145.2 g/(L.h) of acetic acid yield was obtained. Pd dispersion was responsible for the catalytic activity of the Pd-SiW12/SiO2 catalyst.