Catalytic Performances of Silicon Dioxide Supported Titania as Catalyst in Transesterification between Diethyl Oxalate and Phenol

Abstract

A series of silicon dioxide supported titania by the impregnation method for transesterification of diethyl oxalate (DEO) and phenol was carried out under the facile catalytic condition in the liquid phase at 453 k in the atmospheric pressure. Within different TiO2loadings ranging from 1% to 20%, 10% TiO2/SiO2performed best, giving 49.5% conversion of DEO and the total 100% selectivity to ethyl phenyl oxalate (EPO) and diethyl oxalate (DPO). To further study the relationship between catalytic performances and the catalysts structure, several characterization methods, analysis of X-ray diffraction (XRD), Raman spectroscopy measurement and FTIR of adsorbed pyridine studies were utilized. The results of XRD and Raman, showed amorphous structure of TiO2on SiO2below the 10% loading and crystalline form of TiO2phase on SiO2above the 10% loading. In addition, FTIR of adsorbed pyridine studies illuminated the Lewis-type acid sites were responsible for transesterification between DEO and phenol.