Effect of copper nanoparticles dispersion on catalytic performance of Cu/SiOcatalyst for hydrogenation of dimethyl oxalate to ethylene glycol

摘要

Cu/SiOcatalysts, for the synthesis of ethylene glycol (EG) from hydrogenation of dimethyl oxalate (DMO), were prepared by ammonia-evaporation and sol-gel methods, respectively. The structure, size of copper nanoparticles, copper dispersion, and the surface chemical states were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), temperature- programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS) and Nadsorption. It is found the structures and catalytic performances of the catalysts were highly affected by the preparation method. The catalyst prepared by sol-gel method had smaller average size of copper nanoparticles (about 3-4 nm), better copper dispersion, higher Cu+/C0 ratio and larger BET surface area, and higher DMO conversion and EG selectivity under the optimized reaction conditions.