A new low-cost and effective method for enhancing the catalytic performance of Cu–SiO2 catalysts for the synthesis of ethylene glycol via the vapor-phase hydrogenation of dimethyl oxalate by coating the catalysts with dextrin

Abstract

The influence of low-cost dextrin coating on the performance of Cu–SiO2 catalysts for the vapor-phase hydrogenation of dimethyl oxalate (DMO) to ethylene glycol (EG) was systematically investigated. On the 0.05D-Cu–SiO2 catalyst, 99.8% DMO conversion and 92.3% EG selectivity could be obtained at 463K under 2.0gg-catal−1h−1 weight liquid hourly space velocity, which is almost four times higher than that of the catalyst without coating with dextrin. Characterization methods including N2 physisorption, XRD, TEM, H2 TPR, and XPS were carried out to elucidate the structure–performance relationship. Experimental results indicated that copper phyllosilicate contents decreased while well-dispersed CuO and Cu–O–Si units increased. The improved morphology with more compact nanosized crystalline copper structure resulted in more Cu+ species, which lead to better DMO conversion and EG selectivity in a long-term stability test.