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

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 463 K under 2.0 g g(-catal)(-1)h(-1) weight liquid hourly space velocity, which is almost four times higher than that of the catalyst without coating with dextrin. Characterization methods including N-2 physisorption, XRD, TEM, H-2 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. (C) 2017 Elsevier Inc. All rights reserved.