The influence of B-doping on the catalytic performance of Cu/HMS catalyst for the hydrogenation of dimethyloxalate

The influence of boron introduction on the performance of 20 wt.% Cu/HMS catalysts for the catalytic hydrogenation of dimethyloxalate was systematically investigated. It is shown that the boron loading, boron source and the preparation method all have great effect on the catalytic behaviors of the catalyst. Characterization methods including N-2-physisorption, X-ray diffraction, H-2-temperature-programmed reduction, N2O titration, NH3 temperature-programmed desorption, and X-ray photoelectron spectroscopy were carried out to elucidate the structure evolution of the catalyst with the introduction of boron. Experimental results showed that the B2O3 modified catalyst prepared via the ammonia-evaporation-induced synthesis method exhibited the highest conversion and ethylene glycol selectivity because of the higher metallic copper surface area and copper dispersion. The optimum Cu/B mole ratio, which strongly affects the surface composition of the catalyst, was found to be 2/1. 100% DMO conversion and 98% EG selectivity could be obtained over the CuB/HMS(2/1) catalyst under 2.5 h(-1) liquid hour space velocity, which is almost four times higher than that of the one without boron introduction. (C) 2011 Elsevier B.V. All rights reserved.