Highly active and selective copper-containing HMS catalyst in the hydrogenation of dimethyl oxalate to ethylene glycol

Copper-containing mesoporous silica HMS catalysts were prepared by an impregnation method. The surface structures of these catalysts were characterized by N-2-physisorption, X-ray diffraction, transmission electron microscopy, H-2 temperature-programmed reduction, Fourier transform infrared spectroscopy, N2O titration and X-ray photoelectron spectroscopy. The results show that the copper-containing HMS catalysts exhibit superior catalytic performance in the selective hydrogenation of dimethyl oxalate to ethylene glycol compared to the commercial silica-supported ones obtained by the same method. The dimethyl oxalate conversion can reach 100% and the ethylene glycol selectivity can reach 92% at 473 K with 2.5 MPa H-2 pressure and 0.2 h(-1) liquid hour space velocity of dimethyl oxalate over the 5 wt.% Cu-HMS catalyst. The enhanced catalytic performance of copper-HMS catalysts may be attributed to the homogeneous dispersion and uniformity of the active copper species and to the larger copper Surface areas attained on the HMS supports with large pore diameters and surface areas. (c) 2008 Elsevier B.V. All rights reserved.