Methanol synthesis from CO2 hydrogenation over copper catalysts supported on MgO-modified TiO2

Abstract

A serials of copper catalysts supported on TiO2 modified with different amount of MgO were prepared by an impregnation method and tested for methanol synthesis from CO2 hydrogenation. The physico-chemical properties of the catalysts were characterized using XRD, N2 physisorption, N2O titration, XPS, H2-TPR and CO2-TPD techniques. With the increase in amount of MgO, the Cu surface area initially increases and then decreases. The modification of TiO2 with MgO hinders the interaction between CuO and TiO2, resulting in a decline in the reducibility of CuO. Furthermore, the number and strength of the moderate and strong basic sites over the surface of catalyst increase with increasing MgO loading. The catalyst exhibits an optimum catalytic activity as the content of MgO is 1wt%. The CO2 conversion is determined by the Cu specific surface area and the interaction between CuO and TiO2, and the CH3OH selectivity is related to the surface basicity of catalyst.