The influence of La doping on the catalytic behavior of Cu/ZrO 2 for methanol synthesis from CO 2 hydrogenation

Abstract

A series of Cu/ZrO 2 catalysts with various La loadings for methanol synthesis from CO 2 hydrogenation were prepared by a urea–nitrate combustion method. The catalysts were characterized with N 2 adsorption, XRD, reactive N 2O adsorption, XPS, TPR, H 2-TPD and CO 2-TPD techniques, and tested for methanol synthesis from CO 2 hydrogenation. With increasing La loading, the Cu surface area increases first and then decreases, whereas the amount of basic site over catalysts increases continuously. The results of catalytic test reveal that a linear relationship exists between the conversion of CO 2 and the Cu surface area. Moreover, it is found for the first time that the selectivity to methanol is related to the distribution of basic site on the catalyst surface. The presence of La favors the production of methanol, and the optimum catalytic activity is obtained when the amount of La doping is 5% of the total amount of Cu 2+ and Zr 4+.