The influence of La doping on the catalytic behavior of Cu/ZrO2 for methanol synthesis from CO2 hydrogenation

A series of Cu/ZrO2 catalysts with various La loadings for methanol synthesis from CO2 hydrogenation were prepared by a urea–nitrate combustion method. The catalysts were characterized with N2 adsorption, XRD, reactive N2O adsorption, XPS, TPR, H2-TPD and CO2-TPD techniques, and tested for methanol synthesis from CO2 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 CO2 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 Cu2+ and Zr4+.

With increasing La loading, the CO2 conversion takes on a volcano variation trend, whereas the methanol selectivity increases continuously.Figure optionsDownload high-quality image (86 K)Download as PowerPoint slideHighlights
► The presence of La favors the production of methanol.
► The introduction of La affects the Cu surface area of catalyst.
► The introduction of La affects the basicity of catalyst.
► A linear relationship exists between CO2 conversion and the Cu surface area.
► The methanol selectivity is related to the distribution of basic sites of catalyst.