Preparation of Cu/Zn/Al/(Zr)/(Y) catalysts from hydrotalcite-like precursors and their catalytic performance for the hydrogenation of CO2 to methanol

Abstract

Cu/Zn/Al/(Zr)/(Y) hydrotalcite-like compounds with Cu:Zn:Al:Zr:Y atomic ratios of 2:1:1:0:0, 2:1: 0.8:0.2:0, 2:1:0.8:0:0.2, and 2:1:0.8:0.1:0.1 were prepared using the coprecipitation method. The mixed oxides were then obtained by the calcination of the precursors at 500 °C in air, and subsequently evaluated in terms of their catalytic performance for the synthesis of methanol from the hydrogenation of CO2. The asprepared samples were characterized by X-ray diffraction (XRD), thermogravimetric (TG) analysis, N2 adsorption, reactive N2O adsorption, H2 temperature-programmed reduction (H2-TPR), and H2/CO2 temperature-programmed desorption (H2/CO2 TPD) techniques. The results of these analyses showed that the BET specific surface area increased significantly with the introduction of Zr and Y, which was related to the amount of H2O and CO2 evolved from the precursors during calcination. The Cu specific surface area and Cu dispersion properties increased in the order of Cu/Zn/Al