Simple strategy synthesizing stable CuZnO/SiO2 methanol synthesis catalyst

Abstract

The metal particle size distribution of a catalyst can affect the rate of deactivation in many chemical reaction. This work developed a facile method to prepare a well dispersed CuZnO/SiO2 catalyst via rotary evaporation assisted deposition-precipitation method (RE-CZS). By comparison, conventional deposition-precipitation method and ultrasound assisted deposition-precipitation method were applied to synthesize other catalysts (Im-CZS and Ul-CZS), in order to clarify the influence of Cu particle size distribution of the catalyst on catalytic stability of methanol synthesis via CO2 hydrogenation. RE-CZS catalyst possessed the narrowest Cu particle distribution (ca. 4.9–9.1 nm) and thus exhibited the best catalytic stability because of the least Cu particle growth. Im-CZS catalyst showed the broadest Cu particle distribution (ca. 5.3–28.7 nm) and suffered from the most serious particle growth resulting in the least catalytic stability. The Cu particle distribution and the related catalytic stability of the Ul-CZS catalyst lied between RE-CZS catalyst and Im-CZS catalyst. The origin of the tremendous effect of the Cu particle size distribution on the catalytic stability was studied via XRD, N2 adsorption/desorption, N2O chemisorption, ICP-AES, XPS, TEM and temperature-programmed techniques, which suggested that catalyst deactivation was mainly attributed to the growth of Cu particles originating from Ostwald ripening effect.