Effect of Preparation Method on the Structure and Catalytic Performance of CuZnO Catalyst for Low Temperature Syngas Hydrogenation in Liquid Phase

Abstract

CuZnO catalysts were prepared by different methods, characterized by applying a combination of techniques, and the effect of preparation method on the structure and the catalytic performance for syngas hydrogenation at low temperature in liquid phase was investigated. The results showed that due to the difference of the interaction between Cu and Zn, the preparation method greatly affected the crystallinity of CuZnO. The crystallinity of CuZnO had a direct relation with the CO adsorption property. The total CO adsorption amount determined the catalytic activity, the weak adsorption of CO accounted for the methanol synthesis, while the strong adsorption of CO accounted for the ethanol synthesis. CuZnO prepared by the homogeneous precipitation with the lowest crystallinity exhibited the highest total carbon conversion of 68.6% with the methanol selectivity of 84.9%, while CuZnO prepared by the sol gel with the highest crystallinity exhibited the highest ethanol selectivity of 47.6%. The preparation method of CuZnO had a significant effect on the CO adsorption property and then resulted in a substantial modification in the product distribution for the syngas hydrogenation at low temperature in liquid phase. The catalytic activity was determined by the total amount of CO adsorption, the weak CO adsorption accounted for the methanol synthesis and the strong CO adsorption accounted for the ethanol synthesis.