Chinese Journal of Catalysis ›› 2018, Vol. 39 ›› Issue (8): 1294-1302.DOI: 10.1016/S1872-2067(18)63086-4

• Special Column on the 15th International Conference on Carbon Dioxide Utilization (ICCDU XV) • Previous Articles     Next Articles

Effect of alkali metals on the performance of CoCu/TiO2 catalysts for CO2 hydrogenation to long-chain hydrocarbons

Zhibiao Shia,b, Haiyan Yangb, Peng Gaob, Xinqing Chenb, Hongjiang Liua, Liangshu Zhongb,c, Hui Wangb, Wei Weib,c, Yuhan Sunb,c   

  1. a Department of chemistry, College of Sciences, Shanghai University, Shanghai 200444, China;
    b CAS Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China;
    c School of physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
  • Received:2018-03-18 Revised:2018-04-23 Online:2018-08-18 Published:2018-07-04
  • Contact: 10.1016/S1872-2067(18)63086-4
  • Supported by:

    This work was supported by the "Frontier Science" Program of Shell Global Solutions International B. V. (PT65197), the National Natural Science Foundation of China (21773286, 21503260, 21776296), Youth Innovation Promotion Association CAS (20178330), the "Transformational Technologies for Clean Energy and Demonstration", Strategic Priority Research Program of the Chinese Academy of Sciences (XDA21090204), and Shanghai Municipal Science and Technology Commission, China (16DZ1206900).

Abstract:

CoCu/TiO2 catalysts promoted using alkali metals (Li, Na, K, Rb, and Cs) were prepared by the homogeneous deposition-precipitation method followed by the incipient wetness impregnation method. The influences of the alkali metals on the physicochemical properties of the CoCu/TiO2 catalysts and the catalytic performance for CO2 hydrogenation to long-chain hydrocarbons (C5+) were investigated in this work. According to the characterization of the catalysts based on X-ray photoelectron spectroscopy, X-ray diffraction, CO2 temperature-programmed desorption (TPD), and H2-TPD, the introduction of alkali metals could increase the CO2 adsorption and decrease the H2 chemisorption, which could suppress the formation of CH4, enhance the production of C5+, and decrease the hydrogenation activity. Among all the promoters, the Na-modified CoCu/TiO2 catalyst provided the maximum C5+ yield of 5.4%, with a CO2 conversion of 18.4% and C5+ selectivity of 42.1%, because it showed the strongest basicity and a slight decrease in the amount of H2 desorption; it also exhibited excellent catalytic stability of more than 200 h.

Key words: Carbon dioxide hydrogenation, Long-chain hydrocarbons, Carbon dioxide Fischer-Tropsch synthesis, Alkali metal promoters, Cobalt-copper based catalysts