Chinese Journal of Catalysis ›› 2022, Vol. 43 ›› Issue (3): 862-876.DOI: 10.1016/S1872-2067(21)63870-6

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CO2 hydrogenation selectivity shift over In-Co binary oxides catalysts: Catalytic mechanism and structure-property relationship

Longtai Lia,, Bin Yangb,c,, Biao Gaoa, Yifu Wanga, Lingxia Zhangb,c, Tatsumi Ishiharad, Wei Qie,f,*(), Limin Guoa,#()   

  1. aSchool of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
    bChemistry and Material Science College, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310000, Zhejiang, China
    cState Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
    dInternational Institute for Carbon-Neutral Energy Research, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 8190395, Japan
    eHubei Key Laboratory of Bioinorganic Chemistry & Materia Medica, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei, China
    fState Key Laboratory of Advanced Electronic Engineering and Technology, School of Electrical and Electrical Engineering, Huazhong Universi-ty of Science and Technology, Wuhan 430074, Hubei, China
  • Received:2021-06-10 Revised:2021-06-10 Online:2022-03-18 Published:2022-02-18
  • Contact: Wei Qi, Limin Guo
  • About author:First author contact:

    Contributed equally to this work.

  • Supported by:
    National Natural Science Foundation of China(21878116);Natural Science Foundation of Hubei Province(2019CFA070)


The hydrogenation of CO2 into methanol has attracted much attention and In2O3 is a promising catalyst. Introducing metal elements into In2O3 (M/In2O3) is one of the main strategies to improve its performance. However, its mechanism and active sites remain unclear and need to be further elucidated. Here, the noble-metal-free Inx-Coy oxides catalysts were prepared. Much-improved performance and obvious product selectivity shift were observed. The optimized catalyst (In1-Co4) (9.7 mmol gcat-1 h-1) showed five times methanol yields than pure In2O3 (2.2 mmol gcat-1 h-1) (P = 4.0 MPa, T = 300 °C, GHSV = 24000 cm3STP gcat-1 h-1, H2:CO2 = 3). And the cobalt-catalyzed CO2 methanation activity was suppressed, although cobalt was most of the metal element. To unravel this selectivity shift, detailed catalysts performance evaluation, together with several in-situ and ex-situ characterizations, were employed on cobalt and In-Co for comparative study. The results indicated CO2 hydrogenation on cobalt and In-Co catalyst both followed the formate pathway, and In-Co reconstructed and generated a surface In2O3-enriched core-shell-like structure under a reductive atmosphere. The enriched In2O3 at the surface significantly enhanced CO2 adsorption capacity and well stabilized the intermediates of CO2 hydrogenation. CO2 and carbon-containing intermediates adsorbed much stronger on In-Co than cobalt led to a feasible surface C/H ratio, thus allowing the *CH3O to desorb to produce CH3OH instead of being over-hydrogenated to CH4.

Key words: Indium oxide, Cobalt, CO2 hydrogenation, Methanol synthesis, Core-shell structure, Surface C/H ratio