Chinese Journal of Catalysis ›› 2023, Vol. 45: 162-173.DOI: 10.1016/S1872-2067(22)64176-7

• Article • Previous Articles     Next Articles

The role of surface hydroxyls on ZnZrOx solid solution catalyst in CO2 hydrogenation to methanol

Feng Shaa,b, Shan Tanga,c, Chizhou Tanga,c, Zhendong Fenga,c, Jijie Wanga,*(), Can Lia,c,*()   

  1. aState Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, Liaoning, China
    bSchool of Materials Science and Engineering and National Institute for Advanced Materials, Nankai University, Tianjin, 300350, China
    cUniversity of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2022-07-25 Accepted:2022-09-17 Online:2023-02-18 Published:2023-01-10
  • Contact: Jijie Wang, Can Li
  • Supported by:
    Transformational Technologies for Clean Energy and Demonstration(XDA21090202);Fundamental Research Center of Artificial Photosynthesis(FReCAP);Fundamental Research Center of Artificial Photosynthesis(22088102);National Natural Science Foundation of China(22172160)

Abstract:

ZnZrOx solid solution catalyst is an excellent catalyst in methanol synthesis from CO2 hydrogenation. It is still highly aspiration to make any further improvement in catalytic performance. In this work, ZnZrOx solid solution catalyst is prepared with different methods, resulting in different surface property. The ZnZrOx solid solution catalyst prepared by reflux ammonia (ZnZrOx-RA) exhibits higher methanol selectivity of 95.2% and CO2 conversion of 3.3% than that of the catalyst obtained via co-precipitation (ZnZrOx-CP) at 280 °C, 5 MPa. Subsequent kinetics analysis shows that ZnZrOx-RA, in comparison to ZnZrOx-CP, shows a decreased activation energy for methanol synthesis, an increased reaction order in H2, and a similar reaction order in CO2. Structural characterizations indicate that these two catalysts are in solid solution state, while ZnZrOx-RA possesses more Zn-OH species on the surface. The surface Zn-OH species enhance the activation and adsorption of CO2 and H2, and improve the generation and stability of HCOO* species, which promote CO2 hydrogenation to methanol.

Key words: Surface hydroxyl, ZnZrOx solid solution, CO2 hydrogenation, Methanol synthesis, Preparation method