Chinese Journal of Catalysis ›› 2018, Vol. 39 ›› Issue (12): 1929-1941.DOI: 10.1016/S1872-2067(18)63146-8

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Relationship between oxygen species and activity/stability in heteroatom (Zr, Y)-doped cerium-based catalysts for catalytic decomposition of CH3SH

Dingkai Chena, Dehua Zhanga, Dedong Hea,b, Jichang Lua, Liping Zhonga, Caiyun Hana, Yongming Luoa   

  1. a Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, Yunnan, China;
    b Faculty of Chemical Engineering, Kunming University of Science and Technology, Kunming 650500, Yunnan, China
  • Received:2018-05-29 Revised:2018-07-23 Online:2018-12-18 Published:2018-09-26
  • Contact: 10.1016/S1872-2067(18)63146-8
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21667016, 21267011, U1402233).

Abstract:

CeO2,Ce1-xZrxO2, and Ce1-xYxO2-δ(x=0.25, 0.50, 0.75, and 1.00) have been rapidly synthesized to estimate their catalytic behavior in decomposing CH3SH. The role of oxygen vacancies, and the relationship between the oxygen species and catalytic properties of CeO2 andZr-doped and Y-doped ceria-based materials are investigated in detail. Combining the observed catalytic performance with the characterization results, it can be deemed that surface lattice oxygenplays a critical role in methanethiol catalytic conversion over cerium oxides. Ce0.75Zr0.25O2 shows higher catalytic activity for CH3SH decomposition due to the large amount of surface lattice oxygen,readily available oxygen species, and excellent redox properties. Ce0.75Y0.25O2-δ displays better catalytic stability owing to the greater number of oxygen vacancies that would promote bulk lattice oxygen migration to the surface of the catalyst in order to replenish surface lattice oxygen. In addition, the results show that the difference in chemical valence between Ce and the heteroatoms would strongly influence the amount of surface lattice oxygen as well as the mobility of bulk-phase oxygen in these catalysts, thus affecting their activity and stability.

Key words: Cerium-base catalyst, Heteroatom, Surface lattice oxygen, CH3SH decomposition, Bulk oxygen migration