Chinese Journal of Catalysis ›› 2025, Vol. 74: 177-190.DOI: 10.1016/S1872-2067(25)64688-2

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Electronic enrichment on Ni atoms at Ni-CeO2 interfaces: Unraveling the catalytic role in CO methanation and its volcano-type relation with the CeO2 content

Xinli Lia, Xiaonan Zhanga, Zhenzhen Dua, Feixue Hanb, Zhihui Fana, Shaokang Zhanga, Zhenzhou Zhanga, Weifeng Tua,*(), Yi-Fan Hana,b,*()   

  1. aState Key Laboratory of Coking Coal Green Exploitation & Engineering Research Center of Advanced Functional Material Manufacturing, Ministry of Education, Zhengzhou University, Zhengzhou 450001, Henan, China
    bSchool of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
  • Received:2025-01-18 Accepted:2025-03-14 Online:2025-07-18 Published:2025-07-20
  • Contact: *E-mail: yifanhan@ecust.edu.cn (Y.-F. Han), weifengtu@zzu.edu.cn (W. Tu).
  • Supported by:
    National Natural Science Foundation of China(22278379);National Natural Science Foundation of China(22238003);National Natural Science Foundation of China(22208314);National Natural Science Foundation of China(22078307);Natural Science Foundation of Henan(232300421090);Natural Science Foundation of Henan(222301420010)

Abstract:

Tuning the metal-oxide interface to achieve optimal catalytic performance represents a classic yet fast-growing area in catalysis research. This work demonstrated that the decoration of CeO2 clusters onto Ni particles creates electron-enriched Ni sites at the Ni-CeO2 interface with highly efficient CO methanation, by kinetics, chemical titration, and a series of in situ/operando spectroscopic characterizations. These electron-enriched Ni atoms facilitate the back-donation of electrons into the orbital of CO and thus reduce the reaction barrier of CH4 formation, but do not alter the catalytic steps and their kinetic relevance as well as the evolution of surface intermediates during CO methanation. The amount of electron-enriched Ni atoms increases significantly to a maximum value and then decreases as the content of CeO2 increases, leading the formation rates of CH4 to increase in a volcano-type relation with CeO2 contents in xCeNi/Al2O3 catalysts. These insights provide a comprehensive understanding of the nature and the role of the metal-oxide interface and could potentially guide the rational design of highly efficient oxide-supported catalysts for CO methanation.

Key words: CO methanation, Ni catalyst, Interfacial sites, Active sites, In-situ and operando spectroscopy