Chinese Journal of Catalysis ›› 2026, Vol. 82: 348-362.DOI: 10.1016/S1872-2067(25)64926-6

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Core-shell Pd@CeO2/γ‐Al2O3 catalysts: Boosting efficiency and durability in stoichiometric natural gas vehicle exhaust treatment

Run Pana,g,1, Abubakar Yusufa,1, Chengjun Wangb,*(), Jianrong Lic, Zhiyu Xiaoa, Shuai Liud, Yidong Zhonga, Yong Rene, Zheng Wanga, Hainam Doa, John L. Zhoua,*(), George Zheng Chenf, Jun Hea,g,*()   

  1. aDepartment of Chemical and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315000, Zhejiang, China
    bSchool of Chemical and Environmental Engineering, Hunan Institute of Technology, Hengyang 421000, Hunan, China
    cNingbo Key Laboratory of Urban Environmental Pollution and Control, Ningbo (Beilun) Zhongke Haixi Industrial Technology Innovation Center, Ningbo 315000, Zhejiang, China
    dSchool of Mechatronics and Energy Engineering, NingboTech University, Ningbo 315000, Zhejiang, China
    eDepartment of Mechanical, Materials and Manufacturing Engineering, University of Nottingham Ningbo China, Ningbo 315000, Zhejiang, China
    fDepartment of Chemical and Environmental Engineering, Faculty of Engineering, University of Nottingham, Nottingham, UK
    gNottingham Ningbo China Beacons of Excellence Research and Innovation Institute, Ningbo 315000, Zhejiang, China
  • Received:2025-07-23 Accepted:2025-10-21 Online:2026-03-18 Published:2026-03-05
  • Contact: * E-mail: cjwang@hnit.edu.cn (C. Wang),john.zhou@nottingham.edu.cn (J. L. Zhou),jun.he@nottingham.edu.cn (J. He).
  • About author:1 Contributed equally to this work.
  • Supported by:
    Ningbo Natural Science Foundation Grant(2023J024);Ningbo Commonweal Key Research Program(2023S038);Ningbo Key Technology Breakthrough Projects under Yongjiang Science and Innovation 2035 Scheme(2024Z237);Ningbo Key Technology Breakthrough Projects under Yongjiang Science and Innovation 2035 Scheme(2024Z251);Hunan Provincial Natural Science Foundation of China(2025JJ50204)

Abstract:

Natural gas vehicles (NGVs) offer significant environmental advantages by reducing pollutant emissions, but effective exhaust treatment remains a challenge due to high methane emissions and catalyst deactivation over time. This study introduces a core-shell Pd@CeO2/Al2O3 three-way catalyst (TWC) designed to enhance the efficiency and durability of NGV exhaust treatment. The core-shell structure significantly improves catalytic performance. The optimized Pd@Ce/Al (S-500) catalyst demonstrates excellent low-temperature activity, with T50 values of 336 °C for CH4 and 397 °C for NO. It also achieves remarkable reductions of 113 and 177 °C in the T90 for CH4 and NO conversion, respectively, compared to the non-core-shell counterpart, Pd-Ce/Al (S-500). Characterizations reveal enhanced metal-support interactions, increased oxygen vacancies, and optimized Pd-CeO2 interfaces as key active sites. Density functional theory calculations further demonstrate that the core-shell structure facilitates electron transfer at Pd-CeO2 interfaces and lowers energy barriers for three-way reactions, enhancing catalytic efficiency. Notably, the core-shell Pd@Ce/Al (S-500) catalyst maintains high conversion efficiency for CH4 and NO, with only slight losses (5.5% and 6.6%, respectively) over a 100-h time-on-stream stability test, following 16 h of harsh hydrothermal aging at 800 °C, showcasing its long-term stability. These findings provide a deeper understanding of the role of the core-shell Pd@CeO2 structure in Pd-based TWCs and offer valuable insights for designing durable and efficient catalysts to meet the stringent emission standards of NGVs.

Key words: Core-shell catalyst, Pd@CeO2/Al2O3, Natural gas vehicles, Stoichiometric combustion, Three-way catalysis, Hydrothermal stability