Chinese Journal of Catalysis ›› 2025, Vol. 77: 99-109.DOI: 10.1016/S1872-2067(25)64775-9

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Non-thermal plasma to boost lattice oxygen activation in Ce1-xCoxO2-δ catalysts for efficient soot combustion at low temperatures

Feiyang Zhanga,b,1, Yanjun Chena,b,1, Mengyao Suna,b, Peng Wangb, Yuxin Miaob, Zhongyang Zhengb, Shixin Liub,*(), Xuehua Yub, Zhen Zhaoa,b,*()   

  1. aState Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum (Beijing), Beijing 102249, China
    bInstitute of Catalysis for Energy and Environment, College of Chemistry and Chemical Engineering, Shenyang Normal University, Shenyang 110034, Liaoning, China
  • Received:2025-05-03 Accepted:2025-06-24 Online:2025-10-18 Published:2025-10-05
  • Contact: *E-mail: liushixin2008@126.com (S. Liu), zhenzhao@cup.edu.cn, zhaozhen1586@163.com (Z. Zhao).
  • About author:1Contributed equally to this work.
  • Supported by:
    National Key Research and Development Program of China(2022YFB3504100);National Natural Science Foundation of China(22472106)

Abstract:

Effective lattice oxygen (Olatt) activation at low temperatures has long been a challenge in catalytic oxidation reactions. Traditional thermal catalytic soot combustion, even with Pt/Pd catalysts, is inefficient at exhaust temperatures below 200  °C, particularly under conditions of frequent idling. Herein, we report an effective strategy utilizing non-thermal plasma (NTP) to activate Olatt in Ce1-xCoxO2-δ catalysts, achieving dramatic enhancement of the soot combustion rate at low temperatures. At 200 °C and 4.3 W (discharge power, Pdis), NTP-Ce0.8Co0.2O2-δ achieved 96.9% soot conversion (XC), 99.0% CO2 selectivity (S(CO2)) and a maximum energy conversion efficiency (Emax) of 14.7 g kWh-1. Compared with previously reported results, NTP-Ce0.8Co0.2O2-δ exhibits the highest S(CO2) and Emax values. Remarkably, even without heating, XC, Emax, and S(CO2) reached 92.1%, 6.1 g kWh-1, and 97.5%, respectively, at 6.3 W (Pdis). The results of characterization and theoretical calculation demonstrated that Co dopes into the CeO2 crystal lattice and forms an asymmetric Ce-O-Co structure, making oxygen “easy come, easy go”, thereby enabling the rapid combustion of soot over NTP-Ce0.8Co0.2O2-δ. This study highlights the great potential of NTP for activating Olatt and provides valuable insights into the design of efficient NTP-adapted catalysts for oxidation reactions.

Key words: Reactive oxygen species, Lattice oxygen, Asymmetric Ce-O-Co structure, Non-thermal plasma, Soot combustion