Chinese Journal of Catalysis ›› 2025, Vol. 68: 376-385.DOI: 10.1016/S1872-2067(24)60155-5

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An unexpected reversal: The smart performance of hydrogen chloride on SbCe catalysts for NH3-SCR reaction

Caixia Liua, Chaojun Huangb, Baiyu Fanc, Yan Zhanga, Lijing Fanga, Yuhe Wanga, Qingling Liua,*(), Weichao Wangd, Yanguo Chene, Yawei Zhange, Jiancheng Liuf, Fang Dongb, Ziyin Zhangg   

  1. aTianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Technology and State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China
    bChina Merchants Marine and Offshore Research Institute CO., LTD., Shenzhen 518000, Guangdong, China
    cChina Automotive Strategy and Policy Research Center, China Automotive Technology and Research Center Co., Ltd, Tianjin 300300, China
    dTianjin Key Laboratory of Environmental Remediation & Pollution Control, MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
    eTianjin TEDA Co., Ltd., Tianjin 300350, China
    fSchool of Civil Engineering, Tianjin University, Tianjin 300072, China
    gNew Catalytic Materials Engineering Research Center for Air Pollutant Control, Hebei province New Resin Material Technology Innovation Center, Langfang City Beichen Entrepreneurship Resin Materials Incorporated Co., Ltd., Langfang 065000, Hebei, China
  • Received:2024-09-03 Accepted:2024-09-24 Online:2025-01-18 Published:2025-01-02
  • Contact: * E-mail: liuql@tju.edu.cn (Q. Liu).
  • Supported by:
    National Key R&D Program of China(2022YFB3504100);National Key R&D Program of China(2022YFB3504102);Hebei Province Major Scientific and Technological Achievement Transformation Fund(2021004012A);Hebei Province Major Scientific and Technological Achievement Transformation Fund(22281401Z);National Natural Science Foundation of China(22276133);National Natural Science Foundation of China(22076136)

Abstract:

Understanding the influence of HCl on the NH3-selective catalytic reduction reaction mechanism is crucial for designing highly efficient denitrification catalysts. The formation of chlorate species on the surface of the synthesized SbCeOx catalyst, induced by HCl, significantly enhances low-temperature activity, as evidenced by a 30% increase in NO conversion at 155 °C. Furthermore, it improves N2 selectivity at high temperatures, with a notable 17% increase observed at 405 °C. Both experimental results and density functional theory calculations confirm that chlorate species form at Ce sites. This formation facilitates the creation of oxygen vacancies, boosting the oxygen exchange capacity. It also increases NH3 adsorption at the Ce sites, promotes the formation of Sb-OH, and reduces competitive OH adsorption on these sites. Notably, compared with the reaction mechanism without HCl, the presence of chlorate species enhances NH3 adsorption and activation, which is vital for subsequent catalytic reactions.

Key words: NH3-selective catalytic reduction, Chlorate species, SbCeOx catalyst, Density functional theory, HCl