Chinese Journal of Catalysis ›› 2024, Vol. 57: 133-142.DOI: 10.1016/S1872-2067(23)64579-6

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Self-adjusted reaction pathway enables efficient oxidation of aromatic C-H bonds over zeolite-encaged single-site cobalt catalyst

Jian Danga,b, Weijie Lia,b, Bin Qina,*(), Yuchao Chaia, Guangjun Wua, Landong Lia,*()   

  1. aFrontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin 300071, China
    bSchool of Materials Science and Engineering, Nankai University, Tianjin 300350, China
  • Received:2023-10-15 Accepted:2023-12-08 Online:2024-02-18 Published:2024-02-10
  • Contact: * E-mail: qinbin@nankai.edu.cn (B. Qin), lild@nankai.edu.cn (L. Li).
  • Supported by:
    National Natural Science Foundation of China(22202107);National Natural Science Foundation of China(22025203);National Natural Science Foundation of China(22121005);Fundamental Research Funds for the Central Universities (Nankai University)

Abstract:

The selective oxidation of aromatic C-H bonds to high value-added oxygenated products with molecular oxygen remains a key challenge in heterogeneous catalysis. Eligible heterogeneous catalysts are pursued and the reaction mechanism is hotly debated. Herein, we report that zeolite-encaged single-site cobalt ions can efficiently catalyze the model reaction of ethylbenzene aerobic oxidation to acetophenone, outperforming the industrial benchmark catalyst cobalt naphthenate under identical conditions. The self-accelerating phenomenon is observed in the progress of ethylbenzene aerobic oxidation, corresponding to the self-adjusted reaction pathway as revealed by kinetic studies and density functional theory calculations. The formation of reactive O* species on Co sites, resembling the well-known α-O on Fe sites, is identified to be responsible for the self-adjusted reaction pathway of aromatic C-H bond oxidation.

Key words: C-H bonds activation, Heterogeneous catalysis, Co@Y zeolite, Self-accelerating, Reactive O* species