Chinese Journal of Catalysis ›› 2025, Vol. 74: 352-364.DOI: 10.1016/S1872-2067(25)64737-1

• Articles • Previous Articles     Next Articles

Oxidative depolymerization of lignin enhanced by synergy of polyoxometalate and acetic acid

Jiaming Caoa,b, Yuting Liub, Huifang Liub,*(), Chunguang Liud,*(), Junyou Shia,c,*(), Ning Lib,*()   

  1. aMaterial Science and Engineering College of Northeast Forestry University, Harbin 150040, Heilongjiang, China
    bState Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China
    cCollege of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo 255000, Shandong, China
    dDepartment of Chemistry, Faculty of Science, Beihua University, Jilin 132013, Jilin, China
  • Received:2024-12-15 Accepted:2025-04-26 Online:2025-07-18 Published:2025-07-20
  • Contact: *E-mail: liuhuifang@dicp.ac.cn (H. Liu), liucg407@163.com (C. Liu), bhsjy64@163.com (J. Shi), ningli603@dicp.ac.cn (N. Li).
  • Supported by:
    National Natural Science Foundation of China(32130073);National Natural Science Foundation of China(22478380);National Natural Science Foundation of China(22272169);Department of Science & Technology of Liaoning province(2024JH2/102400040);State Key Laboratory of Catalysis(2024SKL-B-007);Natural Science Foundation of Liaoning Province(2024-MSBA-56)

Abstract:

Oxidative catalysis enables lignin depolymerization to yield carbonyl-containing aromatic chemicals for sustainable lignocellulose valorization. The oxidative depolymerization of lignin requires high oxygen pressure and harsh conditions to trade off lignin’s structural complexity and limited solubility. Herein, we developed an oxidation system for lignin depolymerization using a single phosphomolybdic acid (H3PMo12O40) catalyst in acetic acid solvent to address the aforementioned issues. The entire catalytic system was operated under only 0.1 MPa O2 pressure, providing over 20 wt% of aromatic compounds containing aldehydes and carboxylic acids. Theoretical calculations combined with experimental analyses reveal structural transformations and redox behavior driven by the synergistic interaction between H3PMo12O40 and acetic acid. Mechanistic studies detected superoxide radicals, confirming the joint role of catalyst and solvent in oxygen activation, radicals stabilization, and enhanced reaction efficiency. A low-cost, commercially available catalyst with minimal oxygen demand offers a promising route to industrial-scale biomass refining.

Key words: Oxidative catalysis, Lignin valorization, Aromatic chemicals, Phosphomolybdic acid, Organic acid