Chinese Journal of Catalysis ›› 2026, Vol. 85: 272-285.DOI: 10.1016/S1872-2067(26)65032-2

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Dual-site CuS-Co9S8 heterojunctions for efficient and selective glycerol electrooxidation

Yuwei Li, Yuxin He, Zongyao Guo, Jingyi Zhang, Yizhi Wu, Mingkun Jiang, Shiyu Chen, Dan Wu()   

  1. State Key Laboratory of Green and Efficient Development of Phosphorus Resources, Hubei Key Laboratory of Plasma Chemistry and New Materials, School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430205, Hubei, China
  • Received:2025-11-25 Accepted:2025-12-29 Online:2026-06-18 Published:2026-05-18
  • Contact: *E-mail: wudan@wit.edu.cn (D. Wu).
  • Supported by:
    National Natural Science Foundation of China(22402153);Scientific Research Fund Project of Wuhan Institute of Technology(K2024006)

Abstract:

Electrocatalytic oxidation of surplus glycerol from biodiesel production is fundamentally limited by the competitive adsorption of glycerol and OH- ions on catalyst surfaces. To overcome this challenge, a CuS-Co9S8 heterojunction was fabricated via a two-step hydrothermal sulfidation method. This catalyst features spatially and functionally decoupled active sites, in which CuS domains preferentially adsorbs glycerol and Co9S8 promotes OH- activation, thereby balancing surface reactant concentrations and suppressing oxygen evolution side reactions. In-situ Raman spectroscopy and theoretical calculations reveal that interfacial electron redistribution stabilizes high-valent cobalt species and enables dual-site cooperative reactivity. The resulting electrode delivers an industrially relevant current density of 200 mA cm-2 at a low potential of 1.24 V (vs. RHE) with a Faradaic efficiency of 94.8% for formate at 1.5 V. In a flow-type membrane electrode assembly, stable operation over 100 h at 200 mA cm-2 is achieved, yielding a formate production rate of ’86.1 kg m-2. Techno-economic analysis indicates a net profit potential of ’$775 per ton of glycerol processed. This study establishes a general dual-site design principle for overcoming adsorption competition in polyol electrooxidation, offering a scalable pathway for efficient biomass valorization.

Key words: Electrocatalytic glycerol oxidation, Heterojunction, Sulfurization, Co-adsorption, Biomass valorization