Acta Chimica Sinica    

Article

Mn掺杂Co3O4双功能电催化剂在碱性介质下氧还原和析氧反应中的应用

税子怡a,b, 于思乐c, 陆伟a, 许留云b, 刘庆叶a, 赵炜*,a, 刘益伦d   

  1. a西北大学 化工学院 西安 710069;
    b延安大学 化学与化工学院 延安 716000;
    c比亚迪汽车有限公司 西安 710075;
    d西安交通大学 航空航天学院 西安 710049
  • 投稿日期:2024-05-06
  • 基金资助:
    陕西省自然科学基础研究计划资助(2023-JC-YB-046)和陕西省教育厅自然科学基金(23JK0723).

Bifunctional electrocatalysts of Mn-doped Co3O4 for oxygen reduction and oxygen evolution reactions in alkaline medium

Ziyi Shuia,b, Sile Yuc, Wei Lua, Liuyun Xub, Qingye Liua, Wei Zhao*,a, Yilun Liud   

  1. aNorthwest University, School of Chemical Engineering, Xi’an, 710069;
    bCollege of Chemistry & Chemical Engineering, Yan’an University, Yan’an 716000;
    cBYD Automobile Co., Ltd. Xi’an, 710075;
    dSchool of Aerospace, Xi’an Jiao tong University, Xi’an 710049
  • Received:2024-05-06
  • Contact: * E-mail: zhaowei3313@nwu.edu.cn

Rechargeable zinc-air batteries (ZABs) have been extensively studied due to their due to their high energy and power density, high safety and cost-effectiveness, which are considered to be one of the most promising clean power sources in the field of energy storage. Nevertheless, its practical application has been hampered by the sluggish kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) during the discharge and charge processes, respectively. It is well known that Pt and IrO2 are currently considered to be the most efficient ORR and OER catalysts. However, the high cost of precious metal catalysts has hindered their large-scale application. Herein, a series of spinel catalysts (Mnx-Co3O4, x=0, 0.5, 1, 1.5) are prepared by co-precipitation method to achieve bifunctional oxygen electrocatalysis in alkaline media. Meanwhile, the potential of these transition metal oxide catalytic materials as bifunctional catalysts in replacing precious metals has been further explored. The results show that Mn-Co3O4 has excellent ORR performance (onset potential of 0.85 V, half-wave potential of 0.69 V), and significantly enhanced OER performance (overpotential of 0.57 V, the electron transfer resistance of 26.14 Ω), thereby leading to excellent bifunctional property. Furthermore, Density functional theory (DFT) calculations demonstrate that Mn and Co sites can serve as potential active sites for ORR and OER respectively, exhibiting significant synergistic effects in electrocatalytic processes. The characterization results further confirm that the doping of manganese in the catalyst preparation process increases the specific surface area and oxygen vacancies of the catalyst, adjusts the surface chemistry and electronic state of the catalyst, and thus improves the ORR and OER performance of the catalyst. In addition, the catalyst delivers high cycle life of up to 40 h in liquid rechargeable zinc air batteries. In summary, this paper demonstrates that manganese-cobalt bimetallic synergistic catalysis is a promising strategy to enhance the electrocatalytic activity of ORR and OER.

Key words: Oxygen reduction reaction, Oxygen evolution reaction, Spinel oxide, Oxygen vacancy, Catalytic performance