Chinese Journal of Catalysis ›› 2017, Vol. 38 ›› Issue (7): 1281-1290.DOI: 10.1016/S1872-2067(17)62846-8

• Articles • Previous Articles    

Co3O4 nanoparticles assembled on polypyrrole/graphene oxide for electrochemical reduction of oxygen in alkaline media

Suzhen Rena, Yanan Guoa, Shaobo Maa, Qing Maob, Dandan Wua, Ying Yanga, Hongyu Jinga, Xuedan Songa, Ce Haoa   

  1. a College of Chemistry, Dalian University of Technology, Dalian 116024, Liaoning, China;
    b College of Chemical Engineering, Dalian University of Technology, Dalian 116024, Liaoning, China
  • Online:2017-07-18 Published:2017-06-27
  • Contact: 10.1016/S1872-2067(17)62846-8
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21373042).

Abstract:

The development of highly efficient catalysts for cathodes remains an important objective of fuel cell research. Here, we report Co3O4 nanoparticles assembled on a polypyrrole/graphene oxide electrocatalyst (Co3O4/Ppy/GO) as an efficient catalyst for the oxygen reduction reaction (ORR) in alkaline media. The catalyst was prepared via the hydrothermal reaction of Co2+ ions with Ppy-modified GO. The GO, Ppy/GO, and Co3O4/Ppy/GO were characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The incorporation of Ppy into GO nanosheets resulted in the formation of a nitrogen-modified GO po-rous structure, which acted as an efficient electron-transport network for the ORR. With further anchoring of Co3O4 on Ppy/GO, the as-prepared Co3O4/Ppy/GO exhibited excellent ORR activity and followed a four-electron route mechanism for the ORR in alkaline solution. An onset potential of -0.10 V vs. a saturated calomel electrode and a diffusion limiting current density of 2.30 mA/cm2 were achieved for the Co3O4/Ppy/GO catalyst heated at 800℃; these values are comparable to those for noble-metal-based Pt/C catalysts. Our work demonstrates that Co3O4/Ppy/GO is highly active for the ORR. Notably, the Ppy coupling effects between Co3O4 and GO provide a new route for the preparation of efficient non-precious electrocatalysts with hierarchical porous structures for fuel cell applications.

Key words: Non-precious metal electrocatalyst, Co3O4, Polypyrrole, Graphene, Oxygen reduction reaction, Proton-exchange membrane fuel cell