The development and commercialization of fuel cells relies heavily on Pt-based catalysts which are efficient for the sluggish four-electron oxygen reduction reaction (ORR). However, the high cost, scarcity and poor methanol tolerance of Pt pose a great challenge to the widespread adoption of fuel cells technologies.

It is highly desirable to develop low-cost and high-efficient non-precious electrocatalysts for ORR in attempt to replace the expensive Pt based catalysts for fuel cells and metal-air batteries.

Recently, the research team led by Prof. LIANG Hanpu from Qingdao Institute of Bioenergy and Bioprocess Technology (QIBEBT), Chinese Academy of Sciences (CAS), has synthesized isolated single Fe atoms anchored on N doped  carbon (Fe-ISA/NC)  using renewable Auricularia auricular-judae (AAJ) as the precursor without the use of any external Fe sources (Figure 1).

The synthesized Fe-ISA/NC exhibits high specific surface area of 1107 m² g^-1 and excellent activities for ORR in 0.1 M KOH, in terms of an onset potential of 1.0 V vs. RHE and a half-wave potential of 0.89 V vs. RHE, which are much better than that of commerical Pt/C catalyst (Figure 2).

Figure 2. ORR catalysis performance (Image by Wang Xilong)

Furthermore, researchers revealed that the Fe-N₄ moieties together with pyrrolic-N are responsible for the enhanced ORR catalytic performance using X-ray absorption fine structure (XAFS) analysis and density functional theory (DFT) calculations.

This work demonstrates that the renewable biomass is in fact an ideal precursor for  producing single-atom Fe-N-C catalyst and pave the way to the practical applications of non-precious catalysts in fuel cells and other energy conversion systems.

The related findings were published in Carbon.

Contact:

CHENG Jing

Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences

Tel: 86-532-80662647/80662622

E-mail: chengjing@qibebt.ac.cn