In situ synthesis of sustainable highly efficient single iron atoms anchored on nitrogen doped carbon derived from renewable biomass

It is highly desirable to develop low-cost and high-efficient non-precious electrocatalysts for oxygen reduction reaction (ORR) in attempt to replace the expensive Pt based catalysts for fuel cells and metal-air batteries. Herein, a novel, facile and cost-effective strategy is reported to in situ synthesize isolated single iron (Fe) atoms anchored on nitrogen doped carbon (Fe-ISA/NC) with renewable Auricularia auricular-judae as the biomass precursor. The best performing 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, surpassing that of Pt/C and most reported non-precious metal catalysts. Furthermore, superior methanol tolerance and outstanding stability are observed. X-ray absorption fine structure (XAFS) analysis and density functional theory (DFT) calculations reveal that the Fe-N4 moieties together with pyrrolic-N are responsible for the enhanced catalytic performance for ORR.