Unravelling the Structure of Electrocatalytically Active Fe–N Complexes in Carbon for the Oxygen Reduction Reaction |
| |
| Authors: | Yansong Zhu Bingsen Zhang Xin Liu Da‐Wei Wang Prof Dang Sheng Su |
| |
| Institution: | 1. Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, Liaoning, 110016 (China);2. School of Chemistry and Life Science, Anshan Normal University, Anshan, Liaoning, 114005 (China);3. Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, 116023 (China);4. School of Chemical Engineering, UNSW Australia, UNSW Sydney, NSW 2052 (Australia) |
| |
| Abstract: | Non‐precious Fe/N co‐modified carbon electrocatalysts have attracted great attention due to their high activity and stability in oxygen reduction reaction (ORR). Compared to iron‐free N‐doped carbon electrocatalysts, Fe/N‐modified electrocatalysts show four‐electron selectivity with better activity in acid electrolytes. This is believed relevant to the unique Fe–N complexes, however, the Fe–N structure remains unknown. We used o,m,p‐phenylenediamine as nitrogen precursors to tailor the Fe–N structures in heterogeneous electrocatalysts which contain FeS and Fe3C phases. The electrocatalysts have been operated for 5000 cycles with a small 39 mV shift in half‐wave potential. By combining advanced electron microscopy and Mössbauer spectroscopy, we have identified the electrocatalytically active Fe–N6 complexes (FeN6, FeIII(porphyrin)(pyridine)2]). We expect the understanding of the FeN6 structure will pave the way towards new advanced Fe–N based electrocatalysts. |
| |
| Keywords: | active sites electrocatalysts iron Mö ssbauer spectroscopy oxygen reduction reaction |
|
|
