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Unravelling the Structure of Electrocatalytically Active Fe–N Complexes in Carbon for the Oxygen Reduction Reaction
Author(s) -
Zhu Yansong,
Zhang Bingsen,
Liu Xin,
Wang DaWei,
Su Dang Sheng
Publication year - 2014
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201405314
Subject(s) - chemistry , electrocatalyst , oxygen reduction reaction , carbon fibers , oxygen , electrolyte , inorganic chemistry , catalysis , mössbauer spectroscopy , oxygen reduction , pyridine , materials science , crystallography , electrode , electrochemistry , medicinal chemistry , organic chemistry , composite material , composite number
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 Fe 3 C 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–N 6 complexes (FeN 6 , [Fe III (porphyrin)(pyridine) 2 ]). We expect the understanding of the FeN 6 structure will pave the way towards new advanced Fe–N based electrocatalysts.