Iron–Nitrogen Coordination in Modified Graphene Catalyzes a Four‐Electron‐Transfer Oxygen Reduction Reaction. Issue 5 (26th February 2014)

• Record Type: Journal Article
• Authors: Kamiya, Kazuhide; Koshikawa, Hiroyuki; Kiuchi, Hisao; Harada, Yoshihisa; Oshima, Masaharu; Hashimoto, Kazuhito; Nakanishi, Shuji
• Is Part Of: ChemElectroChem. Volume 1:Issue 5(2014)
• Page Start: 877
• Page End: 884
• Publication Date: 2014-02-26
• Subjects: Electrochemistry -- Periodicals; 541.37
• DOI: 10.1002/celc.201300181
• Languages: English
• ISSNs: 2196-0216

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>It is shown that iron–nitrogen (Fe/N) coordination in an Fe/N‐modified graphene (Fe/N‐graphene) electrocatalyst catalyzes a four‐electron transfer oxygen reduction reaction (ORR). The Fe/N‐graphene is synthesized by heat‐treating graphene oxides in the presence of an Fe/N complex at 900 °C for just 45 s. When the heat‐treatment period is increased, the Fe/N coordination bonds are broken and the number of electrons involved in the ORR decreases. Extended X‐ray absorption fine structure analysis and X‐ray absorption spectroscopy (XAS) show that both a complete sp² graphitic structure and a high density of Fe/N coordination structures exist in the Fe/N‐graphene material, which is in contrast to the carbon‐based catalyst prepared by using the conventional pyrolysis method. XAS analysis also reveals that back‐donation from Fe atoms coordinated with N to an O antibonding π* orbital occurrs, promoting the four‐electron transfer ORR.</p> </abstract>