Coordination Chemistry of [Co(acac) sub(2)] with N-Doped Graphene: Implications for Oxygen Reduction Reaction Reactivity of Organometallic Co-O sub(4)-N Species

• Published in: Angewandte Chemie International Edition 2015-01, Vol.54 (43), p.12622-12626
• Main Authors: Han, Jongwoo, Sa, Young Jin, Shim, Yeonjun, Choi, Min, Park, Noejung, Joo, Sang Hoon, Park, Sungjin
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts; Graphene; Ligands; Metalorganic compounds; Methyl alcohol; Reduction; Tolerances
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201504707

Hybridization of organometallic complexes with graphene-based materials can give rise to enhanced catalytic performance. Understanding the chemical structures within hybrid materials is of primary importance. In this work, archetypical hybrid materials are synthesized by the reaction of an organometallic complex, [Co super(II)(acac) sub(2)] (acac=acetylacetonate), with N-doped graphene-based materials at room temperature. Experimental characterization of the hybrid materials and theoretical calculations reveal that the organometallic cobalt-containing species is coordinated to heterocyclic groups in N-doped graphene as well as to its parental acac ligands. The hybrid material shows high electrocatalytic activity for the oxygen reduction reaction (ORR) in alkaline media, and superior durability and methanol tolerance to a Pt/C catalyst. Based on the chemical structures and ORR experiments, the catalytically active species is identified as a Co-O sub(4)-N structure. Active species for ORR: Hybrid materials are synthesized by the reaction of a Co-based organometallic complex with N-doped graphene at room temperature. These materials show high electrocatalytic activity for the oxygen reduction reaction. The coordination around Co is revealed by experimental and theoretical studies, and the catalytically active species is identified as a Co-O sub(4)-N structure.