title: Hemoglobin-carbon nanotube derived noble-metal-free Fe5C2-based catalyst for highly efficient oxygen reduction reaction.
abstract: High performance non-precious cathodic catalysts for oxygen reduction reaction (ORR) are vital for the development of energy materials and devices. Here, we report an noble metal free, Fe5C2 nanoparticles-studded sp(2) carbon supported mesoporous material (CNTHb-700) as cathodic catalyst for ORR, which was prepared by pyrolizing the hybrid adduct of single walled carbon nanotubes (CNT) and lyophilized hemoglobin (Hb) at 700 °C. The catalyst shows onset potentials of 0.92 V in 0.1 M HClO4 and in 0.1 M KOH which are as good as commercial Pt/C catalyst, giving very high current density of 6.34 and 6.69 mA cm(-2) at 0.55 V vs. reversible hydrogen electrode (RHE), respectively. This catalyst has been confirmed to follow 4-electron mechanism for ORR and shows high electrochemical stability in both acidic and basic media. Catalyst CNTHb-700 possesses much higher tolerance towards methanol than the commercial Pt/C catalyst. Highly efficient catalytic properties of CNTHb-700 could lead to fundamental understanding of utilization of biomolecules in ORR and materialization of proton exchange membrane fuel cells for clean energy production.
authors.affiliation: Center for Superfunctional Materials, Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 689-798, Korea.
authors.forename: Varun
authors.initials: V
authors.lastname: Vij
authors.affiliation: Center for Superfunctional Materials, Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 689-798, Korea.
authors.forename: Jitendra N
authors.initials: JN
authors.lastname: Tiwari
authors.affiliation: Center for Superfunctional Materials, Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 689-798, Korea.
authors.forename: Wang-Geun
authors.initials: WG
authors.lastname: Lee
authors.affiliation: Center for Superfunctional Materials, Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 689-798, Korea.
authors.forename: Taeseung
authors.initials: T
authors.lastname: Yoon
authors.affiliation: Center for Superfunctional Materials, Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), UNIST-gil 50, Ulsan 689-798, Korea.
authors.forename: Kwang S
authors.initials: KS
authors.lastname: Kim
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