title: A biosynthetic model of cytochrome c oxidase as an electrocatalyst for oxygen reduction.
abstract: Creating an artificial functional mimic of the mitochondrial enzyme cytochrome c oxidase (CcO) has been a long-term goal of the scientific community as such a mimic will not only add to our fundamental understanding of how CcO works but may also pave the way for efficient electrocatalysts for oxygen reduction in hydrogen/oxygen fuel cells. Here we develop an electrocatalyst for reducing oxygen to water under ambient conditions. We use site-directed mutants of myoglobin, where both the distal Cu and the redox-active tyrosine residue present in CcO are modelled. In situ Raman spectroscopy shows that this catalyst features very fast electron transfer rates, facile oxygen binding and O-O bond lysis. An electron transfer shunt from the electrode circumvents the slow dissociation of a ferric hydroxide species, which slows down native CcO (bovine 500 s(-1)), allowing electrocatalytic oxygen reduction rates of 5,000 s(-1) for these biosynthetic models.
authors.affiliation: Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A&2B Raja SC Mullick Road, Jadavpur Kolkata 700032, India.
authors.forename: Sohini
authors.initials: S
authors.lastname: Mukherjee
authors.affiliation: Department of Chemistry, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
authors.forename: Arnab
authors.initials: A
authors.lastname: Mukherjee
authors.affiliation: Department of Chemistry, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
authors.forename: Ambika
authors.initials: A
authors.lastname: Bhagi-Damodaran
authors.affiliation: Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A&2B Raja SC Mullick Road, Jadavpur Kolkata 700032, India.
authors.forename: Manjistha
authors.initials: M
authors.lastname: Mukherjee
authors.affiliation: Department of Chemistry, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A&2B Raja SC Mullick Road, Jadavpur Kolkata 700032, India.
authors.forename: Abhishek
authors.identifier: http://orcid.org/0000-0002-9166-3349
authors.initials: A
authors.lastname: Dey
mesh_terms: D002384:Catalysis; D004566:Electrodes; D003576:Electron Transport Complex IV / Q000737:chemistry*; D006046:Gold; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D013059:Spectrum Analysis, Raman
chemical_list: D006046:Gold; D003576:Electron Transport Complex IV; D010100:Oxygen