A biosynthetic model of cytochrome c oxidase as an electrocatalyst for oxygen reduction

作者：Mukherjee Sohini; Mukherjee Arnab; Bhagi Damodaran Ambika; Mukherjee Manjistha; Lu Yi; Dey Abhishek^*

来源：Nature Communications, 2015, 6(1): 8467.

DOI：10.1038/ncomms9467

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.

• 出版日期2015-10