Electrode-assisted Catalytic Water Oxidation by a Flavin Derivative

Nat Chem. 2012 Oct;4(10):794-801. doi: 10.1038/nchem.1439. Epub 2012 Aug 26.

Abstract

The success of solar fuel technology relies on the development of efficient catalysts that can oxidize or reduce water. All molecular water-oxidation catalysts reported thus far are transition-metal complexes, however, here we report catalytic water oxidation to give oxygen by a fully organic compound, the N(5)-ethylflavinium ion, Et-Fl(+). Evolution of oxygen was detected during bulk electrolysis of aqueous Et-Fl(+) solutions at several potentials above +1.9 V versus normal hydrogen electrode. The catalysis was found to occur on glassy carbon and platinum working electrodes, but no catalysis was observed on fluoride-doped tin-oxide electrodes. Based on spectroelectrochemical results and preliminary calculations with density functional theory, one possible mechanistic route is proposed in which the oxygen evolution occurs from a peroxide intermediate formed between the oxidized flavin pseudobase and the oxidized carbon electrode. These findings offer an organic alternative to the traditional water-oxidation catalysts based on transition metals.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Carbon / chemistry
  • Catalysis
  • Electrochemical Techniques
  • Electrodes
  • Flavins / chemistry*
  • Oxidation-Reduction
  • Oxygen / chemistry
  • Platinum / chemistry
  • Water / chemistry*

Substances

  • Flavins
  • Water
  • Platinum
  • Carbon
  • Oxygen