Cobalt Carbonate as an Electrocatalyst for Water Oxidation

Shanti G. Patra, Erzsébet Illés, Amir Mizrahi, Dan Meyerstein

Research output: Contribution to journalArticlepeer-review

13 Scopus citations

Abstract

CoII salts in the presence of HCO3 /CO3 2− in aqueous solutions act as electrocatalysts for water oxidation. It comprises of several key steps: (i) A relatively small wave at Epa≈0.71 V (vs. Ag/AgCl) owing to the CoIII/II redox couple. (ii) A second wave is observed at Epa≈1.10 V with a considerably larger current. In which the CoIII undergoes oxidation to form a CoIV species. The large current is attributed to catalytic oxidation of HCO3 /CO3 2− to HCO4 . (iii) A process with very large currents at >1.2 V owing to the formation of CoV(CO3)3 , which oxidizes both water and HCO3 /CO3 2−. These processes depend on [CoII], [NaHCO3], and pH. Chronoamperometry at 1.3 V gives a green deposit. It acts as a heterogeneous catalyst for water oxidation. DFT calculations point out that Con(CO3)3 n−6, n=4, 5 are attainable at potentials similar to those experimentally observed.

Original languageEnglish
Pages (from-to)711-720
Number of pages10
JournalChemistry - A European Journal
Volume26
Issue number3
DOIs
StatePublished - 13 Jan 2020

Keywords

  • cobalt carbonate
  • density functional calculations
  • electrochemistry
  • peroxo-monocarbonate
  • water oxidation

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

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