Nature Communications (Sep 2023)

Self-adaptive amorphous CoOxCly electrocatalyst for sustainable chlorine evolution in acidic brine

  • Mengjun Xiao,
  • Qianbao Wu,
  • Ruiqi Ku,
  • Liujiang Zhou,
  • Chang Long,
  • Junwu Liang,
  • Andraž Mavrič,
  • Lei Li,
  • Jing Zhu,
  • Matjaz Valant,
  • Jiong Li,
  • Zhenhua Zeng,
  • Chunhua Cui

DOI
https://doi.org/10.1038/s41467-023-41070-7
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 11

Abstract

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Abstract Electrochemical chlorine evolution reaction is of central importance in the chlor-alkali industry, but the chlorine evolution anode is largely limited by water oxidation side reaction and corrosion-induced performance decay in strong acids. Here we present an amorphous CoOxCly catalyst that has been deposited in situ in an acidic saline electrolyte containing Co2+ and Cl- ions to adapt to the given electrochemical condition and exhibits ~100% chlorine evolution selectivity with an overpotential of ~0.1 V at 10 mA cm−2 and high stability over 500 h. In situ spectroscopic studies and theoretical calculations reveal that the electrochemical introduction of Cl- prevents the Co sites from charging to a higher oxidation state thus suppressing the O-O bond formation for oxygen evolution. Consequently, the chlorine evolution selectivity has been enhanced on the Cl-constrained Co-O* sites via the Volmer-Heyrovsky pathway. This study provides fundamental insights into how the reactant Cl- itself can work as a promoter toward enhancing chlorine evolution in acidic brine.