Chloride-assisted catalytic water oxidation

Abstract

Rates of electrocatalytic water oxidation to oxygen by Ru(II) polypyridyl complexes are enhanced by added NaCl. Observations based on the single-site catalyst [Ru^II(Mebimpy)(bpy)(OH₂)]²⁺ (Mebimpy is 2,6-bis(1-methylbenzimidazol-2-yl)pyridine; bpy is 2,2′-bipyridine) at pH 7.0 in a phosphate buffer suggest a mechanism involving initial oxidation of the catalyst to Ru^V(O)³⁺ followed by Cl⁻ oxidation to HOCl. Once formed, HOCl is oxidized to O₂.