The role of carbonate in electro-catalytic water oxidation by using Ni(1,4,8,11-tetraazacyclotetradecane)2+

Abstract

NiL_i²⁺ are good electro-catalysts for water oxidation in phosphate or carbonate buffers. The results point out that the active oxidizing agents are L(X)Ni^IVOH^{4−(3−n+1)/(2−n+1)}, where X = PO₄H_n⁽³⁻ⁿ⁾⁻ or CO₃H_n⁽²⁻ⁿ⁾⁻ formed from LNi^IVX₂via a mechanism involving an acid catalyzed O–P or O–C bond heterolysis. Carbonate behaves differently from phosphate as it is a non-innocent ligand and it can be oxidized.