Redox Non‐Innocent Ligand Assisted Electrocatalytic Water Oxidation Catalyzed by a Molecular Cobalt Complex

Abstract Redox‐non innocent ligands play a crucial role in multielectron catalysis by participating in oxidation or reduction processes. High‐valent metal ions are often involved in oxidative catalysis, such as the water oxidation (WO) reaction, acting as a site for electron extraction from the substrate. Redox‐active ligands featuring multiple electron transfer centers can serve a similar function in catalysis. In this study, we explore the electrocatalytic WO reaction using a molecular Co III complex ( 1 ) that incorporates a bis‐pyridine‐dioxime ligand scaffold. This complex acts as a homogeneous electrocatalyst for WO in phosphate buffer solution (PBS) over a wide pH range. At pH 7, 1 demonstrated an overpotential of ∼590 mV and a turnover frequency of 16 s⁻¹. We propose that the oxime and C 6 H 5 –NR 2 arm of the ligand function as a redox cofactor, facilitating the catalysis and highlighting an important strategy for developing WO catalysts. However, in a borate buffer solution (BBS) degradation of 1 was noted accompanied by the deposition of B/CoO x material on the working electrode.