Synthesis and studies of a molecular copper(I)-triazenido electrocatalyst for catalyzing hydrogen evolution from acetic acid and water

The reaction of 1-[(2-carboxyethyl)benzene]-3-[benzothiazole]triazene (HL) and CuCl gives a trinuclear copper(I) complex, [CuI3(L)(L′)2]·THF (1·THF) (L′ = the 1-[(2-carboxymethyl)benzene]-3-[benzothiazole]triazene ion), which has been structurally characterized by X-ray crystallography. Electrochemical studies indicate that this complex can catalyze hydrogen evolution from a neutral buffer with a turnover frequency of 355 (pH 7) moles of hydrogen per mole of catalyst per hour at an overpotential of 789 mV vs SHE. Sustained proton reduction catalysis occurs at a glassy carbon (GC) electrode to give H2 over a 72 h electrolysis period with 94.4% Faradaic yield and no observable decomposition of the catalyst.