Efficient homogeneous electrocatalytic hydrogen evolution using a Ni-containing polyoxometalate catalyst

Abstract

NiCl2·6H2O ([Ni(H2O)6]2Cl2)per sedoes not show electrocatalytic hydrogen evolution reaction activity (HER) in an acidic aqueous medium as well as in neutral water. Interestingly, when [Ni(H2O)6]2+is present in a polyoxovanadate matrix, for example, in the compound K2[Ni(H2O)6]2[V10O28]·4H2O (1), it exhibits homogeneous electrocatalytic HER activity in an acidic aqueous solution with a turn over frequency of 2.1 s−1and an effective low overpotential of 127 mV at pH 2.3. Compound1is the first nickel-containing polyoxometalate catalyst for hydrogen productionviahomogeneous electrocatalytic proton reduction without its decomposition under electrochemical conditions of HER.