The effect of calcination temperature on the electrocatalytic activity of Ni-Co-Ir-oxide and Ni-Co-Ru-oxide anodes in the oxygen evolution reaction in alkaline medium

The influence of calcination temperature on the electrocatalytic properties of thermally-prepared (Ni0.4Co0.6)(0.90)Ir-0.10 oxide and (Ni0.4Co0.6)(0.90)Ru-0.10 oxide in the oxygen evolution reaction (OER) was investigated in an alkaline medium. It was shown that by lowering the calcination temperature, the OER activity of the two materials increased significantly, yielding a maximum at 300 degrees C. The increase in electrocatalytic activity of the oxides was related to the change in intrinsic properties of the anodes, predominantly to the modification of the electronic structure and to the increase in hydroxide content. The (Ni0.4Co0.6)(0.90)Ir-0.10-oxide was found to significantly outperform the current state-of-the-art OER electrocatalyst, pure Ir-oxide, while the electrocatalytic activity of (Ni0.4Co0.6)(0.90)Ru-0.10-oxide was measured to be much higher than that of the Ni0.4Co0.6-oxide base, thus demonstrating the synergistic action of Ni/Co/Ir and Ni/Co/Ru in their oxides.