Hydrogen production by water electrolysis is the most widely used because of its low energy consumption, environmental friendliness and high purity. In water electrolysis, electrode overpotential is the main reason for the increase in power consumption. Therefore, lowering overpotential at the anode where oxygen evolution reactions occur is one of the ways to reduce the cost of hydrogen production. Lowering the electrode overpotential is also important for other electrochemical devices such as fuel cells in addition to water electrolysis. To solve this problem, it is important to develop an electrode catalyst with low electrode overpotential, high conductivity, high corrosion resistance and low cost. In addition, it is necessary to enhance the catalytic activity and stability of the electrode by providing high bonding ability between the catalyst layer and the collector.
IrO2 and RuO2 have been recognized as the most efficient oxygen evolution reaction catalyst in alkaline water electrolysis, but they are scarce and expensive. Hence, there has been a study to develop a non-precious metal electrocatalyst with high oxygen evolution reaction activity and stability and to improve the electrode performance in water electrolysis by enhancing the bonding ability between the catalyst layer and the collector.
Kim Sol Song, a researcher at the Institute of Nano Science and Technology, on the basis of the previous studies, has proposed a method of preparing NiCo2O4 electrocatalytic nano powder of spinel structure and combining it with a nickel foam support using polytetrafluoroethylene (PTFE) binder so as to enhance the performance of the oxygen evolution reaction electrode in alkaline water electrolysis. In addition, he has determined the content of the binder for not reducing the oxygen evolution reaction catalyst performance of the electrodes while enhancing the bonding ability between the catalyst powder and the support.
He has found that the onset potential of oxygen evolution reaction of the catalytic electrode reaches the standard when the content of the PTFE binder is about 20%, and that the potential changes are small and the catalytic electrode is stable in the continuous operation test for 12 hours.
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