The Survey Of Activated Cathode For Alkaline Water Electrolysis

The alkaline water electrolysis technology is mature according with theenvironmental protection requirements in the current hydrogen production, however,its application has been limited because of higher energy consumption. Generally,electrodes with high electro catalytic activity and long service life are considered to beas solution to reducing energy consumption.The plate surface of metal electrodes were electroplated to transform commonmetal electrodes into composite alloy electrodes during alkaline water electrolysis toproduce hydrogen, which can reduce overpotential of hydrogen evolution and finallyleads to a decrement in energy consumption.This paper discussed the electrodeposition method for Ni-Mo-S ternary alloyelectrode. We investigate the impact of the content of Sulfur source and Molybdenumsource and electroplating current density of Nickel-Sulfur and Nickel-Molybdenumrespectively during the preparation for electrodes and the temperature of electrolytesolution on the electrode activity. The results show that, the content of Sulfur sourceand the changes in the current density of Nickel-Sulfur plating stage affected theoverpotential of hydrogen evolution more than that of Nickel-Molybdenum platingstage did. We got the best plating conditions with30g L-1thiourea and25g L-1sodium molybdate in plating solution, the electroplating current density24mA cm-2ofNickel-Sulfur electroplating stage,24mA cm-2of Nickel-Molybdenum electroplatingstage and40°C for electrolyte solution.The prepared Ni-Mo-S cathode did have excellent HER activity, but long termelectrolysis test showed that its coatings came off easily and cell voltage soared. Tofind better novel composite cathode, we investigated Ni-S-Zn, Ni-P-S and Ni-P-Zncathodes. The characterization revealed that the Ni-P-Zn-40°C cathode showed lowand steady cell voltage during long term electrolysis test.Ni-S-Zn cathode was selected out of the novel composite cathodes for furtherresearch. The results showed that the best plating conditions are30g L-1thiourea and10g L-1zinc chloride in plating solution, the electroplating current density24mA cm-2of Nickel-Sulfur electroplating stage,24mA cm-2of Nickel-Zinc electroplatingstage and40°C for electrolyte solution.