(A) study on Ni-alloy electrocatalysts prepared by electrodeposition for water electrolysis

Abstract

Massive utilization of fossil fuels has raised concerns about the possibility of depletion of fossil fuels and is accompanied by enormous environmental risk such as pollutant gas emission, climate change, and waste generation. For reducing the use of fossil fuels, power generation using renewable types of energy, such as solar and wind power, has been drawing much attention. However, the nature of intermittent renewable energy, inability to operate independently of energy demand, remains a challenge. Thus, to address the intermittency of power plants using renewable sources, it is necessary to incorporate an energy storage system that stores excess electricity. Water electrolysis is one of the most promising systems which produce hydrogen using surplus electricity. Water electrolysis is the decomposition of water into oxygen and hydrogen using electricity. To establish a more ideal energy storage system for surplus electricity from renewable energy, the cell efficiencies of alkaline and PEM electrolysis systems should be increased. One of the main factors reducing the efficiency of electrolysis systems is the overpotential required in addition to the theoretical potential at both cathode and anode. To increase the efficiency of electrolysis system, the nickel-based non-precious metal catalysts synthesized by an electrodeposition with high catalytic activity and durability have been studied in this dissertation. The studies not only provide a practically applicable method to prepare HER and OER electrodes for use in industrial water electrolysers (alkaline, PEM electrolysis), with insight into the activities of the catalysts.