Development of Li-Coated NiO Catalyst for Enhanced Alkaline Oxygen Evolution Reaction

Abstract

Oxygen evolution reaction (OER) properties of nickel oxide electrodes are improved by the transition of its oxidation state due to lithium incorporation. The high solubility of Li into the NiO electrode lattice structure synergistically enhances the average oxidation state of Ni^3+/2+ ions, improving the reaction kinetics on active sites. The optimal incorporation level of Li into NiO is found to be 10 wt.%. The cobalt and lanthanum coating catalysts exhibited inherent properties without synergistic improvement. The electrochemical analysis results using a rotating disk electrode (RDE) system indicated the lowest OER overpotential for 10 wt.% Li-incorporated catalyst (480 mV), compared with Co-coated (534 mV) and bard NiO (696 mV) catalysts. The obtained results are expected to improve the reaction kinetics of oxygen evolution catalysis using nickel oxide-based catalysts, specifically for clean and sustainable hydrogen production via alkaline electrolysis.