Recent advances in Ni-based electrocatalysts for low-energy hydrogen production via alternative pathways to water electrolysis

Energy-efficient water electrolysis is one of the most promising techniques for generating green hydrogen as a carbon-free energy source. As a half-reaction of water splitting, the oxygen evolution reaction is kinetically sluggish, leading to large thermodynamic potential gaps compared to the hydrogen evolution reaction. In terms of cost-effective hydrogen generation, mitigating this overpotential is a challenging obstacle, but it remains a hurdle to overcome. It is necessary to advance energy-saving hydrogen production by substituting with an oxygen evolution reaction as a thermodynamically favorable anodic reaction. Additionally, depending on the specific small molecules used for the anodic oxidation reaction, it is possible to reduce environmentally harmful substances and produce value-added chemicals. Nickel-based electrocatalysts have received growing attention for their application in electrochemical reactions due to their affordability, versatility in structural tuning, and ability to function as active sites for bond formation and cleavage. The purpose of this paper is to probe how the morphology, structure, and composition of these catalysts affect the electrocatalyst performance for small molecule oxidation. Explaining these relationships can accelerate the development of sustainable hydrogen production techniques by identifying the design principles of high-performance nickel-based electrocatalysts.