Insights into Kinetics of Temperature-Modulated Water Electrolysis Using Layered Double Hydroxides Electrocatalyst for Hydrogen Generation.

To claim the real-world applications of electrocatalysts in water electrolysis, evaluating their performance at elevated temperatures is imperative. Variations in the operational temperature of water electrolyzers directly impact the reaction kinetics, electrolyte conductivity, and thermodynamic aspects of surface adsorption. This governs the efficiency of hydrogen and oxygen production. In this work, compared to room temperature, the overpotential of the trimetallic layered double hydroxide (LDHs) based nanocatalysts for the oxygen evolution reaction and hydrogen evolution reaction is significantly reduced by 20% and 10%, respectively, at 55°C. The reasons for performance loss beyond this temperature are also elucidated. In-depth density functional theory calculations establish the role of Cu-doping on formation energy, charge density, and density of states of pristine NiCo-LDH. The values of these electronic and thermodynamic parameters play an important role in deciding the applications of an electrocatalyst in advanced electrolyzers.