Promoting Hydrogen Evolution Reaction in Acidic and Neutral Conditions on Co-Based Ternary Electrocatalyst: Enhancing Catalytic Activity via Electrochemical Oxidation

Abstract

Water electrolysis presents significant potential for the sustainable production of green hydrogen. However, its widespread adoption faces several challenges, primarily the high cost and limited availability of Pt-group metal catalysts. To address this challenge, researchers have investigated high-performance catalysts based on affordable transition metals. One such catalyst that has attracted attention is CuCoMo, known for its notable activity and stability in the hydrogen evolution reaction (HER) under alkaline conditions. In this study, we presents an electrodeposited CuCoMo catalyst that is also effective for HER under both acidic and neutral conditions. The catalytic performance was significantly enhanced through electrochemical oxidation. This post-treatment process alters the structure and chemical state of the catalyst surface, enhancing its effectiveness in promoting HER under acidic and neutral environments. The modified catalyst demonstrated overpotentials of 25 and 28 mV, achieving a current density of 10 mA cm^–2 in acidic and neutral conditions, respectively. Furthermore, the catalyst’s performance was assessed in a single cell, where it achieved a current density of 1.05 A cm^–2 at 2.0 V using deionized water as the feedstock. The catalyst exhibited superior HER activity in both half-cell and single-cell evaluations, highlighting its potential as efficient alternative to Pt for practical water electrolyzers.