Enhancing water-dissociation kinetics and optimizing intermediates adsorption free energy of cobalt phosphide via high-valence Zr incorporating for alkaline water electrolysis

Developing high-efficiency electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is required to enhance the sluggish kinetics of water dissociation and optimize the adsorption free energy of reaction intermediates. Herein, we tackle this challenge by incorporating high-valence Zr into CoP (ZrxCo1−xP), which significantly accelerates the elementary steps of water electrolysis. Theoretical calculations indicate that the appropriate Zr incorporation effectively expedites the sluggish H2O dissociation kinetics and optimizes the adsorption energy of reaction intermediates for boosting the alkaline water electrolysis. These are confirmed by the experimental results of Zr0.06Co0.94P catalyst that delivers exceptional electrochemical activity. The overpotentials at the current density of 10 mA cm−2 (j10) are only 62 (HER) and 240 mV (OER) in alkaline media. Furthermore, the Zr0.06Co0.94P/CC||Zr0.06Co0.94P/CC system exhibits superior overall water splitting activity (1.53 V/j10), surpassing most of the reported bifunctional catalysts. This high-valence Zr incorporation and material design methods explore new avenues for realizing high-performance non-noble metal electrocatalysts.