Advancements and Design Strategies for Self-Supported Electrocatalysts Operating in Alkaline Conditions at High-Current-Density
Xiaoxiao Zhang, Xingyu Zhang, Lan Lin, Junjie Lao, Xin Yao
Abstract
Alkaline water splitting is one of the most mature sustainable hydrogen production methods. However, the overall efficiency of alkaline water electrolysis is significantly constrained by the anode oxygen evolution reaction, where the four-electron transfer process leads to slow reaction kinetics, limiting the achievement of efficient and cost-effective hydrogen production at high-current-density. Although substantial efforts have been made in the academic community to enhance the activity of electrocatalysts, challenges remain in achieving high activity and stability of catalysts at high-current-density. To address this challenge, self-supported transition metal catalysts have attracted increasing attention due to their high conductivity and structural stability. This paper first introduces the basic principles of water electrolysis from a thermodynamic perspective, then summarizes the main challenges faced by water electrolysis catalysts at high-current-density, and discusses the advantages of self-supported electrodes in this process. Subsequently, the paper outlines strategies for selecting efficient and stable electrocatalyst substrates and optimizing their performance. Finally, the article highlights the current bottlenecks in the transition of water-splitting electrocatalysts from laboratory research to industrial applications, identifies key challenges for the future, and provides an outlook on future development directions.