Beyond the Catalyst: Mechanistic Insights and Applications of Cation Effects in Alkaline Hydrogen Evolution Reaction

High Resolution Image Download MS PowerPoint Slide The electrochemical hydrogen evolution reaction (HER) is crucial to various sustainable energy applications. In addition to the intrinsic catalytic ability of the electrocatalysts, recent studies have highlighted the pivotal role of alkali metal cations (AMCs) in modulating HER activity through various interfacial interactions. This review provides a comprehensive overview of the current understanding of cation effects in alkaline HER. We first review key experimental observations, including the influence of cation identity, electrode materials, and electrolyte environments on HER kinetics. Mechanistic insights proposed to explain these cation effects are then discussed. Recent advances in catalyst design strategies that utilize cation effects to enhance alkaline HER performance are also summarized. Finally, we highlight key challenges and propose future research directions, emphasizing the need for a deeper molecular-level understanding of cation-mediated interfacial phenomena to unlock opportunities in electrocatalyst development.