Cation effects in electrocatalytic reactions have attracted considerable interest due to their role in modulating reaction kinetics and mechanisms. Here, the authors use constant-potential density functional theory and ab initio molecular dynamics simulations to study the atomic-scale synergy between Na+ ions and stepped Pt(311) surfaces in the alkaline hydrogen evolution reaction, reporting the formation of a Pt–H2O–Na+(H2O)ₓ adduct at the step edges that positions cations closer to the surface compared to Pt(111) terraces, resulting in a lower Volmer step activation energy.
- Qingqing Zhang
- Pengfei Sun
- Zhiyao Duan