UCLA

The hydrogen evolution reaction (HER) is one of the most fundamental and critical reactions in renewable energy conversion. The recent advancement in various platinum (Pt) nanocatalyst designs has led to greatly improved HER activity. It is well recognized that the HER kinetics is drastically slower in alkaline media compared to acidic media, but the descriptors of the HER kinetics are still elusive. Specifically, in the presence of alkali metal cations and hydroxyl anions, the electrode–electrolyte (platinum–water) interface in an alkaline electrolyte is far more complex than that in an acidic electrolyte. The effects of different alkali metal cations (AM+) and pH on these reactions are poorly understood due to a lack of suitable experimental methods. We are combining surface-sensitive electrical transport spectroscopy (ETS) with other electrochemistry techniques and computational studies to probe and understand the fundamental role of different AM+ and pH on the reaction kinetics of HER. Our study provides fundamental insights into how and why AM+ and pH influence the HER in alkaline media. We expect that this research will provide the molecular-level understanding that will shed new insights into electrolyte engineering as an alternative pathway to control electrochemical reaction kinetics.