Designing Atomic Active Centers for Hydrogen Evolution Electrocatalysts

The evolution of hydrogen from water using renewable electrical energy is a topic of current interest. Pt/C exhibits the highest catalytic activity for the H₂ evolution reaction (HER), but scarce supplies and high cost limit its large-scale application. Atomic active centers in single-atom catalysts, single-atom alloys, and catalysts with two atom sorts exhibit maximum atomic efficiency, unique structure, and exceptional activity for the HER. Interactions between well-defined active sites and supports are known to affect electron transfer and dramatically accelerate the reaction. This Review first highlights methods for studying atomic active centers for the HER. Then, active sites with different coordination configurations are described. Active centers with one metal atom, two different metal atoms as well as nonmetal atoms are analyzed at the atomic scale. Finally, future research perspectives are proposed.