The Platinum Standard: A d -Band-Centric Review of Pt-Based Catalysts for the Hydrogen Evolution Reaction

Abstract

Hydrogen is a key component of emerging energy systems due to its high energy density and versatility as a fuel and chemical feedstock. However, most molecular hydrogen is produced from fossil-fuel-based processes, increasing our reliance on volatile commodities. Electrochemical hydrogen generation via the hydrogen evolution reaction (HER) offers a promising route for energy storage and diversification. Platinum (Pt)-based materials exhibit the highest intrinsic HER activity and have become widespread in commercial electrolyzers; however, their scarcity necessitates strategies to maximize utilization. This focused review examines recent advances in Pt-based electrocatalysts through the framework of d-band theory, a powerful model for investigating surface–adsorbate interactions. We summarize key theoretical concepts and explore catalyst designs ranging from bulk surfaces to atomically dispersed systems, along with emerging approaches such as hydrogen spillover and high-entropy alloys (HEAs). By analyzing these developments through the lens of d-band theory, this work defines its scope and limitations and provides practical guidance for its appropriate application in understanding and designing Pt-based HER catalysts.