Pt-based electrocatalyst for hydrogen evolution in acidic electrolytes

Platinum (Pt) based electrocatalysts remain the gold standard for the hydrogen evolution reaction (HER) in acidic environments due to their optimal hydrogen adsorption-free energy (ΔG_H⁎ ≈ 0), high electrical conductivity, and superior chemical stability. However, the scarcity and high cost of Pt necessitate innovative strategies to reduce Pt loading while enhancing catalytic efficiency and long-term durability. This review systematically presents the recent advancements in Pt-based HER electrocatalysts, emphasizing mechanistic insights across the Volmer, Heyrovsky, and Tafel steps, and explores the influence of Pt’s electronic structure and nanostructuring on HER kinetics. Strategies such as alloying with transition metals (e.g., Ni, Co, Zn), developing single-atom catalysts (SACs), and engineering hybrid systems with supports like MXenes, graphene aerogels, and metal carbides are discussed in detail. These approaches optimize active site exposure, electronic modulation, and catalyst-support interactions to achieve high turnover frequencies, low overpotentials, and enhanced electrochemical stability under industrially relevant conditions. The review further highlights key performance indicators such as Tafel slope, mass activity, TOF, and stability, along with advanced synthesis methods, including atomic layer deposition and microwave-assisted reduction. Finally, current challenges in scalability, degradation resistance, and cost-performance trade-offs are evaluated, providing future directions toward sustainable, high-performance HER systems based on Pt. This comprehensive analysis aims to bridge the gap between fundamental catalyst design and practical hydrogen production technologies.