Kang Li, Tianxiang Chen, Shilin Zhang, Siyuan Su, Mingkai Liu, Huiru Xie, Haoxiang Cui, Yuxuan Qie, Xinming Nie, Yan Yan
ABSTRACT Hydrogen production via water electrolysis is a key solution to the global energy crisis. Platinum‐group catalysts, while highly efficient for the hydrogen evolution reaction (HER), are limited by their scarcity and high cost, restricting their industrial application. Nanoalloy electrocatalysts (NAEs) have emerged as promising alternatives due to their adjustable electronic structures, high conductivity, and synergistic active sites. However, they still face challenges in balancing activity and stability, as well as in reaction kinetics. Research shows that precision doping can enhance NAEs' performance by tailoring electronic configurations, optimizing adsorption energetics, and exposing latent active sites. This review explores the mechanistic basis of these doping effects by examining HER mechanisms in acidic and basic media. It systematically categorizes and summarizes doping methods, dividing dopants into noble metals, non‐noble metals, and non‐metals, and detailing their roles and characteristics. A “Relative Improvement (RI)” metric is introduced to quantitatively benchmark performance gains. The review also delves into emerging frontiers like operando characterization, circular catalyst design, and integration with alternative anodic reactions. By highlighting atomic‐level doping as crucial for next‐generation electrolyzers, this review aims to advance economically viable green hydrogen production.