Design principles of electrocatalysts for energy-saving hydrogen production assisted by electrochemical oxidation of small molecules

Electrochemical water splitting represents a highly promising technology for high-purity hydrogen production. By replacing the kinetically sluggish anodic oxygen evolution reaction (OER) with a thermodynamically more favorable oxidation reaction, energy-efficient hydrogen generation can be achieved. This thermodynamic superiority provides the fundamental driving force for energy saving. Significant research efforts have been devoted to designing advanced electrocatalysts for small-molecule oxidation that not only improve reaction kinetics but, more fundamentally, optimize the adsorption free energy of reactive intermediates to minimize the practical overpotential. To gain deeper insights into the current progress and future directions of small-molecule electrochemical oxidation reaction (SMOR) assisted hydrogen production, this review systematically summarizes optimization strategies for electrocatalysts, spanning active sites, electrochemical interfaces, electron transfer pathways and d-band center modulation to maximize their catalytic performance in small-molecule oxidation reactions. Moreover, this review highlights innovative design strategies for high-performance SMOR electrocatalysts, addressing the distinct challenges associated with different reaction systems. It further outlines future research directions for catalyst development and identifies key areas requiring deeper investigation.