Research Progress and Prospects of Prussian Blue Analogs and Their Derivatives in Small-Molecule Oxidative Coupled Hydrogen Production.

In conventional water electrolysis for hydrogen generation, the four-electron transfer mechanism of the oxygen evolution reaction (OER) induces kinetic sluggishness. This sluggishness results in substantial overpotentials and subpar energy conversion efficiencies. Electrochemical small-molecule oxidation reactions possess inherent thermodynamic advantages, thereby effectively reducing the overall operating voltage of the electrolyzer. This voltage reduction provides a novel pathway to overcome the bottleneck imposed by OER kinetics. Prussian blue analogues and their derivatives, which feature tunable metal centers and open cubic framework structures, represent ideal platforms for constructing efficient coupled catalytic systems. This review systematically summarizes their synthetic methods, the influence of electronic structures on catalytic activity, and corresponding optimization strategies, with a specific focus on applications in small-molecule oxidation-assisted hydrogen production. Furthermore, an in-depth analysis of current challenges is presented, and future research directions are outlined. The goal is to provide a theoretical foundation and technical reference for advancing green hydrogen energy technology toward practical breakthroughs.