Perfect Is Perfect: Nickel Prussian Blue Analogue as A High‐Efficiency Electrocatalyst for Hydrogen Peroxide Production

Prussian blue analogues (PBA) are a large family of functional materials with diverse applications such as in electrochemical fields. However, their use in the emerging two‐electron oxygen reduction reaction for clean production of hydrogen peroxide (H 2 O 2 ) is lagging. Herein, a general solvent exchange induced reconstruction strategy is demonstrated, through which an abnormal NiNi‐PBA superstructure is synthesized as a high‐performance electrocatalyst for H 2 O 2 generation. The resultant NiNi‐PBA superstructure has a stoichiometric composition with saturated lattice water, and a leaf‐like morphology composed of interconnected small‐size nanosheets with identical orientation and predominate {210} side surface exposure. Our studies show that the Ni−N centers on {210} facets are the active sites, and the saturated lattice H 2 O favors a six‐coordinated environment that results in high selectivity. The “perfect” structure including stoichiometric composition and ideal facet exposure leads to a high selectivity of ~100 % and H 2 O 2 yield of 5.7 mol g −1 h −1 , superior to the reported MOF‐based electrocatalysts and most other electrocatalysts.