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 (H2O2) 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 H2O2 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 H2O 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 H2O2 yield of 5.7 mol g−1 h−1, superior to the reported MOF‐based electrocatalysts and most other electrocatalysts. A general solvent exchange induced reconstruction strategy is developed for the synthesis of unusual NiNi‐PBA superstructures as a high‐efficiency 2e‐ORR electrocatalyst. The perfect stoichiometric composition with saturated lattice water and {210} dominated facet exposure of NiNi‐PBA collaborately lead to a high 2e‐ORR selectivity of 100 % and H2O2 yield of 5.7 mol g−1 h−1.