Molecule Confined Isolated Metal Sites Enable the Electrocatalytic Synthesis of Hydrogen Peroxide

Abstract The direct synthesis of hydrogen peroxide (H 2 O 2 ) through the two‐electron oxygen reduction reaction is a promising alternative to the industrial anthraquinone oxidation process. Selectivity to H 2 O 2 is however limited by the four‐electron pathway during oxygen reduction. Herein, it is reported that aminoanthraquinone confined isolated metal sites on carbon supports selectively steer oxygen reduction to H 2 O 2 through the two‐electron pathway. Confining isolated NiN x sites under aminoanthraquinone increases the selectivity to H 2 O 2 from below 55% to above 80% over a wide potential range. Spectroscopy characterization and density functional theory calculations indicate that isolated NiN x sites are confined within a nanochannel formed between the molecule and the carbon support. The confinement reduces the thermodynamic barrier for OOH* desorption versus further dissociation, thus increasing the selectivity to H 2 O 2 . It is revealed how tailoring noncovalent interactions beyond the binding site can empower electrocatalysts for the direct synthesis of H 2 O 2 through oxygen reduction.