Support Engineering Strategy to Tackle the Trade-Off Between Catalytic Reactivity and H2O2 Selectivity in Electro-Oxygen Reduction

Direct electrochemical reduction of oxygen to hydrogen peroxide has garnered increasing research attention because of its mild and easy operation relative to the traditional anthra-quinone cycling route. However, currently used carbon supported noble metal electrocatalysts such as Pd and Pt in the form of single atoms or ultrafine nanoparticles greatly suffer from low reactivity and/or selectivity to hydrogen peroxide. We herein report that ultrafine ca. 1 nm Pd nanoparticles that are stabilized on a N and S co-functionalized car-bon support (Pd/NSC) display excellent reactivity and H2O2 selectivity toward electro-oxygen reduction reactions. Our support engineering strategy is expected to open up new opportunities to simultaneously attain high reactivity and H2O2 selectivity in electro-reductions of oxygen.