Mitigating greenhouse gas emissions in the energy and chemical industries requires a transition from current fossil fuel-based thermochemical processes to carbon emission-free electrochemical processes. Given its abundance, atmospheric molecular oxygen is an attractive oxidant for the generation of electricity from chemical fuels (such as H2 or methanol in fuel cells or metals like Zn, Fe, or Al in metal-air batteries ) or for the distributed on-site electrochemical production of hydrogen peroxide. In aqueous systems at room temperature, these separate applications require different selectivity in the terminal product of oxygen reduction, where generating hydrogen peroxide terminates at a net 2-electron/2-proton reduction (hydrogen peroxide production reaction, HPPR: O2 + 2H + + 2e -⇌ H2O2, E 0 = 0.695 V vs. SHE) and fuel cell or metal-air battery applications ideally reduce oxygen to water through a net 4-electron/4-proton process (oxygen reduction reaction, ORR: O2 + 4H + + 4e -⇌ 2H2O, E 0 = 1.23 V vs. SHE).