Promoting H2O2 Production Via 2-Electron Oxygen Reduction By Coordinating Partially Oxidized Pd with Defect Carbon

Electrochemical synthesis of H₂O₂ via 2e^− oxygen reduction reaction (ORR) is a cost efficient and environmentally friendly alternative to the industrial anthraquinone oxidation method In this study, we show that Pd clusters loaded in oxidized carbon nanotubes has supreme activity and selectivity towards H₂O₂ synthesis in acidic media. We calculated the ground state geometry of modeled structures with epoxy functional group and most stable O*/HO* covered Pd nano clusters with varying sizes using DFT methods. The results are summarized in a Sebatier principle-based activity volcano plot. Herein, the calculated limiting potential (U_L) is used an activity descriptor. The results show that the calculated U_L approaches to maximum values in the presence of epoxy functional groups. Our calculations suggest that there is a synergistic effect between Pd and oxygen functional groups in oxidized carbon which enables efficient H₂O₂ formation. Finally, the selectivity towards H₂O₂ formation is reported to be 98% in acidic media with an activity comparable with the state of art Pd/Hg alloy.