2,2’-Dipyridylamine as Heterogeneous Organic Molecular Electrocatalyst for Two-Electron Oxygen Reduction Reaction in Acid Media
Continuous production of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) through the two-electron oxygen reduction reaction (2e-ORR) in distributed electrochemical cells offers important advantages for point-of-use water treatment and pulp bleaching over the complex industrial anthraquinone process. A low-cost, heterogeneous 2e-ORR electrocatalyst with high activity and selectivity is key to meeting the future needs for distributed production of H<sub>2</sub>O<sub>2</sub> with large capacity. Herein, we demonstrate high activity and selectivity of a new heterogeneous organic molecular electrocatalyst, 2,2’-dipyridylamine, with an H<sub>2</sub>O<sub>2</sub> yield of <i>ca.</i> 80%, and an onset potential of <i>ca.</i> 0.60 V <i>vs.</i> RHE in acidic aqueous electrolyte. We show that this acid-compatible, inexpensive, small organic molecule can catalyze 2e-ORR as efficiently as the state-of-the-art catalysts based on mercury-precious metal alloys. We propose different mechanisms of dioxygen electroreduction based on density functional theory calculations, which correlate activity with calculated standard reduction potential of reaction intermediates.
