Scalable neutral H(2)O(2) electrosynthesis by platinum diphosphide nanocrystals by regulating oxygen reduction reaction pathways

Despite progress in small scale electrocatalytic production of hydrogen peroxide (H(2)O(2)) using a rotating ring-disk electrode, further work is needed to develop a non-toxic, selective, and stable O(2)-to-H(2)O(2) electrocatalyst for realizing continuous on-site production of neutral hydrogen peroxide. We report ultrasmall and monodisperse colloidal PtP(2) nanocrystals that achieve H(2)O(2) production at near zero-overpotential with near unity H(2)O(2) selectivity at 0.27 V vs. RHE. Density functional theory calculations indicate that P promotes hydrogenation of OOH* to H(2)O(2) by weakening the Pt-OOH* bond and suppressing the dissociative OOH* to O* pathway. Atomic layer deposition of Al(2)O(3) prevents NC aggregation and enables application in a polymer electrolyte membrane fuel cell (PEMFC) with a maximum r(H(2)O(2)) of 2.26 mmol h(−1) cm(−2) and a current efficiency of 78.8% even at a high current density of 150 mA cm(−2). Catalyst stability enables an accumulated neutral H(2)O(2) concentration in 600 mL of 3.0 wt% (pH = 6.6).