Cu‐doped Ba_0.5Sr_0.5FeO_3‐δ for electrochemical synthesis of hydrogen peroxide via a 2‐electron oxygen reduction reaction¹

AbstractElectrochemical synthesis of hydrogen peroxide (H2O2) via a two‐electron (2e–) oxygen reduction reaction (ORR) has emerged as a sustainable synthesis route compared to the anthraquinone oxidation synthesis process. Ba0.5Sr0.5Fe(1‐x)CuxO3‐δ perovskite is a particularly interesting electrocatalyst for ORR applications owing to its doping flexibility. In this study, we use experimental and computation approaches to study Ba0.5Sr0.5FeO3‐δ with and without copper doping at the B‐site for 2e– ORR. Our electrochemical measurements in oxygen‐saturated alkaline solution show that the selectivity of perovskite electrocatalyst increases from 30% to 65% with (0.05) copper doping in the B‐site and the onset potential is decreased. Density functional theory calculations are used to unravel the role of copper in driving high activity and selectivity toward 2e– ORR. Site‐specific engineering of Ba0.5Sr0.5FeO3‐δ by copper doping in the B‐site exposed unique adsorption sites with improved activity and selectivity for H2O2 formation.