Nitrile-Facilitated Proton Transfer for Enhanced Oxygen Reduction by Hybrid Electrocatalysts

Abstract

To enable efficient energy conversion schemes for our society in the future, breakthroughs in precise thermodynamic and kinetic control of the underlying redox reactions are necessary. Hybrid bilayer membranes (HBMs), comprising a self-assembled monolayer (SAM) covered by a lipid membrane, have been developed recently to regulate the performance of HBM-embedded electrocatalysts. A major technological roadblock in HBM development is the inability to facilitate proton transfer under alkaline conditions where nonprecious metal (NPM) catalysts can rival the performance of their precious metal counterparts. Here, we synthesized proton carriers bearing nitrile groups found in protonophores. These bioinspired proton carriers can facilitate transmembrane proton delivery to an HBM-supported Cu oxygen reduction reaction (ORR) catalyst under alkaline conditions. Our stimuli-responsive proton regulators can turn on the activity of the ORR catalyst on-demand, thereby opening doors to investigate how proton transfer kinetics govern the performance of electrocatalysts for renewable energy conversion processes.