The Interfacial Proton-Transfer Pathway Boosted Acidic Oxygen Evolution

Abstract

Developing efficient and durable acidic oxygen evolution reaction (OER) catalysts for the proton exchange membrane water electrolyzer (PEMWE) is made challenging by sluggish proton transfer. Here, we engineer a fluorinated carbon-coated Co3O4 (F/C–Co3O4) interface based on a “fluorinated-moiety-clothed” concept to promote both deprotonation and interfacial proton transport. Operando spectroscopy and density functional theory calculations indicate that a fluorine species deprotonates OER intermediates through strong electronegative interactions, lowering the free energy barrier by 0.43 eV. More importantly, the released protons are rapidly transported through a continuous hydrogen bond network formed between the F/C and electrolyte, thereby accelerating proton migration while suppressing acid-induced corrosion of Co3O4. As a result, F/C–Co3O4 shows an exceptionally low overpotential of 360 mV at 10 mA cm–2 and remains stable for 170 h in 0.5 M H2SO4. This work presents a molecular strategy for engineering proton-transfer pathways, offering insights into simultaneously achieving high activity and acid stability in non-precious metal OER catalysts.