Dynamic regulation of ionomer/catalyst interface via alcohol coordination engineering: Toward high–efficiency proton and oxygen transport in proton exchange membrane fuel cells

Abstract

To bolster the proliferation of proton exchange membrane fuel cells (PEMFCs), the development of high–performance, low–platinum PEMFCs is imperative. Based on interface alcohol coordination engineering, this study systematically investigates the structure–activity relationships of alcohol additives and their impact on the ionomer/catalyst interface from microscopic interactions to macroscopic catalyst layer (CL) changes. The findings reveal that the alcohol engineering modulates the ionomer/catalyst interface distribution through the coordination with −SO₃H groups, thus improving the O₂ and proton transport capacity of the CL. Tert–heptanol, with its most alkaline structure, forms the strongest coordination with ionomers, resulting in the most notable improvements in a 25.23 % increase in peak power density under H₂–Air conditions. In the optimized tert–heptanol system, peak power densities reach 0.93 W cm⁻² under H₂–Air and 2.49 W cm⁻² under H₂–O₂, with an impressively low O₂ transport resistance of 10.9 s m⁻¹. These insights will inform future ionomer/catalyst interface designs for PEMFCs and related technologies.