Polymer-Scaffold Induced Extensive Hydrogen-Bond Network: Enabling High Transport of Proton and Oxygen in Cathode Catalyst/Ionomer Interfaces.

Uneven ionomer coverage in the cathode catalyst layer of proton exchange membrane fuel cells (PEMFCs) impedes proton conduction and oxygen diffusion, particularly at low platinum loadings. Here, a functionalized polymer-scaffold is designed and constructed by using hydroxy-pyridine polybenzimidazole (PyOHPBI) with abundant hydrogen-bond sites, thereby proposing a hydrogen-bond synergistic strategy to address the challenges of optimizing ionomer distribution and enhancing the transport of protons and gas through the catalyst layer. By integrating molecular dynamics simulations, in situ and ex-situ characterization methods, the design achieves 144.