High-performance ionomerless cathode anion-exchange membrane fuel cells with ultra-low-loading Ag–Pd alloy electrocatalysts

Rapid translation of catalysts from fundamental studies to high-performance devices could facilitate the development and commercialization of anion-exchange membrane fuel cells (AEMFCs). Traditionally, translation from material screening in three-electrode rotating disk electrode cells to AEMFCs is complicated by differences in microenvironments, for example, solid ionomer/membrane vs liquid electrolyte. Here we introduce a platform for translation to devices that utilizes ionomerless ultra-low-loading Ag–Pd alloy electrocatalyst cathodes synthesized by co-physical vapour deposition. Our ionomerless cathodes allow for systematic H2–O2 AEMFC experiments while demonstrating comparable activity trends to those in three-electrode cells. Furthermore, we show that our Ag10Pd90-based AEMFC reaches a peak power density of ∼1 W $${\rm{cm}}_{\rm{geo}}^{-2}$$ cm geo − 2 (geometric area basis) and ∼10 W $${\rm{mg}}_{\rm{PGM}\; \rm{Cathode}}^{-1}$$ mg PGM Cathode − 1 , satisfying the US Department of Energy’s platinum group metal (PGM) loading and cost targets. Our approach shows promise in facilitating the rapid translation between three-electrode studies and AEMFCs, offering a simple and effective design for decreasing PGM loadings.