查看文章

Available methods to analyze proton conduction mechanisms cannot distinguish between two proton-conduction processes derived from the Grotthuss mechanism. The two mechanistic variations involve structural diffusion, for which water movement is indispensable, and the recently proposed “packed-acid mechanism,” which involves the conduction of protons without the movement of water and is typically observed in materials consisting of highly concentrated (packed) acids. The latter mechanism could improve proton conductivity under low humidity conditions, which is desirable for polymer electrolyte fuel cells. We proposed a method with which to confirm quantitatively the packed-acid mechanism by combining ²H and ¹⁷O solid-state magic-angle-spinning nuclear magnetic resonance (MAS-NMR) measurement and ¹H pulsed-field gradient (PFG)-NMR analysis. In particular, the measurements were …