Exceptionally high proton conductivity in Eu₂O₃ by proton-coupled electron transfer mechanism.

ABSTRACT: Proton conductors are typically developed by doping to introduce structural defects such as oxygen vacancies to facilitate ionic transport through structural bulk conduction mechanism. In this study, we present a novel electrochemical proton injection method via an in situ fuel cell process, demonstrating proton conduction in europium oxide (Eu₂O₃) through a surficial conduction mechanism for the first time. By tuning Eu₂O₃ into a protonated form, H-Eu₂O₃, we achieved an exceptionally high proton conductivity of 0.16 S cm^-1. Distribution of relaxation time (DRT) analysis was employed to investigate the proton transport behavior and reveal the significant contribution of surface proton transport to the overall conductivity of Eu₂O₃. Remarkably, H-Eu₂O₃ exhibited a low activation energy for ionic transport, comparable to the best ceramic electrolytes available. The proton-coupled electron transfer (PCET) mechanism describes this novel surficial proton conduction mechanism. These findings provide new possibilities for developing advanced proton conductors with improved performance.

SUBMITTER: Wan S 

PROVIDER: S-EPMC10765062 | biostudies-literature | 2024 Jan

REPOSITORIES: biostudies-literature