Proton-Relaying Adsorbates Induce Non-Nernstian Behavior in Oxygen Reduction.

ABSTRACT: Proton-coupled electron transfer (PCET) is central to energy conversion processes in fuel cells, electrolysis, and biological systems. According to the Nernst equation, the equilibrium potential of PCET shifts by around -60 mV/pH relative to the standard hydrogen electrode at room temperature. Here, we reveal significant deviations from this expected Nernstian behavior in the oxygen reduction reaction (ORR) at Pt(111) in H2SO4/M2SO4 (M = Li, Cs) solutions, with a pronounced dependence on the cation identity, whereas Nernstian behavior is retained in HClO4/LiClO4 solutions. To elucidate the origin of these pH effects, we employ a hierarchical theoretical framework that integrates density functional theory calculations, multistep microkinetic modeling, and the local reaction environment (LRE

SUBMITTER: Zhang L 

PROVIDER: S-EPMC12362434 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature