A waveguide kinetics framework for electrochemical polarization

Abstract

The hydrogen evolution reaction (HER) and the hydrogen oxidation reaction (HOR) constitute the core electrochemical processes in a wide array of clean energy technologies, including but not limited to, water-splitting systems and fuel cells. However, the HER and HOR exhibits an anomalous, non-Nernstian pH dependence that has motivated competing mechanistic narratives yet still lacks a unified, transferable, and quantitatively predictive description across conditions. Here, we introduce a theory-neutral waveguide kinetics framework that reinterprets the polarization curve as a power-flow-like response, enabling a compact modal representation of interfacial kinetics. Without presuming any specific mechanism, the model quantitatively fits four representative polarization datasets historically explained by divergent theories. From each fit, we extract interpretable diagnostics, including a reflection amplitude and a useful-output density, that provide transferable metrics for interfacial efficiency. The framework thus establishes a mechanism-neutral computational diagnostic platform for mechanistic triangulation and operating-regime diagnosis of hydrogen electrocatalysts across the pH spectrum. The hydrogen evolution reaction (HER) and the hydrogen oxidation reaction (HOR) exhibit an anomalous, non-Nernstian pH dependence that has motivated competing mechanistic narratives, however, a unified, transferable, and quantitatively predictive description across conditions remains underexplored. Here, the authors introduce a theory-neutral waveguide kinetics framework that reinterprets the polarization curve as a power-flow-like response, enabling a compact modal representation of interfacial kinetics, and show that the model quantitatively fits four representative polarization datasets traditionally explained by divergent theories.