Theory of Electro-Ionic Perturbations at Supported Electrocatalyst Nanoparticles

TL;DR

This paper introduces a semiclassical model to analyze electrochemical properties of supported electrocatalyst nanoparticles, revealing support-induced charge perturbations and surface charging trends validated by first-principles calculations.

Contribution

The study presents a novel semiclassical model capturing electronic and ionic equilibration in supported nanoparticles, highlighting support effects on surface charge and potential differences.

Findings

Support causes significant perturbations in charge densities.

Surface potentials can differ by more than 0.5 V due to support effects.

Model validated against first-principles calculations.

Abstract

Nanoscopic heterogeneities in composition and structure are quintessential for the properties of electrocatalyst materials. Here, we present a semiclassical model to study the electrochemical properties of supported electrocatalyst nanoparticles (NP). The model captures the correlated electronic and ionic equilibration across NP, support, and electrolyte. It reveals peculiar trends in surface charging of the supported NP, validated by comparison with first-principles calculations. Support-induced perturbations in electronic and ionic charge densities at the NP's active surface manifest as distinct potentials of zero local electronic and ionic charges that could differ by more than 0.5 V in the studied system.