Unified Mapping of Multi-Site Electrocatalytic Activity Using a Single Descriptor

TL;DR

This paper introduces a unified, physics-based mapping method for electrocatalytic activity across multiple sites, accounting for interactions and heterogeneity, enabling better material screening.

Contribution

It develops a reduced descriptor framework that captures complex multi-site interactions and heterogeneity in electrocatalysts, extending Sabatier analysis.

Findings

The method explicitly incorporates lateral adsorbate interactions.

It reveals multi-peaked activity trends due to site heterogeneity.

The framework enables screening of complex alloy catalysts.

Abstract

We present a precise and general method to map the activity of electrocatalysts across multiple sites. Starting from a mean-field statistical mechanics model, we introduce an effective adsorption free energy descriptor that explicitly incorporates lateral adsorbate-adsorbate interactions, enabling the construction of coverage-consistent volcano relationships. Extending this approach, we show that adsorption energetics and interaction strength define a two-dimensional activity landscape that gives rise to a "volcano ridge" that captures the coupled influence of binding and interactions on catalytic performance. For multi-site systems, we demonstrate that the inherently nonlinear coupling between distinct adsorption environments leads to multi-peaked activity trends that cannot be represented by conventional single-site descriptors. To address this, we introduce a reduced descriptor mapping that projects the multidimensional activity landscape onto a single effective coordinate while preserving the underlying physics of site heterogeneity and lateral interactions. The resulting framework generalizes Sabatier-type analysis to complex alloy catalysts and provides a physically interpretable route for screening electrocatalytic materials of arbitrary compositional complexity.