(665a) Decorated Steps As a Novel Alloy Electrocatalyst

Adsorption energies, which represent the strength of chemical bonds between reaction intermediates and metal surfaces, are often correlated across different metals and similar intermediates. These scaling relations can provide valuable insights into the fundamental steps that govern electrocatalytic performance and the adsorption energies that influence them. However, the drawback of scaling relations is that they can limit the effectiveness of electrocatalytic reactions. The discovery of systems that can break adsorption energy scaling relations can provide important insight into electrocatalytic design. Recent investigations have begun to explore the potential of alloy surfaces in breaking linear relationships between adsorption energies due to their unique characteristics.

In our work, we have explored the concept of selective step-decoration, a novel approach where the step-edge of a metal substrate is “decorated” with ad-atoms of another metal. This creates a model alloy surface which exposes two metal atoms with a known composition and structure, which we believe may enable the breaking of scaling relations. Using Density Functional Theory calculations, we investigated the adsorption behavior of *O, *OH, and *H on a variety of stepped surfaces (M(553), where M is a transition metal) using two different models: (1) M(553) steps decorated with metal ad-atoms and (2) M-ad-atom surface alloys (SA) created at the M(553) steps.

Based on preliminary results, we can infer that both SA and step-decorated sites exhibit distinct characteristics that could be explored to enhance catalytic performance. This finding suggests that SA and step-decoration possess specific features that differ from flat surface structures. By investigating the mechanisms behind the performance differences observed between SA, step-decoration, and (553) step-sites, we can identify novel approaches to modify the electronic/geometric properties of catalyst surfaces and break scaling relations. Therefore, exploring the unique features of SA and step-decoration on step-sites holds great promise for advancing the field of electrocatalysis.