The ensemble effects on adsorption and dehydrogenation of ethylene on PdAu(001) bimetallic surfaces

TL;DR

This study uses first-principles calculations to explore how ensemble effects influence ethylene adsorption and dehydrogenation on PdAu(001) surfaces, revealing key factors affecting catalytic activity.

Contribution

It provides new insights into how ensemble effects impact ethylene dehydrogenation on PdAu(001), highlighting the role of Pd-Au bridges in catalytic processes.

Findings

Decomposition of ethylene is unlikely on Pd monomers or second neighborhoods.

Activation energies depend strongly on ensemble effects.

No clear link between surface activity and Pd-d band center.

Abstract

First-principles calculations are performed to study the adsorption and dehydrogenation of ethylene on PdAu(001) bimetallic surfaces. The activation energies for C-H bond breaking of ethylene strongly depend on the ensemble effect. Particularly, ethylene is unlikely to decompose on the most popular ensembles of PdAu(001), Pd monomers or Pd second neighborhoods, since the Pd-Au bridges are less attractive towards vinyl and the eliminated H atom than the Pd-Pd bridges in the transition state. Correlations are found among the activation energies, reaction energies and adsorption energies, but no obvious relationship exist between the surface activity and the Pd-d band center.