Core electron binding energies of adsorbates on Cu(111) from first-principles calculations

TL;DR

This paper demonstrates how first-principles delta-SCF calculations can accurately predict core-level binding energy shifts for various adsorbates on Cu(111), aiding the interpretation of XPS spectra in catalysis research.

Contribution

It introduces a computational approach to interpret XPS spectra by calculating core-level shifts for adsorbates on Cu(111), improving spectral assignment accuracy.

Findings

Calculated binding energy shifts agree with experimental data

The method helps identify misassigned peaks in spectra

Provides a computational tool for surface chemistry analysis

Abstract

Core-level X-ray Photoelectron Spectroscopy (XPS) is often used to study the surfaces of heterogeneous copper-based catalysts, but the interpretation of measured spectra, in particular the assignment of peaks to adsorbed species, can be extremely challenging. In this study we demonstrate that first principles calculations using the delta Self Consistent Field (delta-SCF) method can be used to guide the analysis of experimental core-level spectra of complex surfaces relevant to heterogeneous catalysis. Specifically, we calculate core-level binding energy shifts for a series of adsorbates on Cu(111) and show that the resulting C1s and O1s binding energy shifts for adsorbed CO, CO2, C2H4, HCOO, CH3O, H2O, OH and a surface oxide on Cu(111) are in good overall agreement with the experimental literature. In the few cases where the agreement is less good, the theoretical results may indicate the need to re-examine experimental peak assignments.