Factors that influence hydrogen binding at metal-atop sites

Huiling Zheng; Hao Li; Long Luo; Zhen Zhao; Graeme Henkelman

doi:10.1063/5.0056774

Factors that influence hydrogen binding at metal-atop sites

J Chem Phys. 2021 Jul 14;155(2):024703. doi: 10.1063/5.0056774.

Authors

Huiling Zheng¹, Hao Li², Long Luo³, Zhen Zhao¹, Graeme Henkelman²

Affiliations

¹ State Key Laboratory of Heavy Oil Processing, College of Science, China University of Petroleum-Beijing, Changping District, Beijing 102249, China.
² Department of Chemistry and the Oden Institute for Computational Engineering and Sciences, University of Texas at Austin, Austin, Texas 78712-0231, USA.
³ Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA.

PMID: 34266273
DOI: 10.1063/5.0056774

Abstract

The d-band model has proven to be effective for understanding trends in the chemisorption of various adsorbates on transition metal surfaces. However, hydrogen adsorption at the atop site of transition metals and their bimetallic alloy surfaces do not always correlate well with the d-band center of the adsorption site. Additionally, the d-band model cannot explain the disappearance of the local minima for H adsorption at the hollow site on the potential energy surface of 5d single-atom element doped Au and Ag(111) surfaces. Here, we use a simple model with factors, including the d-band center, filling of the d-band, renormalized adsorbate states, coupling matrix elements, and surface-adsorbate bond lengths, to correlate with the density functional theory calculated H binding energies on both mono- and bimetallic (111) surfaces. Our results suggest that H adsorption at metal-atop sites is determined by all these factors, not only by the d-band center. The strong adsorption of H at the atop sites of 5d metal surfaces can be explained by their lower repulsive contribution.