Vertical-orbital band center as an activity descriptor for hydrogen evolution reaction on single-atom-anchored 2D catalysts

Wen Qiao; Shiming Yan; Deyou Jin; Xiaoyong Xu; Wenbo Mi; Dunhui Wang

doi:10.1088/1361-648X/abe9da

Vertical-orbital band center as an activity descriptor for hydrogen evolution reaction on single-atom-anchored 2D catalysts

J Phys Condens Matter. 2021 May 13;33(24). doi: 10.1088/1361-648X/abe9da.

Authors

Wen Qiao¹, Shiming Yan¹, Deyou Jin¹, Xiaoyong Xu², Wenbo Mi³, Dunhui Wang¹

Affiliations

¹ School of Electronics and Information, Hangzhou Dianzi University, Hangzhou 310018, People's Republic of China.
² School of Physics Science and Technology, Yangzhou University, Yangzhou, 225002, People's Republic of China.
³ Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, School of Science, Tianjin University, Tianjin 300354, People's Republic of China.

PMID: 33631737
DOI: 10.1088/1361-648X/abe9da

Abstract

The d-band center descriptor based on the adsorption strength of adsorbate has been widely used in understanding and predicting the catalytic activity in various metal catalysts. However, its applicability is unsure for the single-atom-anchored two-dimensional (2D) catalysts. Here, taking the hydrogen (H) adsorption on the single-atom-anchored 2D basal plane as example, we examine the influence of orbitals interaction on the bond strength of hydrogen adsorption. We find that the adsorption of H is formed mainly via the hybridization between the 1s orbital of H and the vertical d_z2orbital of anchored atoms. The other four projected d orbitals (d_xy/d_x2-y2, d_xz/d_yz) have no contribution to the H chemical bond. There is an explicit linear relation between the d_z2-band center and the H bond strength. The d_z2-band center is proposed as an activity descriptor for hydrogen evolution reaction (HER). We demonstrate that the d_z2-band center is valid for the single-atom active sites on a single facet, such as the basal plane of 2D nanosheets. For the surface with multiple facets, such as the surface of three-dimensional (3D) polyhedral nanoparticles, the d-band center is more suitable.

Keywords: 2D catalysts; basal plane; electrocatalysts; first-principle calculation; hydrogen evolution reaction.