Prediction of Stable Surfaces of Metal Oxides through the Unsaturated Coordination Index

Shunsaku Yasumura; Takashi Kamachi; Takashi Toyao; Ken-Ichi Shimizu; Yoyo Hinuma

doi:10.1021/acsomega.3c04253

Prediction of Stable Surfaces of Metal Oxides through the Unsaturated Coordination Index

ACS Omega. 2023 Aug 1;8(32):29779-29788. doi: 10.1021/acsomega.3c04253. eCollection 2023 Aug 15.

Authors

Shunsaku Yasumura¹, Takashi Kamachi², Takashi Toyao³, Ken-Ichi Shimizu³, Yoyo Hinuma⁴

Affiliations

¹ Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro, Tokyo 153-8505, Japan.
² Department of Life, Environment and Applied Chemistry, Fukuoka Institute of Technology, 3-30-1 Wajiro-Higashi, Higashi-ku, Fukuoka 811-0295, Japan.
³ Institute for Catalysis, Hokkaido University, N-21, W-10, Kita, Sapporo 001-0021, Hokkaido, Japan.
⁴ Department of Energy and Environment, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31, Midorigaoka, Ikeda 563-8577, Osaka, Japan.

Abstract

This study proposes the unsaturated coordination index, σ, as a potential descriptor of the stability of metal-oxide surfaces cleaved from bulk. The value of σ, the number of missing bonds per unit area, can be obtained very quickly using only crystallographic data, namely, the bulk geometry. The surface energies of various binary oxides, with and without atom relaxation, were calculated. Their correlations with σ had good coefficients of determination (R²) values, particularly in high-symmetry crystals. The proposed descriptor is very useful for an initial evaluation of stable metal-oxide surfaces without conducting any surface model calculations.