Nature of Versatile Chemisorption on TiC(111) and TiN(111) Surfaces

TL;DR

This study uses density-functional calculations to analyze chemisorption on TiC(111) and TiN(111) surfaces, revealing surface resonances and a concerted-coupling model that predicts adsorption behaviors relevant to catalysis and growth.

Contribution

It introduces a concerted-coupling model explaining chemisorption on TiC(111) and TiN(111) surfaces, linking surface resonances to adsorption energies.

Findings

Strong Ti3d-derived surface resonances at the Fermi level.

Adsorption energies peak at oxygen with 9 eV.

The model predicts chemisorption versatility across different adatoms.

Abstract

Density-functional calculations on the polar TiX(111) (X = C, N) surfaces show (i) for clean surfaces, strong Ti3d-derived surface resonances (SR's) at the Fermi level and X2p-derived SR's deep in the upper valence band and (ii) for adatoms in periods 1-3, pyramidic trends in atomic adsorption energies, peaking at oxygen (9 eV). A concerted-coupling model, where adatom states couple to both kinds of SR's in a concerted way, describes the adsorption. The chemisorption versatility and the general nature of the model indicate ramifications and predictive abilities in, e.g., growth and catalysis.