open access

https://hdl.handle.net/2115/79144

Linear Correlations between Adsorption Energies and HOMO Levels for the Adsorption of Small Molecules on TiO2 Surfaces

英語

2019-08-29

American Chemical Society

Journal of physical chemistry c

123(34)

20988-20997

Adsorption is a fundamental step in catalysis on a solid surface, and therefore, its understanding is important for explaining its behavior. This work investigated the adsorption of various small molecules, including H-2, N-2, CO, CO2, CH4, NH3, H2O, H2S, dimethyl sulfoxide, alkanes, alkenes, alkynes, aromatic compounds, alcohols, aldehydes, ketones, nitriles, carboxylic acids, amides, and amines, on the anatase (101) and rutile (110) surfaces of TiO2, using periodic density functional theory calculations and statistical methods. Adsorption energies were computed at the same level of theory to obtain a clean and consistent data set. A linear relationship was observed between the adsorption energies of these molecules and their highest occupied molecular orbital (HOMO) levels, whereas no obvious correlation was evident for the lowest unoccupied molecular orbital levels. Improved correlations between the adsorption energies and HOMO levels were generated by dividing these, molecules into two subgroups: hydrocarbons and heteroatom- containing compounds. Interactions between frontier molecular orbitals and the surfaces were considered, to gain a better understanding of the significant correlations that were identified. The data show that these relationships can be primarily ascribed to the interactions between the HOMO of the small molecule and conduction state of the TiO2 surface. The statistical analysis using machine learning demonstrated that the HOMO and dipole moment are the first and second most important properties, respectively, in terms of rationalizing and predicting the adsorption energies.

学術雑誌論文

Accepted Manuscript

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of Physical Chemistry C, copyright c American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acs.jpcc.9b05707.

1932-7447