Adsorption of benzene, phenol, propane and carbonic acid molecules on oxidized Al(111) and alpha-Al2O3(0001) surfaces: A first-principles study

TL;DR

This study uses first-principles calculations to investigate how small organic molecules like benzene, phenol, propane, and carbonic acid adsorb on oxidized and clean aluminum and alumina surfaces, revealing weak or no adsorption in most cases.

Contribution

It provides detailed ab initio insights into molecule-surface interactions on Al(111) and alpha-Al2O3(0001), highlighting the effects of oxidation and surface type on adsorption behavior.

Findings

Benzene weakly adsorbs on Al(111), no adsorption on alumina.

Phenol weakly adsorbs on alumina, not on aluminum surfaces.

Carbonic acid strongly binds to alumina, not to aluminum.

Abstract

We present the results of ab initio calculations describing the adsorption of certain small organic molecules on clean and oxidized Al(111) surfaces as well as on the alpha-Al2O3(0001) surface. Our results show that adsorption of benzene on the clean and oxidized Al(111) surfaces is generally weak, the adsorption energy being at most around -0.5 eV per benzene molecule, and the molecule adsorbed at a considerable distance from the surfaces. The adsorption energy varies weakly at the different adsorption sites and as a function of the oxygen coverage. For the alumina surface, we find no benzene adsorption at all. We have also calculated a phenol molecule on the aluminium and alumina surfaces, since it is similar to the benzene molecule. The results show a weak adsorption for phenol on the alumina surface and no adsorption on the aluminium or oxidized aluminium surfaces at all. For the propane molecule there is no adsorption on either the oxidized aluminium or the alumina surface, whereas the carbonic acid molecule binds strongly to the alumina but not to the aluminium surface.