Adsorption of Methanol on Aluminum Oxide: A Density Functional Study

TL;DR

This study uses density functional theory to analyze how methanol molecules chemically adsorb onto the alpha-Al2O3(0001) surface, revealing details about adsorption energy, charge transfer, and surface structural changes.

Contribution

It provides a detailed first-principles investigation of methanol adsorption on aluminum oxide surfaces, including adsorption energies and atomic structure modifications.

Findings

Adsorption energy of methanol is approximately 1.01 eV/molecule.

Methanol adsorbs chemically by donating electrons to the surface.

Surface atomic structure changes notably upon adsorption.

Abstract

Theoretical calculations based on density functional theory have made significant contributions to our understanding of metal oxides, their surfaces, and the binding of molecules at these surfaces. In this paper we investigate the binding of methanol at the alpha-Al2O3(0001) surface using first-principles density functional theory. We calculate the molecular adsorption energy of methanol to be E^g_ads=1.03 eV/molecule. Taking the methanol-methanol interaction into account, we obtain the adsorption energy E_ads=1.01 eV/molecule. Our calculations indicate that methanol adsorbs chemically by donating electron charge from the methanol oxygen to the surface aluminum. We find that the surface atomic structure changes upon adsorption, most notably the spacing between the outermost Al and O layers changes from 0.11 Angstrom to 0.33 Angstrom.