Activated O2 dissociation and formation of oxide islands on the Be(0001) surface: Another atomistic model for metal oxidation

TL;DR

This study uses first-principles molecular dynamics to model the initial oxidation process of Be(0001), revealing barrierless oxygen dissociation after the first molecule and the formation of oxide islands, expanding understanding of metal surface oxidation.

Contribution

It introduces a new atomistic model for Be surface oxidation, highlighting barrierless dissociation of subsequent O2 molecules and limited mobility of dissociated oxygen atoms.

Findings

Oxide islands form and grow laterally on Be(0001) surface.

Only the first O2 dissociation encounters an energy barrier.

Dissociated oxygen atoms are less mobile on Be(0001) than on Al(111).

Abstract

By simulating the dissociation of O2 molecules on the Be(0001) surface using the first-principles molecular dynamics approach, we propose a new atomistic model for the surface oxidation of sp metals. In our model, only the dissociation of the first oxygen molecule needs to overcome an energy barrier, while the subsequent oxygen molecules dissociate barrierlessly around the adsorption area. Consequently, oxide islands form on the metal surface, and grow up in a lateral way. We also discover that the firstly dissociated oxygen atoms are not so mobile on the Be(0001) surface, as on the Al(111) surface. Our atomistic model enlarges the knowledge on metal surface oxidations by perfectly explaining the initial stage during the surface oxidation of Be, and might be applicable to some other sp metal surfaces.