Chemisorption of a molecular oxygen on the UN (001) surface: ab initio calculations

TL;DR

This study uses ab initio DFT calculations to analyze how molecular oxygen interacts with the UN (001) surface, revealing mechanisms of dissociation and oxidation relevant to uranium mononitride's reactivity.

Contribution

It provides detailed insights into the dissociation pathways of O2 on UN (001), explaining the rapid oxidation process through first-principles calculations.

Findings

O2 molecules can spontaneously dissociate on UN (001) surface

Dissociation depends on molecule orientation and position

Oxidation of UN occurs rapidly in air due to these mechanisms

Abstract

The results of DFT GGA calculations on oxygen molecules adsorbed upon the (001) surface of uranium mononitride (UN) are presented and discussed. We demonstrate that O2 molecules oriented parallel to the substrate can dissociate either (i) spontaneously when the molecular center lies above the surface hollow site or atop N ion, (ii) with the activation barrier when a molecule sits atop the surface U ion. This explains fast UN oxidation in air.