$Ab$ $initio$ study of the adsorption and dissociation of nitrogen molecule on Fe(111) surface

TL;DR

This study uses density functional theory to analyze how nitrogen molecules adsorb and dissociate on Fe(111) surfaces, revealing the importance of molecular orientation and surface morphology in the process.

Contribution

It provides new insights into the dissociation mechanism of N2 on transition metal surfaces, highlighting the role of molecular orientation and electronic interactions.

Findings

N2 adsorbs when oriented parallel to the surface

Fe(111) surface is more active than Fe(100) for dissociation

Electron transfer to N2 antibonding orbitals facilitates dissociation

Abstract

The adsorption and dissociation of nitrogen molecule on Fe(111) surface is studied by density functional theory calculations. The simulation results show that the molecule needs to acquire parallel orientation with respect to the surface for the adsorption and dissociation. In addition, Fe(111) surface is more active in dissociating N2 than Fe(100) surface due to its morphology. The interaction between antibonding molecular orbitals of N2 and partially filled $3d$ orbitals of Fe atoms on the surface may be the key to the molecular dissociation of N2. To break down the triple bond of N2, the electron density on the surface needs to be partially transferred to the molecule to fill the antibonding molecular orbitals of the nitrogen molecule. The present result may provide some insights on the dissociation mechanism of molecules over transition metal surfaces.