Interplay between Bonding and Magnetism in the Adsorption of NO on Rh Clusters

TL;DR

This study investigates how NO molecules adsorb on small Rh clusters, revealing a complex interplay where bonding weakens magnetism and affects adsorption energies, contrasting with larger surfaces.

Contribution

It provides new insights into the competition between bonding and magnetism in small metal clusters using density functional theory.

Findings

NO bonds more strongly to Rh clusters than to bulk surfaces

Adsorption quenches the magnetism of Rh clusters

Size-dependent trends in adsorption are washed out by magnetic effects

Abstract

We have studied the adsorption of NO on small Rh clusters, containing one to five atoms, using density functional theory in both spin-polarized and non-spin-polarized forms. We find that NO bonds more strongly to Rh clusters than it does to Rh(100) or Rh(111); however, it also quenches the magnetism of the clusters. This (local) effect results in reducing the magnitude of the adsorption energy, and also washes out the clear size-dependent trend observed in the non-magnetic case. Our results illustrate the competition present between the tendencies to bond and to magnetize, in small clusters.