Strong chemisorption of CO on M@Bn− (M = Co, Ir, Rh, Ru, Ta, Nb, n = 8–10) clusters: an implication for wheel boron clusters as CO gas detectors

Abstract

In this study, the adsorption behavior of carbon monoxide (CO) gas molecules on anionic M@B_n⁻ (M = Co, Ir, Rh, Ru, Ta, Nb, n = 8–10) clusters has been systematically investigated by employing density functional theory (DFT). It was found that CO adsorption on boron clusters proceeds spontaneously and easily, accompanied with a dramatic structural deformation for the corresponding M@B_n⁻ clusters. Large adsorption energies ranging from −22.82 to −27.38 kcal mol⁻¹ have been observed for CO on boron clusters. The kinetic stabilities of the formed complexes have been verified by ab initio molecular dynamics. The IR spectra and adiabatic detachment energy of the M@B_n⁻ clusters have been discussed before and after CO adsorption. In addition, the adsorption behavior of the other small gas molecules, such as CO₂, N₂, CH₄, H₂O, and O₂, have also been explored. The potential applications of these wheel boron M@B_n⁻ clusters in the detection of CO gas have been proposed for the first time.