Strong chemisorption of CO${}_2$ on B${}_{10}$-B${}_{13}$ planar-type clusters

An ab initio density functional study was performed investigating the adsorption of CO${}_2$ on the neutral boron B${}_n$ ($n=10-13$) clusters, characterized by planar and quasiplanar ground-state atomic structures. For all four clusters, we found strong chemisorption energy of CO${}_2$ reaching 1.6 eV for B${}_{12}$ at the cluster edge sites with the adsorbed molecule in the plane of the cluster. A configuration with chemisorbed dissociated CO${}_2$ molecule also exists for B${}_{11}$ and B${}_{13}$ clusters. The strong adsorption is due to the bending of the CO${}_2$ molecule, which provides energetically accessible fully in-plane frontier molecular orbitals matching the edge states of the clusters. At the same time, the intrinsic dipole moment of a bent CO${}_2$ molecule facilitates the transfer of excess electronic charge from the cluster edges to the molecule.