Formation of a bi-rhodium boron tube RhB and its great CO capture ability.

The geometries, bonding and abilities for CO capture of the doubly rhodium-doped boron cluster RhB are presented. DFT calculations using the TPSSh functional show that the doubly doped RhB is stable in a high symmetry shape (D) in which two Rh dopants are vertically and oppositely coordinated to nonagonal faces of a (2 × 9) double ring B tube, having the form of a teetotum toy. Bonding of the tube is analysed using different schemes for partition of total electron density (EDI_D, AIM). The high thermodynamic stability of RhB can be rationalized in terms of its electron distribution in which both Rh atoms share delocalized bonds with B atoms. Molecular dynamic simulations also confirm its stability within a range of temperatures. Exploration of the interaction of gas phase CO molecules with RhB suggests that this tubular structure has a great ability for capture and transformation of carbon dioxide. Formation of two new strong bonds of CO with the B-B edges of RhB favour its capture through a dissociative adsorption mechanism in which a nearly spontaneous dissociation of CO into CO and BO groups follows its attachment.