Title : Adsoption and dissociation of Isocyanic acid (HNCO) on Rh(001) surface: ADFT study
Abstract:
The adsorption and dissociation of HNCO molecule into CO and NH species on the flat Rh(001) surface have been investigated using density functional theory (DFT) with the standard GGA-PBE functional and associated with the van der Waals (vdW) dispersion correction effect of vdW-DF-revPBE [1]. The bridge site is found to be the most energetically stable for CO as well as for HNCO molecule, while the hollow one is obtained for NH. However, the dispersion correction inclusion to the PBE changes the order of preferential site for the CO while for NH the most stable site remains the same, associated with the reduces of adsorption energy. Furthermore, the use of Climbing-Image Nudged Elastic Band (CI-NEB) method to determine the minimum energy path for the molecular HNCO dissociation into NH and CO on the Rh(001) surface, allowed obtain an activation energy of 0.55 (0.51) eV for the standard PBE (PBE functional including vdW-DF-revPBE dispersion). This current study therefore suggests that the rapid reduction of nitrogen oxide, a chemical combustion process designed to remove harmful NO from harmful combustor exhaust, is a high temperature process, when the Rh(001) slab is used as a reaction surface. The electronic structures analysis, in term of projected density of states and electronic density, unravels the origin of HNCO molecular dissociation on the Rh(001) surface.
