A theoretical study of the adsorption and reaction of SO2 at surface and step sites of the MgO(100) surface

摘要: Abstract The interaction of SO 2 with acid and basic sites a clean, fully dehydroxilated, MgO(100) surface has been investigated by means ab initio cluster model calculations. Full geometry optimization the complexes carried out at SCF level. nature bonding analyzed in detail performing decomposition energy as sum electrostatics, polarization charge transfer contributions. adsorbs molecularly five-coordinated Mg 2+ 5c cations forming an electrostatically bound complex where is bridge-bonded to two adjacent centres. formation strongly chemisorbed sulphite, 2− 3 , species occurs when interacts O ions. However, very different reactivity observed for five-coordinated, surface, four-coordinated, step, sites. In fact, ions are rather unreactive while stable 4c step non-activated process. regular defect MgO explained terms Madelung potential these hence energetic cost MgOSO transfer. No evidence found sulphate, 4 species. computed vibrational photoemission features forms adsorbed physisorbed chemisorbed, consistent corresponding experimental spectra.