Two gold surfaces and a cluster with remarkable reactivity for CO oxidation, a density functional theory study

We calculate the energetics of CO oxidation on extended surfaces of particular structures chosen to maximize their reactivity towards either O2 dissociation, after which CO + O to CO2 is a facile reaction, or to CO2 from molecular O2 and CO. We identified two configurations of Au atoms for which the energetics of these reactions are feasible. A site consisting of four Au atoms in a square geometry appears well suited for dissociating oxygen. A Au38 cluster exposing this site provides the most favourable energetics for the CO oxidation

Surface reactions of nitrogen oxide and ethylene on rhodium(111)

Temperature programming of NO and C2H4 coadsorbed on Rh(111) gives rise to the desorption of a number of gases. Where H2, H20, CO2 and N2 are the main products at low C2H4 coverages, significant amounts of HCN, CO and NO evolve at higher C2H4 coverages. Static SIMS indicates the formation of a large supply of adsorbed CN species, part of which desorbs as HCN, while the remainder decomposes and is responsible for delayed formation of N2. For the highest C2H4 coverages the majority of the initially adsorbed NO desorbs as HCN