2011/08/23 by Martin Amft, Amft, Martin, Natalia V. Skorodumova +1
Chemistry · Materials Science · Physics and Astronomy · #Atomic and Molecular Clusters (physics.atm-clus) #Catalytic Processes in Materials Science #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Nanocluster Synthesis and Applications #Nanomaterials for catalytic reactions #cond-mat.mes-hall #physics.atm-clus
paper · pdf · doi:10.48550/arxiv.1108.4669
arxiv created 2011/08/23 · openalex publication_date 2011/08/23 · arxiv updated 2011/08/24 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The present density functional theory study addresses the question whether the presence of H2O influences the catalytic activity of small gold clusters, Au1-4/MgO(100), towards the oxidation of carbon monoxide. To this end, we studied the (co-)adsorption of H2O and CO/O2 on these gold clusters. The ground state structures in the presence of all three molecular species, that we found, are Au1O2/MgO and Au2-4CO/MgO with H2O adsorbed on the surface in the proximity of the clusters-molecule complex. In this configuration the catalytic activity of Au1-4/MgO is indifferent to the presence of H2O. We also found that a stable, highly activated hydroperoxyl-hydroxyl complex, O2H OH, can be formed on Au1,3/MgO. For the catalytic active system Au8/MgO, it has been predicted that this complex opens an alternative catalytic reaction pathway towards CO oxidation. Our results suggest that this water mediated catalytic cycle is unlikely to occur on Au1,3/MgO. In the case of Au1/MgO the cycle is interrupted by the dissociation of the remaining (OH)2 complex after forming the first CO2 molecule. On Au3 /MgO the O2 H OH complex is likely to decompose upon the impact of a CO molecule, since three of its bond dissociation energies are comparable to the reaction barrier of the CO to CO2 oxidation.