Catalytic activity of small MgO-supported Au clusters towards CO oxidation: A density functional study
2010 (English)In: Physical Review B Condensed Matter, ISSN 0163-1829, E-ISSN 1095-3795, Vol. 81, no 19, 195443- p.Article in journal (Refereed) Published
In order to explain the experimentally found catalytic characteristics of Au1-4 /MgO (100) we have performed a comprehensive density functional study of these systems and their ability to (co)adsorb CO and O2 molecules. Starting from the carefully determined ground-state structures we have analyzed binding mechanisms, the influence of spin-orbit coupling, and charge redistributions in Au1-4 /MgO+CO (O2). Experimentally Au1,2 /MgO were found to be inactive under a mixed atmosphere. We show that O2 strongly binds to Au1 /MgO that prevents coadsorption. Although a catalytic reaction cycle towards CO oxidation, analogous to the gas phase reaction involving Au 2-, is energetically possible for Au2 /MgO, the cluster will get blocked by a strongly bound CO. On the other hand, the catalytic activity of Au3,4 /MgO could be explained by their ability to coadsorb CO and O2, hence indicating the occurrence of a Langmuir- Hinshelwood-type reaction mechanism for these clusters.
Place, publisher, year, edition, pages
2010. Vol. 81, no 19, 195443- p.
IdentifiersURN: urn:nbn:se:uu:diva-133240DOI: 10.1103/PhysRevB.81.195443ISI: 000278142000132OAI: oai:DiVA.org:uu-133240DiVA: diva2:360612