Grant Johnson - Gas-phase reactivity of gold oxide cluster cations with CO

Version 1

      Publication Details (including relevant citation   information):

    JOURNAL OF PHYSICAL CHEMISTRY C

      Volume:   112

        Issue: 26

        Pages: 9730-9736

    DOI:10.1021/jp801514d

    Published: JUL 3 2008

      Abstract:

        Gold oxide cluster cations, containing one to four gold atoms and   between one and five oxygen atoms, were investigated employing   guided-ion-beam mass spectrometry to gain insight into their   reactivity with CO. Clusters with one atomically bound oxygen   atom (AuO+, Au2O+, and Au3O+) were found to be reactive and   selective toward oxidation of one CO molecule facilitated by   adsorption of a second CO. Furthermore, the mono-oxide clusters   with an odd number of gold atoms (AuO+ and AU(3)O(+)) were   determined to be more reactive than AU20+. Species with higher   oxygen content favored adsorption of one CO molecule onto the   cluster accompanied by the loss of either one or two 02   molecules, indicating that binding of O-2 molecules to positively   charged gold clusters does not prevent the subsequent   chemisorption of CO. Clusters with two or more gold atoms   exhibited products corresponding to loss of AuO2 when reacted   with CO. Positively charged gas-phase gold clusters, therefore,   may be broken apart by the exothermic adsorption of CO. Product   cluster ions resulting from these O-2 and AuO2 loss processes   appear to show further reactivity for both the oxidation of CO   and the adsorption of additional CO molecules. These findings   provide insight into the role of positively charged centers in   gold based nanocatalysis.

      Address (URL): http://pubs.acs.org/doi/full/10.1021/jp801514d