Roldan Martinez, Alberto ![]() |
Abstract
We have studied with DFT supercell calculations the role of the charge and of the MgO support in the activation of O2 by a Au5 cluster. We considered gas-phase Au5 and Au5− clusters and Au5 deposited on a stepped MgO surface and on the same surface in the presence of a specific defect, a (H+)(e−) center. On this center, Au5 forms a stable Au5− supported species. O2 activation depends on the charge state of the gold cluster, but this is not a sufficient condition. In fact, it is only on Au5−/MgO that O2 becomes activated (superoxo species). The reason is that O2− is bound at the interface between Au5 and the oxide and benefits from the interaction with the ionic support, an effect which is missing on free Au5−. The activation of the O−O bond on supported anionic gold clusters does not result in a substantial reduction of the dissociation barrier which remains about 2 eV. The implications for low-temperature CO oxidation on very small Au clusters are discussed.
Item Type: | Article |
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Date Type: | Publication |
Status: | Published |
Schools: | Chemistry |
Subjects: | Q Science > QD Chemistry |
Publisher: | ACS Publications |
ISSN: | 1932-7447 |
Last Modified: | 28 Oct 2022 08:51 |
URI: | https://orca.cardiff.ac.uk/id/eprint/72408 |
Citation Data
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