CO oxidation by copper cluster anions*
1 East Tokyo Laboratory, Genesis
Research Institute, Inc., 717-86
Futamata, Ichikawa, Chiba
2 Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
3 Cluster Research Laboratory, Toyota Technological Institute: in East Tokyo Laboratory, Genesis Research Institute, Inc., 717-86 Futamata, Ichikawa, Chiba 272-0001, Japan
Received in final form: 28 November 2012
Published online: 6 March 2013
Reactions of CO and O2 on size-selected copper cluster anions, Cun- (n = 4–11), have been investigated at the collision energy of 0.2 eV by use of a guided ion beam-tandem mass spectrometer. Oxygen-adsorbed copper anions, CunO2-, in particular Cu5O2- and Cu9O2-, show an evidence of the CO oxidation, that is, the formation of the monoxide CunO−. The density functional theory calculation reveals that the CO oxidation occurs more exothermically on Cu5O2- and Cu9O2- than the other clusters. This can be explained by the relatively small dissociation energy of their Cu–O bonds. In addition, the calculations on Cu5O2+/- indicate that the CO oxidation proceeds via a low-energy pathway for the anion owing to the structural rearrangement of the copper cluster compared to the cation.
ISSPIC 16 - 16th International Symposium on Small Particles and Inorganic Clusters, edited by Kristiaan Temst, Margriet J. Van Bael, Ewald Janssens, H.-G. Boyen and Françoise Remacle.
Present address: New Industry Creation Hatchery Center (NICHe), Tohoku University, 6-6-4 Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan.
© EDP Sciences, Società Italiana di Fisica and Springer-Verlag 2013