| AVS 55th International Symposium & Exhibition | |
| Surface Science | Tuesday Sessions |
| Session SS-TuP |
| Session: | Surface Science Poster Session |
| Presenter: | J.P. Oh, University of Tsukuba, Japan |
| Authors: | J.P. Oh, University of Tsukuba, Japan T. Kondo, University of Tsukuba, Japan Y. Suda, Toyohashi University, Japan D. Sekiba, University of Tsukuba, Japan H. Kudo, University of Tsukuba, Japan J. Nakamura, University of Tsukuba, Japan |
| Correspondent: | Click to Email |
Adsorption and desorption of CO on Pt vapor-deposited on highly oriented pyrolytic graphite (HOPG) have been investigated by temperature programmed desorption (TPD) of CO and in-situ helium atom scattering (HAS). Pt particles deposited on HOPG with sub-monolayer coverage are found to exhibit lower temperature desorption peak of CO at ~300 K at a heating rate of 0.5 K/sec. With increasing Pt coverage on HOPG, the desorption peak of CO at 450 K becomes dominant as observed on Pt single crystals. It was confirmed by Rutherford backscattering spectroscopy (RBS) measurements that any impurities other than carbon and Pt do not exist in the HOPG sample. These results indicate that the Pt particles deposited on a graphite surface with sub-monolayer coverage has significantly different properties for CO adsorption from that of Pt single crystal: lower adsorption energy of CO on Pt of Pt/HOPG than that for Pt single crystal. The reduction in the adsorption energy has been attributed to the interface interaction between Pt particles and graphite surface based on the separately conducted scanning tunneling microscopy experiment. Simultaneous measurement of HAS with CO-TPD indicated, the morphological change of the specific Pt particles at ~350 K. Scanning electron microscope observation before and after annealing the Pt/HOPG sample also reveals that Pt particle is mobile at higher temperatures above 350 K. However, sintering of Pt leading to an increase of particle size was not observed.