| AVS 57th International Symposium & Exhibition | |
| Surface Science | Tuesday Sessions |
| Session SS-TuP |
| Session: | Surface Science Poster Session |
| Presenter: | H. Geisler, Texas State University - San Marcos |
| Authors: | J.L. Walters, Texas State University - San Marcos G. Arellano, Texas State University - San Marcos W.A. Harrison, Texas State University - San Marcos C.A. Ventrice Jr., Texas State University - San Marcos H. Geisler, Texas State University - San Marcos |
| Correspondent: | Click to Email |
The adsorption kinetics of CO on Cr(110) and on Cr2O3(0001)/Cr(110) was investigated using temperature programmed desorption (TPD). The adsorption of CO was performed with the substrate maintained at 120 K, and a feedback control system was used to generate linear heating rates. For the Cr2O3(0001)/Cr(110) surface a saturation coverage of CO was measured to occur at 0.5 L. The desorption kinetics is estimated to be 1st order with an attractive lateral interaction between CO molecules. The Redhead method was used to measure the activation energy for desorption of the CO. This analysis resulted in a value of 49.2 kJ/mol ± 2.6 kJ/mol for the activation energy. For the adsorption of CO on Cr(110) no CO desorption is detected for coverage below 0.5 L. This indicates that at this coverage all of the CO is dissociating and reacting with the Cr(110) surface. Deposition of 1L CO on clean Cr(110) shows only one broad signal at 300 K. By deposition of 2 L of CO or larger, a shift of the signal to 280 K and the appearance of a second signal at 210 K can be observed. The broadening and shifting of the desorption signals can be attributed to the lateral interact between the CO molecules and their adsorption on different binding sites on the Cr(110) surface.