| AVS 56th International Symposium & Exhibition | |
| Surface Science | Monday Sessions |
| Session SS1-MoM |
| Session: | Vibrational Spectroscopy and Surface Reactions |
| Presenter: | K. Mudiyanselage, Pacific Northwest National Laboratory |
| Authors: | K. Mudiyanselage, Pacific Northwest National Laboratory C.W. Yi, Sungshin Women's University, Korea J. Szanyi, Pacific Northwest National Laboratory |
| Correspondent: | Click to Email |
Reactions of NO2 (in the pressure range of 1.0 × 10-9 - 1.0 × 10-4 Torr) with BaO(> 20 MLE), amorphous-Ba(OH)2 and crystalline-Ba(OH)2 supported on Pt(111) were studied using infrared reflection absorption spectroscopy (IRAS), temperature programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). The amorphous and crystalline Ba(OH)2 layers were prepared by adsorbing H2O on BaO(> 20 MLE)/Pt(111) at 300 and 425 K, respectively. The amorphous-Ba(OH)2 layer partially converts to Ba(NOx)2 (nitrites and nitrates) following exposure to elevated NO2 pressure (~1.0 × 10-4 Torr) at 300 K. The exposure of the crystalline-Ba(OH)2/Pt(111) system to NO2 at 425 K leads to the desorption of H2O and the complete conversion of the crystalline-Ba(OH)2 layer to Ba(NOx)2, which consists of mainly crystalline nitrates and a small amount of nitrites. Adsorption of NO2 on BaO(> 20 MLE)/Pt(111) at 425 K also forms crystalline nitrates. The amounts of NOx uptaken by BaO(> 20 MLE)/Pt(111) and crystalline-Ba(OH)2/Pt(111) systems at 425 K are very similar as determined by the NO TPD peak areas.