| AVS 54th International Symposium | |
| Surface Science | Wednesday Sessions |
| Session SS1-WeM |
| Session: | Oxide Surface Reactivity |
| Presenter: | J. Szanyi, Pacific Northwest National Laboratory |
| Authors: | J. Szanyi, Pacific Northwest National Laboratory C.-W. Yi, Pacific Northwest National Laboratory J.H. Kwak, Pacific Northwest National Laboratory |
| Correspondent: | Click to Email |
The adsorption and reaction of NO2 on a thick (> 30 ML), pure BaO film deposited onto an Al2O3/NiAl(110) substrate at 90 K and the higher temperatures were investigated with surface science techniques such as temperature programmed desorption (TPD), infrared reflection absorption spectroscopy (IRAS), and x-ray photoelectron spectroscopy (XPS) techniques. For the first time, it was clearly demonstrated that BaO readily reacts with NO2 to initially form nitrite-nitrate ion pairs by the cooperative adsorption mechanism predicted by theoretical calculation. These nitrite/nitrate pairs readily form even at 90 K. In the decomposition process of these pairs first the nitrite species release an NO molecule, and nitrate species decompose in two steps: at lower temperature as NO2 only, then, at higher temperature, as NO + O2. The results of NO2 adsorption/reaction on this model system are identical to those we have found on a high surface area 20 wt.% BaO/γ-Al2O3 sample with the exception of surface nitrates that were only observed on the high surface area material.