Reactions of NO2 with Ba(OH)2 on Pt(111)
The interaction of NO2 with amorphous and crystalline Ba(OH)2 supported on Pt(111) was studied in the wide pressure range of 1.0 × 10-9 to 1.0 × 10-4 Torr and compared to that with a thick (> 20 monolayer equivalent (MLE)) BaO film 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 exposing a thick BaO (> 20 MLE) layer on Pt(111) to H2O at 300 and 425 K, respectively. The amorphous and crystalline Ba(OH)2 layers partially convert to Ba(NOx)2 (nitrites and nitrates) following their 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, however, 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. The amounts of NOx stored by BaO (> 20 MLE)/Pt(111) and crystalline Ba(OH)2/Pt(111) systems upon their exposure to NO2 at 425 K are comparable. The thus-formed bulk crystalline Ba(NO3)2 phase decomposes in two steps, both releasing NO and O2, in accord with the melting/decomposition scheme for bulk Ba(NO3)2.
- Research Organization:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1000601
- Report Number(s):
- PNNL-SA-71210; 30469; KC0302010
- Journal Information:
- Journal of Physical Chemistry C, 114(40):16955-16963, Journal Name: Journal of Physical Chemistry C, 114(40):16955-16963 Journal Issue: 40 Vol. 114; ISSN 1932-7455; ISSN 1932-7447
- Country of Publication:
- United States
- Language:
- English
Similar Records
NO2 uptake under practically relevant conditions on BaO/Pt(111)
Reactivity of a Thick BaO Film Supported on Pt(111): Adsorption and Reaction of NO2, H2O and CO2