التفاصيل البيبلوغرافية
| العنوان: |
Interaction of molecular nitrogen with vanadium oxide in the absence and presence of water vapor at room temperature: Near-ambient pressure XPS. |
| المؤلفون: |
Balogun, K., Chukwunenye, P., Anwar, F., Ganesan, A., Adesope, Q., Willadsen, D., Nemšák, S., Cundari, T. R., Bagus, P. S., D'Souza, F., Kelber, J. A. |
| المصدر: |
Journal of Chemical Physics; 9/14/2022, Vol. 157 Issue 10, p1-10, 10p |
| مصطلحات موضوعية: |
VANADIUM oxide, WATER vapor, MOLECULAR interactions, X-ray photoelectron spectroscopy, OXIDE coating, VANADIUM |
| مستخلص: |
Interactions of N2 at oxide surfaces are important for understanding electrocatalytic nitrogen reduction reaction (NRR) mechanisms. Interactions of N2 at the polycrystalline vanadium oxide/vapor interface were monitored at room temperature and total pressures up to 10−1 Torr using Near-Ambient Pressure X-ray Photoelectron Spectroscopy (NAP-XPS). The oxide film was predominantly V(IV), with V(III) and V(V) components. XPS spectra were acquired in environments of both pure N2 and equal pressures of N2 and H2O vapor. In pure N2, broad, partially resolved N1s features were observed at binding energies of 401.0 and 398.7 eV, with a relative intensity of ∼3:1, respectively. These features remained upon subsequent pumpdown to 10−9 Torr. The observed maximum N surface coverage was ∼1.5 × 1013 cm−2—a fraction of a monolayer. In the presence of equal pressures of H2O, the adsorbed N intensity at 10−1 Torr is ∼25% of that observed in the absence of H2O. The formation of molecularly adsorbed H2O was also observed. Density functional theory-based calculations suggest favorable absorption energies for N2 bonding to both V(IV) and V(III) cation sites but less so for V(V) sites. Hartree–Fock-based cluster calculations for N2–V end-on adsorption show that experimental XPS doublet features are consistent with the calculated shake-up and normal, final ionic configurations for N2 end-on bonding to V(III) sites but not V(IV) sites. The XPS spectra of vanadium oxide transferred in situ between electrochemical and UHV environments indicate that the oxide surfaces studied here are stable upon exposure to the electrolyte under NRR-relevant conditions. [ABSTRACT FROM AUTHOR] |
|
Copyright of Journal of Chemical Physics is the property of American Institute of Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) |
| قاعدة البيانات: |
Complementary Index |
Find this article in full text from Scitation.