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Title: Ammonia formation from NO reaction with surface hydroxyls on rutile TiO2 (110) - 1×1

Abstract

The reaction of NO with hydroxylated rutile TiO2(110)-1×1 surface (h-TiO2) was investigated as a function of NO coverage using temperature-programmed desorption. Our results show that NO reaction with h-TiO2 leads to formation of NH3 which is observed to desorb at ~ 400 K. Interestingly, the amount of NH3 produced depends nonlinearly on the coverage of NO. The yield increases up to a saturation value of ~1.3×1013 NH3/cm2 at a NO dose of 5×1013 NO/cm2, but subsequently decreases at higher NO doses. Preadsorbed H2O is found to have a negligible effect on the NH3 desorption yield. Additionally, no NH3 is formed in the absence of surface hydroxyls (HOb’s) upon coadsorption of NO and H2O on a stoichiometric TiO2(110) (s-TiO2(110)). Based on these observations, we conclude that nitrogen from NO has a strong preference to react with HOb’s on the bridge-bonded oxygen rows (but not with H2O) to form NH3. The absolute NH3 yield is limited by competing reactions of HOb species with titanium-bound oxygen adatoms to form H2O. Our results provide new mechanistic insight about the interactions of NO with hydroxyl groups on TiO2(110) .

Authors:
; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
1184925
Report Number(s):
PNNL-SA-106365
48287; KC0302010
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physical Chemistry C, 119(2):1130-1135
Country of Publication:
United States
Language:
English
Subject:
Nitric Oxide; Ammonia; TiO2(110); Surface Hydroxyls; Environmental Molecular Sciences Laboratory

Citation Formats

Kim, Boseong, Kay, Bruce D., Dohnalek, Zdenek, and Kim, Yu Kwon. Ammonia formation from NO reaction with surface hydroxyls on rutile TiO2 (110) - 1×1. United States: N. p., 2015. Web. doi:10.1021/jp5109619.
Kim, Boseong, Kay, Bruce D., Dohnalek, Zdenek, & Kim, Yu Kwon. Ammonia formation from NO reaction with surface hydroxyls on rutile TiO2 (110) - 1×1. United States. doi:10.1021/jp5109619.
Kim, Boseong, Kay, Bruce D., Dohnalek, Zdenek, and Kim, Yu Kwon. Thu . "Ammonia formation from NO reaction with surface hydroxyls on rutile TiO2 (110) - 1×1". United States. doi:10.1021/jp5109619.
@article{osti_1184925,
title = {Ammonia formation from NO reaction with surface hydroxyls on rutile TiO2 (110) - 1×1},
author = {Kim, Boseong and Kay, Bruce D. and Dohnalek, Zdenek and Kim, Yu Kwon},
abstractNote = {The reaction of NO with hydroxylated rutile TiO2(110)-1×1 surface (h-TiO2) was investigated as a function of NO coverage using temperature-programmed desorption. Our results show that NO reaction with h-TiO2 leads to formation of NH3 which is observed to desorb at ~ 400 K. Interestingly, the amount of NH3 produced depends nonlinearly on the coverage of NO. The yield increases up to a saturation value of ~1.3×1013 NH3/cm2 at a NO dose of 5×1013 NO/cm2, but subsequently decreases at higher NO doses. Preadsorbed H2O is found to have a negligible effect on the NH3 desorption yield. Additionally, no NH3 is formed in the absence of surface hydroxyls (HOb’s) upon coadsorption of NO and H2O on a stoichiometric TiO2(110) (s-TiO2(110)). Based on these observations, we conclude that nitrogen from NO has a strong preference to react with HOb’s on the bridge-bonded oxygen rows (but not with H2O) to form NH3. The absolute NH3 yield is limited by competing reactions of HOb species with titanium-bound oxygen adatoms to form H2O. Our results provide new mechanistic insight about the interactions of NO with hydroxyl groups on TiO2(110) .},
doi = {10.1021/jp5109619},
journal = {Journal of Physical Chemistry C, 119(2):1130-1135},
number = ,
volume = ,
place = {United States},
year = {Thu Jan 15 00:00:00 EST 2015},
month = {Thu Jan 15 00:00:00 EST 2015}
}