Structural sensitivity of NO decomposition over a V-O-W/Ti(Sn)O 2 catalyst

• Published in: Catalysis today Vol. 119; no. 1; pp. 199 - 203
• Main Authors: Banaś, J., Tomašić, V., Wesełucha-Birczyńska, A., Najbar, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-01-2007
• Subjects: Nitrogen oxide decomposition; Rutile-supported vanadia-tungsta catalyst; Surface species structure; Surface species structure; Rutile-supported vanadia-tungsta catalyst; Nitrogen oxide decomposition
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2006.08.043

NO decomposition at 673
K as a function of contact times over a V-O-W/Ti(Sn)O
2 catalyst obtained by sol–gel method and pretreated at 673
K in helium stream was investigated and compared with that over a Cu-ZSM-5 catalyst. Feed containing 4% NO in a helium stream was used in both the cases.
The V-O-W/Ti(Sn)O
2 catalyst showed higher activity as well as higher selectivity to dinitrogen than the Cu-ZSM-5 catalyst over the whole range of used contact times (0.375–15
g
s
cm
−3).
The highest activity of the V-O-W/Ti(Sn)O
2 catalyst, especially at higher normalised contact times (
τ/
τ
max
>
0.25), was shown to result from vanadia-like surface layer formation with high tungsten content. It was also shown that the decrease in activity as contact time decreased is connected with tungsta monolayer formation on the V-O-W hybrid crystallites composed of tungsta, V-W oxide bronze and vanadia.