Journal of Molecular Catalysis A: Chemical 175 (2001) 179–188
Reaction intermediates in the selective reduction
of NO with propene over Ga
2
O
3
-Al
2
O
3
and
In
2
O
3
-Al
2
O
3
catalysts
Masaaki Haneda
a,b,c,∗
, Emmanuel Joubert
a
, Jean-Christophe Ménézo
a
,
Daniel Duprez
a
, Jacques Barbier
a
, Nicolas Bion
b
, Marco Daturi
b
, Jacques Saussey
b
,
Jean-Claude Lavalley
b
, Hideaki Hamada
c
a
Laboratoire de Catalyse en Chimie Organique (LACCO), UMR 6503, CNRS-Université de
Poitiers, 40 Avenue du Recteur Pineau, 86022 Poitiers Cedex, France
b
Laboratoire de Catalyse et Spectrochimie, UMR 6506, CNRS-ISMRA,
6 Bd du Maréchal Juin, F-14050 Caen Cedex, France
c
National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 5,
1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
Received 9 January 2001; received in revised form 12 April 2001; accepted 5 May 2001
Abstract
Minor products formed in the reaction of NO + C
3
H
6
+ O
2
over Ga
2
O
3
-Al
2
O
3
and In
2
O
3
-Al
2
O
3
were identified by using
GC–MS technique. A lot of minor products, such as oxygenated, nitrile, nitrite compounds and higher hydrocarbons were
detected on both catalysts. The formation of surface nitrile species in the NO + C
3
H
6
+ O
2
reaction was also recognized in
the diffuse reflectance FT–IR spectra. FT–IR spectra showed that the reaction starts with the formation of adsorbed nitrate
(NO
3
-
) species via NO oxidation by O
2
. From the comparison of the distribution of minor products in NO + C
3
H
6
+ O
2
and 2-nitropropane oxidation, a reaction pathway in which NO reduction proceeds through the formation of organic nitro
compounds and subsequent decomposition to some oxygenated and nitrile compounds was proposed. © 2001 Elsevier Science
B.V. All rights reserved.
Keywords: NO reduction by propene; Ga
2
O
3
-Al
2
O
3
; In
2
O
3
-Al
2
O
3
; GC–MS; Diffuse reflectance FT–IR spectroscopy
1. Introduction
Selective reduction of nitrogen oxide (NO
x
) with
hydrocarbons is one of the most desirable control
technologies for the abatement of NO
x
in diesel
and lean burn engine exhausts. While a lot of in-
∗
Corresponding author. Tel.: +81-298-61-9326;
fax: +81-298-61-4647.
E-mail address: m.haneda@aist.go.jp (M. Haneda).
vestigations have focused on zeolite-based catalysts
[1–3], metal oxide-based catalysts represented by
alumina were also found to catalyze the selective
reduction of NO [4,5]. Recently, we systematically
investigated the catalytic activity of metal-supported
alumina (In, Co, Ag, Sn, Ga, Mn/Al
2
O
3
) prepared
by impregnation method [6]. Of these catalysts,
In/Al
2
O
3
and Ga/Al
2
O
3
showed relatively high ac-
tivity. It was also found that the catalysts prepared
by sol–gel method are more effective than those
1381-1169/01/$ – see front matter © 2001 Elsevier Science B.V. All rights reserved.
PII:S1381-1169(01)00215-1