Catalysis Today 70 (2001) 91–105
Interaction of N
2
, CO and NO with Cu-exchanged ETS-10:
a compared FTIR study with other Cu-zeolites
and with dispersed Cu
2
O
S. Bordiga
a,∗
, C. Pazé
a
, G. Berlier
a
, D. Scarano
a
, G. Spoto
a
,
A. Zecchina
a
, C. Lamberti
b
a
Dipartimento di Chimica IFM, I-10125 Via P. Giuria 7, Torino, Italy
b
Dipartimento di Chimica IFM, Unità INFM Torino-Università, I-10125 Via P. Giuria 7, Torino, Italy
Abstract
After a brief overview of the reasons why, in spite of the high fraction of framework Ti(IV) atoms, Engelhard titanosilicate
(ETS-10) cannot be used as competitive catalyst in partial oxidation reactions, we draw the attention on the fact that the high
cation density of ETS-10 can be the key property for potential new catalytic applications of this recent material. Among
all, cation exchange with Cu
2+
can yield to Cu-ETS-10, a promising material for environmental catalysis. We so present a
detailed characterization of this material using N
2
, CO and NO as probe molecules. In spite of the rather high complexity of
the obtained spectra, a comparison with similar experiments (described in the literature or ad hoc performed for this work) on
other Cu-exchanged zeolites and on Cu
2
O dispersed on silica and on MCM-41, allows a full interpretation of the spectroscopic
properties. It is shown that copper is present both as counterion and in the form of Cu
2
O nanoclusters dispersed in the ETS-10
channels and in the external surface. Finally, IR spectroscopy has been used to demonstrate that Cu-ETS-10 is active in the
decomposition of NO. © 2001 Published by Elsevier Science B.V.
Keywords: Titanosilicate; ETS-10; FTIR spectroscopy; CO; N
2
; NO; Cu-exchanged zeolites; NO decomposition
1. Introduction
Engelhard titanosilicate (ETS-10) is a new microp-
orous crystalline material belonging to the family of
Ti-substituted silicates containing Ti in octahedral co-
ordination [1,2]. Because of its inherently disordered
nature, preventing the use of conventional diffraction
approaches, the structure of ETS-10 was solved only
5 years after its synthesis by Anderson et al. [3–5]. To
Paper submitted for publication on Catalysis Today as an article
in the special issue devoted to Jean-Claude Lavalley’s 60th birthday
entitled: “IR Spectroscopy Applied to Catalysis”.
∗
Corresponding author. Tel.: +39-011-6707858;
fax: +39-011-6707855.
E-mail address: bordiga@ch.unito.it (S. Bordiga).
achieve this goal, high resolution transmission elec-
tron microscopy, powder X-ray diffraction, solid state
NMR and molecular modeling techniques were used.
They proved that ETS-10 framework is composed of
corner-sharing SiO
4
tetrahedra and TiO
6
octahedra
linked through bridging oxygen atoms, and that two
sets of perpendicular 12-ring channels having an el-
liptical cross-section 7.6Å × 4.9 Å are present. The
recent single crystal study by Wang and Jacobson [6]
has confirmed the model of Anderson et al. To have a
complete view on the recent progresses obtained in the
synthesis and in the characterization of microporous
titanosilicates and mixed octahedra–tetrahedra frame-
work oxides, the reader should refer to the review of
Rocha and Anderson [7].
0920-5861/01/$ – see front matter © 2001 Published by Elsevier Science B.V.
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