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Name (Title):
Ajayan Vinu
Affiliation:
MANA, International Center for Materials Nanoarchitectonics
Address:
1-1 Namiki, Tsukuba, Japan
Email: vinu.ajayan@nims.go.jp
Home Page: http://www.nims.go.jp/super/HP/vinu/websitevinu/V-top.htm
Presentation Title:
Highly Crystalline and Active Nanoporous Metallosilicate Nanocages
Abstract:
Mesoporous silica materials discovered by Mobil researchers have received much attention in
the recent years because of their application in various fields such as catalysis, adsorption and
separation, and nanodevices. 1-4 However, these materials are amorphous in nature and lack
acidity, which is not suitable for acid catalyzed reactions. Here we aim to fabricate mesoporous
materials with crystalline wall structure, which are expected to provide a lot of acid sites. Highly
ordered crystalline mesoporous titano and zinc silicate materials with excellent textural properties
were successfully synthesized for the first time with amphiphilic surfactant [3-
(trimethoxysilyl)propyl] hexadecyldimethylammonium chloride as a structure directing agent
under hydrothermal synthesis condition at 150 °C via rotating mode. The materials were
thoroughly characterized by powder XRD, HR-FESEM and nitrogen adsorption isotherms. Both
the samples show a peak at lower angle which is a typical characteristic of a well ordered
mesoporous structure, and several peaks at
higher angle, suggesting that the samples are
highly crystalline in terms of both the order
of the pores and the atoms (not shown).
Well-ordered rectangular shaped crystals
with uniform size, which are similar to that
of microporous titanosilicates (TS-1), are
clearly seen in the sample (Fig. 1). Similar
well ordered crystals are observed for zinc
silicates. The textural parameters of the
samples have also been studied. It is found
that both titano and zinc silicate samples
exhibit the surface area of ca. 500 m 2 /g and
large pore volume. Moreover, the catalytic
activity of the materials has been evaluated
on several acid catalyzed reactions. The
detailed results will be discussed during the
presentation.
Poster Session PIS-3
Fig 1 (right): HR-FESEM image of crystalline
mesoporous titano silicates.
References:
K. Ariga, A. Vinu*, Q. Ji, O. Ohmori, J. Hill, S. Acharya, J. Koike, S. Shiratori,” Angew. Chem.
Int. Ed., 47, 7254-7257 (2008).
A. Vinu*, Adv. Funct. Mater. 18, 816-827 (2008)
P. Srinivasu, S. Alam, V.V. Balasubramanian, S. Velmathi, D.P. Sawant, W. Bohlmann, S.P.
Mirajkar, K. Ariga, S.B. Halligudi, A. Vinu,*, Adv. Funct. Mater. 18, 640-651 (2008)
D.P. Sawant, J. Justus, V.V. Balasubramanian, K. Ariga, P. Srinivasu, S. Velmathi, S.B. Halligudi,
A. Vinu*,” Chem. Euro. J., 14, 3200-3212 (2008).
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