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A quartenary ammonium compound, hexadecyltrimethylammonium
bromide was usedas an organic template in the synthesis of
MCM-41. Various metal-containing MCM-41 were synthesized with
adding Ti,V,Ga or Al to replace the silicoposition. The
objective of this study was to study the morphology and charac-
terization properties of metal-added MCM-41 and to compare the
physical properties of these materials. X-ray diffraction
(XRD) examination was used in the characterization of the
hexagonal crystalline structure of the materials. The morphology
and structurewere observed by transmission electron microscopy
(TEM) and scanning electronmicroscopy (SEM). The surface areas
and pore size distributions were calculatedby N2 sorption
measurement. The environment of the silicon atoms inside the
tetrahedral unit of the walls was analyzed by 29Si MAS NMR. THe
coordination of aluminum was measured by 27Al MAS NMR. The
thermal stability analysis of thesamples were measured by
thermogravimetric analysis (TGA) and differentialthermal
analysis (DTA). The hexagonal arrays structure of MCM-41 was
observedby TEM and the pores were highly aligned. From the
results of XRD, one can conclude that the crystallinity
increased with increasing the gallium contentand gallium was
easier to incorporate into the framework than aluminum. The
crystalline of V-MCM-41 was better than that of [V,Al]-MCM-41.
It was alsobetter than that of Ti-MCM-41 when Catapal alumina
was used as the source ofaluminum. It is opposite when sodium
aluminate was used as the source of aluminum. It was also shown
that Catapal alumina was easier to incorporate intothe framework
than sodium aluminate. However,it was contrary to the results
from 27 Al NMR which showed that sodium aluminate was easier
than Catapal aluminum. As te results of TGA and DTA, the bond
associated with MCM-41 are classified to five kinds of bonding.
The first one is the bond associatingbetween the template and
Si-O-, which is the weakest. The second one is the bond
associating between the template and Al-O-, which is stronger
than that of Si-O- and that of Ga-O-, the third one. However, it
is weaker than that of Ti-O-and V-O-. From the measurement of N2
sorption, the surface area of [V,Al]-MCM-41was the lowest and
the surface area of [Ti,Al]-MCM-41 was the largest when sodium
aluminate was used as the source of aluminum other than Catapal
alumina.However, the wall of [Ti,Al]-MCM-41 was thicker when
Catapal alumina was used as the source of aluminum other than
sodium aluminate. It is demonstrated from SEMthat he morphology
of [Ga,Al]-MCM-41 was analogous to that of [Ti,Al]-MCM-41,where
the morphology of [V,Al]-MCM-41 was different from them. The
crystals of[Ga,Al]-MCM-41 and [Ti,Al]-MCM-41 were spherical
particles packages, where thatof [V,Al]-MCM-41 was larger size
of plates agglomerate. From the results of 27 Al MAS NMR
experiment, a small part of aluminum had been expelled from the
framework of MCM-41 upon calcination. The results of 29 Si MAS
NMR indicate thatthe range of T-O-T angles in the calcined [Ga,
Al]-MCM-41 was wider than that inthe synthesized samples.
However, it was not affected in [V,Al]-MCM-41 uponcalcination.
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