Res. Chem. Intermed.
, Vol. 34, No. 2–3, pp. 267–286 (2008)
Koninklijke Brill NV, Leiden, 2008.
Also available online - www.brill.nl/rci
Improvement of the hydrothermal stability of MCM-48
mesoporous molecular sieves
, YAOFENG SHAO
, JINLONG ZHANG
Lab for Advanced Materials and Institute of Fine Chemicals, East China University of Science and
Technology, 130 Meilong Road, Shanghai 200237, P. R. China
Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai,
Osaka 599-8531, Japan
Received 18 November 2007; accepted 20 January 2007
Abstract—This is a review of our recent reports about improving the hydrothermal stability of
MCM-48 mesoporous molecular sieves and the related works done by other groups. It presents
the different effects of direct addition of various anions, including F
on the improvement of the hydrothermal stability of MCM-48. The different effects of anions on
the improvement of the hydrothermal stability and the critical factors inﬂuencing the formation of
hydrothermally stable MCM-48 are also explained by careful analysis and discussion.
Keywords: MCM-48; hydrothermal stability; ﬂuoride ions; promoter anions; silicates.
M41S mesoporous molecular sieves have drawn much attention from various
research ﬁelds since they were invented in 1992 . MCM-48 is a noticeable
member among M41S materials due to its highly interwoven channel structure,
which can effectively avoid pore block by guest molecules. Nevertheless, most
of the current research is on with MCM-41, another member of the M41S materials
due to the difﬁcult synthesis for MCM-48 [2– 7]. MCM-48 is an intermediate of
hexagonal MCM-41 and lamellar MCM-50, so its cubic Ia3d mesophase is unstable
and liable to transform into other mesoporous phases, which results in the poor
reproducibility of its preparation [8, 9]. Moreover, the hydrothermal stability of
MCM-48 in boiling water is very weak. Considering that most applications of
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