Sulfated zirconia (SZ) was supported on siliceous hollow tubular MCM-41 mes
oporous molecular sieve by using a one-step incipient wetness impregnation
method with zirconium sulfate as the precursor. The SZ/MCM-41 catalyst was
obtained by thermal decomposition of the precursor in air. The resultant ca
talyst was characterized with various techniques, such as nitrogen physisor
ption, X-ray diffraction, SEM, and TEM. It was shown that the well-ordered
channels of MCM-41 support arranged in hexagonal arrays while the hollow tu
bular morphology was retained. Both tetragonal and monoclinic phases of zir
conia were developed in the catalysts. With the addition of a proper amount
of aluminum as a promoter, resulting in catalyst SZA/MCM-41, the transform
ation of zirconia from metastable tetragonal phase to monoclinic phase was
retarded. The catalytic activity of SZA/MCM-41 catalyst in the isomerizatio
n of n-butane was dramatically improved in comparison to the activities of
SZ/MCM-41 or SZA/silica. (C) 2001 Elsevier Science B.V. All rights reserved
.