V. Umamaheswari et al., Isomorphous substitution of Mn(II), Ni(II) and Zn(II) in AlPO-31 molecularsieves and study of their catalytic performance, P I A S-CH, 112(4), 2000, pp. 439-448
Citations number
17
Categorie Soggetti
Chemistry
Journal title
PROCEEDINGS OF THE INDIAN ACADEMY OF SCIENCES-CHEMICAL SCIENCES
Isomorphously substituted molecular sieves, MAPO-31, NAPO-31 and ZAPO-31, w
ere prepared under mild hydrothermal conditions from gels containing source
s of aluminium, phosphorus, appropriate metal and dipropylamine (DPA), pres
umably acting as a structure-directing template. They were characterized by
XRD, FTIR, TGA, inductively coupled plasma (ICP), ESR, Brunauer, Emmett, T
eller (BET) and diffusion reflectance spectroscopy (DRS) techniques. In the
XRD, the peak at 2 theta = 16.7 degrees of the metal substituted AlPO-31 i
s more intense than that of pure AlPO-31 suggesting preferential occupation
of the plane corresponding to it as compared to other planes. The O-H stre
tch in the IR spectra of the metal-substituted molecular sieves is blue-shi
fted with respect to the parent AlPO-31 molecular sieves possibly due to me
tal substitution. The g values obtained from the ESR spectra of MAPO-31 and
NAPO-31 also substantiate framework substitution. Ethylation of toluene wa
s carried out between 300 and 450 degrees C over the above catalysts as a m
odel test reaction. The high toluene conversion over metal-substituted mole
cular sieves proves the isomorphic substitution of metal ions in the AlPO-3
1 framework.