The detection of all of the aluminium present in steamed
zeolite H-Y catalysts by 27Al MAS NMR at high field (18.8 T,
800 MHz for 1H) is reported; further, it is shown that it is
possible by 27Al MAS and MQMAS measurements to clearly
identify four separate aluminium environments characteristic
of these materials and to unambiguously assign their
coordinations.
intensities of both spectra indicate that signal is observed from
100% of the aluminium present.
The MQMAS experiment introduced by Frydman and
Harwood12 (Fig. 2) correlates peaks in the MAS dimension (F2)
to signals in the isotropic dimension (F1), with shifts in this
dimension being a linear combination of isotropic chemical and
Revised: August 6, 2003 |
Published: August 1, 2000
Citation
Fyfe C.A., J.L. Bretherton, and L.Y. Lam. 2000.Detection of the ‘invisible aluminium’ and characterisation of the multiple aluminium environments in zeolite USY by high-field solid-state NMR.Chemical Communications.