Determination of the Al-T1/Al-T2 ratio in MAZ zeolites using line shapes of MQ MAS NMR

The MQ MAS NMR is used to evaluate the real, individual line shape of the A l signals in the 1D Al-27 MAS NMR spectrum of zeolite materials. By the app lication of these real line shapes, an improved deconvolution of the 1D MAS NMR spectrum is achieved. This methodology was applied to the two tetrahed rally coordinated Al sites in mazzite zeolite, resulting in an accurate det ermination of the Al-T1/Al-T2 ratio. The method proposed here yields signif icant higher Al-T1/Al-T2 ratios then those obtained from the classical deco nvolution of the 1D Al-27 MAS NMR by two Lorentzian shaped lines. This impl ies an enrichment of Al in the 12-membered channel compared to the ratio pr oposed earlier in the literature.