Fig. 2

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27Al (left) and 29Si (right) MAS NMR spectra of (a) the parent NaY zeolite, (b) after dealumination with SiCl4, (c) HCl washing and (d) finally desilication with NaAlO2. The 29Si NMR spectrum of NaY shows the deconvolution into five peaks corresponding to Si(nSi, 4-nAl) environments that was used to calculate the framework Si/Al ratio. Asterisks in 27Al NMR spectra indicate spinning side bands.