《Table 2 Physical structural properties of the samples》

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《“蒸汽相转化”法制备球形多级Y沸石（英文）》

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Figure 7（a）and（b）are 29Si MAS NMR spectra of sample YS-5.18 and the corresponding dried gel YP-5.18，respectively.The resonances atδ=-108～-105 are assigned to Si（4Si，0Al）sites，and thoseδ=-105～-95 are assigned to Si（3Si，1Al）sites；moreover，those atδ=-95～-92，-92～-86，and-86～-80，are respectively assigned to the Si（2Si，2Al），Si（1Si，3Al），and Si（0Si，4Al）[26].The calculated framework Si/Al ratio of sample YS-5.18 is about 1.65（Table 1），which is slightly lower than 1.73 detected by EDS.It can be seen from Fig.7（b）that the resonances assigned to Si（0Si，4Al），Si（1Si，3Al）and Si（2Si，2Al）sites can be obviously observed in dried gel YP-5.18，indicating that the primary zeolite framework has been practically formed in dried gel yielded from the gel mixture after treated at 60℃for 24h.The calculated framework Si/Al ratio of dried gel YP-5.18 is about 1.27（Table 1），which is rather lower than 1.65 of the final product YS-5.18.The aforementioned results suggest that the primary zeolite framework formed during the preparation of the dried gel has a rather lower Si/Al ratio as compared with the one in final products.The calculated framework Si/Al ratio and the different aluminium coordination are shown in Table 1.It can be inferred that the primary zeolite framework formed during preparing dried gel is rich in Al-，and Si-species entering the zeolite framework fall behind the Al-species.Combining with the FT-IR result as shown in Fig.5，it can be further deduced that some building units or minicrystals with primary zeolite framework，which are not yet detected by XRD or TEM because of very small spatial scale，have been really formed during the preparation of the dried gel precursors.