Characterization of Framework Hetero-atom (B, Ti, Fe) in Y-type Zeolite
Acta Phys. -Chim. Sin.
2006, 22 (01):
The structure and properties, such as the unit cell parameters, framework vibration bands, characteristic electronic transition, deductibility of heteroatom-containing Y zeolites, were investigated by XRD, FT-IR, UV-Vis-DRS, TG, and NMR. It showed that suitable hetero-atom incorporation into the zeolite framework does not change the crystallographic form of zeolite Y. The unit cell of zeolite BY is shrinked and the framework vibration bands shift to higher frequency comparing with zeolite Y. The unit cell sizes of zeolite TiY and FeY are increased and framework vibration bands shift to lower frequency. The 11B MAS-NMR shows that atom B is in the tetrahedral position of the framework, which differs from zeolite Y impregnated boron. UV-Vis-DRS spectra suggest that atom Ti in zeolite TiY differs from extra atom Ti evidently and the zeolite FeY reduced by hydrogen at 600 ℃ does not have reduction peaks, but zeolite Y impregnated Fe is reduced completely at the same conditions. The results suggest that the hetero-atoms, B, Ti, and Fe, all enter the framework of zeolite Y.
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