MAS NMR Study on the Microstructural Changes of Zeolite-NaY under Neutron Irradiation

Autor: L. W. Beck, Binxi Gu, Jian Chen, Rodney C. Ewing, L. M. Wang
Rok vydání: 2003
Předmět:
Zdroj: MRS Proceedings. 792
ISSN: 1946-4274
0272-9172
DOI: 10.1557/proc-792-r3.27
Popis: The results of high-resolution solid-state magic angle spinning nuclear magnetic resonance (MAS NMR) indicate the bond angles of Al-O-Si decrease with the increase of neutronirradiation dose, but there are only minor changes for Si-O-Si bond angles in the current dose range studied. This suggests that zeolite with higher Si/Al ratio is more resistant to neutron irradiation damage. It is also found that [AlO6] formed at higher dose range. The ratio of Si/Al changed from 2.57 before neutron irradiation to 2.76 when the dose reached 2.25×1019 n/cm2, which shows that mild dealumination occurred during neutron irradiation. The strontium ion exchange experiments have been conducted for neutron irradiated, thermally treated and original zeolite samples, respectively. It is found that the ion-exchange ability of neutron-irradiated zeolite-NaY is between those of original and heat-treated zeolite samples. The distortion of the framework under neutron irradiation by the decrease of Al-O-Si bond angles and the formation of [AlO6] is partially responsible for the ion-exchange variability variation of zeolite-NaY.
Databáze: OpenAIRE
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