Acta Phys. -Chim. Sin. ›› 1998, Vol. 14 ›› Issue (02): 169-172.doi: 10.3866/PKU.WHXB19980214

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States and Assignment of Aluminium in Zeolite β

Yang Chun, Xu Qin-Hua   

  1. Department of Chemistry,Nanjing University,Nanjing 210093
  • Received:1997-06-13 Revised:1997-09-22 Published:1998-02-15
  • Contact: Xu Qin-Hua

Abstract:

The states of aluminum in zeolites β were investigated with FTIR spectroscopy. Three kinds of aluminium, framework, nonframework and transient state aluminium, were detected in template-removed zeolite β. The states of aluminium in our samples strongly depends on the nature of the compensating cation, consistent with Brougeat-Lami et al's conclusion. But some new assignments of aluminum species and new opinions about the states of aluminum and their transformation are proposed. From the experimental results, we suggest that, the distortion and tension of zeolite lattice occur when protons, which possess high electron affinity , are located at cationic sites, leading to the breakage of Al-- O bond and the removal of aluminium. The distortion is released when H+ is replaced by other cations (e.g. Na+ ) so that transient state aluminium can go back into the framework, while the cationic nonframework aluminium species enter the solution upon the ion-exchange.

Key words: Zeolite β, State and assignment of aluminium, FTIR