H.R.E.M. on intergrowths of cubic and hexagonal faujasite

✍ Scribed by A. J. Bons; J. L. Lievens; J. P. Verduijn; W. J. Mortier

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 293 KB
• Volume: 25
• Category: Article
• ISSN: 1059-910X
• DOI: 10.1002/jemt.1070250211

✦ Synopsis

JNTRODUCTION

Faujasi te is a zeolite with widespread industrial applications. The crystal structure of faujasite (structure type FAU) can be described as a cubic close packing of so-called sodalite cages connected by double six-rings of SiOl tetrahedra. The corresponding hexagonal close-packed structure was predicted bj7 Breck (Breck, 1974) and was called Breck's Structure Six. Only recently methods were found to sjmthesize the hexagonal polytype of faujasi te using crown-ethers as templates (Delprato et a1. 1989), and the code EMT kvas assigned to this structure. EMT draws much attention because its three-dimensional channel system is comparable \i:i th FAU, while higher Si/AI ratios can be obtained leading to more stable crjstals with different catalytic and separation properties. In this communication u.e demonstrate the importance of' transmission electron microscopy (TEM) to the characterization of EMT.