DEALUMINATION OF ZEOLITE-Y BY H4EDTA

被引：40

作者：

DATKA, J ^{[1
]}

KOLIDZIEJSKI, W ^{[1
]}

KLINOWSKI, J ^{[1
]}

SULIKOWSKI, B ^{[1
]}

机构：

[1] UNIV CAMBRIDGE,DEPT CHEM,CAMBRIDGE CB2 1EW,ENGLAND

来源：

CATALYSIS LETTERS | 1993年 / 19卷 / 2-3期

关键词：

HIGHLY SILICEOUS ZEOLITES; SICL4; CP MAS NMR; HYDROXYL NESTS;

D O I：

10.1007/BF00771751

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Solid-state NMR shows that the treatment of zeolite Y by H4EDTA dealuminates the zeolite framework. Since no extra-framework aluminium is found, all the Al removed from the framework is subsequently washed out of the crystallites in the form of an H4EDTA complex. Unlike with hydrothermal dealumination or treatment with SiCl4, H4EDTA gives defective crystals in which framework vacancies created by the expulsion of aluminium are not healed by silicon from other parts of the framework. The likely reason for this is the slow intracrystalline diffusion of Si(OH)4 at low temperatures. Si-29 CP/MAS NMR and infrared spectra confirm the creation of hydroxyl nests in the zeolitic framework. A small amount of disordered siliceous phase responsible for a low intensity Si-29 MAS NMR shoulder at -110 ppm is produced in the process.

引用

页码：159 / 165

页数：7