A study of the dealumination methods for zeolite L

✍ Scribed by P Bartl; W.F Hölderich

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 177 KB
• Volume: 38
• Category: Article
• ISSN: 1387-1811
• DOI: 10.1016/s1387-1811(00)00147-5

✦ Synopsis

The dealumination of zeolite L was attempted by steaming, treatment with ammonium hexa¯uorosilicate, and with silicon tetrachloride. The zeolite framework can be dealuminated most eectively through ion exchange into the sodium form followed by treatment with silicon tetrachloride. The crystalline structure remains essentially intact. FTIR spectroscopy and 29 Si MAS-NMR attest to the most intense dealumination. However, after the treatment with silicon tetrachloride, the zeolite loses its nitrogen adsorption capacity almost entirely, probably because of pore blockage by amorphous silica and/or alumina. Steaming leads to intense structural collapse, as does treatment with ammonium hexa¯uorosilicate beyond a limited extent.