Synthesis of zeolite ZSM-4
US4021447A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1975 |
| Grant date | May 3, 1977 |
| Priority date | — |
| Expiry date | Apr 30, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S423/26
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
As synthesized by previous methods, ZSM-4 zeolites are crystallized in the presence of substantial amounts of a tetramethylammonium hydroxide or halide. When synthesized in this way, they contain the tetramethylammonium cation as well as a metal cation such as sodium. To obtain a more catalytically active form, the sodium ion must be exchanged to very low levels. Catalysts prepared in this manner have been found to be quite low in stability. By synthesizing these zeolites in the presence of pyrrolidine or choline salts, ZSM-4 having a different organic nitrogen containing cation but the same crystal structure as previously prepared ZSM-4 is obtained. Catalysts made therefrom are, surprisingly, much more stable than those prepared from ZSM-4 made by previous methods.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.