Imidazolium structure directing agents in zeolite synthesis: Exploring guest/host relationships in the synthesis of SSZ-70
Abstract
The synthesis of high-silica molecular sieve SSZ-70 is investigated using a variety of imidazolium structure directing agents (SDAs) that are designed to explore the nature of the guest (SDA)/host (SSZ-70) interactions. The SDAs are symmetric 1,3-disubstituted imidazoliums that span a wide range of hydrophobicity from 1,3-dimethylimidazolium (Σ(C + N) = 7) to 1,3-bis(2,6-diisopropylphenyl)imidazolium (Σ(C + N) = 29). Reactions with fluoride or hydroxide as mineralizing agent are investigated in pure-silica, borosilicate, and aluminosilicate inorganic compositions. The original borosilicate synthesis is extended to pure-silica and aluminosilicate compositions using five SDAs. The five SDAs span Σ(C + N) = 13 (1,3-bis(isobutyl)imidazolium) to Σ(C + N) = 19 (1,3-bis(cycloheptyl)imidazolium and 1,3-bis(norborn-2-yl)imidazolium) and four contain cycloalkyl groups. Thirteen screening reaction conditions (total of 160 syntheses) produced 11 different known molecular sieves.
Additional Information
© 2009 Elsevier. Received 28 September 2009; accepted 17 November 2009. Available online 20 November 2009. This work was supported by the Chevron Energy Technology Company. Electron microscopy was performed by I.Y. Chan (Chevron Energy Technology Company). The authors would like to thank Allen Burton (Chevron Energy Technology Company) for thoughtful discussions and suggestions.Additional details
- Eprint ID
- 17919
- Resolver ID
- CaltechAUTHORS:20100409-142845517
- Chevron Energy Technology Company
- Created
-
2010-04-26Created from EPrint's datestamp field
- Updated
-
2021-11-08Created from EPrint's last_modified field