Chinese Journal of Catalysis ›› 2012, Vol. 33 ›› Issue (1): 85-91.DOI: 10.1016/S1872-2067(10)60291-4

• Research papers • Previous Articles     Next Articles

A Dynamic Organic Structuring-Directing Agent for Pure-Silica-Zeolite AST and LTA Syntheses

Minwei SUN1, Heather K. HUNT2, Christopher M. LEW1, Rui CAI1, Yan LIU1, Yushan YAN1,*   

  1. 1Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521, USA; 2Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
  • Received:2011-08-23 Revised:2011-10-02 Online:2012-01-16 Published:2015-05-26

Abstract: Pure-silica-zeolite (PSZ) AST and LTA are synthesized successfully by using the same structure-directing agent (SDA) molecule, but at different concentrations. A dynamic organic SDA is proposed to discuss the mechanism of phase discrimination between AST and LTA. Data suggest that the SDA molecules can self-assemble into dimer or trimer complexes at different concentrations by π-π interactions, and these differences can be taken advantage of to selectively synthesize either PSZ AST or LTA. These deviations from the Liebau’s rules indicate that small changes in SDA chemistry, structure, and order in solution can have a great impact on the structure selectivity of the zeolite synthesis.

Key words: zeolite, synthesis, dynamic structure-directing agent, π-&pi, conjugation, Liebau’s rules