(256a) Seed-Assisted Synthesis of Zeolite Beta and Green Beta in Organic Structure-Directing Agent-Free System

Zeolite beta is an aluminosilicate zeolite possessing three-dimensionally intersected 12-membered-ring pore system and is one of the most industrially important zeolites as catalyst and adsorbents for its excellent characteristic properties. The conventional beta has been hydrothermally synthesized from aluminosilicate gel by using an organic structure-directing agent (OSDA) such as tetraethylammonium hydroxide (TEAOH).^[1] However, the use of OSDA still causes high expenses, complex process, mass-consumption of energy and outbreak of environmental burden. To overcome these difficulties, very recently, B. Xie et al. reported the synthesis of OSDA-free beta by adding calcined beta seed in Na-aluminosilicate gel in the absence of OSDA.^[2] According to their report, the compositions of reactant gel and seed were very limited in a restricted narrow range, and characterization has not been fully investigated and reproducibility is still unknown. In the present study, OSDA-free beta was synthesized based on the seed-induced crystallization system by using reacting gel and seed with wide range of chemical composition. Moreover, from a viewpoint of green chemistry, we tried to synthesize ″Green Beta″ to develop the recycling process of ultimate synthesis of OSDA-free beta. Finally, remarkable properties of OSDA-free beta and Green Beta are introduced and discussed. Detailed feature of synthesis and characteristic properties of obtained OSDA-free beta and Green Beta will be demonstrated in the presentation.

[1] Wadlinger, R. L.; Kerr, G. T.; Rosinski, E. J. U.S. Pat., 3 308 069 1967. [2] Xie, B.; Song, J.; Ren, L.; Ji, Y.; Li, J.; Xiao, F.-S. Chem. Mater. 2008, 20, 4533.