Synthesis and Monte Carlo Structure Determination of SSZ-77: A New Zeolite Topology

David J. Earl, Allen W. Burton, Thomas Rea, Kenneth Ong, Michael W. Deem*§, Son-Jong Hwang, Stacey I. Zones
Department of Chemistry and Center for Molecular & Materials Simulations, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, Pennsylvania 15260, Chevron Energy Technology Company, Richmond, California 94802, Departments of Bioengineering and Physics & Astronomy, Rice University, 6100 Main Street - MS142, Houston, Texas 77005, and The Division of Chemistry and Chemical Engineering, MC 210-41, California Institute of Technology, Pasadena, California 91125
J. Phys. Chem. C, 2008, 112 (24), pp 9099–9105
DOI: 10.1021/jp7116856
Publication Date (Web): May 23, 2008
Copyright © 2008 American Chemical Society

University of Pittsburgh.

Chevron Energy Technology Company.

*

To whom correspondence should be addressed. E-mail: mwdeem@rice.edu.

§

Rice University.

California Institute of Technology.

Abstract

A new molecular sieve topology has been determined from a multistage Monte Carlo computer simulation procedure using the program ZEFSAII. The material, SSZ-77, consists of alternating layers present in the RUT and AST topologies, and intergrowths may be possible in the way that this material grows. The product first arose from a synthesis where it appears that the degradation of the quaternary ammonium structure directing agent (SDA) produced the viable organo-guest molecule in the structure formation. The synthesis requires the use of Ge as well as Si as lattice components. In the absence of Ge, only RUT forms. An additional study was carried out to determine the suitable size of guest molecules in a series spanning trimethylamine to tetraethylammonium in the presence of benzyltrimethylammonium. It is found from NMR investigations that none of the larger molecules are occluded within the cages of the SSZ-77 structure, and that the primary occluded species is trimethylamine or tetramethylammonium.

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History

  • Published In Issue June 19, 2008
  • Article ASAPMay 23, 2008
  • Received: December 12, 2007
    Revised: March 25, 2008

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