Synthesis Strategies for New Zeolite Catalysts with Diquaternary Ammonium Molecules

Allen Burton

Chevron Research
Richmond, California

Abstract

The zeolite community has recently prepared a number of new zeolite structures by employing diquaternary ammonium molecules as structure directing agents (SDAs). In particular, several novel multidimensional medium-pore zeolites have been discovered that provide interesting comparisons with ZSM-5 in their structural features and catalytic behaviours. I will first discuss how we have used diquaternary pyrrolidinium molecules in fluoride-mediated gels to synthesize new zeolites like SSZ-74, SSZ-75, and SSZ-83. I will emphasize the structural elucidation and properties of SSZ-74, an exceptional zeolite that possesses ordered tetrahedral site vacancies. In the second part of the discussion, I will describe how we have prepared diquaternary ammonium molecules from enamine precursors. One of these SDA is used to prepare the novel zeolite SSZ-82, and several of the molecules are selective for the aluminosilicate and borosilicate versions of the SSZ-26/33 family, which has very few known SDA molecules.

Speaker’s Biography - Allen Burton received his BS in Chemistry at the University of Maryland at College Park , and his PhD in Chemical Engineering from the University of Delaware under the guidance of Prof. Raul Lobo. It was here Allen discovered his passion for zeolite synthesis, which he continued under the postdoctoral guidance of Prof Mark Davis at CalTech. In 2001 , Allen accepted a position in the research group at Chevron's Research facility in Richmond, CA. Despite his admitted ineptitude in the game of golf, on weekends he can sometimes be found at the golf range (swearing at golf balls and throwing his irons).