This latest grant covers zeolites that, when unmodified, are shaped like cylinders, with their pores running the length of the cylinder. Molecules that enter these pores must travel much farther than needed during the course of the reaction. As a result, the catalysts are more susceptible to the formation of coke, a carbon-rich deposit that blocks the pores and deactivates the catalyst.
Like all crystals, these zeolites grow when new molecules of the crystal material attach to specific locations (known as growth sites) on the zeolite surface. Rimer and Maayan are developing peptoids that bind to the zeolite surfaces at these sites. A segment of the peptoid will then physically block the growth sites, thus frustrating the attachment of additional molecules to the crystal.
By blocking these sites, he aims to change the shape of these zeolites from cylinders to flat platelets. This will significantly improve the lifetime of catalysts by reducing coke formation in various reactions. As a result companies should be able to carry out these processes more efficiently and for less money than before.
Just as importantly, using modified zeolites would require little to no changes in the manufacturing processes used by companies in the chemicals sector, said Rimer.
"This is something that could be integrated into an existing process very easily, without requiring equipment upgrades or dramatic changes in operating conditions," Rimer explained. "So from an economic perspective, this could be very attractive for industry."
|Contact: Jeannie Kever|
University of Houston