Presenter: Thomas John Whynot

Faculty Sponsor: Wei Fan

School: UMass Amherst

Research Area: Chemical and Biomolecular Engineering

Session: Poster Session 4, 2:15 PM - 3:00 PM, Auditorium, A46

ABSTRACT

Zeolites are versatile aluminosilicate materials used in catalysis, separations, and adsorption processes. The mordenite (MOR) zeolite framework features a large 12-membered ring channel and a one-dimensional pore system that enables shape-selective reactions. Increasing the Si/Al ratio reduces the number of aluminum sites in the MOR framework, which enhances hydrothermal stability, decreases acidity, and is associated with lower coke formation and higher catalytic activity. This study investigates the hydrothermal synthesis of high silica MOR starting from both amorphous silica and interzeolite conversion of faujasite (FAU). Dehydrated precursor gels favored higher energy metastable frameworks such as beta, while increasing water content did not yield substantial amounts of MOR. However, when FAU was used instead of silica as the precursor material under the same conditions, pure MOR formed via interzeolite conversion in 3 to 6 hours, much faster than the 20 hours required when starting from amorphous silica. These results show that the structural ordering in the precursor strongly directs the final product formed and demonstrate the effectiveness of interzeolite conversion as a targeted synthesis strategy. In addition, the use of dealuminated FAU as the starting material provides a new pathway to synthesizing high silica MOR for use in catalysis, adsorption, and separations.