Special Student/Faculty ChBE Seminar: Dongxia Liu
Thursday, December 4, 2014
11:00 a.m.-12:15 p.m.
Room 2108, Chemical and Nuclear Engineering Building
Professor Jeffery Klauda
Design, Synthesis and Mechanistic Understanding of Hierarchical Lamellar Zeolites for Energy Conversion Applications
Department of Chemical and Biomolecular Engineering
University of Maryland
Energy is clearly a global grand challenge problem for the 21st century. In our research group, we combine our expertise in materials science, catalysis, and separation, aiming to create innovative catalyst and membrane technologies that enable active and selective chemical conversions with particular focus on the catalytic conversion of C1 feedstocks. In this seminar, I will present our recent work on developing innovative meso-/microporous lamellar zeolite catalysts and mechanistic understanding of their textural and catalytic properties in catalytic reactions. Hierarchical meso-/microporous zeolites couple the catalytic features of micropores and the improved access and transport consequence of mesopores in a single material, possessing the capacity of processing large molecules. The synthesis and catalytic behavior investigation of meso-/microporous zeolites has become the subject of intense research. We have developed a simple one-step dual template synthesis method to tailor the textural properties of lamellar zeolite materials. Implications of the tunable meso-/microporosity on the spatial distribution and catalytic performance of active sites in lamellar zeolite catalysts have been studied using organic chemical titration, x-ray photoelectron spectroscopy and direct methane aromatization reactions. Volcano-type dependence between the hierarchy factor, distribution of active sites, and product formation rate with the dual template ratios in the hydrothermal synthesis suggest that the textural and composition properties and thus the catalytic performance of the catalysts can be optimized by the designed zeolite synthesis. The capability of forming hierarchical lamellar zeolites with tunable meso-/microporosity is important to keep their potential applications as broad as possible for a specific zeolite structure in catalytic reactions.