T. Michael Duncan

Current Research & Projects

Heterogeneous Catalysis and Materials Processing

Our research program concerns studies in heterogeneous catalysis and advanced materials to determine the molecular basis for macroscopic effects such as chemical, electrical, and mechanical properties. The investigations involve spectroscopic characterization with nuclear magnetic resonance (NMR) spectroscopy as the primary tool, complemented with established methods, notably infra-red spectroscopy and mass spectrometry. Through this characterization, we are able to devise, for example, mechanisms of catalytic reactions or the effects of processing on material micro-structures. This offers the potential to improve the reaction or the processing of materials.

Our current thrust in heterogeneous catalysis is the study of dynamics, such as adsorption and desorption, surface diffusion, and reaction. The unique capacity of NMR spectroscopy to characterize surface dynamics derives from the correspondence between the time scales for these key phenomena and the characteristic times for NMR excitation and relaxation. We are applying NMR methods to in situ studies of flow reactors at steady-state reaction conditions to identify reactive intermediates. The mass transfer of reactants and products in porous catalysts at various degrees of deactivation is characterized by pulsed field gradient techniques.

We are also applying NMR spectroscopy to provide an elemental-selective non-invasive probe of chemical processes such as the synthesis of novel ceramics by sol-gel and polymerization techniques, the properties of two-dimensional polymer intercalates, and elastomeric polymers.

T. M. Duncan - Research Projects

Graduate Research

"Elastomer Structure/Property Relations Investigated with Deuterium NMR Spectroscopy," Kim McLoughlin, Ph.D. 1996

"Diffusion and Deactivation in a Zeolite Acid Catalyst Investigated by Solid-State and Pulsed Field-Gradient NMR," Tim Carroll, Ph.D., 1996.

Undergraduate Research

"Reactivity of Alumina and Alumino-Silicates for the Catalysis of Methanol to form Dimethyl Ether" Robert Crane, 1992.

"Studies of the Mechanism and Kinetics of the Alumina-Catalyzed Reaction of Methanol to form Dimethyl Ether," Catherine Labelle, 1992-94.

"Carbon Monoxide Adsorbed on Isolated Rhodium Atoms: Exchange of Oxygen with the Substrate," Kathleen Vaeth, 1993-94

"Synthesis and Molecular Weight Distribution of Silicone Rubber," Carol Szeto, 1993-94

"Synthesis and Characterization of Monomers for Elastomer Networks: Deuterated Hexamethylcyclotrisiloxane," Susan Minch, 1993.

"2H NMR Study of Molecular Motion in Polyethylene," Arundhati Kotwal, 1993.

"Multi-Nuclear NMR Study of Mixed-Oxide Glasses," Arundhati Kotwal, 1994.

"Adsorption and Reaction of Simple Hydrocarbons on Zeolites," Jack Geilfuss, 1993-95

"Synthesis of Zeolitic Materials with Large Crystals," Christine Haakenson, 1993.

"Characterization of Mechanical Properties of Novel Elastomers," Christine Haakenson, 1994.

"Studies of the Mechanism and Kinetics of Zeolite-Catalyzed Formation of Coke Deposits," Rakesh Kadakia, 1994

"Adsorption and Diffusion in Zeolites before and after Coking," Chantaraporn Phalakornkule, 1994-95

"2H NMR Studies of Stressed Elastomers - Design and Testing of a Device to Compress Samples," Kristen Powers, 1995.

"Adsorption, Reaction, and Diffusion of Simple Hydrocarbons in Zeolites: Experiments and Simulations," Todd Zion, 1995-97.

"Development of a Device for Frequency-Response Measurements of Diffusion in Porous Catalysts," Douglas Hassell, 1995.

"2H NMR Studies of Stressed Elastomers," Jean Waldbieser, 1995.

"Carbon Monoxide Adsorbed on Isolated Rhodium Atoms: Exchange of Oxygen with the Substrate" Numan Waheed, 1996-97.

"Frequency-Response Measurements of Diffusion in Porous Catalysts," Todd Wernicke, 1996.

"1H NMR Studies of Novel Polymers," (joint with Professor Gianellis, MS&E) Jean Waldbieser, 1996.

"Random-Walk Simulations of Intra-crystalline and Extro-crystalline Diffusion of C-3 Hydrocarbons in Zeolite-X," Anna Godfrey, 1996-98.