THEORETICAL & COMPUTATIONAL CHEMISTRY
B.S., North Dakota State University, 1985
Ph.D., University of Minnesota, 1989
NSF Postdoctoral Fellow, University of Houston, 1990-92
Office: 310 INSCC
Activities & Awards
- National Science Foundation Young Investigator Award 1993-1998
Our interests span several areas of research, particularly combustion of complex systems, solvation phenomena, zeolite catalysis, solid-liquid and solid-gas interfacial properties.
1. Combustion Chemistry. Kinetics and mechanisms of polyatomic gas-phase reactions plays important roles in many combustion systems. This information is the main bridge between chemistry and engineering. Our rather ambitious goal is to develop a new complete modeling tool that allows one to generate kinetic models of complex combustion systems with associated thermodynamic and kinetic parameters. This development consists of three components, namely 1) a direct ab initio dynamics tool for predicting kinetics of gas-phase chemical reactions from first principles; 2) chemical information management system and 3) an automated mechanism generator. We are currently applying these components to study combustion of hydrocarbon fuels, thermal decomposition of energetic materials, namely HMX, and carbon gasification process.
2. Solvation. Most chemical reactions occur in solution. Solvent effects can vary the reaction rate by several offers of magnitude or completely alter the reaction mechanism. Many theoretical efforts have been devoted to solvation, yet many challenges remain. Two of such challenges that attracted our attention are 1) modeling reactions in solution by a quantum chemistry method and 2) predicting thermochemistry of solvation, i.e. enthalpy, entropy and free energy of solvation as functions of temperature. From the dielectric continum methodology, we have been developing a solvation model called Generalized Conductor-like Screening Model (GCOSMO) for a solute in a arbitrary shape cavity. With this model, we were able to perform efficient quantum mechanical calculations of solvent effects on solute structures and reaction profiles and to successfully model solvent effects on spectroscopic properties. We are currently developing a computational methodology for calculating thermochemistry of solvation using an intergral equation theory, namely the Reference Interaction Site Model (RISM).
3. Zeolite Catalysis. Zeolites have been used as catalysts in many industrial processes, in addition to many other uses due to their microporous structures. Modeling reactivity of zeolites has been a theoretical challenge. Our focus has been to model mechanisms, kinetics and dynamics of reactions in zeolites using a new embedded cluster method developed in our lab. In this method, the reactive center is modeled as a cluster embedded in a Madelung field due to the extended structure of zeolite.
This allows the reactive center to be treated at an accurate level of electronic structure theory while the effects of the zeolite lattice are effectively included. Combining this with the direct ab initio dynamics method will provide us a tool to predict kinetics of reactions in zeolites. We are currently investigating several interesting problems, namely adsorption, proton siting and mobility, and reactions of hydrocarbon in zeolites.
4. Interfacial Phenomena. Molecular processes at solid-liquid interfaces play important roles in environmental chemistry and many technologies. Examples include transportation of groundwater contaminats, electrode phenomena, corrosion and dissolution. However, modeling such processes at the molecular level has many challenges due to the mobility of the liquid phase and the periodicity of the solid crystal. To model chemical reactivity at solid-liquid interface we have developed a new computational methodology that combines the embedded cluster method with a dielectric continuum solvation model. We are currently studying several systems, namely Al2O3-water interface and photocatalytic activity of TiO2-water interface. In a related area, we also interested in modeling reactions at the solid-gas interfaces. Reactivity of a gas/solid interface is often governed by its surface defects. To model reactions at such defects, we use an embedded cluster methodology developed in our lab. Work is being carried out for studying reactivity of vacancy and charge defects on TiO2 surfaces.
- Quantum Molecular Modeling of Virtual Kinetic Laboratory: http://vklab.hec.utah.edu Reactions in Solutions: "An Overview of the Dielectric Continuum Methodology", T.N. Truong, Inter. Rev. Phys. Chem. 17, 525 (1998).
- Quantum Mechanical Study of Molecular Weight "Grow Process by Combination of Aromatic Molecules", A. Violi, T.N. Truong, A. F. Sarofirm, Combustion and Flame126, 1506 (2001).
- A Full Quantum Embedded Cluster Study of" Proton Siting in Chabazite", P. Treesukol, J.P. Lewis, J. Limtrakul, T.N. Truong, Chem. Phys. Lett. 350, 128 (2001).
- Nature of the Excited State of Rutile TiO2(110) "Surface with Absorbed Water", V. Shapovalov, T.N. Truong, Surface Science 498, L103 (2002).
- Electronic Structure and Chemical Reactivity of" Metal Oxides-Water Interfaces", T.N. Truong, M.A. Johnson, E.V. Stefanovich, in Structure and Reactivity of Solid-Liquid Interfaces, W. Halley Ed., ACS Symposium Series, Vol. 789, 124 (2001).
- First Principles Kinetics for"CO Desorption during Gasification of Coal", A. Montoya, F. Mondragon, T.N. Truong, J. Phys. Chem. A 106, 4236 (2002).
- Kinetics of Hydrogen Abstraction Reaction Class H + HC(sp3): An Application of the Reaction Class Transition State Theory", S. Zhang, T.N. Truong, J. Phys. Chem. A, submitted.