Research Interests

Molecular Beam Studies of Nitrogen Reactions on Iron-Sulfur Surfaces Research in the Minton group involves the use of molecular beam techniques to study the details of chemical interactions that occur in the gas phase and at the gas-surface interface.  In the ABRC, molecular beam techniques will be used to understand the mechanisms by which molecular nitrogen reacts on iron-sulfur surfaces to produce ammonia or precursors to ammonia.  If we can achieve a molecular level understanding of the mechanisms by which N₂ reacts, then we will have a good idea about what kinds of surfaces are likely to be reactive.  This knowledge can help guide and anchor calculations by Robert Szilagyi’s group and can be used to suggest directions for experiments by Martin Schoonen’s and Dan Strongin’s groups.  In addition, knowledge of the mechanisms can help us understand the detailed chemistry that determines the products seen in Schoonen’s and Strongin’s experiments.  Finally, we might even be able to start to glean the reason for the structural motifs that are seen in catalysts in biological systems.  There are many variables to be explored in the experiments, including N₂ translational energy, surface temperature, surface morphology, and surface chemistry.  With regard to surface chemistry, the ratio of Fe to S at the surface and the presence of adsorbed hydrogen or other species, such as potassium, may strongly affect the outcome of N₂ collisions with the surface.

The scheme to the right  illustrates the concept of the first set of experiments.  The idea is to use a beam of deuterium atoms to hydrogenate an iron-sulfur surface with D atoms and then bombard this surface with a beam of energetic N₂ molecules.  It is possible that the N₂ will dissociatively chemisorb to the surface and then start reacting with D atoms in a sequence of reactions that eventually leads to ND₃, which will desorb from the surface.  The detection of ND₃ (by mass spectrometry) would be unequivocal evidence for N₂ dissociation on the surface.  We will run this experiment under different conditions of surface temperature, surface morphology, and surface chemistry, as well as with different N₂ beam energies.  We hope to be able to identify reactive surfaces and understand what conditions are most efficient for promoting the ammonia producing reactions. 

Selected Publications

“Beam-Surface Scattering Studies of the Individual and Combined Effects of VUV Radiation and Hyperthermal O, O₂, or Ar on FEP Teflon Surfaces,” A. L. Brunsvold, H. P. Upadhyaya, J. Zhang, and T. K. Minton, ACS Appl. Mat. Interfaces, in press, to be published January 2009.

“Unusual Mechanisms Can Dominate Reactions at Hyperthermal Energies: An Example from O(³P) + HCl → ClO + H,” J. Zhang, J. P. Camden, A. L. Brunsvold, H. P. Upadhyaya, T. K. Minton, and G. C. Schatz, J. Am. Chem. Soc. 130, 8896-8897 (2008).

“Hyperthermal Ar Atom Scattering from a C(0001) Surface,” K. D. Gibson, S. J. Sibener, H. P. Upadhyaya, A. L. Brunsvold, J. Zhang, T. K. Minton, and D. Troya, J. Chem. Phys. 128, 224708 (2008).

“Protection of Polymer from Atomic-Oxygen Attack by Thin Coatings of Al₂O₃ Prepared by Atomic Layer Deposition,” R. Cooper, H. P. Upadhyaya, T. K. Minton, X. Du, S. M. George, and M. R. Berman, Thin Solid Films 516, 4036-4039 (2008).

“Dynamics of Hyperthermal Collisions of O(³P) and CO,” A. L. Brunsvold, H. P. Upadhyaya, J. Zhang, R. Cooper, T. K. Minton, M. Braunstein, and J. W. Duff, J. Phys. Chem. A 112, 2192-2205 (2008).

“Crossed-Beams and Theoretical Studies of the O(³P) + H₂O à HO₂ + H Reaction Excitation Function,” A. L. Brunsvold, J. Zhang, H. P. Upadhyaya, T. K. Minton, J. P. Camden, J. T. Paci, and G. C. Schatz, J. Phys. Chem. A 111, 10907-10913 (2007).

“Morphological Changes at a Silver Surface Resulting from Exposure to Hyperthermal Atomic Oxygen,” L. Li, J. C. Yang, and T. K. Minton, J. Phys. Chem. C 111, 6763-6771 (2007).  [featured on journal cover]

“Hyperthermal Reactions of O and O₂ with a Hydrocarbon Surface: Direct C–C Bond Breakage by O and H-Atom Abstraction by O₂,” J. Zhang, H. P. Upadhyaya, A. L. Brunsvold, and T. K. Minton, J. Phys. Chem. B 110, 12500-12511 (2006).

“Homogeneous Silica Formed by the Oxidation of Si(100) in Hyperthermal Atomic Oxygen,” M. Kisa, L. Li, J. Yang, T. K. Minton, W. Stratton, P. Voyles, X. Chen, K. van Benthem, and S. J. Pennycook, J. Spacecraft and Rockets 43, 431-435 (2006).

 “Spatially Anisotropic Etching of Graphite by Hyperthermal Atomic Oxygen,” K. T. Nicholson, T. K. Minton, and S. J. Sibener, J. Phys. Chem. B 109, 8476-8480 (2005).

Lab Personnel

Jianming Zhang
Senior Research Scientist
jzhang@montana.edu

Li Che*
Post-Doctoral Associate
liche@chemistry.montana.edu

Sridhar Lahankar
Post-Doctoral Associate  
slahankar@chemistry.montana.edu  

Bohan Wu
Post-Doctoral Associate
bwu@chemistry.montana.edu

Linhan Shen
Undergraduate Student
linhan.shen@gmail.com

Collaborators

Mitchio Okumura (atmospheric chemistry)
Department of Chemistry
Caltech

George Schatz (theoretical reaction dynamics and nanoscience)
Department Chemistry
Northwestern

Xueming Yang (photocatalysis, reaction dynamics)
State Key Laboratory for Reaction Dynamics
Dalian Institute of Chemical Physics
Dalian, P. R. China

Steven Sibener (surface science)
Department of Chemistry
University of Chicago

Judy Yang (electron microscopy)
Department of Materials Science
University of Pittsburgh

Matthew Braunstein (theoretical chemistry)
Spectral Sciences, Inc.
Burlington, MA

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