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Greg Kimmel

Chemical Physics & Analysis
Pacific Northwest National Laboratory
PO Box 999
MSIN: K8-88
Richland, WA 99352


Dr. Greg Kimmel investigates thermal and non-thermal reactions at surfaces and interfaces. These reactions are important in a wide range of applications including catalysis, photocatalysis, radiation chemistry and waste processing. Since high-energy radiation typically produces numerous low-energy secondary electrons that are chemically active, the low-energy electrons (<100 eV) frequently play a dominant role in radiation chemistry. In addition, the presence of surfaces or interfaces modifies the reactions and processes compared to what occurs in the bulk. In photocatalysis, visible and/or UV photons are used to initiate a variety of reactions. However, a detailed understanding of the underlying physical and chemical processes is often lacking. Dr. Kimmel and his colleagues use surface science techniques to investigate thermal and non-thermal reactions at surfaces and interfaces. This work addresses several important issues, including the need to understand the relative importance of the primary excitation source compared to the secondary electrons it produces, energy transfer at surfaces and interfaces, and new reaction pathways at surfaces. Dr. Kimmel also investigates the structure of water films at interfaces. Understanding the structure of the water films provides a foundation for the development of a detailed understanding of the reactions at aqueous interfaces.

Research Interests

  • energetic processes at surfaces and interfaces in fields such as radiation chemistry, waste processing, and advanced materials synthesis.
  • the structure of water at interfaces
  • chemistry on oxide surfaces

Education and Credentials

  • Ph.D. Applied Physics, Cornell University, Thesis topic: Charge exchange processes for atoms and molecules scattering from metal surfaces.
  • B.S. Engineering Physics (with distinction), Cornell University

Affiliations and Professional Service

  • American Physical Society
  • American Chemical Society

Awards and Recognitions

PNNL Publications


  • Petrik NG, MA Henderson, and GA Kimmel. 2015. "Insights into Acetone Photochemistry on Rutile TiO2(110). 1. Off-Normal CH3 Ejection from Acetone Diolate." Journal of Physical Chemistry C 119(22):12262-12272.  doi:10.1021/acs.jpcc.5b02477
  • Petrik NG, MA Henderson, and GA Kimmel. 2015. "Insights into Acetone Photochemistry on Rutile TiO2(110). 2. New Photodesorption Channel with CH3 Ejection along the Surface Normal." Journal of Physical Chemistry C 119(22):12273-12282.  doi:10.1021/acs.jpcc.5b02478
  • Yoon Y, Y Du, JC Garcia, Z Zhu, Z Wang, NG Petrik, GA Kimmel, Z Dohnalek, MA Henderson, RJ Rousseau, NA Deskins, and I Lyubinetsky. 2015. "Anticorrelation between Surface and Subsurface Point Defects and the Impact on the Redox Chemistry of TiO2(110)." Chemphyschem 16(2):313-321.  doi:10.1002/cphc.201402599


  • Kimmel GA, T Zubkov, RS Smith, NG Petrik, and BD Kay. 2014. "Turning things downside up: Adsorbate induced water flipping on Pt(111)." Journal of Chemical Physics 141(18):18C515.  doi:10.1063/1.4896226
  • Lercher JA, AM Appel, T Autrey, RM Bullock, DM Camaioni, HM Cho, DA Dixon, Z Dohnalek, F Gao, VA Glezakou, MA Henderson, JZ Hu, E Iglesia, AJ Karkamkar, BD Kay, GA Kimmel, JC Linehan, J Liu, I Lyubinetsky, D Mei, CHF Peden, RJ Rousseau, GK Schenter, WJ Shaw, J Szanyi, H Wang, Y Wang, and RS Weber. 2014. "Multifunctional Catalysts to Synthesize and Utilize Energy Carriers." In Frontiers at the Interface between Homogeneous and Heterogeneous Catalysis, II, pp. 207-219.  U.S. Department of Energy, Office of Science, Washington, DC. 
  • Petrik NG, and GA Kimmel. 2014. "Probing the photochemistry of chemisorbed oxygen on TiO2(110) with Kr and other co-adsorbates." Physical Chemistry Chemical Physics. PCCP 16(6):2338-2346.  doi:10.1039/c3cp54195a
  • Petrik NG, RJ Monckton, S Koehler, and GA Kimmel. 2014. "Distance-dependent radiation chemistry: Oxidation versus hydrogenation of CO in electron-irradiated H2O/CO/H2O ices." Journal of Physical Chemistry C 118(47):27483-27492.  doi:10.1021/jp509785d
  • Petrik NG, RJ Monckton, S Koehler, and GA Kimmel. 2014. "Electron-stimulated reactions in layered CO/H2O films: Hydrogen atom diffusion and the sequential hydrogenation of CO to methanol." Journal of Chemical Physics 140(20):Article No. 204710.  doi:10.1063/1.4878658


  • Petrik NG, and GA Kimmel. 2013. "Multiple Non-Thermal Reaction Steps for the Photooxidation CO to CO2 on Reduced TiO2(110)." The Journal of Physical Chemistry Letters 4(3):344-349.  doi:10.1021/jz302012j


  • Du Y, NG Petrik, NA Deskins, Z Wang, MA Henderson, GA Kimmel, and I Lyubinetsky. 2012. "Hydrogen Reactivity on Highly-hydroxylated TiO2(110) Surfaces Prepared via Carboxylic Acid Adsorption and Photolysis." Physical Chemistry Chemical Physics. PCCP 14(9):3066-3074.  doi:10.1039/C1CP22515D
  • Kimmel GA, MD Baer, NG Petrik, J VandeVondele, RJ Rousseau, and CJ Mundy. 2012. "Polarization- and Azimuth-Resolved Infrared Spectroscopy of Water on TiO2(110): Anisotropy and the Hydrogen-Bonding Network." The Journal of Physical Chemistry Letters 3(6):778-784.  doi:10.1021/jz3001079
  • Lin X, Y Yoon, NG Petrik, Z Li, Z Wang, VA Glezakou, BD Kay, I Lyubinetsky, GA Kimmel, RJ Rousseau, and Z Dohnalek. 2012. "Structure and Dynamics of CO2 on Rutile TiO2(110)-1x1." Journal of Physical Chemistry C 116(50):26322-26334. 
  • Petrik NG, and GA Kimmel. 2012. "Adsorption geometry of CO versus coverage on TiO2(110) from s- and p-polarized infrared spectroscopy." Journal of Physical Chemistry Letters 3(23):3425-3430.  doi:10.1021/jz301413v
  • Smith RS, NG Petrik, GA Kimmel, and BD Kay. 2012. "Thermal and Non-thermal Physiochemical Processes in Nanoscale Films of Amorphous Solid Water." Accounts of Chemical Research 45(1):33-42.  doi:10.1021/ar200070w


  • Feibelman PJ, GA Kimmel, RS Smith, NG Petrik, T Zubkov, and BD Kay. 2011. "A unique vibrational signature of rotated water monolayers on Pt(111): predicted and observed." Journal of Chemical Physics 134(20):Article No. 204702.  doi:10.1063/1.3591966
  • Petrik NG, and GA Kimmel. 2011. "Electron- and hole-mediated reactions in UV -irradiated O2 adsorbed on reduced rutile TiO2(110)." Journal of Physical Chemistry C 115(1):152-164.  doi:10.1021/jp108909p
  • Petrik NG, and GA Kimmel. 2011. "Oxygen Photochemistry on TiO2(110): Recyclable, Photoactive Oxygen Produced by Annealing Adsorbed O2." The Journal of Physical Chemistry Letters 2(21):2790-2796.  doi:10.1021/jz201225c


  • Petrik NG, and GA Kimmel. 2010. "Off-normal CO2 desorption from the photooxidation of CO on reduced TiO2(110)." The Journal of Physical Chemistry Letters 1(17):2508-2513.  doi:10.1021/jz100884w
  • Petrik NG, and GA Kimmel. 2010. "Photoinduced Dissociation of O2 on Rutile TiO2(110)." The Journal of Physical Chemistry Letters 1(12):1758-1762.  doi:10.1021/jz100513e


  • Akin MC, NG Petrik, and GA Kimmel. 2009. "Electron-Stimulated Reactions and O-2 Production in Methanol-Covered Amorphous Solid Water Films." Journal of Chemical Physics 130(10):Art. No. 104710. 
  • Kimmel GA, J Matthiesen, M Baer, CJ Mundy, NG Petrik, RS Smith, Z Dohnalek, and BD Kay. 2009. "No Confinement Needed: Observation of a Metastable Hydrophobic Wetting Two-Layer Ice on Graphene." Journal of the American Chemical Society 131(35):12838-12844. 
  • Petrik NG, and GA Kimmel. 2009. "Nonthermal Water Splitting on Rutile TiO2: Electron-Stimulated Production of H-2 and O-2 in Amorphous Solid Water Films on TiO2(110)." Journal of Physical Chemistry C 113(11):4451-4460. 
  • Petrik NG, Z Zhang, Y Du, Z Dohnalek, I Lyubinetsky, and GA Kimmel. 2009. "Chemical Reactivity of Reduced TiO2(110): The dominant role of surface defects in oxygen chemisorption." Journal of Physical Chemistry C 113(28):12407-12411.  doi:10.1021/jp901989x


  • Grieves GA, NG Petrik, J Herring-Captain, B Olanrewaju, A Aleksandrov, RG Tonkyn, SE Barlow, GA Kimmel, and TM Orlando. 2008. "Photoionization of Sodium Salt Solutions in a Liquid Jet." Journal of Physical Chemistry C 112(22):8359-8364.  doi:10.1021/jp7102534
  • Kimmel GA, and NG Petrik. 2008. "Tetraoxygen on Reduced Ti02(110): Oxygen Adsorption and Reactions with Oxygen Vacancies." Physical Review Letters 100(19):Art. No. 196102.  doi:10.1103/PhysRevLett.100.196102


  • Kimmel GA, NG Petrik, Z Dohnalek, and BD Kay. 2007. "Crystalline Ice Growth on Pt(111) and Pd(111): Nonwetting Growth on a Hydrophobic Water Monolayer." Journal of Chemical Physics 126(11):Art. No. 114702. 
  • Lane CD, NG Petrik, TM Orlando, and GA Kimmel. 2007. "Electron-Stimulated Oxidation of Thin Water Films Adsorbed on TiO2(110)." Journal of Physical Chemistry C 111(44):16319-16329.  doi:10.1021/jp072479o
  • Lane CD, NG Petrik, TM Orlando, and GA Kimmel. 2007. "Site-Dependent Electron-Stimulated Reactions in Water Films on TiO2(110)." Journal of Chemical Physics 127(22):Art. No. 224706. 
  • Petrik NG, and GA Kimmel. 2007. "Hydrogen Bonding, H-D Exchange, and Molecular Mobility in Thin Water Films on TiO2(110)." Physical Review Letters 99(19):Art.No.196103.  doi:10.1103/PhysRevLett.99.196103


  • Kimmel GA, NG Petrik, Z Dohnalek, and BD Kay. 2006. "Layer-by-Layer Growth of Thin Amorphous Solid Water Films on Pt(111) and Pd(111)." Journal of Chemical Physics 125(4):044713-1 - 044713-12.  doi:10.1063/1.2218844
  • Petrik NG, AG Kavetski, and GA Kimmel. 2006. "Electron-Stimulated Production of Molecular Oxygen in Amorphous Solid Water on Pt(111): Precursor Transport Through the Hydrogen Bonding Network." Journal of Chemical Physics 125(12):124702 (11 p.). 
  • Petrik NG, AG Kavetski, and GA Kimmel. 2006. "Electron-Stimulated Production of Molecular Oxygen in Amorphous Solid Water." Journal of Physical Chemistry B 110(6):2723-2731. 


  • Garrett BC, DA Dixon, DM Camaioni, DM Chipman, MA Johnson, CD Jonah, GA Kimmel, JH Miller, T Rescigno, PJ Rossky, SS Xantheas, SD Colson, AH Laufer, D Ray, PF Barbara, DM Bartels, KH Bowen, KH Becker, SE Bradforth, I Carmichael, JV Coe, LR Corrales, JP Cowin, M Dupuis, KB Eisenthal, JA Franz, MS Gutowski, KD Jordon, BD Kay, JA La Verne, SV Lymar, TE Madey, CW Mccurdy, D Meisel, S Mukamel, AR Nilsson, TM Orlando, NG Petrik, SM Pimblott, JR Rustad, GK Schenter, SJ Singer, A Tokmakoff, LS Wang, C Wittig, and TS Zwier. 2005. "Role of Water in Electron-Initiated Processes and Radical Chemistry: Issues and Scientific Advances." Chemical Reviews 105(1):355-389.  doi:10.1021/cr030453x
  • Kimmel GA, NG Petrik, Z Dohnalek, and BD Kay. 2005. "Crystalline Ice Growth on Pt(111): Observation of a Hydrophobic Water Monolayer." Physical Review Letters 95(16):166102. 
  • Lynch DJ, WE Wilson, MT Batdorf, MB Resat, GA Kimmel, and JH Miller. 2005. "Monte Carlo Simulation of the Spatial Distribution of Energy Deposition for an Electron Microbeam." Radiation Research 163(4):468-472. 
  • Petrik NG, and GA Kimmel. 2005. "Electron-Stimulated Sputtering of Thin Amorphous Solid Water Films on Pt(111)." Journal of Chemical Physics 123(5):054702 (1-7). 
  • Petrik NG, and GA Kimmel. 2005. "Low-Energy Electron-Stimulated Luminescence of Thin H20 and D20 Layers on Pt(111)." Journal of Physical Chemistry B 109(33):15835-15841. 
  • Sowa MB, LE Kathmann, BA Holben, BD Thrall, and GA Kimmel. 2005. "Low-LET Microbeam Investigation of the Track-End Dependence of Electron-Induced Damage in Normal Human Diploid Fibroblasts." Radiation Research 164(5):677-679. 
  • Sowa MB, MK Murphy, JH Miller, JC McDonald, DJ Strom, and GA Kimmel. 2005. "A Variable-Energy Electron Microbeam: A Unique Modality for Targeted Low-LET Radiation." Radiation Research 164(5):695-700. 


  • Petrik NG, and GA Kimmel. 2004. "Electron-Stimulated Production of Molecular Hydrogen at the Interfaces of Amorphous Solid Water Films on Pt(111)." Journal of Chemical Physics 121(8):3736-3744. 
  • Petrik NG, and GA Kimmel. 2004. "Electron-Stimulated Reactions in Thin D2O Films on Pt(111) Mediated by Electron Trapping." Journal of Chemical Physics 121(8):3727-3735. 


  • Dohnalek Z, GA Kimmel, P Ayotte, RS Smith, and BD Kay. 2003. "The Deposition Angle-Dependent Density of Amorphous Solid Water Films." Journal of Chemical Physics 118(1):364-372. 
  • Kimmel GA, M Persson, Z Dohnalek, and BD Kay. 2003. "Temperature Independent Physisorption Kinetics and Adsorbate Layer Compression for Ar Adsorbed on Pt (111)." Journal of Chemical Physics 119(13):6776-6783. 
  • Petrik NG, and GA Kimmel. 2003. ""Electron-Simulated Reactions at the Interfaces of Amorphous Solid Water Films Driven by Long-Range Energy Transfer from the Bulk"." Physical Review Letters 90(16):166102. 
  • Smith RS, Z Dohnalek, GA Kimmel, GR Teeter, P Ayotte, JL Daschbach, and BD Kay. 2003. "Molecular Beam Studies of Nanoscale Films of Amorphous Solid Water." Chapter 14 in Water in Confining Geometries, ed. V. Buch and J.P. Devlin, pp. 337-357.  Springer-Verlag, New York, NY. 


  • Smith RS, Z Dohnalek, GA Kimmel, KP Stevenson, and BD Kay. 2002. "The Relationship between the Self-diffusivity of Supercooled and Amorphous Solid Water." In 220th American Chemical Society National Meeting: Liquid Dynamics experiment, simulation, and theory; ACS Symposium series, vol. 820, ed. Fourkas, J. T., pp. 198-213.  American Chemical Society, Washington, D.C.. 
  • Sowa MB, GA Kimmel, JH Miller, JC Mcdonald, MK Murphy, DJ Strom, BD Thrall, NF Metting, and SD Colson. 2002. "Spatially Resolved Single-Cell Irradiator to Study Bystander Responses to Low-LET Radiation." Radiation Research 158(3):375-376. 


  • Ayotte P, RS Smith, KP Stevenson, Z Dohnalek, GA Kimmel, and BD Kay. 2001. "Effect of Porosity on the Adsorption, Desorption, Trapping and Release of Volatile gases by Amorphous Solid Water." Journal of Geophysical Research. Planets 106(E12):33,387-33,392. 



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