Zdenek DohnalekSenior Research Scientist II, Fundamental and Computational Sciences Directorate, Chemical and Material Sciences Division, Chemical Structure and Dynamics
http://emslbios.pnl.gov/id/dohnalek_z Updated: January 25, 2007
Current Activities and Projects
Our research deals with fundamental model system experimental studies that are necessary to understand complex processes that take place in heterogeneous catalysis, the environment, and at the aqueous-mineral interface. The work focuses on adsorption/desorption dynamics and kinetics, binding, and reactivity of small adsorbates on model, well characterized surfaces. Molecular beam scattering instrumentation is used to study physisorption and chemisorption on single crystal metal and metal oxide surfaces. The adsorption of weakly bound species such as N2 or Ar is used in spectroscopic fashion to determine the distribution of various surface binding sites, including defects, the chemical identity of the surface and its specific surface area. A number of novel deposition methods (e.g. reactive-layer assisted deposition and reactive ballistic deposition) were developed and are used to prepare clusters and nanoporous films of oxides with tailored chemical properties. Complementing the beam-based work, information about oxide nanocluster growth and reactivity is obtained, often with atomic resolution, using scanning-tunneling/atomic-force microscopy. Systems recently investigated include a number of adsorbates on epitaxial MgO(100) and nanoporous MgO films, ethylene hydrogenation on thin epitaxial and nanoporous Pd films, and partial oxidation of alcohols on WO3 clusters supported on TiO2(110). Properties of such structured materials are compared with those of single crystals or well-ordered epitaxial films. This comparison is an important tool helping us to understand the structure-reactivity relationships for various catalytic and environmentally important reactions.
Adsorption - desorption phenomena on surfaces of monocrystalline and nanoporous oxide films. Thermally induced phase transitions in thin films. Atomically resolved imaging of model catalytic systems
Surface chemistry of Si(100) - STM, ESDIAD, TPD.
Ph.D. degree in physical chemistry (University of Pittsburgh, group of Prof. John T. Yates, Jr.)
Awards, Honors, & Appointments
M. T. Thomas Award for Outstanding Postdoctoral Achievement in the William R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory