CENECI Research Groups and Capabilities

Scott Anderson, University of Utah

Core Expertise: Surface and cluster chemistry, ion beam and nanoparticle trap methods. Size-selected supported catalysts, chemistry under extreme conditions, reaction dynamics, nanoparticle production

The Anderson Lab has developed cluster ion beam methods to examine effects of cluster size on the activity of ultradisperse supported catalysts, and to examine properties of materials prepared by hyperthermal cluster impacts on surfaces. We are developing single particle trapping to allow study of surface chemistry under extreme conditions, including non-equilibrium reactions at high temperatures.

Sylvia T. Ceyer, Massachusetts Institute of Technology

Core Expertise: Molecular Beam Activation, Surface Scattering, Surface Reaction Dynamics, Inelastic Electron Scattering for Interfacial Vibrational Spectroscopy.

Professor Ceyer is a physical chemist with research interests in the area of molecule-surface reaction dynamics as related to heterogeneous catalysis and semiconductor etching. Her group has uncovered sources of the apparent lack of surface reactivity under ultrahigh vacuum conditions and then used that knowledge to effect high pressure heterogeneous catalytic reactions in an ultrahigh vacuum environment where microscopic reaction steps can be discerned. Illustrative Laboratory Capability: The proposed experiments probing the bulk H and bulk O non-equilibrium species will be carried out in a ultrahigh vacuum chamber coupled to a triply differentially pumped and energetic molecular beam source. The bulk species are detected spectroscopically by high resolution electron energy loss spectroscopy, a vibrational spectroscopy sensitive to both absorbates and adsorbates. The desorbed reaction products are detected by a mass analyzer. Crystal temperatures span the range from 8 K to > 1400 K.

Erica Corral, University of Arizona

Core Expertise: Novel processing of ultra high temperature ceramics using spark plasma sintering and investigation of their behavior at high temperature for application in aerospace thermal protection material systems.

The Corral Lab focuses on using our spark plasma sintering furnace in order to create new compositions of ultra-high temperature ceramics that are high temperature resistant above 2000°C. We use a range of high temperature test facilities to study their oxidation behavior in simulated aerospace flight environments. As a result we aim to study the refractory oxide scales that form upon exposure to high-temperature gas mixtures in order to gain new fundamental understanding of oxidation resistant mechanisms.

William L. Hase, Texas Tech University

Core Expertise: Applications and development of chemical dynamics simulations for projectile collisions with surfaces, both reaction and energy transfer, and for interfacial heat transfer; "direct dynamics" coupled to electronic structural theory.

The Hase research group will extend their simulations of projectile collisions with surfaces, and of physical and chemical properties of interfaces, to address the themes of the Center. The computational tools will include electronic structure theory and chemical dynamics calculations, including development of new simulation techniques and models. The coupling of electronic structure theory with classical trajectories for direct dynamics, is an important research tool.

Manos Mavrikakis, University of Wisconsin-Madison

Core Expertise: Electronic structure calculations of solids and surface reactions; reaction mechanisms and first-principles-based catalytic materials screening.

The current research focus of the Mavrikakis Group is the quantum mechanics of bond breaking and bond making events on transition metal and alloy surfaces. One aspect of his research addresses the fundamentals of surface reaction mechanisms, and another one focuses on the advancement of materials design from first-principles. Of particular interest is the design of metastable Near-Surface Alloys (NSAs) suitable for low temperature, energy-efficient, and highly-selective catalytic transformations. Applications of interest include heterogeneously catalyzed reactions and fuel cells.

Timothy K. Minton, Montana State University

Core Expertise: Crossed-beams and beam-surface scattering studies of energy transfer and reaction dynamics at hyperthermal energies, with applications to materials and low Earth orbit chemistry.

Professor Minton is known for his research on reaction dynamics involving hyperthermal atomic beams, produced with a unique laser-detonation source. Beam-surface and crossed-beams scattering with a rotatable mass spectrometer detector, as well as molecular beam exposures with in situ (TPD and Auger) and ex situ (AFM, STM, SEM, XPS, XANES, EXAFS) analysis techniques, are readily available. Seminal data have been collected on hyperthermal reactions of O(3P) with carbon, hydrocarbon, fluorocarbon, and ionic liquid surfaces and with H2, N2, CH4, C2H6, C2H2, HCl, CO, and CO2. The data have revealed many previously unknown reaction pathways. The experiments, in synergy with theory, have shown that hyperthermal reactions often circumvent the minimum energy path. Minton’s focus will be on further hyperthermal beam development, dynamics of hyperthermal interfacial interactions and of their gas-phase analogs, and materials growth and etching with hyperthermal beams.

Margaret Murnane, University of Colorado

Core Expertise: Ultrafast x-ray spectroscopy and imaging of molecular, surface, materials and nanosystems, with a focus on capturing the coupled motions of charges, spins, phonons, and photons at the space-time limits.

In a recent breakthrough, the Murnane-Kapetyn group demonstrated that coherent x-ray beams spanning the entire soft x-ray region of the spectrum (UV-kEV) can be generated using high harmonic upconversion of a femtosecond laser. This advance provides a unique new tool for probing nonequilibrium and charge transfer reactions at surfaces, interfaces and materials at the fastest timescales (< 1fs) and smallest spatial scales (<10 nm). Ultrafast x-rays, by virtue of their short wavelength, are ideal as a probe of even the fastest (i.e. electronic) dynamics in matter at the nanoscale. Using elemental absorption edges, site-specific chemical dynamics can be captured, providing unique capabilities for frontier energy and materials science research. Of particular interest is the study of surface chemical reactions that are relevant to heterogeneous catalysts, to exploit the interactions between a catalytic surface and adsorbed reactant to specifically promote reactions leading to target products. These short lived states are extremely small fractions of the overall population of the reacting species, and little direct experimental information is available about the nature of the intermediates and transition states that lie along the reaction coordinate for transformation from reactants to products.

Gilbert M. Nathanson, University of Wisconsin-Madison

Core Expertise: Experimental studies of collisions and reactions at gas-liquid interfaces.

The Nathanson group uses molecular beams to explore collisions between gases and liquids, focusing on acid-base reactions at the surfaces of salty glycerol and monolayer-coated sulfuric acid important in atmospheric chemistry. They seek to develop a “blow-by-blow” picture of gas-liquid reactions through interfacial analogs of bulk solvation, hydrogen bonding, the "like dissolves like" rule, proton exchange, and acid-base reactions.

Illustrative Laboratory Capability: The proposed experiments involving collisions of alkali metal atoms with protic liquids will be carried out in a gas-liquid scattering machine that allows preparation of vertical, continuously renewed liquid surfaces of sulfuric acid and pure and salty glycerol and cold salty water. A mass spectrometer will monitor scattered Na atoms and the desorption of H atoms and H2 molecules as well as desorbing organic species created by reactions with solvated electrons and H atoms. This apparatus has been used to map out the interfacial and bulk-phase pathways for collisions of DCl molecules with liquid glycerol.

David J. Nesbitt, University of Colorado, NIST, and JILA

Core Expertise: Non-equilibrium scattering of molecules/radicals at gas-liquid and gas-molten metal interfaces, high resolution laser and ion imaging based probes of quantum-state resolved surface collision dynamics.

The Nesbitt group is pursing multiple research directions involving quantum state-resolved dnamics of collisional processes at the gas-liquid interface. Experimental approaches are based on a novel combination of i) supersonic molecular beams, ii) clean liquid surfaces in high vacuum conditions, and iii) a suite of high resolution laser methods for detection of internal (rotation vibration, electronic state) and translational excitation in the scattered products. Current systems of interest range from ion solvation dynamics in hydrogen bonded liquids, "green" solvents such as room temperature ionic liquids, self-assembled monolayers as liquid mimetics with controllable interfacial chemistry properties to molten metals such as Ga and even Au.

Teri Odom, Northwestern University

Core Expertise: Multi-scale Nanofabrication; Unconventional Plasmonic Materials; Single Particle Imaging and Spectroscopy; 3D Plasmonic Hole Arrays and Particle Arrays; Sensing

The Odom group focuses on manipulating materials at the 100-nm scale and investigating their size and shape-dependent optical properties. We have invented mult-scale nanopatterning tools that can create plasmonic structures with exceptional optical properties. The key, differentiating feature of our plasmonic materials is their 3D structure and their multi-scale (1 nm, 10 nm, 100 nm) architecture. For example, arrays of 3D nanoholes and nanopyramids are new plasmonic metamaterials capable of ultra-sensitive biomolecular detection. Pyramidal nanoshells can be used in imaging and therapeutic applications. Also, we designed a new type of planar, diffractive microlens based on micron-sized patches of nanoholes that exhibit structured illumination in 3D. These mult-scale materials support highly intense, localized electromagnetic fields that can be used to interrogate non-equilibrium molecular processes.

George Schatz, Northwestern University

Core Expertise: Theoretical Studies of Gas Phase and Gas-Surface (Liquid and Solid) Collisions including Reactions and Energy Transfer; Reactivity of Species in Electronically Excited States

The Schatz group will build on expertise with modeling gas/surface collisions under nonequilibrium conditions to do theoretical modeling of reaction dynamics in all 3 themes of the proposed research. The main tools will be electronic structure and dynamics methods based on classical dynamics and trajectory surface hopping. These dynamics simulations will use mixed quantum mechanics/molecular mechanics force fields, including the possibility of changing the partitioning between QM and MM atoms on the fly.

Steven J. Sibener, University of Chicago

Core Expertise: Molecular Beam & SPM Studies of Surface Chemistry, Energy Transfer, and Reaction Dynamics; Polymer Thin Films; Oxidation of Materials, Nanostructures, Single-Molecule Chemistry.

Sibener’s group has constructed several novel gas-surface scattering and STM/AFM instruments with which one can incisively probe the dynamics and mechanistic chemical kinetics of complex heterogeneous reactions. Supersonic and hyperthermal beams of a wide range of chemical species are generated in his laboratory. The Sibener group has elucidated the atomic-level details for fundamental metallic oxidation and chemical transformations at surfaces. His group is also a leader in using STM and AFM to examine, in real-time, structural evolution during reactions, nanoscale ensembles, and surfaces. Illustrative Laboratory Capability: The proposed energetic molecular beam/FTIR experiments will be conducted in a two-level UHV system. In addition to a full suite of surface analysis spectroscopies, this instrument contains a new high-throughput FTIR optics train to monitor on-surface chemical moieties, a 3-fold differentially pumped supersonic beam source, and a mass analyzer to characterize the beam and reactions.

Charlie Sykes, Tufts University

Core Expertise: Atomic-scale imaging and composition/reactivity analysis of catalytically relevant metal alloy surfaces, with a focus on surface chemistry at the single atom limit.

The Sykes group utilizes state of the art scanning probes to map the geometric and electronic properties of catalytically relevant metal alloy surfaces at the nanoscale. Using temperature programmed reaction studies of well define model catalyst surfaces structure-property-activity reactions are drawn. Of particular interest is the addition of individual atoms of a reactive metal to a relatively inert host. In this way reactivity can be tuned, and provided the energetic landscapes are understood, novel bifunctional catalytic systems can be designed with unique properties that include low temperature activation and highly selective chemistry.

Dmitri V. Talapin, University of Chicago

Core Expertise: Chemical synthesis of nanomaterials, Bottom up assembly of functional solids, Charge and heat transport in nanostructured materials.

Talapin’s group focuses on chemistry, physics, and materials science of inorganic nanostructures. By combining expertise in colloidal synthesis, self-assembly and characterization, his group creates novel materials for electronic, photovoltaic, thermoelectric and catalytic applications. They create unprecedented materials through synthesis of complex, often multifunctional building block, assembling them into long-range ordered superlattices and designing surface chemistryies that enable strong exchange coupling between the components.