Horia Metiu, Ph.D. - US grants

Dr. Metiu is supported by the Physical Chemistry Program to work on the development of theoretical methods to compute the rate coefficients of some of the most basic thermal processes in surface science: diffusion of hydrogen on a metal surface and the desorption of hydrogen on a metal surface and the desorption of alkali from metal surfaces. These are prototypes of two of the most common chemical processes: proton transfer over and through a barrier and a curve crossing from an ionic neutral state. They are both induced by the thermal fluctuations on the surface and are thus simple examples of reactions taking place in a condensed medium. In addition, Dr. Metiu and his students plan to work on the photodissociation of CH3I. A quantitative connection between the dynamics on the upper states and the spectroscopic signals given by the decomposing molecule will be established. This research program will be assisted by the acquistion of a new computer workstation that will strongly enhance the computational power available to support this program. By acquiring the new workstation, Dr. Metiu's group will accelerate appreciably the turn around time for the computed results and will have good access to the NSF-supported supercomputer centers. This additional hardware is provided under NSF initiative to support Computational Science and Engineering.

Professor Horia Metiu is supported by a grant from the Theoretical and Computational Chemistry Program to perform theoretical simulations of silicon growth on surfaces and time dependent quantum theoretical treatments of the effects of ultrashort laser pulses on molecular solutes. In the first area of research, Metiu will use correlation function theory to calculate the rates of all the elementary kinetic steps involved in the epitaxial growth process: the sticking of atoms to the surface, their jumps from one surface site to another, the dependence of the jumping rate on local configuration of adsorbed atoms, and the final sites involved in the jump. These rates will be used in a kinetic Monte Carlo program to simulate the kinetics of epitaxial growth of silicon. In the second area of research, Metiu will develop methods capable of analyzing the results of novel experiments with ultrashort pulses which are used to probe the dynamics of solute molecules. He will also explore the theoretical consequences of coherence and interference in generating laser signals that are very sensitive to the quantum dynamics. %%% This research will provide an important molecular level understanding of epitaxial growth on semiconductor surfaces and of techniques for laser control of chemical processes in solution.

Horia Metiu is supported by a grant from the Theoretical and Computational Chemistry Program to continue his research in quantum dynamics. Three areas of research are being studied: 1) wave packet interferometry is being extended to nonlinear spectroscopy as a sensitive method for studying highly excited states; 2) a technique is being developed for calculating photon absorption and Raman scattering cross sections for systems with few quantum degrees embedded in a bath of classical ones, e.g. an electron solvated in a zeolite; and 3) a time dependent theory is being developed for treating exciton formation and tunneling in confined semiconductor structures, e.g. quantum wells, wires, dots and clusters. There are many interesting biochemical, chemical and solid state systems in which an electron interacts with a complex environment. The spectroscopy of the electron connects this interaction to observable quantities and gives us a chance to understand the underlying dynamical mechanisms. Furthermore the properties of electrons and holes in confined semiconductor structures are being extensively studied in the hope of using them in opto-electronic and tunneling devices. Metiu will employ the techniques of time dependent quantum mechanics to study the behavior of electrons, holes and excitons in these systems. This work will help to provide useful intuitive models for the behavior of these complex systems.

Horia Metiu of UC Santa Barbara is supported by the Theoretical and Computational Chemistry Program to perform computer simulations of forces acting on ions and water molecules inside a zeolite, and to use these results to explore how the species move through the zeolite. Also, proton transfer rates will be calculated, and complete kinetic descriptions and mechanisms will be evaluated. Rigorous methodology will be applied to small unit cell zeolites, with specific studies of sodium ion and water migration through sodalite and the reaction of ammonia with acidic chabazite. These processes are widely used in industrial applications, yet very little is known about them at an atomic level. All energy calculations will be performed with density functional theory, which considers the full unit cell of the solid. Rate constants of the important processes will be calculated using correlation function theory or transition state theory. The results will be used in a kinetic Monte Carlo program to simulate migration and kinetics over very long time and space scales. It is anticipated that the ability to calculate the properties of molecules inside zeolites will be improved to the point that this methodology will assist in the rational design of industrial processes.

Zeolites are crystalline, porous solids that have the ability to absorb inside them a variety of molecules. This absorption is selective (certain molecules are preferred to others) and the selectivity can be used to separate various gases, to remove noxious products from a gas stream, or to replace undesirable ions with benign ones. Zeolites and their absorbed guest molecules interact strongly enough to induce unusual chemical reactions within the zeolite frame. This property has practical importance and is exploited to modify the hydrocarbon content of various products in the oil industry. The outcomes from this computer simulation project will improve the understanding of how fast molecules move inside a zeolite, what determines absorption selectivity, and what causes changes in the chemical behavior of the absorbed species.

9871849 Metiu We plan to synthesize and assemble dilute magnetic semiconductor nanostructures and study their transport and optical properties by using near field optical microscopy. It is well known that by reducing the size of a semiconductor structure we can affect and control the properties of the electrons in it. We know practically nothing about the way in which this size reduction affects the magnetic properties of these systems, even though we expect these effects to be considerable. We will prepare nanocrystalline "dots" of II-VI semiconductor doped with divalent transition metal ions with magnetic properties (Mn(II), Cr(II), Fe(II) and Cu(II) ). We can thus study the effect of confinement on the exchange interactions and the magneto-optical properties of these materials. We plan to use a near field microscope to perform femtosecond and cw studies of the magneto-optical properties of individual dots and to determine how these properties depend on dot sizes. We also plan to create ensembles of such dots so that we can study the collective effects created by the interaction between the dots. One of our most important tools is the near field optical microscope. This is a wonderful tool with many exciting uses, but the quantitative interpretation of the measurements is hampered by the lack of a quantitative theory of the electromagnetic fields produced in the structure being studied. We propose to develop new theoretical methods for solving this problem. %%% The kind of studies proposed here are motivated by the need of making smaller electronic devices and denser computer memories. As the elements of these devices become smaller the properties of the electrons in them are being modified. We cannot design these devices if we cannot anticipate and understand how the electrons in them will behave. Our work hopes to fill this gap in our understanding. The ultimate computer will be a device in which the electrons themselves are computing elements. The main candidates right now are systems in which various spin states are being excited, since they maintain the information imparted to them (coherence) for the longest time. This is one additional reason why the study of spin behavior in small structures may impact future technologies.

This award is being supported by the Office of Multidisciplinary Activities; the Division of Materials Research, Directorate for Mathematical and Physical Sciences; and the Division of Electrical and Communications Systems, Directorate for Engineering.***

A new computer-based classroom is being established to support continued curricular developments in the undergraduate biochemical, materials, and analytical chemistry areas of the department, and to provide additional support for computer-based instruction in our introductory physical chemistry course. Novel features of the developments include the use of actual experimental data from advanced research instruments in laboratory and classroom experiences that are designed to (1) provide appreciation of the roles of protein crystallography and NMR spectroscopy in the determination of biological structures, (2) allow students to perform homework in physical chemistry classes that is based on solving realistic problems, (3) support further development of the uses of simulations and data processing to provide more trenchant presentations of concepts in physical chemistry, and (4) provide the means to present more effectively essential concepts in solid state chemistry. Students impacted by this project include those majoring in chemistry, biology, and engineering; we estimate that about 400 advanced undergraduates in a dozen formal courses will be affected yearly by the project. Instructional materials developed will be freely distributed by means of the WWW. While intended to be used exclusively for the support of instruction at the advanced undergraduate level, the facilities of the classroom are being made available to undergraduate research students and to various K-12 outreach efforts operated by other units of the campus when the classroom is not being used for these purposes.

With support from the Major Research Instrumentation (MRI) Program, the Department of Chemistry and Biochemistry at the University of California in Santa Barbara will acquire a Beowulf cluster. This equipment will enhance research in a number of areas including a) simulation of biomaterial microstructures; b) simulation and interpretation of single molecule spectroscopy experiments; c) field-theoretic computer simulations of polymers and complex fluids; and d) modeling and computation of flow-structure interaction in multi-phase and complex fluids.

A cluster of fast, modern computer workstations is vital to serving the computing needs of active research departments. Such a "computer network" also serves as a development environment for new theoretical codes and algorithms, provides state-of-the-art graphics and visualization facilities, and supports research in state-of-the-art applications of parallel processing. These studies will have a significant impact in a wide number of areas, including materials science and physics.

Wodtke
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This award establishes a long-term Partnership for International Research and Education for Electron Chemistry and Catalysis at Interfaces (PIRE-ECCI) between the University of California Santa Barbara (UCSB) and the Dalian Institute for Chemical Physics (DICP) in Dalian, China. The focus area for research is modern heterogeneous catalysis with a multidisciplinary approach that seeks to increase contacts between the fields of surface science, catalysis and chemical dynamics at interfaces, thus striving for a "first principles understanding" of technologically important catalytic systems. Members of the team represent diverse scientific viewpoints, from surface chemical dynamics, to theoretical simulations of surface chemistry, to engineering applications of catalysis.

A major part of the research and education plan involves support for graduate students and postdocs at UCSB and DICP to pursue collaborative research in chemistry. Extended research visits will include Chinese language and cultural sensitivity training for UCSB participants, with similar reciprocal support given to the Chinese participants coming to UCSB. Two summer schools on catalysis will be held at UCSB and a biannual scientific workshop will be held in Dalian. Special educational opportunities concerning the issues of technology transfer in international high-tech business will be organized and provided by the UCSB Technology Management Program.

The Partnerships for International Research and Education Program seeks to create new international collaborations through long-term, large-scale projects that contribute to the development of a diverse, globally-educated U.S. science and engineering workforce. The program is a major initiative in the NSF Office of International Science and Engineering.

TECHNICAL SUMMARY:

This award is made on a proposal submitted to the PetaApps Solicitation. The Office of Cyberinfrastructure, the Division of Materials Research and Office of Multidisciplinary activities in the Mathematical and Physical Sciences Directorate, the Engineering Directorate, and the Computer and Information Science and Engineering Directorate contribute funds to this award.

This PetaApps project focuses on hybrid quantum mechanical-atomistic-mesoscale simulations of ion transport and translocation of biopolymers such as DNA and RNA through nanometer scale pores and channels in silica and silicon nitride membranes. The PIs aim to develop a predictive hierarchical petascale simulation framework for: (1) Highly accurate quantum mechanical simulations to describe chemical processes in translocating biopolymers; (2) multibillion-atom molecular dynamics simulations for structural properties and dynamical processes of biopolymers in confined fluidic environments in solid state membranes, with interatomic interactions validated by quantum mechanical calculations and key experiments; (3) hybrid molecular dynamics and adaptive lattice Boltzmann simulations in which molecular dynamics is embedded close to the surfaces of nanopores/nanochannels and lattice Boltzmann in the rest of the fluid; (4) accelerated dynamics approaches to reach macroscopic time scales for direct comparison with experimental data; (5) meta-scalable, self-tuning multicore parallel simulation algorithms; and (6) automated model transitioning to embed higher fidelity simulations inside coarser simulations on demand with controlled error propagation to quantify uncertainty.

After validation, this hierarchical petascale simulation framework will be used to study: (1) Translocation kinetics and dynamics of DNA through silica and silicon nitride nanopores; (2) electronic properties of translocating DNAs for sequential identification of nucleotides; (3) ionic screening of surface charges in nanopores/nanochannels; (4) streaming electrical current generated by pressure-driven liquid flow in individual silica nanochannels as a function of channel height, pressure gradient, and salt concentration; (5) pressure-driven DNA transport in confined silica channels for novel diagnostic applications such as artificial gels and entropic trap arrays; and (6) surface functionalization, polarity switching, and transient response of silica nanotube, nanofluidic transistors.

This project supports training a new generation of graduate students to develop the tools needed to attack complex system level problems. They will learn to combine theory, modeling, and high performance computer simulation. Students will participate in a dual-degree program in which they will fulfill Ph.D. requirements within their own discipline and master?s degree requirements in computer science with specialization in high performance computing and simulations.
This award also supports the computational science workshops for underrepresented groups. Undergraduate students and faculty mentors from Historically Black Colleges and Universities and Minority Serving Institutions participate in a special one-week intense hands-on experience in parallel computing and immersive and interactive visualization. African American, Hispanic and Native American students will be recruited through USC?s Center for Engineering Diversity and women through USC?s Women in Science and Engineering Program.

NON-TECHNICAL SUMMARY:

This award is made on a proposal submitted to the PetaApps Solicitation. The Office of Cyberinfrastructure, the Mathematical and Physical Sciences Directorate, the Engineering Directorate, and the Computer and Information Science and Engineering Directorate contribute funds to this award.

This award supports the development of software for the most advanced, ?petascale,? high performance supercomputers that will enable simulations that can capture phenomena that span across a range of length and time scales. The PIs will focus on a problem of particular importance, how biomolecules move through nanometer-sized pores in inorganic materials like silica and silicon nitride. The simulation can capture detailed physics of the problem and may illuminate possible applications to sequencing DNA and RNA molecules. The PIs will also focus on how charged atoms and molecules move through channels with dimensions on nanometer length scales more generally. There are potential applications to evolving ?lab-on-a-chip? technologies that seek to miniaturize laboratory analysis functions to the size of electronic device chips.

Developed software will be distributed and can be used by a broad community of researchers in a variety of disciplinary and multidiscplinary research involving materials research, chemistry, engineering, physics, and nanotechnology.

This project supports training a new generation of graduate students to develop the tools needed to attack complex system level problems. They will learn to combine theory, modeling, and high performance computer simulation to solve complex problems. Students will participate in a dual-degree program in which they will fulfill Ph.D. requirements within their own discipline and master?s degree requirements in computer science with specialization in high performance computing and simulations.

This award also supports the computational science workshops for underrepresented groups. Undergraduate students and faculty mentors from Historically Black Colleges and Universities and Minority Serving Institutions participate in a special one-week intense hands-on experience in parallel computing and immersive and interactive visualization.

In this research supported by the Analytical and Surface Chemistry Program, Professors Buratto, Bowers, and Metiu and their groups will prepare, characterize, and test three new types of nanoscale catalysts, having one feature in common: very small, isolated, well-defined, catalytically active sites. They will prepare and study (a) very small Aun and Agn mass-selected clusters supported on oxide, (b) very small mass-selected, binary clusters such as PdmAun supported on oxides, and (c) very small, mass-selected oxide clusters supported on oxides. A variety of techniques will be used, in a concerted manner, to study these important catalytic processes: model catalytic systems will be prepared by depositing mass-selected clusters on oxide surfaces to ensure atom-by-atom control of catalyst size; all samples will be prepared and studied in ultra-high vacuum by surface science techniques (AES, XPS) as well as by STM/ AFM before, during and after the catalytic chemistry; and density functional theory (DFT) will be used to calculate the structure of the clusters, their XPS spectrum and their chemical activity. Through the work proposed here they will develop a detailed understanding of the catalytic chemistry of these materials and find out how this chemistry depends on size, composition and the nature of the substrate. While the focus of the research is on the catalytic activity of specific nanoscale catalysts, there is a high probability that the results will be applicable to other systems. In addition, it is hoped that the concepts developed through this research will help optimize important industrial processes using these nanoscale catalysts and provide insight into the discovery of new nanoscale catalytic materials.
The research funded by this grant will be interdisciplinary. Graduate students will interact continuously with three different research groups, will have daily contact with other outstanding scientists, and will acquire hands-on experience in a large number of techniques of surface science, gas-phase chemistry, scanned probe microscopy, and high level theory. The research will provide a valuable opportunity for graduate education, found in very few places in the world. Researchers supported by this grant (including PIs) will also be active in outreach to K-12 schools in the Santa Barbara area to present a tutorial on an atomistic view of heterogeneous catalysis and to show an atomically-resolved picture of our model catalyst systems. This will be included in the currently active outreach program in the chemistry department at UCSB. A series of lectures on catalysis by nanostructures will be developed and included as part of a course in nanoscience currently taught in the materials chemistry curriculum.

This PIRE renewal award expands support for a pioneering U.S.-China partnership in chemistry, chemical engineering, and materials science, and adds additional Chinese institutions and a new alliance with two German institutions to the project. This multidisciplinary research and education effort focuses on catalytic systems that are technologically important in the development of clean energy and energy conservation. Global energy and environmental challenges require international science and technology cooperation and this project takes advantage of the major roles the U.S. and China play in creating and using energy. This partnership brings together complementary expertise and diverse viewpoints and provides U.S. researchers and students with access to expertise, facilities, and instrumentation not available in the U.S.

The project's research focus is modern heterogeneous catalysis with an emphasis on well-defined nanostructured materials as both catalysts and catalyst supports. Catalysis occurs when a substance, the catalyst, changes the rate of a chemical reaction; heterogeneous catalysis occurs when the catalysts chemical phase (solid, liquid, or gas) differs from that of the reactants. This project?s research will improve our fundamental understanding of catalyst structure, function, and activity. It will also unite nanoscience, catalysis, and photocatalysis approaches to explore phenomena with relevance to energy-related issues such as H2 production, CH4 utilization, biomass conversion and CO2 activation and sequestration. Specific research areas include: quantum dot antenna/photocatalysts for CO2 reduction, selective oxidation of hydrocarbons by supported and doped metal oxides, spontaneous formation of catalytic nanostructures, and nanoscale optical imaging and spectroscopy. The PIRE research team will also explore various types of catalyst supports, including oxide nanowires, mesoporous carbon and silica, as well as new gold and platinum complex catalysts.

U.S. graduate students and postdoctoral researchers will participate in 3-6 month research visits to research laboratories in China. They will be trained in Chinese language and culture and will have opportunities to develop project management, communication, and mentoring skills, thus equipping them with the technical, cultural, and language tools to become effective research leaders. A lecture course in technology transfer, and its accompanying Technology Transfer Study Tour to national and multinational companies operating in China, will be expanded, addressing technology transfer in the U.S. and China, and giving students a working knowledge of Chinese industrial research and development (R&D) operations. The project will continue its yearly international workshops that bring together graduate students and postdoctoral researchers with domestic and international senior researchers and industrial leaders to exchange ideas about research directions, with the participation of both Chinese and German research partners. A new enhancement to the workshop will be a half-day seminar on ethics in international science, with a particular focus on how culture influences ethical decision-making.

This project has potential for broad impact well beyond the individual researchers. At the national level, it embeds U.S. individuals and institutions within a research alliance that includes two strategically important countries, China and Germany. It also links U.S. students with collaborating scientists from two U.S. Department of Energy National Laboratories. At the institutional level, the funding for increased numbers of graduate students, post-doctoral researchers and research groups will bolster UCSB's catalysis/surface-science community and strengthen UCSB's role as a focal point for an innovative international research network. Industrial R&D is an increasingly globalized endeavor and career target for U.S. Ph.D. students, and this award will enable UCSB to attract more high-quality graduate students by providing access to international expertise, equipment, training, and networking opportunities. This project strengthens UCSB's institutional capacity to engage in international research and education partnerships via multiple mechanisms, including wide dissemination of lessons learned. In the original PIRE award, UCSB and DICP successfully negotiated a ground-breaking Intellectual Property Agreement, removing many barriers to collaboration and providing a template for other universities to cultivate research partnerships in China. The project will continue and expand its campus-wide activities, including a seminar series on U.S. - China socio-economic, policy, and scientific topics, and co-hosting events to promote awareness and interest in Chinese culture. UCSB will pilot the use of its AccessGrid video-conferencing classroom to internationalize PIRE-related courses and research activities, thus broadening the university's internationalization via the cyberinfrastructure. Finally, the project will bring Santa Barbara City College, a two-year college, with its expertise in the ethics of science and technology, into the international network.

U.S. collaborating institutions include: University of California at Santa Barbara and Santa Barbara City College (CA), as well as U.S. Department of Energy's Pacific Northwest National Laboratory (WA) and Argonne National Laboratory (IL). Chinese collaborating institutions include: Dalian Institute of Chemical Physics - Chinese Academy of Sciences (CAS), Dalian University of Technology, Xiamen University, Zhejiang University (Hangzhou), University of Science and Technology of China (Hefei), Tsinghua University (Beijing), Suzhou Institute of Nano-tech and Nano-bionics - CAS, and Fudan University (Shanghai). German collaborating institutions include: Max-Planck-Institut für Biophysikalische Chemie (Göttingen) and Fritz-Haber-Institut der Max-Planck-Gesellschaft (Berlin).

This project is cofunded by NSF's Office of International Science and Engineering and the Division of Chemistry.

Renewable energy sources including wind and solar can supply a significant amount of electrical energy in the US; however, because of their intermittent nature, the potential of these two energy sources can be fully exploited only if a suitable energy storage system is provided. Considering the requirements of energy capacity, efficiency and cost of this application, the hydrogen-bromine fuel cell has been identified as the most suitable electrical energy storage system. This system has many advantages among which are extremely fast reaction kinetics, high energy storage capacity, and high reliability. The potential was recognized by industrial teams which attempted to develop commercial systems; however, the use of expensive Pt-based catalysts on unstable electrode supports, the high cost, durable and high-performance membranes, and non-optimal cell configurations did not allow for widespread deployment of these fuel cells at the capacities required to have an impact on US energy requirements. The goal of this project is to generate the enabling science and create the engineering technologies needed to develop the regenerative hydrogen-bromine fuel cell system into a cost-effective, efficient, and reliable large-scale energy storage system for renewable energy sources. Four main focus areas have been identified: the design and synthesis of low-cost and durable eletrocatalysts with high reactivity and selectivity for the hydrogen and bromine reactions; the development of highly selective and durable proton conducting membranes for hydrobromic acid operation; the development of electrode microstructures and cell designs that minimize transport effects and maximize conversion efficiency; identification of system configurations and operation that are optimal for integration to the electrical grid. In terms of broader impacts, providing economical technologies to facilitate the transition from fossil fuels to sustainable energy sources is a grand challenge of the 21st century. Production of abundant, cheap, clean, reliable, renewable energy is the key, and the search for and commercialization of these energy sources will be the next great global industry. The discoveries, insights, and knowledge gained from this project will have impacts on other electrochemical power systems and may find applications in areas such as electric vehicles and residential/commercial power. The educational and outreach component of this project will help create a new diverse generation of engineers and researchers who will play a major role in development of this technology and the creation of a new energy industry. The outcome of this project will contribute to fundamental advances in electrocatalysis, polymer science, electrode design, nano-manufacturing and integration of large-scale energy storage to the electrical grid.

The FY 2010 EFRI-SEED Topic that supports this project was sponsored by the US National Science Foundation (NSF) Directorates for Engineering (ENG), Mathematical and Physical Sciences (MPS) and Social, Behavioral and Economic Sciences (SBE), and Computer & Information Science and Engineering in collaboration with the US Department of Energy (DOE) and the US Environmental Protection Agency (EPA).

The Chemical Catalysis Program supports Professors Steven Buratto, Michael Bowers, and Horia Metiu from the University of California at Santa Barbara (UCSB) to prepare, characterize, and test two new types of nanostructured catalysts, having the common feature of being very small, isolated, well-defined catalytically-active sites. The investigators have designed and constructed a unique, highly versatile apparatus which allows production of model catalysts (both metals and metal oxides) by deposition of mass-selected nanoclusters from the gas phase onto single crystal oxide supports. These well-defined nanocluster catalysts are characterized using a normal array of surface science methods and, in addition, utilization of ultrahigh vacuum combined with scanning-tip microscopy (UHV-STM) methods to probe the size and shape of the nanoclusters before and after reaction. The chemistry of such model catalysts is monitored in UHV using temperature-programmed desorption (TPD) and temperature-programmed reaction (TPR) and at elevated pressures using a high pressure batch reactor attached to the surface science chamber. Specifically, the investigators will prepare and study the catalytic activity of very small VxOy mass-selected clusters supported on single crystal titanium dioxide (110) surfaces in the oxidative dehydrogenation of methanol to formaldehyde. They will probe the catalytic activity as a function of both x and y to develop a model for the reaction mechanism. They will also prepare and study the catalytic activity of very small mass-selected, binary clusters such as palladium/gold and platinum/tin alloys of various compositions supported on single crystal titanium dioxide (110) surfaces in the synthesis of vinyl acetate and the selective hydrogenation of alkenes as a function of composition as well as develop a model for the reaction mechanism.

A large number of industrial processes use nanometer-size clusters (both metal and metal oxide) supported on oxide surfaces to perform reactions that would not take place, or would be commercially unsuccessful if performed on the bulk material. In research supported by this grant the investigators will utilize state-of-the-art experimental and theoretical methods to probe the catalytic activity of well-defined nanocluster catalysts in great detail and develop a fundamental understanding of the catalytic chemistry at the atomic level. The concepts developed through this research will help optimize important industrial processes using these nanoscale catalysts and provide valuable insight into the discovery of new nanoscale catalytic materials. Researchers supported by this grant will also be active in outreach to K-12 schools in the Santa Barbara area. They plan to develop a tutorial presentation on an atomistic view of heterogeneous catalysis that will be included in the currently active outreach program in the department at UCSB. In addition, researchers working on this project will visit high schools in the Santa Barbara and Ventura Counties three times per year to discuss their research and its impact as well as to promote science education.

Chemical catalysis involves a chemical substance, called a catalyst, which lowers energy costs and creates more selective product distributions by providing another pathway for the chemical reaction of interest. Catalysts are often employed to generate environmentally friendly fuels, such as hydrogen which burns cleanly to water, and are also used to produce value-added chemicals, like carbon monoxide and methanol which can be made from sustainable crop sources. Because of the importance, catalyst function is a major driving force of research in the chemistry community. Transition metals and transition metal oxides possess many of the desired chemical properties for catalysts that can activate the bonds in CO2, H2O and CH4, which are particularly promising feedstocks for a more sustainable production of fuels and value-added chemicals. These metals and their oxides can be especially active as small atomic clusters in the 0.00000005 inch or nanometer size range. Nanoclusters exhibit enhanced reactivity due to their unique geometric and electronic characteristics such as under-coordinated surface atoms, modified inter-atomic spacings and large surface to volume ratio. In this project, Drs. Buratto, Bowers and Metiu produce model catalysts of both metals and metal oxides by deposition of well-defined, atomically-precise nanoclusters from the gas phase onto metal and metal oxide supports. These model systems are then tested for their reactivity in the production of hydrogen and methanol, important as both clean-burning fuels and chemical feedstocks. The research team's unique capability to control nanocluster composition atom-by-atom provides the requisite level of detail to understand the chemistry on the atomic level and provides important insight into the development of new catalytic systems. Drs. Buratto, Bowers and Metiu and graduate students supported by this project are active in outreach to high school students in the Santa Barbara and Ventura Counties to discuss their research and its impact as well as promote science education.

With funding from the Chemical Catalysis Program of the Chemistry Division, Drs. Buratto, Bowers and Metiu prepare, characterize, and test two new classes of nanoscale catalysts based on the atom-by-atom assembly of small bimetallic and metal oxide clusters having one feature in common; they have very small, isolated, well-defined, catalytically-active sites and enhanced catalytic activity. The research centers on the preparation of well-defined PdAun and PtSnm clusters supported on single crystal TiO2(110) and well-defined FexOy supported a single crystal Pt(111) in the inverse catalyst geometry. These model systems are prepared by depositing mass-selected clusters from the gas phase onto single crystal surfaces to control catalyst size and composition. Samples are then studied in ultra-high vacuum by x-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM) to determine composition and structure. Temperature programmed reaction (TPR) is used to probe the activity to the water gas shift reaction, CO oxidation, and methanol synthesis. Density functional theory (DFT) is used to calculate the structure of the clusters, their XPS spectrum and their chemical activity, and these data are then compared to experiment. The results are used to develop a detailed fundamental understanding of the catalytic chemistry at the atomic level that will in turn help optimize important industrial processes, and improve the performance of the existing catalysts or uncover new ones. The research groups of Drs. Buratto, Bowers and Metiu are committed to K-12 outreach and the promotion of science in general. They are incorporating their research in heterogeneous catalysis into the University of California Santa Barbara's (UCSB's )5th grade outreach program. This program brings 5th grade students from elementary schools in the Santa Barbara area to the UCSB campus for hands-on science activities. The research team is also working with the teachers to develop a lesson in catalysis that is appropriate for the 5th grade curriculum and then incorporate it into the outreach program. In addition, graduate students supported by this project are active in outreach to high school students in the Santa Barbara and Ventura Counties to discuss their research and its impact, as well as to promote science education.