Synthesis and Characterization, Kinetic Studies, and Density Functional Theory
Heterogeneous Catalysts are key to mitigating climate change, forging a renewable energy and chemicals industry, and providing a high quality of life throughout the globe without sacrificing our environment. At UF, we study catalysis through a combination of synthesis, characterization, and kinetic studies (Hagelin-Weaver and Hibbitts), surface science studies of interfacial chemistry (Weaver), and density functional theory calculations to give insights into atomistic behavior (Hibbitts).
Jason WeaverExxon Mobil Gator Alumni Faculty Endowed Professor
OUR RESEARCH FOCUSES ON ADVANCING THE MOLECULAR-LEVEL understanding of surface chemical reactions that are important in applications of heterogeneous catalysis. My students and I investigate chemical reactions on solid surfaces using a wide array of analysis methods based on ultrahigh vacuum (UHV) surface chemistry and physics, including methods that provide information about surface reaction kinetics, adsorbed intermediates, atomic scale surface structure and the chemical states of adsorbed molecules and atoms of the solid. We make rigorous comparisons between our experimental data and predictions of molecular simulations, and find that this approach is a powerful way in which to identify elementary steps in surface reaction networks. We also investigate the catalytic behavior of well-defined surfaces using in situ synchrotron-based techniques to enable comparisons between the results of our model UHV studies and the behavior of working catalysts.
GROWTH AND SURFACE CHEMISTRY OF OXIDE THIN FILMS
We are investigating the growth and chemical properties of oxide thin films that develop on the surfaces of late transition metals during oxidation catalysis. This work is motivated by findings that metal oxide layers form on metallic catalysts in oxygen-rich environments, and that such oxide layers can play a decisive role in determining catalytic performance. In our research, we produce oxide thin films for characterization in UHV by oxidizing metallic surfaces using atomic oxygen beams or through controlled exposure to O2 in an isolated reaction cell. This approach allows us to investigate oxide films under well-controlled conditions, and gain insights about the growth and surface chemical properties of oxides that are central to several catalytic applications, such as the catalytic combustion of natural gas, exhaust gas remediation in automobiles and selective oxidation processes. Key topics of focus include the oxidation mechanisms of late transition-metal surfaces and the chemistry of small molecules on metal oxide surfaces, particularly the oxidation of light alkanes. Our work continues to advance the molecular-level understanding of catalytic reaction mechanisms on late transition-metal oxides.
CATALYSIS ON MULTIFUNCTIONAL SURFACES
We are also studying oxidation chemistry on mixed-metal oxides and metal-oxide nanostructures. These types of materials feature different types of surface domains separated by interfacial regions at which the constituents make atomic contact. Such multifunctional surfaces can exhibit unique catalytic properties as a result of cooperativity among the coexisting surface domains as well as distinct chemical properties of the interfacial regions. Our main goals are to determine how coexisting sites and domains influence catalytic reaction processes and develop structure-reactivity relationships that may be used to design multifunctional surfaces that promote selective oxidation catalysis. We are particularly interested in understanding how to modify these surfaces to achieve high selectivity and activity for converting light alkanes to value-added products such as olefins and organic oxygenates.
Ph.D., 1998, Stanford University
Awards & Distinctions
- Herbert Wertheim College of Engineering Doctoral Dissertation Adviser/Mentoring Award, 2018-2019
- Exxon Mobil Gator Alumni Faculty Endowment for Chemical Engineering, 2018
- William P. and Tracy Cirioli Term Professor, 2017
- American Vacuum Society Fellow
- National Science Foundation CAREER Award
- “Facile dehydrogenation of ethane on the IrO2(110) surface”, Y. Bian, M. Kim, T. Li, A. Asthagiri and J.F. Weaver, J. Am. Chem. Soc. 140 (2018) 2665-2672.
- “Understanding the intrinsic surface reactivity of single and multilayer PdO(101) on Pd(100)”, V. Mehar, M. Kim, M. Shipilin, M. Van den Bossche, J. Gustafson, L.R. Merte, U. Hejral, H. Grönbeck, E. Lundgren, A. Asthagiri and J.F. Weaver, ACS Catal. 8 (2018) 8553-8567.
- “Growth and structure of Tb2O3(111) films on Pt(111)”, C. Lee, V. Mehar and J. F. Weaver, J. Phys. Chem. C 122 (2018) 9997-10005.
- “Kinetic coupling among metal and oxide phases during CO oxidation on partially-reduced PdO(101): Influence of gas-phase composition”, J.F. Weaver, J. Choi, V. Mehar and C. Wu, ACS Catal. 7 (2017) 7319−7331.
- “Low-temperature activation of methane on the IrO2(110) surface”, Z. Liang, T. Li, M. Kim, A. Asthagiri and J.F. Weaver, Science 356 (2017) 298-301.