In addition to its annual lectures, ChBE hosts a weekly seminar throughout the year with invited lecturers who are prominent in their fields. Unless otherwise noted, all seminars are held on Wednesdays in the Molecular Science and Engineering Building ("M" Building) in G011 (Cherry Logan Emerson Lecture Theater) at 4 p.m. Refreshments are served at 3:30 p.m. in the Emerson-Lewis Reception Salon.

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Phillip Christopher, University of California, Riverside

“Structural and Dynamic Characteristics of Supported Metal Catalysis at the Atomic Scale”

Abstract

The use of heterogeneous catalysts for important chemical conversions ranging from pollution mitigation to energy production relies on the design of active catalytic sites consisting of metal nanostructures supported on high surface area oxide materials.  Key to design of these systems is the identification of active site geometries and compositions that are optimized for desired catalytic reactions. These active sites vary in structural diversity from single metal atoms on oxide supports to unique interfaces between faceted metal nanoparticles and oxide supports, making their characterization complex. This difficulty is further complicated because the exposure of oxide-supported metals to reactive environments can induce significant transformations in the structure of the metal, support, and interactions between the metal and support. The dynamic transformations in catalytic structures induced by exposure to reactions can cause significant changes in the reactivity of the structures, requiring detailed in-situ analysis to identify active site motifs. I will highlight a few examples where we exploit quantitative and in-situ spectroscopy and microscopy to characterize heterogeneous catalysts at atomic scale and identify how reactive conditions modify active site structures and relate this to catalytic performance.

Biography

Phil Christopher received his B.S. from University of California, Santa Barbara in 2006 and his M.S and Ph.D. from University of Michigan in 2011 all in Chemical Engineering. He joined the University of California, Riverside in September 2011 as an Assistant Professor with joint appointments in the Chemical & Environmental Engineering Department and Materials Science & Engineering Program. Prof. Christopher has won various awards including the 2012 Young Scientists Award from the International Congress on Catalysis, 2014 Army Research Office Young Investigator Award, and 2016 NSF Early CAREER Award.  Prof. Christopher’s research group focuses broadly on heterogeneous catalysis with interest in understanding fundamental aspects of active site characteristics and reaction mechanisms and applying these insights to the design of new materials and processes for chemicals and fuels production, as well as environmental protection.