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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“Computational Insight into Catalytic Ammonia and Ethanol Synthesis”

Andrew J. Medford, Stanford University

Abstract:
The ability to design and predict catalytic materials using computational methods is an exciting prospect both scientifically and economically. The ammonia synthesis reaction is a classic example in heterogeneous catalysis due to its relatively simple and industrial relevance. Using a combination of density functional theory (DFT), linear energy relationships, and microkinetic modeling, the trends in activity of elemental transition-metal catalysts are examined for the ammonia synthesis reaction. The results show that the method reproduces known experimental trends, and that the findings are robust despite the uncertainty in DFT energies.

Catalytic ethanol synthesis is a promising route to production of high-value synthetic fuels; however, there is currently no commercial process due to the lack of sufficiently active and selective catalysts. The ethanol synthesis reaction is explored using the techniques introduced for ammonia synthesis, demonstrating that the approach is transferrable and can provide intuition about complex reaction networks. The findings explain the difficulty in developing transition-metal higher alcohol catalysts, and indicate design principles for discovering new catalysts. Using the resulting activity and selectivity maps, several alloys are identified as likely candidates for ethanol synthesis. Preliminary experimental testing is presented, and some future directions for computational discovery of novel catalysts for ethanol synthesis and other catalytic reactions are discussed.