452415 Combined Experimental and Theoretical Study of Ethanol Catalytic Conversion to 1,3-Butadiene on MgO

Tuesday, November 15, 2016: 9:00 AM
Franciscan B (Hilton San Francisco Union Square)
William Taifan, Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA and Jonas Baltrusaitis, Chemical Engineering, Lehigh University, Bethlehem, PA, Lehigh University, Bethlehem, PA

Biomass can serve as a sustainable and renewable carbon source.  Ethanol is relatively inexpensive and widely available and can its catalytic upgrading has been proposed as a viable route of indirect biomass valorization.  1,3-butadiene, the most important monomer for synthetic rubber, has been produced via catalytic processing of ethanol during World War II by USSR and USA, using Lebedev and Ostromislensky processes, respectively. The former utilized catalytic conversion of ethanol to 1,3-butadiene in one-step over MgO/SiO2 catalystswhile the latter utilized a two-step process with the first step of ethanol dehydrogenation to acetaldehyde over Cu/SiO2 catalysts and transforming acetaldehyde into 1,3-butadiene over a tantalum-based catalyst during the second step.  Recent abundance of shale gas resulted in a different catalytic cracker product distribution dominated by ethylene.  This caused a worldwide shortage of C4 hydrocarbons such as 1,3-butadiene.  Since ethanol can be produced using variety of biomass processing routes, including fermentation and gasification, it recently reemerged as the green route to catalytically form 1,3-butadiene but improvements in yields are necessary. 

In this study, we identified the reaction intermediates and mechanisms of ethanol on MgO surface by combining both theoretical and experimental study by means of DFT, in-situ FTIR and TPSR.  A complex mechanism involving acetaldehyde, crotyl species as well as unexpected pathway via ethylene are discussed.

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