429644 Single Site Catalysts for Propene Dehydrogenation

Wednesday, November 11, 2015: 12:50 PM
355E (Salt Palace Convention Center)
Andrew (Bean) Getsoian1, Bo Hu2, Jeffrey T. Miller3 and Adam S. Hock1, (1)Chemical Sciences and Engineering, Argonne National Laboratory, Lemont, IL, (2)Dept. Of Chemical and Biological Sciences, Illinois Institute of Technology, Chicago, IL, (3)School of Chemical Engineering, Purdue University, West Lafayette, IN

Selective dehydrogenation of light alkanes to olefins is a key technology for converting abundant alkane feedstocks into high value precursors for the polymer and fuel industries. A number of single site, silica-supported cations are able to catalyze this reaction with high selectivity; however, the design principles governing catalytic activity are not yet known. X-ray absorption spectroscopy indicates that reactivity proceeds without a change of oxidation state at the active site, and in some cases, metal hydride intermediates may be identified by Raman spectroscopy. These results are consistent with density functional modeling suggesting a heterolytic C-H bond cleavage mechanism for alkane dehydrogenation. Activity of the site is found to depend on both the Lewis acidity of the cation and the metal-oxygen bond strength between the cation and the silica support. Greater understanding of these structure-function relationships has guided synthesis of precatalysts that more readily form the active metal hydride structure under reaction conditions, leading to significant increases in catalytic performance.

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See more of this Session: Fundamentals of Supported Catalysis II
See more of this Group/Topical: Catalysis and Reaction Engineering Division