416847 Band Gap As a Descriptor of Catalytic Activity in Mixed Metal Oxide Oxidation Catalysts

Tuesday, November 10, 2015: 4:55 PM
355E (Salt Palace Convention Center)
Andrew (Bean) Getsoian1, Zheng Zhai2 and Alexis T. Bell2, (1)Chemical Sciences and Engineering, Argonne National Laboratory, Lemont, IL, (2)Department of Chemical and Biomolecular Engineering, University of California - Berkeley, Berkeley, CA

The development of descriptors to relate catalytic performance to material physico-chemical properties is a primary goal of catalysis research. We have found that for a series of mixed metal oxide oxidation catalysts (Bi3FeMo2O12, Bi2Mo2.5W0.5O12, and Bi(1-x/3)V(1-x)Mo(x)O4 for 0 < x < 1), the activation energy for the rate-determining step in the selective oxidation of propene to acrolein can be related to the band gap of the oxide, as measured by diffuse reflectance UV-Visible spectroscopy. That is, band gap is a descriptor for catalytic activity. Detailed theoretical analysis of the mechanism of propene oxidation has enabled the bond-breaking and bond-forming events occurring in the rate-determining transition state to be linked to the electronic excitation taking place in a band gap measurement, which in turn is a function of oxide composition. We further show that the dependence of the band gap on composition can be predicted from knowledge of the energies and sizes of the unoccupied d orbitals on each transition metal center in the oxide. The principles discussed in this talk provide a basis for the rational formulation of superior oxidation catalysts.

Getsoian A.; Zhai Z.; Bell A.T. J. Am. Chem. Soc. 2014, 136 (39), 13684-13697.

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