ED-XAS Data Reveal In-situ Time-Resolved Adsorbate Coverage on Supported Molybdenum Oxide Catalysts during Propane Dehydrogenation

Journal Article · Fri Feb 02 00:00:00 EST 2007 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2644610· OSTI ID:21054697

Ramaker, David; Gatewood, Daniel ^[1]; Beale, Andrew M; Weckhuysen, Bert M ^[2]

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1. Department of Chemistry, George Washington University, Washington D.C. 20052 (United States)
2. Inorganic Chemistry and Catalysis, Dept. of Chem., Utrecht University, Sorbonnelaan 16, 3584 CA Utrecht (Netherlands)

Energy-Dispersive X-ray Absorption Spectroscopy (ED-XAS) data combined with UV/Vis, Raman, and mass spectrometry data on alumina- and silica-supported molybdenum oxide catalysts under propane dehydrogenation conditions have been previously reported. A novel {delta}{mu} adsorbate isolation technique was applied here to the time-resolved (0.1 min) Mo K-edge ED-XAS data by taking the difference of absorption, {mu}, at t>1 against the initial time, t=0. Further, full multiple scattering calculations using the FEFF 8.0 code are performed to interpret the {delta}{mu} signatures. The resulting difference spectra and interpretation provide real time propane coverage and O depletion at the MoOn surface. The propane coverage is seen to correlate with the propene and/or coke production, with the maximum coke formation occurring when the propane coverage is the largest. Combined, these data give unprecedented insight into the complicated dynamics for propane dehydrogenation.

• OSTI ID: 21054697
• Journal Information: AIP Conference Proceedings, Vol. 882, Issue 1; Conference: XAFS13: 13. international conference on X-ray absorption fine structure, Stanford, CA (United States), 9-14 Jul 2006; Other Information: DOI: 10.1063/1.2644610; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
ADSORPTION
ALUMINIUM OXIDES
CATALYSIS
CATALYSTS
COMPUTERIZED SIMULATION
DEHYDROGENATION
F CODES
MASS SPECTROSCOPY
MOLYBDENUM OXIDES
MULTIPLE SCATTERING
PROPANE
PROPYLENE
RAMAN SPECTROSCOPY
SILICON COMPOUNDS
SURFACES
TIME RESOLUTION
X-RAY SPECTRA
X-RAY SPECTROSCOPY