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Moessbauer spectra of ferrite catalysts used in oxidative dehydrogenationRoom temperature Mossbauer spectroscopy was used to examine bulk changes which occur in low surface area CoFe2O4 and CuFe2O4 catalysts as a result of contact with various mixtures of trans-2-butene and O2 during oxidative dehydrogenation reactions at about 420 C. So long as there was at least some O2 in the gas phase, the CoFe2O4 spectrum was essentially unchanged. However, the spectrum changed from a random spinel in the oxidized state to an inverse spinel as it was reduced by oxide ion removal. The steady state catalyst lies very near the fully oxidized state. More dramatic solid state changes occurred as the CuFe2O4 underwent reduction. Under severe reduction, the ferrite was transformed into Cu and Fe3O4, but it could be reversibly recovered by oxidation. An intense doublet located near zero velocity persisted in all spectra of CuFe2O4 regardless of the state of reduction.
Document ID
19730021376
Acquisition Source
Legacy CDMS
Document Type
Contractor Report (CR)
Authors
Cares, W. R.
(Rice Univ. Houston, TX, United States)
Hightower, J. W.
(Rice Univ. Houston, TX, United States)
Date Acquired
September 2, 2013
Publication Date
January 1, 1971
Subject Category
Chemistry
Report/Patent Number
NASA-CR-133740
Accession Number
73N30108
Funding Number(s)
CONTRACT_GRANT: NGR-23-005-074
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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