CO + H/sub 2/ reaction over nitrogen-modified iron catalysts. Quarterly technical progress report, January 1-March 31, 1984 [electronic resource].
- Published
- Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 1984.
- Physical Description
- Pages: 28 : digital, PDF file
- Additional Creators
- United States. Department of Energy. Office of Scientific and Technical Information
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- Restrictions on Access
- Free-to-read Unrestricted online access
- Summary
- We have found that the nitride catalysts lose substantial amounts of nitrogen during the initial minutes of Fischer-Tropsch synthesis. In order to further study the stability of these catalysts, we have concentrated on the decomposition of the nitride in hydrogen. In addition, we have prepared a range of epsilon-Fe/sub x/N (2 < x < 3) phases. The Moessbauer parameters from these phases will aid in the identification and fitting of the transient epsilon phases formed during the carburization of Xi-Fe/sub 2/N. Extremely rapid nitrogen loss has been observed from Xi-Fe/sub 2/N in H/sub 2/ at 523 K both in constant velocity Moessbauer and in transient mass spectrometer experiments. In order to study the phase change from Xi-Fe/sub 2/N to ..cap alpha..-Fe in more detail, the hydrogenation temperature was decreased to 473 K and intermediate samples were quenched in liquid nitrogen to lock in the phase distribution for subsequent Moessbauer study. The spectra show complete conversion to ..cap alpha..-Fe at or before 21 minutes at 473 K. The intermediate samples show evidence of an extremely sharp gradient; only a very small amount of ..gamma..' or epsilon phase is observed. Thus, a moving front model of the phase transformation appears to be appropriate. Mass spectroscopy of the hydrogenation of Xi-Fe/sub 2/N at 523 K showed similar behavior to that of both the ..gamma..' and epsilon phases, in which an active surface species and a slowly activating one were observed. The H/sub 2/ was replaced by D/sub 2/ in this experiment in order to observe partially hydrogenated surface species in the initial spike of ammonia. All NH/sub x/D/sub y/ (x + y = 3) species were observed in this spike, indicating extremely rapid surface H/D exchange with gaseous ammonia. The fragmentation pattern of NH/sub 3/ in the mass spectrometer was also determined and will be used to calculate initial NH/sub x/ surface contributions. 23 references, 3 figures, 3 tables.
- Report Numbers
- E 1.99:doe/pc/50804-6
doe/pc/50804-6 - Subject(s)
- Other Subject(s)
- Catalysts
- Stability
- Fischer-Tropsch Synthesis
- Iron Nitrides
- Carburization
- Catalytic Effects
- Hydrogenation
- Phase Transformations
- Carbon Monoxide
- Experimental Data
- High Temperature
- Hydrogen
- Mass Spectroscopy
- Moessbauer Effect
- Research Programs
- Temperature Dependence
- Carbon Compounds
- Carbon Oxides
- Chalcogenides
- Chemical Reactions
- Data
- Elements
- Hardening
- Information
- Iron Compounds
- Nitrides
- Nitrogen Compounds
- Nonmetals
- Numerical Data
- Oxides
- Oxygen Compounds
- Pnictides
- Spectroscopy
- Surface Hardening
- Surface Treatments
- Transition Element Compounds
- Note
- Published through SciTech Connect.
07/01/1984.
"doe/pc/50804-6"
"DE84014466"
Delgass, W.N.
Purdue Univ., Lafayette, IN (USA) - Funding Information
- FG22-82PC50804
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