CO + H/sub 2/ reaction over nitrogen-modified iron catalysts. Quarterly technical progress report, April 1-September 30, 1985
A 4.5 wt % supported on Carbolac - 1 catalyst was prepared by incipient wetness and characterized by in-situ Moessbauer spectroscopy. The reduced catalyst exhibited superparamagnetic iron at RT as well as extreme sensitivity to oxygen. Both of these results are indicative of small (approx.20A), very highly dispersed iron crystallites. After nitriding to xi-Fe/sub 2/N followed by Fischer-Tropsch synthesis (with 3:1 H/sub 2//CO at 250/sup 0/C) for 20 hrs, the sample was re-reduced in H/sub 2/ for 8 hrs at 400/sup 0/C. The re-reduced spectrum showed that approx.84% of the iron appeared to be bulk-like, indicating that the reaction environment can induce iron migration on the catalyst. Computer simulation of the decomposition of a ..gamma..-Fe/sub 4/N catalyst in hydrogen at 523 K indicates that the observed ammonia evaluation curve can be modeled by a two step process. The model incorporates a conversion from a homogeneous mixture of nitrogen in the core into a surface nitrogen species, which is subsequently hydrogenated to ammonia. The model demonstrates that competition between this nitrogen surface species and adsorbed hydrogen for the available surface sites can account for the maximum in the observed NH/sub 3/ evoluation rate. Other models incorporating shrinking core distribution of nitrogen in the core failed to fit the experimental results.
- Research Organization:
- Purdue Univ., Lafayette, IN (USA). School of Chemical Engineering
- DOE Contract Number:
- FG22-82PC50804
- OSTI ID:
- 6356366
- Report Number(s):
- DOE/PC/50804-11; ON: DE86004169
- Country of Publication:
- United States
- Language:
- English
Similar Records
CO + H/sub 2/ reaction over nitrogen-modified iron catalysts. Quarterly technical progress report, January 1-March 31, 1984
CO+H/sub 2/ reaction over nitrogen-modified iron catalysts. Quarterly technical progress report, April 1, 1984-June 30, 1984
Related Subjects
10 SYNTHETIC FUELS
ALKANES
ALKENES
AMMONIA
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL PREPARATION
CHEMICAL REACTIONS
DATA
ELEMENTS
EXPERIMENTAL DATA
FISCHER-TROPSCH SYNTHESIS
HYDRIDES
HYDROCARBONS
HYDROGEN COMPOUNDS
INFORMATION
IRON
IRON COMPOUNDS
IRON NITRIDES
MATHEMATICAL MODELS
METALS
MOESSBAUER EFFECT
NITRIDATION
NITRIDES
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NUMERICAL DATA
ORGANIC COMPOUNDS
PHASE STUDIES
PNICTIDES
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS