Hydrogenation of carbon monoxide over Raney iron-manganese catalysts: effect of leaching reagents on activity and selectivity

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6917452

Chen, K R

The activity and selectivity of Raney Fe-Mn catalysts for the production of low molecular weight olefins (C/sub 2/-C/sub 4/) from H/sub 2/ and CO were investigated. The Raney catalysts were prepared by extracting Al from an Fe-Mn-Al alloy with different reagents including NaOH, KOH, LiOH, and NH/sub 4/OH. The data on the extent of Al extraction indicated that NaOH was the most effective leaching reagent. The ratios of Fe to Mn remained constant in the catalysts regardless of the leaching agent used, while the Al content of the catalysts was found to be dependent on the degree of leaching. The NaOH and KOH leached catalysts chemisorbed greater amounts of H/sub 2/ and CO. The NaOH and LiOH leached catalysts were more selective for low molecular weight olefins. The activity of the KOH leached catalyst was similar to that of the NaOH leached catalyst. Magnetite were found in the NaOH leached catalyst, while a mixed phase comprised of ..cap alpha..-iron, magnetite and FeAl/sub 3/ was identified in the other catalysts by X-ray diffraction study. The presence of an ..cap alpha..-iron phase was identified in all the reduced catalysts. Except for the NaOH leached catalyst, FeAl/sub 3/ was also identified in all the reduced catalysts. The predominant carbide phase in the spent KOH leached catalyst was Chi-Fe/sub 5/C/sub 2/ while the predominant carbide phase in the other spent catalysts was epsilon-Fe/sub 2.2/C. Surface Fe was determined to be present as an iron oxide phase after leaching, and as an Fe metal phase after reduction by ESCA (Electron Spectroscopy for Chemical Analysis). The Mn was found to be in the oxide state during all stages in the life of the catalysts. The spent catalyst surface was found to be almost completely covered by carbon for the NaOH leached, KOH leached and coprecipitated catalysts, while relatively smaller portions of the catalyst surface were covered by carbon for the spent LiOH leached and NH/sub 4/OH leached catalysts.

• Research Organization: Utah Univ., Salt Lake City (USA)
• OSTI ID: 6917452
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010408* -- Coal
Lignite
& Peat-- C1 Processes-- (1987-)
ALKALI METAL COMPOUNDS
ALKENES
ALLOYS
ALUMINIUM
ALUMINIUM ALLOYS
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CHEMISORPTION
COHERENT SCATTERING
DIFFRACTION
DISSOLUTION
ELECTRON SPECTROSCOPY
ELEMENTS
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROGENATION
HYDROXIDES
IRON
IRON ALLOYS
LEACHING
MANGANESE
MANGANESE ALLOYS
METALS
METHANATION
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PRODUCTION
REMOVAL
SCATTERING
SEPARATION PROCESSES
SODIUM COMPOUNDS
SODIUM HYDROXIDES
SORPTION
SPECIFICITY
SPECTROSCOPY
SURFACE PROPERTIES
SYNTHESIS
TRANSITION ELEMENTS
X-RAY DIFFRACTION