Isosynthesis reactions of CO/H/sub 2/ over zirconium dioxide
The isosynthesis reactions of an equimolar mixture of carbon monoxide and hydrogen were studied over zirconium dioxide catalysts. The main objectives of this work were: (1) to investigate the reaction pathway, (2) identify the surface intermediates leading to the formation of i-butene, and (3) determine the mechanisms of carbon chain propagation. The reactions were conducted at 250-450/sup 0/C, 35 atm (500 psig) total pressure, and 100-200 cc/min total flow rate in a differential reactor. Oxygenated intermediates are proposed to exist on the zirconia surface. This is supported by the observations that oxygenated products were favored at lower reaction temperatures or at shorter residence times. Propylene, propionaldehyde, acetone, i-propanol, and n-propanol were used as probe molecules to examine the chain growth and branching mechanisms, leading to the formation of i-butene. Reaction schemes are proposed. Carbon-13 labeled acetone and methanol were utilized to examine quantitatively the above two schemes. The labeled acetone studies revealed that both the branched and linear olefins were formed from the acetone added. The presence of carbon-13 carbons in linear olefins indicated that methylation at the acetone methyl occurred. The labeled methanol studies revealed that aldol-type condensation did proceed over zirconia, leading to the formation of branching olefins.
- Research Organization:
- Texas Univ., Austin (USA)
- OSTI ID:
- 5659887
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BUTENES
CHEMICAL PREPARATION
CARBON MONOXIDE
CHEMICAL REACTIONS
HYDROGEN
ZIRCONIUM OXIDES
CATALYTIC EFFECTS
CATALYSIS
ALKENES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
ELEMENTS
HYDROCARBONS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM COMPOUNDS
090121* - Hydrocarbon Fuels- Chemical Synthesis- (1976-1989)