Reduction behavior and metathesis activity of WO sub 3 /Al sub 2 O sub 3 catalysts. III. The activation of WO sub 3 /Al sub 2 O sub 3 catalysts

Journal Article · Thu Nov 30 23:00:00 EST 1989 · Journal of Catalysis; (USA)

DOI:https://doi.org/10.1016/0021-9517(89)90284-4· OSTI ID:6842520

Grunert, W; Feldhaus, R; Anders, K ^[1]; Shpiro, E S; Minachev, Kh M ^[2]

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1. Central Institute of Organic Chemistry, Leipzig (USSR)
2. N.D. Zelinsky Institute of Organic Chemistry, Moscow (USSR)

The activation of WO{sub 3}/Al{sub 2}O{sub 3} catalysts for the metathesis of propene (573 K, 0.1 MPa, flow reactor) was investigated. For catalysts containing {le}12 wt% WO{sub 3} the best activation procedure is a thermal treatment in flowing inert gas at a temperature depending on the WO{sub 3} content (up to 1143 K at 0.5-4 wt% WO{sub 3}). The specific activity of W after these procedures and the reducibility of W(VI) show opposite trends. Hydrogen as an activation medium is inferior to Ar at WO{sub 3} contents {le}12 wt% but with a 23-wt% WO{sub 3}/Al{sub 2}O{sub 3} catalyst conditions were found where activation in H{sub 2} yields higher activities than an inert treatment at the same temperature. The propene metathesis was found to be first order in propene at 573 K and 0.1 MPa. The apparent activation energy decreases from 40 to 25 kJ/mole with increasing WO{sub 3} content. The results imply that the active sites are formed exclusively from W(VI) precursors when the WO{sub 3} content is {le}12 wt%. At high WO{sub 3} content prereduction under appropriate conditions leads to surfaces with coexisting W(IV) and W(VI) precursors.

• OSTI ID: 6842520
• Journal Information: Journal of Catalysis; (USA), Journal Name: Journal of Catalysis; (USA) Vol. 120:2; ISSN 0021-9517; ISSN JCTLA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020400* -- Petroleum-- Processing
ACTIVATION ENERGY
ALKENES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ARGON
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL ACTIVATION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
ELEMENTS
ENERGY
FLUIDS
GASES
HEAT TREATMENTS
HYDROCARBONS
HYDROGEN
ISOMERIZATION
KINETICS
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PROPYLENE
QUANTITY RATIO
RARE GASES
REACTION KINETICS
REDUCTION
REFRACTORY METAL COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TUNGSTEN COMPOUNDS
TUNGSTEN OXIDES