Dimerization catalyst systems, their preparation, and use
View Patent ↗A method for preparing a nickel-containing composition, and a composition prepared by such method, are disclosed including the steps of: a) mixing a phosphorous compound with a nickel complex having nickel bonded to a heteroatom to thereby form a nickel-phosphorous-containing mixture; and b) contacting the nickel-phosphorous-containing mixture with a supported partially hydrolyzed alkylaluminum compound, thereby forming such nickel-containing composition. Use of such nickel-containing composition in the dimerization of propene is also disclosed.
1. A method comprising:
a) mixing a phosphorous compound with a nickel complex comprising nickel bonded to a heteroatom, to thereby form a nickel-phosphorous-containing mixture; and
b) contacting said nickel-phosphorus-containing mixture with a supported partially hydrolyzed alkylaluminum compound, thereby forming a nickel-containing composition that has an activity sufficient for at least 84% selectivity to hexenes in conversion of propene, wherein said nickel complex comprises at least one compound having the following structure:
wherein:
R is selected from alkyl, aryl, alkenyl, hydrogen, and combinations thereof, any of which optionally can be partially oxidized or partially substituted by nitrogen-functional groups having the general formulas OH, OR, and NH y R z , respectively;
y=3−z; and
z ranges from 1 to 3.
2. The method of claim 1 wherein said nickel complex comprises the following compound:
3. The method of claim 1 wherein said phosphorus compound has the formula R n PY 3-n ;
R is selected from alkyl, aryl, alkenyl, hydrogen, and combinations thereof, any of which optionally can be partially oxidized or partially substituted by nitrogen-functional groups having the general formulas OH, OR and NH y R z , respectively;
Y is selected from hydrogen and halogen;
y=3−z;
z ranges from 1 to 3, and
n ranges from 1 to 3.
4. The method of claim 1 wherein said phosphorous compound is selected from the group consisting of tributyl phosphine, triphenyl phosphine, triisopropyl phosphine, and combinations thereof.
5. The method of claim 1 wherein said supported partially hydrolyzed alkylaluminum compound is supported partially hydrolyzed trimethylaluminum.
6. The method of claim 1 wherein the support of said supported partially hydrolyzed alkylaluminum compound is silica.
7. The method of claim 1 wherein said method is performed at a temperature in the range of from about −20° C. to about 150° C.
8. The method of claim 1 wherein a solvent is added in step a); and wherein said solvent is removed in step b), thereby forming said nickel-containing composition.
9. The method of claim 8 wherein said solvent is toluene.
10. The method of claim 1 , wherein the nickel-containing composition has an activity sufficient for conversion of at least 60 weight percent of propene to hexenes.
11. The method of claim 1 , wherein the nickel-containing composition has an activity sufficient for 100% selectivity to hexenes in conversion of propene.