DIMERIZATION OF ETHYLENE CATALYZED BY A NICKEL-CATALYST SUPPORTED ON POROUS POLYMERS

We have tested the possibility of using polymer-supported catalysts in a heterogeneous way (gas-solid) for the dimerization of ethylene. The catalyst is prepared by complexation of NiCl2, by a phosphine group supported on a resin followed by reduction with Al(C2H5)2Cl. Good selectivity in butene synthesis has been achieved with a yield up to 80% of but-1-ene. The formation of oligomers is observed, and these oligomers become embedded in the polymer support, giving rise to decrease of both the specific area and the pore volume. It is proposed that the embedding process causes the deactivation of the catalyst by coverage of the active sites and pore blockage. Correlation between the efficiency of the catalyst and the texture of the different supports is shown. © 1990.