A comparison of Cr Sio2 and Cr AlPO4 polymerization catalysts. I. Kinetics

Abstract

Ethylene polymerization over Cr/aluminophosphate has been examined and compared to that over Cr/silica. The two catalysts display quite different kinetics and produce important differences in the polymer as well, but this may result from slight variations in a common underlying mechanism of polymerization. The active site on both catalysts is seen as a transient species in a series of consecutive reactions, including reduction, alkylation, and decay. This model has been used to analyze and interpret the development and decline of activity under various polymerization conditions. © 1986.