Tuning the Redox Chemistry of a Cr/SiO₂ Phillips Catalyst for Controlling Activity, Induction Period and Polymer Properties.

ABSTRACT: The Cr/SiO₂ Phillips catalyst has taken a central role in ethylene polymerization ever since its discovery in 1953. This catalyst is unique compared to other ethylene polymerization catalysts, since it is active without the addition of a metal-alkyl co-catalyst. However, metal-alkyls can be added for scavenging poisons, enhancing the catalyst activity, reducing the induction period and altering polymer characteristics. Despite extensive research into the working state of the catalyst, still no consensus has been reached. Here, we show that by varying the type of metal-alkyl co-catalyst and its amount, the Cr redox chemistry can be tailored, resulting in distinct catalyst activities, induction periods, and polymer characteristics. We have used in-situ UV-Vis-NIR diffuse reflectan

SUBMITTER: Jongkind MK 

PROVIDER: S-EPMC7496818 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature