METHODS OF PREPARING ACTIVE CHROMIUM/ALUMINA CATALYSTS VIA TREATMENT WITH SULFATE AND POLYMERS PRODUCED USING THE CHROMIUM/ALUMINA CATALYSTS

摘要

Methods of preparing a polymerization catalyst are provided that includecontacting a support comprising alumina with a sulfating agent and withchromium. The support can be calcined after loading the sulfating agent andthe chromium on the support. Alternatively, the sulfating agent can be loadedon the support while calcining it. Alternatively, the support can be calcinedafter contacting it with the sulfating agent and before contacting it with anorganochromium compound. Catalysts compositions comprising chromium and asulfate treated alumina support that were formed by the foregoing method areprovided. The catalyst compositions have increased catalyst activity. Methodsof producing a polymer include contacting at least one olefin with thecatalyst compositions are provided. The polymer compositions exhibitrelatively low levels of long chain branching and relatively high molecularweights.