Effect of Light on the Activity of Metallocene Catalysts in the Gas‐Phase Polymerisation of Ethylene

It was found that halogen light can have a strong effect on the polymerisation activity of silica‐supported metallocene catalysts. Three different metallocene catalysts have been tested in the gas‐phase polymerisation of ethylene. The effect of activation depends not only on the type of transition metal, but also on the wavelength and intensity of light. The activation by light was found to be a reversible process.