Abstract: The method of preparation of AlCl₃ catalyst immobilized on γ-Al₂O₃ was investigated. AlCl₃ generated by reacting CCl₄ with pure γ-Al₂O₃ at 500℃ and γ-Al₂O₃ with bimodal meso-and macro-pore structure were used as immobilizing agent and support, respectively, to prepare the catalyst. The effect of various factors of immobilization conditions on catalytic property in isobutene polymerization was examined. The catalyst, in which the mass fraction of AlCl_x is about 7.5 and x=2.2, showed a high activity, selectivity and stability, and no considerable differences in the catalytic behavior were founDIn the following ranges: reaction temperature, 300-400 ℃; reaction time, 0.5-4.0 h; flow of CCl₄ of adding, 1.15-2.01 mL/h for 15 mL γ-Al₂O₃. Additionally, it was shown that the catalytic property in isobutene polymerization is not only dependent on the nature of support, but also on its geometric structure. Compared with the catalysts having micro-porous and meso-porous structure which showed a poor stability, the catalyst with meso-and macro-pore bimodal structure exhibited a very high stability, and was supposed to be most suitable one, anDIt was ascribed to that in the case of the latter, harmfuLInfluence of intraparticle diffusion caused by "pore clogging" of large product molecules in the pore channel effectively reduced.

Key words: AlCl₃ immobilization, γ-Al₂O₃, Isobutene polymerization