Alkylation of biphenyl with propylene using acid catalysts

Alkylation of biphenyl with propylene was carried out over various zeolites such as HY, H-ZSM-5, Beta, MCM-22, SSZ-25 and SSZ-26. The influence of zeo lite structure on reaction activity and selectivity was studied. The alkyla tion activity follows the order: Y > Beta approximate to SSZ-26 > MCM-22 > SSZ-25 > ZSM-5. The influence of framework Si/Al ratio and crystal size for the tri-directional 12 member ring structures (Y and Beta) has been studie d and it has been observed that, under the reaction conditions used here, t he process is not diffusion controlled. High selectivity to ortho-isopropyl biphenyl (o-IPBP) was obtained using MCM-22 and SSZ-25 zeolites, both with a MWW structure, The high o-IPBP selectivity as well as the differences obs erved between the two zeolite samples have been explained on the bases of d ifferences in crystal size and assuming that on this zeolite structure the reaction only takes place on the external surface. (C)2000 Elsevier Science B.V. All rights reserved.