The title reaction has been investigated over Beta zeolites of different Si
/Al ratio. Surface acidity has been assessed by adsorption microcalorimetry
and FTIR, using pyridine as probe molecule. Catalytic tests were carried o
ut at 623 K and 40 bar in liquid phase, with decalin as solvent, in flow re
actor. Isopropylation is initially accompanied by remarkable oligomerisatio
n/cracking of the reactant alcohol and limited cracking of the solvent. The
formation of the small-sized products of the side reactions is initially f
avoured over the cumbersome alkylation products, due to the slow diffusion
rate of the latter. Transalkylation between polyisopropylnaphthalenes and n
aphthalene sets in, leading to increasing conversion of naphthalene with ti
me-on-stream. For the strongly dealuminated sample naphthalene conversion r
eaches a maximum and then decreases; the decreasing trend seems associated
to insoluble coke formation and the confinement of transalkylation at the p
ore mouth. (C) 1999 Elsevier Science B.V. All rights reserved.