Naphthalene alkylation with isopropyl alcohol (IPA) to obtain 2,6-diisopropylnaphthalene (2,6-DIPN) was studied over HY and steam-treated HY zeolite catalysts in a continuous down flow micro reactor under atmospheric pressure with cyclohexane as the solvent. The catalytic performance of the catalysts for naphthalene conversion and yield for 2,6-DIPN increases with steaming temperature, suggesting higher acid strength is required for the dialkyaltion. Under reaction conditions, 250 degreesC, with a feed of naphthalene: isopropanol:cyclohexane = 1:3:10 (molar ratio) and space velocity WHSV = 4.86h(-1), 86% naphthalene conversion and a 2,6-DIPN yield of 40% was obtained with HY-700 catalyst. (C) 2003 Elsevier B.V. All rights reserved.