Process for preparing a catalyst support which process comprises a) mixing pentasil zeolite having a bulk silica to alumina molar ratio in the range of from 20 to 150 with water, a silica source and an alkali metal salt, b) extruding the mixture obtained in step (a), c) drying and calcining the extrudates obtained in step (b), d) subjecting the calcined extrudates obtained in step (c) to ion exchange to reduce the alkali metal content, and e) drying the extrudates obtained in step (d); process for preparing a catalyst by furthermore impregnating such support with platinum in an amount in the range of from 0.001 to 0.1 wt % and tin in an amount in the range of from 0.01 to 0.5 wt %, each on the basis of total catalyst; ethylbenzene dealkylation catalyst obtainable thereby and a process for dealkylation of ethylbenzene which process comprises contacting feedstock containing ethylbenzene with such catalyst.