Desilicated MTW zeolite was developed for long chain hydrocarbon cracking such as n-heptane cracking. The catalytic performance of desilicated ZSM-12 (MTW) zeolite was investigated for n-heptane cracking in a fixed bed reactor at 650 degrees C and atmospheric pressure. Average conversion of 75.3% was achieved with a stability of 240 min. Higher selectivity to olefins (63.51%) was observed over a mesoporous MTW catalyst (treated with 0.2 M sodium hydroxide for 10 min) with average propylene to ethylene ratio (P/E) of 0.73. Desilicated MTW zeolite was prepared by using alkaline treatment under microwave irradiation to obtain ZSM-12 with larger pore volume (mesopores), larger surface area and different strength of acid sites. Maximum mesopore volume was 0.53 cm(3) g(-1) with external surface area of 437 m(2) g(-1). This is a remarkable result for mesoporous MTW prepared by post-alkaline treatment. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.