In this study, tetraoctyl ammonium chloride (TOAC) ionic liquid supported on K+-montmorillonite clay (K10) was prepared by the adsorption of the ionic liquid onto the clay. The TOAC-K10 was characterized by elemental analysis (EA), BET, C-13 NMR, Al-27 NMR, SEM, TEM, and FT-IR. The surface area and average pore diameter of the TOAC-K10 decreased with the immobilization of TOAC onto K10. The TOAC-K10 showed good catalytic activity for the synthesis of cyclic carbonate from allyl glycidyl ether (AGE) and carbon dioxide. The effects of reaction parameters such as reaction temperature, reaction time, and CO2 pressure on the reactivity of TOAC-K10 in a conventional heating batch reactor are discussed. Microwave irradiation was also applied for the reaction, and good conversions of AGE were obtained within <1 h. The catalytic performance was highly dependant on the weight of catalyst, microwave power, and CO2 pressure. The catalyst in the microwave system could be reused for up to 4 consecutive runs without significant loss of its initial activity. (C) 2011 Elsevier B. V. All rights reserved.