A series of lithium ion impregnated CaO (Li/CaO) catalysts was prepared by following the earlier reported [22] wet chemical method. In a typical preparation 10 g of calcium oxide was mixed with 40 mL of deionized water to form a slurry and to this 10 mL aqueous solution of Li2CO3 of desired concentration was added to obtain 0.5–5 wt% Li in CaO. The resulted slurry was stirred for 2 h at room temperature (30 °C), and finally dried at 120 °C in oven for 24 h. The prepared catalysts were designated as x-Li/CaO, where x being the wt% of lithium in CaO.