The Co-Catalyst Effect of Zeolites on Acidic Ionic Liquid Catalyzed One-Pot Conversion of Cellulose to Ethyl Levulinate and Levulinic Acid in Aqueous Ethanol

The effect of three different zeolites: ZSM-5, zeolite-β and zeolite-Y on 1-(1- propylsulfonic)-3-methylimidazolium chloride catalyzed one-pot conversion of cellulose to ethyl levulinate and levulinic acid in 40 % (v/v) aq. ethanol was studied by measuring ethyl levulinate, levulinic acid and 5-hydroxymethylfurfural yields with and without zeolites. The zeolite type ZSM-5 as a co-catalyst produced the highest enhancement in yields and more pronounced effect is observed in ethyl levulinate yields. The highest improvement is seen at 180 °C, 24 h experiment; for instance, the reaction carried out with ZSM-5 as a co-catalyst produced 29.5 % yield of ethyl levulinate, whereas the reaction without zeolite produced 16.3 % yield under similar conditions.