Acidic ionic liquids containing variable cationic head groups for catalytic isomerization of n-hexane

Catalytic isomerization of n-hexane to its corresponding branched liquid hydrocarbon isomers by three different ionic liquids (ILs) having general formula; [BmimCl center dot 2AlCl(3)], [BPyCl center dot 2AlCl(3)] and [Et3NHCl center dot 2AlCl(3)] were investigated in the present work. Due to the optimum acidic nature of the ILs, the reaction moves through faint conditions in a liquid-liquid biphasic reaction mode, this confirms a minimum extent of unwanted cracking side-reactions. ILs showed good catalytic activity due to their appreciable Bronsted and Lewis acidity. The BmimCl center dot 2AlCl(3) and Et3NHCl center dot 2AlCl(3) show higher conversion of n-hexane compared to BPyCl center dot 2AlCl(3) under similar reaction condition. The selectivity of isomers is lower at higher conversion range. On increasing the reaction time and temperature, the conversion of n-hexane rises up, while the selectivity of i-alkanes and i-hexanes were reduced. The optimal reaction temperature, reaction time and IL/n-hexane ratio were 30 degrees C, 24 hand 1:1, respectively; the conversion of n-hexane is 25.7%, 11.52%, 36.3%, the selectivity to i-alkanes is 97.58%, 99.55%, 99.16%, and selectivity to i-hexane 87.28%, 70.10%, 95.86%, respectively. (C) 2019 Elsevier B.V. All rights reserved.