Hydrolysis of cellulose in SO3H-functionalized ionic liquids

► MCC was hydrolyzed into furans efficiently catalyzing by MnCl2 in various ionic liquids. ► The acidity and structure of ILs were important aspects for MCC hydrolysis. ► SO3H-functionalized ionic liquids showed higher activity than non-functionalized ILs. ► A mechanism was proposed to explain the promoting catalysis of MnCl2 in MnCl2-ILs system.