Efficient Hydrolysis of Cellulose over a Novel Sucralose-Derived Solid Acid with Cellulose-Binding and Catalytic Sites

A new sucralose-derived solid acid catalyst (SUCRA-SO3H), containing -Cl and -SO3H functional groups, has been shown to be highly effective for hydrolyzing beta-1,4-glucans, completely hydrolyzing cellobiose (1) into glucose (2) in 3 h and converting the microcrystalline cellulose pretreated by the ionic liquid into glucose (2) with a yield of around 55% and a selectivity of 98% within 24 h at a relatively moderate temperature (393K). The enhanced adsorption capacity that the catalyst has for glucan by virtue of the presence of chloride groups that act as cellulose-binding sites offers the possibility of resolving the existing bottleneck in heterogeneous catalysis to hydrolyze cellulose, namely, the low accessibility of cellulose to the reaction position in typical solid catalysts. The apparent activation energy for hydrolysis of cellobiose (1) with SUCRA-SO3H was 94 kJ/mol, which was much lower than that with sulfuric acid (133 kJ/mol) and the corresponding sucrose-derived catalyst (SUCRO-SO3H) without chlorine groups (114 kJ/mol).