Efficient hydrolysis of cellulose to glucose catalyzed by lignin-derived mesoporous carbon solid acid in water

Two kinds of mesoporous carbon solid acids (LDMCE-SO3H and LDMCS-SO3H) were successfully prepared using masson pine alkali lignin as carbon source by evaporation-induced self-assembly (EISA) and salt-induced self-assembly (SISA) followed by sulfonation, respectively. In terms of preparation process, SISA (self-assembly in water and preparation time of 2 days) is greener and simpler than EISA (self-assembly in ethanol and preparation time of 7 days). The prepared LDMCE-SO3H and LDMCS-SO3H exhibit obvious differences in structural characteristics such as pore channel structure, specific surface area, mesopore volume and the density of -SO3H groups. Furthermore, the catalytic performances of LDMCE-SO3H and LDMCS-SO3H were investigated in the hydrolysis of microcrystalline cellulose in water, and the glucose yields of 48.99% and 54.42% were obtained under the corresponding optimal reaction conditions. More importantly, the glucose yields still reached 28.85% and 30.35% after five runs, and restored to 39.02% and 45.98% through catalysts regeneration, respectively, demonstrating that LDMCE-SO3H and LDMCS-SO3H have excellent recyclability and regenerability.