Catalytic Conversion of Cellulose into 5-Hydroxymethylfurfural Using [PSMIM]HSO and ZnSO·7HO Co-catalyst in Biphasic System

Production of 5-hydroxymethylfurfural (HMF) from microcrystalline cellulose (MCC) was studied in 1-(3-sulfonic acid)-propyl-3-methylimidazolium hydrogen sulfate ([PSMIM]HSO)–HO/THF biphasic system with catalytic amount of ZnSO·7HO. The effects of various reaction parameters such as catalyst charge, reaction temperature and the volume ratio of water to tetrahydrofuran were investigated. The highest HMF yield of 58.8 % and TRS yield of 64.8 % were obtained at 160 °C for only 60 min by [PSMIM]HSO and ZnSO·7HO as co-catalyst. A possible mechanism was proposed to explain the high activity of [PSMIM]HSO and ZnSO·7HO as co-catalyst. After being separated from the organic phase, the aqueous phase could be reused and demonstrated stable activity after four successive runs.