Energy & Fuels, Vol.34, No.8, 9643-9653, 2020
An Efficient Heterogeneous Acid Catalyst DICAT-1 for One-Pot Conversion of Sucrose into 5-(Hydroxymethyl)furfural
5-(Hydroxymethyl)furfural (HMF) is a trending biogenic platform molecule for the production of multiple energy, fuel, and chemical products, and it can be synthesized by using C-6 sugars and/or its oligomers and polymers. In the present paper, the heterogeneous solid acid catalyst DICAT-1, with characteristic properties, exhibited one-pot conversion of sucrose into 5-HMF. The DICAT-1 triggered in-situ hydrolysis, isomerization, and dehydration of sucrose to yield 5-HMF in the presence of the low boiling point (LBP) green solvent isopropyl alcohol (IPA) in combination with the cosolvent DMSO. Of the tested solvents water, IPA, DMF, DMSO, and IPA:DMSO, the use of IPA in combination with DMSO shows the profound effect on sucrose dehydration. Exploration of DICAT-1 in the presence of IPA:DMSO (70:30 v/v) resulted in a 5-HMF yield of >77%. The central composite design model (CCD) was used to find out the best operating conditions for the solvent ratio and catalyst concentration. Moreover, the process intensification study depicted the remarkable effect of solvent, reaction temperature, time, sucrose concentration, catalyst concentration, and autogenous pressure of the solvent on the yield of 5-HMF. In- process analysis was conducted by using HPLC, and the product was characterized by using HPLC, ATR-FTIR, GC-MS, and LC-MS. The plausible reaction mechanism for the DICAT-1-mediated sucrose to 5-HMF conversion was also proposed. Characteristic properties of DICAT-1 such as the porosity and presence of accessible -SO3H acid active sites favor the one-pot conversion. Moreover, the catalyst recyclability test for five consecutive runs showed consistent 5-HMF yields. Thus, DICAT-1 was found to be an efficient and robust catalyst for sucrose dehydration in the IPA:DMSO solvent mixture.