Efficient Conversion of Xylose into Furfural Using Sulfonic Acid-Functionalized Metal–Organic Frameworks in a Biphasic System

A novel approach was developed to efficiently produce furfural from xylose via sulfonic acid-functionalized metal–organic frameworks (MOFs) MIL-101(Cr)-SO3H in a biphasic cyclopentyl methyl ether (CPME)/H2O-NaCl solvent system. This paper compared the differences in structure and properties of these catalysts synthesized at different molar ratios of metal salt and organic ligand. In addition, xylose conversion and furfural yield under different reaction conditions were discussed in detail. 70.8% furfural yield with 97.8% xylose conversion was achieved at the following conditions: 0.4 g of xylose, 0.27 g of catalyst, 26 wt % NaCl referred to H2O, 12 g of mixed solution of CPME/H2O (mass ratio 2:1), 443 K for 180 min. This new approach gained higher furfural yield in a shorter time and the catalyst was recycled five times after a simple filtration, washing, and drying with receptive loss of the product.