Conversion of biomass-derived carbohydrates into 5-hydroxymethylfurfural over sulfonated zirconium/tin mixed-metal metal–organic frameworks in deep eutectic solvents-water based biphasic system

Abstract

5-hydroxymethylfurfural (5-HMF) is a key platform chemical that can be applied to generate varied value-added products. Herein, the sulfonated zirconium/tin Mixed-Metal metal–organic frameworks (MOFs), Sn/UiO-66-SO3H catalysts were employed for catalytic conversion of biomass-derived carbohydrates (glucose, sucrose, maltose, starch, and cellulose) to 5-HMF in green deep eutectic solvents (DESs)-water based biphasic system. The Sn/UiO-66-SO3H catalysts were prepared by infiltrating Sn4+ into the UiO-66-SO3H via post-synthesis modification. The synthesized catalysts were characterized by PXRD, SEM, FTIR, N2 adsorption–desorption analysis, XPS, ICP-OES, NH3-TPD and Py-FTIR. The synergistic effect of Zr4+ and Sn4+ increased the total acidity and pore size of MOFs, thus promoting the catalytic performance of MOFs towards carbohydrates conversion to 5-HMF. The 24-Sn/UiO-66-SO3H with impregnation of Sn4+ for 24 h presented desired catalytic ability, which resulted in 81.5 % and 41.7 % 5-HMF yields from glucose and cellulose in DES betaine-malic acid–water/MIBK biphasic system, respectively. Moreover, the five-recycling test for 24-Sn/UiO-66-SO3H demonstrated excellent reusability of the prepared catalyst. This study offered a novel sulfonated Mixed-Metal strategy on MOFs in DES betaine-malic acid–water based biphasic system for the production of 5-HMF from biomass-derived carbohydrates.