Separation and purification of 5-hydroxymethylfurfural by metal–organic frameworks

Abstract

5-Hydroxymethylfurfural (HMF) is an important sugar-based platform chemical that can be produced from fructose by acid-catalyzed dehydration. However, the efficient removal of by-products formic acid (FA), levulinic acid (LA) and residual fructose to obtain high purity HMF remains a challenge, especially the separation of LA and HMF. Herein, MOF-808 could selectively adsorb impurity components with high uptake capacity and high selectivity factor (α_imp./HMF), such as fructose (245 mg g_ads⁻¹, 47.4), FA (155 mg g_ads⁻¹, 41.3), and LA (303 mg g_ads⁻¹, 57.8). Moreover, the adsorption kinetic constants of FA and LA in MOF-808 could reach remarkably high values of 58.0 h⁻¹ and 25.9 h⁻¹, respectively. The efficient adsorption separation performance of MOF-808 is attributed to its abundant unsaturated paired sites and hard Lewis acidity. Additionally, MOF-808 showed outstanding separation performance and cycling stability in column separation. This study indicates coordination interactions are effective for the separation and purification of HMF.