Efficient one-pot fructose to DFF conversion using sulfonated magnetically separable MOF-derived Fe3O4 (111) catalysts

Abstract

Aerobic oxidation of carbohydrate-derived 5-hydroxymethylfurfural (HMF) into high added-value 2,5-diformylfuran (DFF) has attracted much attention in recent years. However, the direct synthesis of DFF from cheap and abundant carbohydrates via HMF as an intermediate through a one-pot process is highly desirable but challenging. In this work, we have developed a highly efficient and recyclable non-noble heterogeneous catalyst for one-pot conversion of fructose into DFF with extremely high yields (>99%). The catalyst was prepared by a simple pyrolysis method using Fe-based metal–organic frameworks (MOF) as a template and sulfur powder as a dopant. The pyrolysis of the MOF template under interactions of Ostwald ripening and Kirkendall effects led to the formation of uniform octahedral Fe₃O₄ nanoparticles with exposed (111) crystal facets highly dispersed on sulfur doped carbon. The superior selectivity to DFF over the designed Fe-based catalyst is related to the low adsorption energy of DFF on the support as well as the existence of non-oxidized sulfur that makes the catalytic system less oxidative.