Furan-Grafted Iron MOF Turns Waste Cooking Oil Into Biodiesel, Shrugging

Chinese researchers report an iron-based metal-organic framework (MOF) catalyst designed to convert waste cooking oil into biodiesel despite water and free-fatty-acid contamination. The problem with fryer oil is that impurities poison conventional catalysts, corrode equipment, and demand costly pretreatment. The team’s approach coats the pores of an iron MOF with hydrophobic furan rings derived from biomass. Their catalyst, labeled FFF, converted soybean oil to biodiesel with a 98.48% yield, and maintained performance in simulated waste oil containing 5% water and 15% oleic acid, reaching 89.1% yield in the first cycle. The design builds on an earlier bifunctional catalyst (AMF) based on NH2-MIL-101(Fe), but addresses AMF’s hydrophilic vulnerability by grafting FDCA, a biomass-derived ligand, to tune the framework and repel water while keeping iron active sites accessible.