Iron(III)-modified tungstophosphoric acid supported on silica-pillared montmorillonite as catalysts for fructose conversion to methyl levulinate

BACKGROUNDBecause of the decline in conventional sources of energy and the increasing pollution, the fossil fuel based energy structures is being replaced by renewable energy based structures such as biomass energy. Among current biodiesel sources, methyl levulinate (ML) obtained from catalytic conversion of renewable carbohydrate with methanol has received a great deal of attention. Silica-pillared montmorillonites (MMTSi) functionalized by iron-modified tungstophosphoric acid (HPWFe) were prepared, and their physicochemical properties and catalytic effects on ML production studied. RESULTSCatalysts characterization demonstrated the high dispersion and Keggin structure of HPWFe in the framework of MMTSi. Effects of various reaction parameters and catalyst recycling on the reaction performance were studied to optimize fructose conversion. With 4-HPWFe-MMTSi as the catalyst, an optimized ML yield of around 74 mol% was obtained at 180 degrees C for 1 h, and the recovered catalyst after calcination was found to retain high activity after being reused five times. CONCLUSIONThe prepared HPWFe-MMTSi catalysts showed high porosity, perfect Brnsted-Lewis acidity and high thermal stability, which made their catalytic activity for fructose conversion and catalyst reusability values higher than others reported in the literature. (c) 2017 Society of Chemical Industry