A spherical AlPO₄ supported WO₃ catalyst for reductive etherification of furfural to Euro 95 standard gasoline fuel additives

Spherical AlPO₄ supported WO₃ catalysts were synthesized and characterized by XRD, N₂ sorption isotherm, SEM, TEM and NH₃-TPD, and used as a catalyst for the production of Euro 95 standard gasoline fuel additives from biomass-derived furfural via reductive etherification. Compared with the AlPO₄ catalyst, the surface acidity increased after the impregnation of tungsten oxide. The activity and stability of the catalysts also improved with the impregnation of tungsten oxide on AlPO₄. However, the existing catalytic system cannot provide high conversion to furfural and selectivity to ether due to the formation of side reactions. To optimize the reaction conditions, the effect of temperature, catalyst amount, furfural/isopropanol molar ratio, and choice of hydrogen donor were studied. Under these optimized conditions, a high conversion of furfural (92%) and a yield of isopropyl furfuryl ether (IPFE) (83%) were obtained with the byproducts of furfuryl alcohol and acetal. The WO₃/AlPO₄ catalyst also achieved a high yield of ether with various aldehydes and alcohols via reductive etherification.