Mesoporous zirconia-based mixed oxides as versatile acid catalystsfor producing bio-additives from furfuryl alcohol and glycerol

Abstract

Mesostructured zirconium-based mixed oxides (MZM) are versatile solid acid catalysts for the chemicalvalorisation of biomass, within sugar and fatty acid platforms of biorefineries. MZM catalysts contain-ing tungsten and/or aluminium were prepared via a templating route that allows the texture and acidproperties to be improved. Their catalytic potential was explored for synthesising different types ofinteresting oxygenated fuel bio-additives, specifically levulinate esters, furfuryl alkyl ethers and glyc-erol acetals of the type 1,3-dioxolane and 1,3-dioxane. Levulinate esters are synthesised from furfurylalcohol (FA), which is produced industrially from lignocelluloses; the acetals are obtained from glycerol,which is a coproduct of the industrial production of biodiesel. The performances of the MZM catalystshave been compared with those of zirconium–(tungsten and/or aluminium) mixed oxides synthesisedvia conventional co-precipitation (without a template). Structure–activity relationships were establishedwhich reveal advantages of the templating route used for the synthesis of the MZM catalysts. The MZMcatalysts were more active and led to higher total yields of bio-additives (e.g. up to 86% yield at 100% FAconversion, 140◦C, 30 min reaction) than the catalysts prepared by co-precipitation (e.g. up to 45% yieldat 88% FA conversion), under similar reaction conditions. Detailed catalytic and characterisation studieswere carried out for the used catalysts.