Application of Hierarchical H–Y Zeolites in Hydroxyalkylation–Alkylation of 2-Methylfuran with Furfural to Produce Jet Fuel Precursors

Abstract

Producing jet fuel-range alkanes from lignocellulosic biomass is critical for achieving carbon neutrality in the aviation industry. However, carbon–carbon (C–C) coupling reactions are required to increase the molecular weight of hydrocarbon precursors, which can be further processed to yield jet fuel-range alkanes. In this work, two different hierarchical H–Y zeolites (H–Y-mod-1 and H–Y-mod-2) were synthesized using a surfactant-templating method to catalyze the hydroxyalkylation–alkylation (HAA) reactions of 2-methylfuran (2-MF) with furfural (FF) to produce a C₁₅ hydrocarbon precursor. Specifically, hierarchical H–Y-mod-1 zeolite achieved a ninefold increase in C₁₅ precursor yield (71.7 ± 0.2 mol %) compared to parental H–Y zeolite (4.3 ± 0.1 mol %) at 80 °C for 5 h of residence time. This enhanced catalytic activity of the hierarchical H–Y-mod-1 zeolite was attributed to its mesoporosity and strong Brønsted acidity in comparison to parental H–Y. Catalyst recyclability studies showed that hierarchical H–Y-mod-1 can be used up to three times, with a 28.7% decrease in C₁₅ yield only after the third recycling cycle. These findings suggest that fine-tuned acidic zeolites can be leveraged to catalyze HAA reactions to produce jet fuel precursors.