Solvent-free cashew nut shell liquid upgrading into sustainable aviation fuel over tandem Ru/NbOPO4-Hβ catalytic system

• Novel catalytic route converting CNSL into SAF-range hydrocarbons; • Hβ-catalyzed isomerization enhanced isoand n -paraffin formation; • 60.2 wt% SAF yield with controlled paraffinic distribution; • Produced SAF exhibited a low freezing point (−63 °C); • Fuel properties align with aviation fuel specifications. Sustainable aviation fuels (SAFs) represent one of the most promising near-term solutions for decarbonizing the aviation sector, and utilizing waste-derived feedstocks can significantly enhance both their economic and environmental viability. However, developing new technological pathways presents considerable challenges, as conversion processes must be specifically designed to address the chemical complexity of each feedstock. In this context, was presented a novel catalytic process for upgrading cashew nut shell liquid (CNSL) into hydrocarbons suitable for SAF applications, employing a physical mixture of the Ru/NbOPO 4 catalyst with Hβ zeolite. Comprehensive characterization revealed the formation of unique RuO 2 nanostar structures that undergo in situ reduction, effectively promoting hydrodeoxygenation reactions. This innovative tandem catalyst system achieved complete conversion of CNSL phenolic compounds into 60.2 wt% SAF-range hydrocarbons, with an isoto-normal paraffin ratio of 2.7 and a freezing point of −63 °C. The predicted fuel properties indicate that the resulting hydrocarbons meet established aviation fuel specifications. In summary, this research introduces an original and efficient catalytic strategy for converting CNSL into paraffinic aviation fuel blendstocks, thereby expanding the technological potential of waste-based feedstock streams for sustainable, low-carbon aviation.