Tailoring Aromatic-to-Cycloalkane Ratios for Sustainable Aviation Fuel by Hydrodeoxygenation of Isoeugenol over Nickel Aluminate Spinel-based Catalyst

Abstract The efficient production of sustainable aviation fuels (SAFs) from lignin-derived biomass remains a major challenge due to the difficulty of simultaneously generating both aromatics and cycloalkanes in the specific ratios required by fuel specifications. In particular, hydrodeoxygenation (HDO) of isoeugenol involves competing pathways: full hydrogenation to produce cycloalkanes, and selective deoxygenation that preserves the aromatic ring. To date, no catalytic system has successfully combined high selectivity for both hydrocarbon classes under mild conditions.Here, we demonstrate that a nickel aluminate spinel-derived catalyst, synthesized via a simple one-pot sol-gel method, overcomes this limitation by enabling, for the first time, the direct production of SAF-compatible blends with 16 wt% aromatics and 30 wt% cycloalkanes at 275°C and 20 bar H₂. The superior selectivity arises from the tailored structural and surface properties of the spinel support, which balance hydrogenation and deoxygenation pathways. The catalyst exhibits excellent reproducibility, facile product separation, and scalability, offering a practical route for one-pot, large-scale SAF production from lignocellulosic feedstocks. This work addresses a key bottleneck in biomass valorization, representing a significant advance in catalyst design for renewable aviation fuels.