Direct conversion of enzymatic hydrolysis lignin to jet fuel via relay catalysis.

Abstract

The selective transformation of lignin into valuable products remains challenging due to its structural heterogeneity and tendency to undergo recondensation. Here we report a spatially engineered bifunctional core-shell catalyst, Ni@H-beta, featuring nanodispersed Ni species on the external shell of a zeolite containing Brønsted acid sites within the core. This architecture enables a relay catalytic process involving hydrogenation on the Ni-rich surface followed by acid-catalyzed deoxygenation within the microporous framework. Under optimized conditions, Ni@H-beta achieves complete liquefaction of enzymatic hydrolysis lignin without char formation, yielding 50.1 wt% monomers predominantly composed of jet-fuel-range cycloalkanes. Operando NMR spectroscopy combined with density functional theory reveals a hydrogenation-first pathway that reduces deoxygenation barriers and enhances selectivity. Integrated process simulation, techno-economic analysis and life-cycle assessment further indicate that the EHL-to-jet-fuel process is economically competitive and environmentally advantageous compared with conventional petroleum-derived jet fuel.