Mesopore-Engineered Zeolite Boosts Depolymerization of Technical Lignin

Abstract The cleavage of recalcitrant methylene linkages in technical lignin is critical for its valorization but remains inefficient due to poor mass transfer in microporous catalysts. Here, we report a simple alkaline desilication treatment of commercial Hβ zeolite that creates open mesopores without compromising acidity. The resulting hierarchical catalyst enhances oligomer diffusion, boosting the yield of monomeric and dimeric phenolics from the depolymerization of five technical lignin oligomers to 9.8–25.2 wt %, which is a 1.9- to 2.7-fold increase relative to conventional hydrogenolysis that only cleaves C–O bonds. Complete hydrodeoxygenation of these phenolics yields a mixture of mono- and bicyclic cycloalkanes with a carbon-number (C9–C20) distribution overlapping that of Jet-A fuel, highlighting their potential as drop-in blending components for sustainable aviation fuel. This work provides a scalable, cost-effective, and green catalytic route that directly addresses the mass-transfer bottleneck in technical lignin depolymerization.