Ru nanoparticles on HZSM-5 with strong metal–support interactions for efficient hydrodeoxygenation of lignin-derived phenols under mild conditions

Hydrodeoxygenation of lignin-derived phenols into high-value cycloalkanes under mild conditions is challenging. Herein, we report a Ru NPs @HZSM-5 catalyst with a unique metal-support interactions that achieves 100 % guaiacol conversion and 99.7 % cyclohexane selectivity at 160 °C and 1 MPa H 2 . Comparative studies with single-atom and aggregated Ru catalysts reveal that well-dispersed Ru nanoparticles coupled with acid sites offer superior activity and selectivity. Kinetic analysis and in situ DRIFTS demonstrate a sequential mechanism involving rapid hydrogenation of the aromatic ring followed by rate-limiting deoxygenation steps. Characterizations and CO-DRIFTS confirm particle sizes, optimal metal-support interactions, and enhanced acidity in Ru NPs @HZSM-5. Theoretical calculations further reveal favorable electronic states and lower energy barriers for deoxygenation on Ru NPs @HZSM-5. The catalyst also shows broad substrate compatibility, efficiently converting various lignin-derived phenolics. This work provides valuable insights into the critical synergy between metal nanoparticles and acidic supports for efficient lignin upgrading.