Selective Hydrogenolysis of Biomass-Derived Aromatic Alcohols over 2D-MoCO MXene by a Reversible Redox-Relay Mechanism.

Selective CH-OH hydrogenolysis of biomass-derived aromatic alcohols to produce methyl aromatics is crucial for synthesizing sustainable fuels and chemicals; yet traditional metal-acid bifunctional catalysis possesses significant challenges owing to its complex reaction network. Herein, a 2D-MoCO MXene was fabricated, demonstrating an efficient hydrogenolysis of 5-hydroxymethyl furfural into 5-methyl furfural, achieving an impressive yield (99.5 %) at the mild reaction temperature of 90 °C. Catalytic mechanism investigations reveal that 2D-MoCO facilitate the activation and cleavage of the CH-OH bond through a redox mechanism, driven by the strong CH-OH affinity of the Mo-Mo metallic plane. In the absence of H, hydrogen from O-H group is the source for methyl formation from CH-OH. Under a H atmosphere, H is activated to remove residual oxygen species, boosting selective hydrogenolysis while suppressing furan and CH=O hydrogenation. Furthermore, the catalyst exhibited broad universality for synthesizing methyl aromatics from various furfuryl alcohols, benzyl alcohols, and hydroxycyclopentenones. This study presents a novel redox-relay mechanism in advanced MXene catalysis, offering a straightforward hydrogenolysis pathway for challenging substrates.