Fabricating high temperature stable Mo-Co9S8/Al2O3 catalyst for selective hydrodeoxygenation of lignin to arenes

Achieving high-temperature stability/duration without compromising the activity remains an arduous task in catalyst design, particularly for MoS2 materials. Herein, a robust catalyst with Mo doped Co9S8 nanoparticles anchored on Al2O3 matrix is fabricated, which could selectively convert lignin to arenes with high hydro-deoxygenation activity, selectivity and particularly excellent stability. In the hydrodeoxygenation of diphenyl ether, this catalyst afforded 99.8% conversion and 91.0% yield of benzene at 265 ? for at least 10 reaction runs. The resultant Mo-Co9S8 structure with chemical connection by covalent bonds of Mo-S-Co type on the Co9S8 surface demonstrates strong ability in the adsorption and activation of oxygen-containing substrates, which enables the effective C-O cleavage whilst avoids undesirable hydrogenation of benzene ring. The superior stability and water-resistance at elevated temperature was attributed to the anchoring effect of Al2O3 matrix and protection of surface-rich Co9S8 species to the active Mo-Co9S8 center. This strategy provides new sights for the rational design of efficient and stable sulfide catalysts towards the applications in demanding high-temperature reactions.

Automated summary

A stable catalyst with Mo-doped Co9S8 nanoparticles anchored on Al2O3 matrix was fabricated, which showed high selectivity and stability in the hydrodeoxygenation of lignin. The Mo-Co9S8 structure demonstrated strong ability in the adsorption and activation of oxygen-containing substrates, enabling effective C-O cleavage and avoiding undesirable hydrogenation reactions. The superior stability and water-resistance were attributed to the anchoring effect of Al2O3 matrix and protection of surface-rich Co9S8 species.