Surface Engineering of CoMoS Nanosulfide for Hydrodeoxygenation of Lignin-Derived Phenols to Arenes

We propose a surface atom engineering strategy to obtain a well-dispersed Co-incorporated MoS2 nanomaterial, which maximizes the Co-Mo-S phase and achieves high activity in hydrodeoxygenation (HDO) of lignin-derived phenolic compounds. It was shown by X-ray diffraction, transmission electron microscopy, Ramanspectroscopy, high-sensitivity low-energy ion scattering, and X-ray photoelectron spectroscopy that plenty of accessible Co-Mo-S phase were generated on the catalyst surface, which could accelerate the hydrodeoxygenation (HDO) reaction. Notably, most of the Co-Mo-S phases were located at the top surface of MoS2, which explained the full deoxygenation performance of the CoMoS catalyst. Moreover, among the diverse lignin-derived oxygenated compounds, phenolic hydroxyl HDO was structure-sensitive relative to diphenyl ether over Co-doped MoS2 catalysts. Effective conversion of mixed phenols to corresponding arenes such as BTX (benzene, toluene, and xylene) with high yield (>85%) and stable recyclability was exhibited by using the CoMoS catalyst with highly dispersed Co-Mo-S phase.