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.