Hydrogenation of phenol on the inert MoS ₂ surface: a density functional theory perspective

Low-stacked MoS2 catalysts are known to promote C–O bond hydrogenolysis in phenolic compounds, yet the role of the basal plane–often regarded as catalytically inert–in hydrogenolysis remains unclear. In this work, density functional theory is employed to investigate the C–O bond hydrogenolysis via hydrogenation of phenol on the bilayer MoS2 basal plane and its implications for C–O bond activation. We show that phenol and hydrogenated phenol preferentially adsorb in a parallel configuration, maximising electrostatic interaction between their aromatic rings and the basal plane. This adsorption facilitates charge transfer from the phenol C–O bond to the basal plane. Hydrogenation of phenol at its hydroxyl group is kinetically feasible on the basal plane. It induces electronic changes at the oxygen atom, thereby weakening the C–O bond. These results demonstrate that, although traditionally considered inert, the MoS2 basal plane can promote C–O bond hydrogenolysis through hydrogenation, providing a mechanistic basis for its contribution to phenolic hydrodeoxygenation in low-stacked MoS2 catalysts.