Influence of MoS2 catalyst morphology on the hydrodeoxygenation of phenols

The hydrodeoxygenation (HDO) activity of several unsupported MoS2 catalysts, each with different morphology, has been determined using the reactants phenol, 4-methylphenol and 4-methoxyphenol. Exfoliated MoS2 catalyst was compared to crystalline MoS2, MoS2 prepared by in situ decomposition of ammonium heptamolybdate (AHM) and MoS2 prepared by in situ decomposition of molybdenum naphthenate (MoNaph). Exfoliated MoS2 had the highest first-order rate constant per Mo edge site for the consumption of phenol and 4-methylphenol. Hydrogenolysis of the C–OH bond of 4-methylphenol was favored over MoS2 with a lower degree of stacking (MoS2 derived from AHM) whereas aromatic ring hydrogenation of phenol was favored over MoS2 with a higher degree of stacking (exfoliated MoS2).