MgFe hydrotalcites-derived layered structure iron molybdenum sulfide catalysts for eugenol hydrodeoxygenation to produce phenolic chemicals

Abstract Hydrodeoxygenation (HDO) is an effective alternative to produce value-added chemicals and liquid fuels by removing oxygen from lignin-derived compounds. Sulfide catalysts have been proved to have good activity for the HDO and particularly high selectivity to phenolic products. Herein, we presented a novel way to prepare the layered structure sulfide catalysts (MgFeMo-S) derived from MgFe hydrotalcites via the intercalation of Mo in consideration of the memory effect of the calcined hydrotalcite. By varying the Mg/Fe mole ratio, a series of MgFeMo-S catalysts were successfully prepared and characterized by nitrogen adsorption/desorption isotherms, X-ray diffraction (XRD), transmission electron microscopy (TEM), and inductively coupled plasma optical emission spectrometer (ICP-OES). The characterization results indicated that the MgFeMo-S catalyst has retained the unique layered structure, which can facilitate uniform dispersion of the MoS 2 species on both the surface and interlayer of the catalysts. For the HDO of eugenol, the Mg 1 Fe 2 Mo-S catalysts exhibited the best HDO activity among all the catalysts due to its higher active metal contents and larger pore size. The HDO conversion was 99.6% and the yield of phenolics was 63.7%, under 5 MPa initial H 2 pressure (measured at RT) at 300 °C for 3 h. More importantly, MoS 2 species deposited on the interlayer galleries in the MgFeMo-S catalysts resulted in dramatically superior HDO activity to MoS 2 /Mg 1 Fe 2 -S catalyst. Based on the mechanism investigation for eugenol, the HDO reaction route of eugenol under sulfide catalytic system has been proposed for the first time. Further applicability of the catalyst on HDO of more lignin-derived compounds was operated, which showed good HDO activity and selectivity to produce aromatic products.