Fe-modified MoS₂/NC catalyst for hydrodeoxygenation of lignin into aviation fuel-range arenes

Lignin contains abundant aromatic ring structures, which can be converted into green sustainable aviation fuel-range arenes through hydrodeoxygenation (HDO). A series of supported FeMoS/NC catalysts were synthesized by a hydrothermal method. The HDO performance of the catalysts was evaluated using 4-ethylguaiacol as a model compound at 340 °C under 3 MPa H2. The MoS2/NC catalyst exhibited a deoxygenation degree of 83.4%, whereas the Fe-modified catalyst (Fe0.3MoS/NC) attained complete deoxygenation (100%) with an arenes selectivity of 78.6%. Beyond the optimal ratio, the deoxygenation degree is inversely proportional to the Fe/Mo molar ratio. The catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), low-temperature nitrogen adsorption (BET method) and X-ray photoelectron spectroscopy (XPS). The characterization results indicated that the introduction of Fe enhanced the uniform dispersion of MoS2 on the NC support surface. This modification further increased the acidity of the catalyst surface and raised the concentration of sulfur vacancies, thereby promoting the adsorption of oxygen-containing compounds. Furthermore, the HDO performance of the Fe0.3MoS/NC catalyst was evaluated using actual lignin as a feedstock under the conditions of 340 °C, 3 MPa H2 and 12 h. The results showed a green hydrocarbon yield of 65.5%, of which the C8–C16 fraction accounted for 54.4% of the total hydrocarbons. Within this fraction, aromatic compounds constituted 63.4%, suggesting its potential use as green aviation fuel-range arenes. This work thus establishes a viable catalytic pathway for efficient conversion of lignin to arenes.