Ni-Mo Alloy Anchored on Carbon Nitride Coated Γ-Al2o3 for Hydrodeoxygenation of Lignin-Derived Phenols into Aviation Fuel-Range Cycloalkanes

Abstract

Lignin-derived phenols, with their high energy density and rich aromatic structure, are potentially high-quality feedstocks for the production of aviation fuel-range cycloalkanes. Herein, we fabricated a Ni-Mo alloy catalyst anchored on graphitic carbon nitride (g-C3N4) coated γ-Al2O3 (10Ni-5Mo/CN@γ-Al2O3), which could completely hydrodeoxygenate various lignin-derived phenols into cycloalkanes under mild conditions. 10Ni-5Mo/CN@γ-Al2O3 significantly catalyzed the hydrodeoxygenation of lignin oil at 240 oC under 3 MPa H2 for 8 h, achieving a deoxygenation degree of 96.5% and a high propylcyclohexane selectivity (41.8%), and the resulting products met the requirements for aviation fuels. The study results showed that electron transfer within Ni-Mo alloys and the strong interaction between g-C3N4 and surface anchored Ni-Mo alloys in 10Ni-5Mo/CN@γ-Al2O3 facilitated the dissociation of H2 into active hydrogen to hydrogenate the aromatic rings. Meanwhile, the formation of oxygen vacancies enhanced the adsorption and activation ability of the catalyst for oxygen-containing substrates, which was beneficial for the demethoxylation and dehydroxylation reactions. This work provides a new strategy for constructing supported non-noble metal catalysts for the hydrodeoxygenation of lignin oil into aviation fuels.

Keywords: Lignin oil, Hydrodeoxygenation, cycloalkanes, Ni-Mo alloy, oxygen vacancies