Sulfur‐Free Bimetallic Nix‐Fey/γ‐Al2O3 Catalysts for the Hydrodeoxygenation of Methyl Laurate to Biofuel

Abstract

AbstractThe Ni/γ‐Al2O3, Nix‐Fey/γ‐Al2O3 and Fe/γ‐Al2O3 catalysts are prepared by impregnation method, and the influence of nNi/nFe on the performances of the prepared catalysts for the methyl laurate hydrodeoxidation (HDO) was evaluated. The prepared catalysts and precursors were characterized by BET, H2‐TPR, XRD, and H2‐TPD, which confirmed the existence of NiFe alloy is advantageous to improve the catalytic activity, and the synergistic effect between Ni and Fe was elucidated. The catalytic properties of the studied Nix‐Fey/γ‐Al2O3 catalysts with low Fe content was significantly worse than that of monocomponent Ni/γ‐Al2O3 catalyst, due to the migration and agglomeration of highly dispersed Ni0 species on the corresponding catalyst surface. The introduction of Fe species had significant influence on the HDO performances and product selectivity of the Ni‐based catalyst. The higher Fe content can promote the main reaction path from hydrodecarbonylation/hydrodecarboxylation to hydrodeoxygenation, which results in the high C12 alkane selectivity on the corresponding catalysts and inhibits the cracking reaction. The bimetallic Ni3‐Fe7/γ‐Al2O3 catalyst had the best methyl laurate hydrogenation performances. The conversion of methyl laurate was 93.3 % and the selectivity of alkane compounds could reach 90 % on the Ni3‐Fe7/γ‐Al2O3 catalyst at the reaction temperature of 340 °C.