A solution-phase synthesis of supported Ni2P catalysts with high activity for hydrodesulfurization of dibenzothiophene

•A solution-phase approach to prepare Ni2P/MCM-41catalysts based on Ni(acac)2 and TPP was described.•The catalysts were synthetized under mild temperature and atmospheric pressure.•The phosphorous precursor and TOA used in our approach are cheap.•The catalysts obtained by the proposed approach showed high HDS activity and dispersion.

A novel solution-phase low temperature synthesis of a supported Ni2P catalyst is described. This uses nickel acetylacetonate (Ni(acac)2) and low cost triphenylphosphine (TPP) in the presence of the coordinating solvent tri-n-octylamine (TOA) to form Ni2P/MCM-41 catalysts. The catalysts were characterized by X-ray diffraction (XRD), N2-adsorption specific surface area measurements (BET), CO uptake, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The effects of the synthesis temperature, and initial P/Ni molar ratio on the formation of the Ni2P phase were studied. The formation of the crystalline phase follows the order Ni < Ni12P5 < Ni2P with increasing synthesis temperature. The high initial P/Ni molar ratio favored the formation and dispersion of the Ni2P phase, and a mixture of the Ni12P5 and Ni2P phases was observed in the sample with the low initial P/Ni molar ratio of 0.5. The dibenzothiophene (DBT) hydrodesulfurization (HDS) activity increased with reaction temperature in all cases. The catalysts synthesized at 603 K with an initial P/Ni molar ratio of 6 exhibited good DBT HDS activity. The DBT conversion was close to 100% at 613 K, which was much higher than that of the catalyst prepared by the conventional temperature programmed reduction (TPR) method (DBT conversion 43%). During the HDS reaction, the superficial phosphosulfide phase NixPySz was formed on the surface of the catalyst; this showed higher activity than Ni2P.

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