Effect of supports on the supported Ni2P catalysts prepared by the phosphidation using triphenylphosphine in liquid phase

• Ni2P/Al2O3, Ni2P/MgAlO and Ni2P/MgO were prepared by phosphidation with PPh3 in liquid phase.
• Ni2P/Al2O3 and Ni2P/MgAlO exhibited high CO uptakes and thus possessed many active sites of Ni2P.
• Ni2P/Al2O3 and Ni2P/MgAlO exhibited the excellent performance for the hydrotreating reactions.
• Ni2P/MgAlO was superior over Ni2P/SiO2 for the hydrogenation of tetralin to decalin.
• CO uptakes were greatly decreased on the used catalysts due to the presence of S on Ni2P surfaces.

Ni2P/Al2O3, Ni2P/MgAlO and Ni2P/MgO catalysts were prepared by the phosphidation of corresponding Ni/Al2O3, Ni/MgAlO and Ni/MgO with triphenylphosphine in liquid phase and compared with the previously reported Ni2P/SiO2 catalyst. It was found that the Ni2P/Al2O3 and Ni2P/MgAlO prepared by the pre-reduction at 723 K followed by the phosphidation at 443 K exhibited the high activities for the hydrotreating reactions. The two catalysts possessed small and homogeneously distributed Ni2P particles (6.5 and 8.3 nm, respectively) with high CO uptakes (305 and 269 μmol/g, respectively). After the hydrotreating reactions, the Ni2P phase in the catalysts remained and the sizes of Ni2P particles increased a little to 6.9 and 9.2 nm, respectively. However, the CO uptakes on the used Ni2P/Al2O3 and Ni2P/MgAlO catalysts were greatly decreased to 68 and 74 μmol/g, respectively, owing to the incorporation of S into the Ni2P surfaces. According to the CO uptakes on the used catalysts, it was found that the TOF values of hydrodesulphurization of dibenzothiophene on the Ni2P/Al2O3, Ni2P/MgAlO and Ni2P/SiO2 were similar, indicating that these supports did not affect the HDS activity, while the TOF values of hydrogenation of tetralin to decalin were significantly higher on Ni2P/MgAlO than on Ni2P/SiO2, indicating that Ni2P/MgAlO might be better than Ni2P/SiO2 for the hydrotreating reactions.

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