Preparation of TiO₂-Al₂O₃ Support and Hydrodenitrogenation over Ni₂P/TiO₂-Al₂O₃Catalyst

Abstract

A series of TiO 2 -Al 2 O 3 composite supports were prepared by co-precipitation of titanium sulfate and aluminium nitrate , and the nickel phosphide catalysts were prepared by incipient wetness impregnation and in situ H 2 reduction method. The catalysts were characterized by XRD, N 2 adsorption, TPR, TEM and XPS techniques. Their hydrodenitrogenation (HDN) performances were evaluated by using quinoline as model molecules . The results show that TiO 2 was evenly dispersed on massive γ-Al 2 O 3 surface. The introduction of TiO 2 weakened the strong interaction between Al 2 O 3 and phosphate, and improved the reducibility of the precursors , facilitating to the formation of Ni 2 P active phase. TiO 2 acted as an electronic promoter for the Ni-P catalyst and enhanced both the hydrogenation and C-N bond cleavage activities. Different Ti / Al molar ratio had great influence on HDN activity of the catalyst. The Ni 2 P /TiO 2 -Al 2 O 3 with Ti/Al ratio of 1/8, exhibited the highest activity for quinoline HDN.