Highly active Ni2P/SiO2 catalysts phosphorized by triphenylphosphine in liquid phase for the hydrotreating reactions

Abstract

A highly loaded and dispersed 60%Ni/SiO2 catalyst was phosphorized by triphenylphosphine (PPh3) in liquid phase for the preparation of highly loaded and dispersed Ni2P/SiO2 catalysts. It was found that without pre-reduction, the Ni/SiO2 was difficult to be phosphorized by PPh3, and large Ni2P particles were resulted at the high phosphidation temperatures (543–593K). When the Ni/SiO2 was pre-reduced, the highly dispersed nano nickel particles formed were easily phosphorized by PPh3 at the lower temperatures (443–543K). The resulted Ni2P/SiO2 catalyst phosphorized by PPh3 at 443K possessed small and homogeneous Ni2P particles (∼6nm) with the high Ni2P active site density (324μmol/g) as titrated by the adsorption of CO. It was significantly more active than the Ni2P/SiO2 catalyst phosphorized by PH3 in gas phase with the Ni2P active site density of 263μmol/g for the hydrodesulphurization of dibenzothiophene and hydrogenation of tetralin to decalin in a model diesel.