Preparation of nickel phosphide/SBA-15/cordierite monolithic catalysts and catalytic activity for hydrodesulfurization of dibenzothiophene

A series of nickel phosphide/SBA-15/cordierite monolithic catalysts with Ni contents from 2.5 wt.% to 12.4 wt.% and initial P/Ni molar ratio of 1/2 were prepared and their activity for the hydrodesufurization (HDS) of dibenzothiophene (DBT) was evaluated. The structure of the catalysts was investigated by X-ray diffraction (XRD), N-2 adsorption-desorption isotherms and scanning electron microscope (SEM). The results showed that the nickel phosphides phase had not been observed in the monolithic catalysts when Ni content was less than 7.4 wt.%. The Ni2P phase and Ni12P5 phase were found when Ni content was from 9.9 wt.% to 12.4 wt.%. The DBT conversion can reach 99.2% at 380 degrees C when Ni content was 9.9 wt.%. The activity of the monolithic catalyst was as good as that for the nickel phosphide/SBA-15 powder catalyst at 380 degrees C for the HDS of DBT, which indicated that there was no diffusive restriction on monolithic catalysts. Biphenyl (BP) selectivity over the monolithic catalysts was evidently higher than that for the nickel phosphide/SBA-15 powder catalyst when the temperature was over 320 degrees C. (C) 2009 Elsevier B.V. All rights reserved.