Characteristics of CoMo catalysts supported on modified MCM-41 and MCM-48 materials for thiophene hydrodesulfurization

Abstract

The potential of two different mesoporous materials, MCM-41- and MCM-48-supported sulfided CoMo bimetallic catalysts, for hydrodesulfurization (HDS) of thiophene at specific conditions was explored to investigate the effect of channel connectivity on HDS activity. The hydrothermal stability of MCM-41 and MCM-48 was improved remarkably by a post-salt treatment technique. Aluminum incorporation to mesoporous material frameworks improved acidity and hydrothermal stability. Mesoporous-material-supported CoMo catalysts with different Co/Mo atomic ratios were prepared by coimpregnation of Co(NO3)(2)center dot 6H(2)O and (NH4)(6)Mo(7)O(24)center dot 4H(2)O. The characterization of the catalysts was carried out by X-ray diffraction (XRD), N-2 adsorption/desorption, NH3-temperature-programmed desorption (NH3-TPD), transmission electron microscopy (TEM), CO chemisorption, elemental analysis (EA), and C-13 NMR. MCM-41-supported catalysts showed a small decrease in activity compared to MCM-48-supported catalysts. The optimal Co/Mo atomic ratio for MCM-41- and MCM-48-supported series of catalysts was 3:7. The aluminosilicate-supported CoMo catalysts showed higher activities than their siliceous counterparts.