Hits:

Indexed by:会议论文

Date of Publication:2011-01-01

Included Journals:Scopus

Abstract:H2S was used in stead of O2 to passivate a Ni2P/MCM-41 catalyst, which was evaluated in the hydrodesulfurization (HDS) of dibenzothiophene (DBT). It was found that H2S passivation was superior to the conventional O2 passivation because it gave a higher HDS activity and required no re-reduction. Characterization of X-ray photoelectron spectroscopy revealed that the sulfur species on the surface of the H2S-passivated Ni2P/MCM-41 were polysulfide ligands rather than S2- or S22- and the sulfur species were partially oxidized. Sulfur analysis of the spent catalysts revealed that the HDS activity correlated with the sulfur content retained on Ni2P/MCM-41, suggesting that sulfur is part of the active sites of the HDS reaction. MoP/MCM-41 and WP/MCM-41 were prepared from its oxidic precursors by a sulfidation-reduction procedure. The resulting catalyst, MoP/MCM-41(SR), showed considerably higher catalytic activity in the HDS of DBT and 4,6-dimethyldibenzothiophene (4,6-DMDBT) than its counterpart prepared by reduction (MoP/MCM-41(R)). Comparison of the HDS performance of MoP/MCM-41(SR) with mixtures of MoP/MCM-41(R) and MoS2/MCM-41 excluded the synergetic effect of separate MoS2 and MoP phases in MoP/MCM-41(SR). A shift of the Mo 3d5/2 binding energy from 228.6 to 229.1 eV was observed in the XPS spectra, which might be related with the incorporation of sulfur in the MoP structure.