Investigation of 4,6-dimethyldibenzothiophene hydrodesulfurization over a highly active bulk MoS2 catalyst

摘要

The hydrodesulfurization(HDS)of 4,6-dimethyldibenzothiophene was investigated in a batch-stirred microautoclave reactor over a laboratory-synthesized MoS_2 catalyst.The reaction was found to proceed through two main parallel pathways:direct desulfurization(DDS)and hydrogenation(HYD).The effect of a wide range of H2S concentrations on the HDS activity and selectivity was studied.Contrary to the well-known inhibition of HDS caused by H_2S,the global catalytic activity of HDS was enhanced more than two times with inclusion of H2S in the reaction zone.The increase in the activity is attributed to a significant enhancement in the hydrogenation reaction route,while the direct desulfurization products were only slightly affected.It is suggested that H_2S modifies the active sites so that they can be exploited more efficiently in the hydrogenation reaction.