Molybdenum ions have been exchanged into ZSM-5 zeolite by a solid-state reaction. The exchanged molybdenum ions were confirmed by EPR spectroscopy. The catalytic activity of MoZSM-5 zeolite on hydrodesulfurization reaction of thiophene was compared to those of HZSM-5 and CuZSM-5 zeolite catalysts at the same reaction condition. HDS reactions were undertaken in the temperature range of 300℃ to 450℃ using continuous-flow fixed-bed type microreactor system. Reaction products were analyzed by gas chromatography and GC/MS. Analyzed products were hydrogen sulfide, butenes, benzene, toluene, 2-methylthiophene, 3-methylthiophene, and xylenes. The observed aromatic compounds seemed to be related to the channel structure and acidity of ZSM-5 zeolite. The catalytic activities on HDS reactions increased in this order; MoZSM-5 ＞ CuZSM-5 ＞ HZSM-5. In case of MoZSM-5 zeolite, catalytic activity increased with the increase of Molybdenum content. Overall conversions of thiophene increased with increasing temperature and with decreasing hydrogen gas flow rate in all catalysts. The difference of HDS catalytic activities may be caused by different interactions of thiophene molecules with catalytic active sites.
