Catalizadores de Mo₂C and MoS₂ soportados en MCM-48 para la hidrodesulfuracion de dibenzotiofeno

A series of Mo₂C and MoS₂ catalysts supported on MCM-48 were synthesized. The active species were incorporated into the mesopore structure by two methods: a) in situ Mo(CO)₆ decomposition and simultaneous sulfuration of molybdenum with elemental sulfur at 250 °C and b) conventional carburation of molybdenum oxide with CH₄/H₂ mixture at 700 or 800 °C for 1, 2 or 3 h, followed by sulfuration with elemental sulfur at 250 °C. The syntheses of mesoporous material type MCM-48 and of Mo₂C were successful. The method (a) allowed MoS₂ formation, while in the method (b) a mixture of Mo₂C and MoS₂ was obtained, where the proportion of MoS₂ depended on the carburation conditions, its higher percentage was obtained from the sample carburated at 700 °C for 1 h. The catalyst activity in the hydrodesulfurization of dibenzothiophene depended on the proportion of MoS₂ present. The simultaneous presence of both species Mo₂C and MoS₂ appears to enhance the catalytic activity per mass unit respect to MoS₂ alone. All catalyst samples were only selective to direct hydrodesulfurization of dibenzothiophene to biphenyl.