Conversion of ethane into benzene on Mo 2C/ZSM-5 catalyst

Abstract

The reaction of ethane on unsupported and supported molybdenum compounds has been investigated at 773–973 K. ZSM-5 was used as support. Reaction products were analyzed using gas chromatography. Changes in the composition of catalyst samples were followed by X-ray photoelectron spectroscopy. Unsupported MoO 3 is partially reduced with ethane above 800 K to give H 2O and CO 2. The formation of H 2, C 2H 4 and CH 4 was also observed. Mo-free ZSM-5 exhibited relatively high activity towards dehydrogenation, hydrogenolysis and aromatization of ethane above 773 K. Deposition of MoO 3 on ZSM-5 significantly enhanced the conversion of ethane and also the selectivity of benzene production. Alteration of the catalytic behaviour of MoO 3/ZSM-5 in time on-stream at 773–973 K was attributed to the reaction of MoO 3, to carbon deposition and to the formation of Mo 2C. Unsupported Mo 2C catalyzed the dehydrogenation of ethane without producing benzene. In contrast, Mo 2C/ZSM-5 was found to be an effective catalyst in the aromatization of ethane. At 973 K the conversion of ethane was ∼67% and the selectivity to benzene formation 31%.