CONVERSION OF ETHANE INTO BENZENE ON MO2C ZSM-5 CATALYST/

The reaction of ethane on unsupported and supported molybdenum compoun ds has been investigated at 773-973 K. ZSM-5 was used as support. Reac tion products were analyzed using gas chromatography. Changes in the c omposition of catalyst samples were followed by X-ray photoelectron sp ectroscopy. Unsupported MoO3 is partially reduced with ethane above 80 0 K to give H2O and CO2. The formation of H-2, C2H4 and CH4 was also o bserved. Mo-free ZSM-5 exhibited relatively high activity towards dehy drogenation, hydrogenolysis and aromatization of ethane above 773 K. D eposition of MoO3 on ZSM-5 significantly enhanced the conversion of et hane and also the selectivity of benzene production. Alteration of the catalytic behaviour of MoO3/ZSM-5 in time on-stream at 773-973 It was attributed to the reaction of MoO3, to carbon deposition and to the f ormation of Mo2C. Unsupported Mo2C catalyzed the dehydrogenation of et hane without producing benzene. In contrast, Mo2C/ZSM-5 was found to b e an effective catalyst in the aromatization of ethane. At 973 K the c onversion of ethane was similar to 67% and the selectivity to benzene formation 31%. (C) 1998 Elsevier Science B.V.