Methane dehydroaromatization over Fe-M/ZSM-5 catalysts (M= Zr, Nb, Mo)

The effect of the co-impregnation of fifth period transition metals (Zr, Mo and Nb) with Fe on ZSM-5 for the methane dehydroaromatization at 750 °C was studied. Characterization tests of XRD, TPR-H2, surface area (BET), TPD-NH3, SEM/TEM, FTIR and TPO were used to enlighten the catalytic properties and the coke formation. The strength and type of acid sites look similar, however the TPR results show that the co-impregnated metals influenced significantly the reducibility of Fe. Samples with Mo and Nb interact more strongly with Fe, while Fe–Zr present a reduction profile similar to the pure Fe supported on ZSM-5. The Fe–Zr catalyst decreases the induction period and controlled the coke deposition showing the most promising results for long term reactions.