Aromatization of n-hexane over Ga, Mo and Zn modified H-ZSM-5 zeolite catalysts

• Aromatization of n-hexane was studied over Mo, Zn and Ga modified H-ZSM-5 catalyst.
• Aromatic activity was dominant for Ga and Zn modified catalysts.
• Addition of Mo enhanced cracking activity of the H-ZSM-5 catalyst at 500 °C.
• High reaction temperatures (> 550 °C) lead to a decrease in aromatic selectivity.

n-Hexane aromatization was investigated at 500 °C on parent and metal (i.e. Ga, Mo and Zn) modified H-ZSM-5 zeolite catalysts. Conversion reached 88% over H-ZSM-5 and was stable. Addition of metal resulted in lower conversion (< 80%). Formation of aromatic compounds was favored on Ga/H-ZSM-5 (> 35%) and Zn/H-ZSM-5 (> 40%) while H-ZSM-5 and Mo/H-ZSM-5 showed higher cracking activity. Gallium and zinc favored aromatization. At 600 °C a decrease in activity with increasing TOS was observed. A decrease in aromatics selectivity was also observed. The aromatics selectivity with increase in TOS of Ga/H-ZSM-5 (43–27%) and Mo/H-ZSM-5 (35–27%) catalysts was higher than for Zn/H-ZSM-5 (46–7%).

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