Ethane dehydrogenation over manganese oxides supported on ZSM-5 zeolites

Mn-ZSM5 catalysts are shown to have high reaction rates, C2H4 selectivity and stability for the ethane dehydrogenation reaction. The specific reaction rate increases with the Mn loading until the optimal Mn amount of 3.4 wt% for zeolites with a Si/Al ratio of 12. Structure characterizations and spectra analysis have unveiled that this catalyst contains MnO2 nanoparticles on the zeolite external surface and (MnOH)+ groups on the external surface of the zeolite. The MnO2 nanoparticles contain the catalytic sites for ethane dehydrogenation while the (MnOH)+ groups help stabilize the oxide particles, leading to the high stability of the Mn-ZSM5 catalyst for EDH. As a result, the Mn-ZSM5 samples can catalyze EDH for over 150 h at 600 °C with a high reaction rate (>10 mmolC2H6 gcat−1 h−1) and high C2H4 selectivity (>98%). The spent catalyst can also be regenerated by calcination in dry or wet air (3% steam).