h i g h l i g h t s• Fe/Al-Lap catalysts with mesoporous structure were synthesized.• Iron oxide mainly exists in form of isolate Fe 3+ in an oxidic environment.• Fe/Al-Lap catalysts show high catalytic activities at low temperature.• The high catalytic activities are ascribed to the interaction between iron oxide and alumina.• The formed Fe 2 (SO 4 ) 3 and elemental sulfur deposits on surface cause catalyst deactivation. g r a p h i c a l a b s t r a c tThe catalytic reaction and deactivation mechanisms for H 2 S selective oxidation over Fe/Al-Lap catalysts are shown in the illustration. The catalytic reaction follows Mars-van Krevelen mechanism. Moreover, the interaction between iron oxide and alumina, the strong acidity of the catalysts and the well dispersion of iron oxide improve the catalytic performance efficiently. Meanwhile, the catalyst deactivation is mainly due to the formation of Fe 2 (SO 4 ) 3 and elemental sulfur deposits on the surface. a r t i c l e i n f o b s t r a c tA series of iron oxide supported on alumina-intercalated clay catalysts (named Fe/Al-Lap catalysts) with mesoporous structure and high specific surface area were prepared. The structural and chemical properties were studied by nitrogen sorption isotherms, X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (UV-vis DRS), X-ray photoelectron spectra (XPS), Fourier transform infrared spectroscopy (FTIR), H 2 temperature-programmed reduction (H 2 -TPR) and NH 3 temperature-programmed desorption (NH 3 -TPD) techniques. It was realized that iron oxide mainly existed in the form of isolated Fe 3+ in an oxidic environment. Fe/Al-Lap catalysts showed high catalytic activities in the temperature range of 120-200 • C without the presence of excessive O 2 . This can be attributed to the interaction between iron oxide and alumina, which improve the redox property of Fe 3+ efficiently. In addition, the strong acidity of catalysts and good dispersion of iron oxide were also beneficial to oxidation reaction. Among them, 7% Fe/AlLap catalyst presented the best catalytic performance at 180 • C. Finally, the catalytic and deactivation mechanisms were explored.Crown

A series of V 2 O 5 supported on CeO 2 -intercalated clay catalysts (named V 2 O 5 /Ce-Lap catalysts) with mesoporous structure and high specific surface area were prepared. The structural characteristics and physicochemical properties were studied in detail. These catalysts were evaluated for the H 2 S selective oxidation. It was revealed that all V 2 O 5 /Ce-Lap catalysts showed high catalytic activities in the temperature range of 120-220 1C due to the redox reaction of highly dispersed V 5+ species, and the catalytic mechanism obeyed a redox process, i.e. a stepwise mechanism. Additionally, the chemically absorbed oxygen also played an important role in H 2 S selective oxidation. Among them, the 5% V 2 O 5 /Ce-Lap catalyst presented the best catalytic activity and excellent regenerability at 180 1C. Finally, the catalyst deactivation mechanism was explored.

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