Selective catalytic oxidation of H_2S over iron oxide supported on alumina-intercalated Laponite clay catalysts

摘要

A 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℃ 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/Al-Lap catalyst presented the best catalytic performance at 180℃. Finally, the catalytic and deactivation mechanisms were explored.