Selective oxidation of H2S over Fe supported on Zr-intercalated Laponite clay mesoporous composite catalysts at low temperature

Abstract

A series of iron supported on Zr-intercalated clay composite catalysts with mesoporous structure, a high specific surface area, and high thermal stability were successfully synthesized (named Fe/Zr-Lap catalysts) and tested for H2S selective oxidation. The structural characteristics and physicochemical properties of the catalysts were investigated using various methods. The iron species existed mainly as isolated Fe3+ and polymeric (FeO)n species in an octahedral coordination. All of the Fe/Zr-Lap catalysts exhibited excellent catalytic activity at relatively low temperatures (120–200 °C). The 8% Fe/Zr-Lap catalyst presented the best catalytic performance at 180 °C. It is likely that highly dispersed iron species, abundant chemically adsorbed oxygen vacancies, synergistic effect of iron and zirconium species, and improved reducibility played important roles in the reaction. Besides, the reaction and deactivation mechanisms were also proposed.