TEXTURE AND STRUCTURE VARIATION OF PEROVSKITE LaFeO3/ZSM-5 DURING HIGH-TEMPERATURE DESULFURIZATION.

Perovskite LaFeO3/ZSM-5 is synthesized via citrate route for H2S removal at high temperatures. It shows good thermal stability after heat treatment at 500–700∘C with respect to slight changes in crystallographic phase and textural property. It presents the optimal desulfurization performance at 600∘C with sulfur capacity of 1017 μ mol S/g and products of S, LaS2, and Fe7S8. Sulfidation at 500∘C yields the same products as sulfidation at 600∘C but displays the lowest sulfur capacity of 408 μ mol S/g. Sulfidation at 700∘C produces La2O2S, Fe3S4, and unreacted LaFeO3. The activation energy of the sulfidation reaction over LaFeO3/ZSM-5 is 109.6 kJ/mol. [ABSTRACT FROM AUTHOR]