Abstract: H₂S adsorption and reaction on CeO₂, TiO₂, and γ-Al₂O₃ were studied by temperature programmed surface reaction (TPSR). Ceria had the best desulfidation ability. The pretreatment atmosphere affected H₂S adsorption and reaction on ceria, and desulfidation efficiency increased in the order of inert atmosphere, reducing atmosphere, oxidizing atmosphere. H₂S was first adsorbed on pretreated ceria at room temperature. On increasing the temperature in an Ar (99.99%) atmosphere, part of the H₂S desorbed below 673 K, and another part reacted with the surface oxygen on ceria to produce sulfur and water below 473 K, and SO₂ between 473 and 673 K, which further reacted with lattice oxygen and was transformed into sulfate above 673 K. The sulfate decomposed into SO₂ again at 873 K. To avoid the complex regeneration, it is advisable to carry out desulfidation below 673 K when using ceria as adsorbent.

Key words: ceria, hydrogen sulfide, adsorption, temperature-programmed surface reaction