Study on the structure of Mo/MgO catalysts for H₂S wet oxidation

The effect of molybdena loading on the activity of Mo/MgO catalysts in the H₂S wet oxidation at room temperature was studied. The prepared Mo/MgO catalysts were characterized to correlate the physical and structural property of Mo/MgO catalysts with the activity of H₂S wet oxidation. No sulfur oxides were detected in the exit gas streams, indicating that the oxidation of H₂S to SO₂ could be prevented in the wet catalytic oxidation. The Mo/MgO catalysts with below 6 wt % MoO₃ maintained the H₂S removal efficiency above 99% up to 9 hr. The activity in H₂S wet oxidation increased up to 6 wt % MoO₃ and then decreased with further increase in molydena loading. The dispersed MgMoO₄ phases were active species, while the crystallites of MgMoO₄ and Mg₂Mo₃O₁₁ phases were inactive in H₂S wet oxidation.