Effects of PH2O, PH2S, PH2 on the surface properties of anatase–TiO2 and γ-Al2O3: a DFT study

Abstract Using density-functional theory combined with surface thermochemistry, the effects of sulfo-reductive conditions ( P H 2 O , P H 2 S , P H 2 , and  T ), including those prevailing in the industrial process of hydrodesulfurization (HDS), are investigated for two catalytic supports: anatase–TiO 2 and γ -Al 2 O 3 . It is found that under the usual HDS conditions, H 2 S may partially sulfide the (001) surface of anatase–TiO 2 , leading to the formation of μ 2 -S species together with two hydroxyl groups. The (110) surface of γ -Al 2 O 3 is sulfided only if the water pressure is very low, leading to the formation of sulfhydryls and hydroxyls. The effect of H 2 pressure is also addressed. A comparison with published experimental data (such as TPR, IR, XPS) is supplied.

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