摘要：

Fe–V pure and mixed sulfides have been prepared from solutions containing iron nitrate and/or ammonium tetrathiovanadate and precipitation with ammonium sulfide. After treatment with H 2 S (15%)–H 2 at 673 K, they exhibit quite high surface area from 57 to 5 m 2 ·g 1 . X-ray diffraction and Mssbauer spectroscopy show the existence of a continuum from the pyrrhotite phase (Fe 0.85 S) to a V 3 S 4 -like phase (V 0.74 S). The structure of the solids is not modified by the catalytic tests which consist in hydrodesulfurization (HDS) of thiophene, hydrogenation (HYD) of toluene, and hydrodeporphyrinization (HDP) of vanadyl octaethyl porphyrine. X-ray photoelectron spectroscopy characterizations indicate a surface Fe–V homogeneity in the mixed sulfides corresponding to the bulk composition and show an effective surface oxidation of the prepared or tested samples occuring during air exposure. Surface compounds like VOSO 4 , V 2 O 5 , Fe 2 O 3 , xH 2 O, and FeOOH have been identified. Concerning the catalytic behaviors, it is worth mentioning that bulk Fe 0.85 S is only active for HDP whereas bulk V 0.74 S has a high potential activity in HDS, HYD, and HDP by comparison with bulk MoS 2 . Moreover, a synergy effect is detected for about 30 atomic% in Fe which origin could be assigned to an optimal dispersion of the V active sites.

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