Iron-containing SBA-15 as catalyst for partial oxidation of hydrogen sulfide

A family of Fe-containing SBA-15 silica synthesized by a simple one-pot hydrothermal method was synthesized and tested in the hydrogen sulfide partial oxidation for sulfur production at 200 °C and atmospheric pressure. All these materials maintain the porous hexagonal structure of SBA-15 showing a good chemical and mechanical stability. Isolated Fe3+ species are mainly observed at high Si/Fe ratio (ca. 40). However, extra framework iron oligomers and/or aggregated iron oxide clusters are mainly observed for samples with Si/Fe ratio lower than 10. High H2S conversion and high selectivity to sulfur (higher than 99%), with very low selectivity to SO2 (lower than 0.5% at H2S conversion between 60 and 80%), have been achieved. Moreover, the TOF decreases when increasing the amount of iron in the catalysts.

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► Fe-containing SBA-15 is active and selective in partial oxidation of hydrogen sulfide.
► Isolated Fe3+ species can be considered as active and selective sites.
► The presence of iron oxide particles decreases the productivity per iron atom.
► Minor changes at the surface of catalysts after catalytic tests are observed.