I. I. Zakharov, A. N. Startsev, O. V. Voroshina, A. V. Pashigreva, N. A. Chashkova, and V. N. Parmon
Boreskov Institute of Catalysis, Siberian Division, Russian Academy of Sciences.
Abstract
The molecular mechanism of interaction of two hydrogen sulfide molecules with the (CoIII−Ho)2S2(SH2)4 model active center containing occluded hydrogen was studied by the density functional theory method with the B3P86 hybrid exchange-correlation functional. The reaction was found to occur in the following elementary steps: molecular adsorption of hydrogen sulfide ⇒ dissociative chemisorption ⇒ S–S bond formation in the surface intermediate {2CoIII – (µ-S2) + 2H(ads)} with the release of the first hydrogen molecule into the gas phase H2(g) ⇒ the release of the second hydrogen molecule into the gas phase H2(g) ⇒ the formation of cyclooctasulfur in the reaction 4S2(ads) → S8(ads).
