Gas phase acceptorless dehydrogenative coupling of ethanol over bulk MoS2 and spectroscopic measurement of structural disorder

Nanolayered cobalt–molybdenum sulphides (Co–Mo–S) catalyse borrowing hydrogen C–S bond formation reactions of thiols or H2S with alcohols

“…More specifically, it depends on the composition of the mixed phase of cobalt sulphides, with superior activity when the latter is mainly composed by Co 3 S 4 , and it is also associated with the presence of transient Co–Mo–S-like structures,26 which vanish after the first catalytic run. In addition, MoS 2 plays a key role not only in the hydrogenation step, but also in the dehydrogenation of the alcohol 28…”

“…These results clearly show that in the borrowing hydrogen strategy, apart from the hydrogenation activity of the catalyst, its dehydrogenation ability is also important. In this sense, the presence of MoS 2 in the investigated Co–Mo–S catalysts seems to be crucial to efficiently accomplish the dehydrogenation of the alcohol, 28 since it remains largely unreactive when the molybdenum-free Co x S y material is used as the catalyst.…”

“…In addition, MoS 2 plays a key role not only in the hydrogenation step, but also in the dehydrogenation of the alcohol. 28 …”

Isobutane Dehydrogenation over Bulk and Supported Molybdenum Sulfide Catalysts

“…Two bulk MoS 2 catalysts were studied, hereby denoted as MoS 2 -C and MoS 2 -R. MoS 2 -C is a highly crystalline, <2 μm nanopowder from Sigma-Aldrich and was used as purchased. MoS 2 -R was synthesized via co-precipitation of Mo­(CO) 6 and S 8 in refluxing decalin as reported in the literature and prepared previously by us. ,, Molybdenum sulfide was also supported on several metal oxides (TiO 2 , ZrO 2 , and Al 2 O 3 ) by adapting the co-precipitation method. TiO 2 anatase and ZrO 2 from Sigma-Aldrich and Al 2 O 3 (70:30 δ/γ crystal phase) from Alfa Aesar were used as received.…”

“…We have previously investigated several bulk MoS 2 catalysts for ethanol dehydrogenation and observed a wide range of structural and catalytic properties among these materials, , thus providing the impetus to test different morphologies of MoS 2 as light alkane dehydrogenation catalysts. Here, we report rates, selectivities, and apparent activation barriers of isobutane dehydrogenation at low per-pass conversion and before the materials might begin to deactivate significantly, such that the intrinsic properties of the different material preparations can be compared.…”