Dehydrogenation of ethylbenzene to styrene catalyzed by Co, Mo and CoMo catalysts supported on natural and aluminum-pillared claysEffect of the metal reduction

Physicochemical properties of vanadium impregnated Al-PILCs: Effect of vanadium source

“…Significant decreases in the adsorbed volumes below P/P o values lower than 0.01 took place especially for the wet impregnated samples. These results are in accordance with the literature data reported for a second metal impregnation into Al-PILCs [23,24,39]. Calcination at 500 • C did not significantly alter the isotherms' behavior.…”

Characterisation of coking activity during supercritical hydrocarbon pyrolysis

“…Polishing a surface favours the presence of Chromium atoms on the surface, which increases the catalytic activity of the tube [55]. Molybdenum, Nickel, Manganese and Potassium are known to play an important catalytic role [56], [57]. This catalytic effect also depends on the fluid composition: as an example [58], it plays a role in the n-hexane conversion and not in the benzene one for the same experimental configuration.…”

Dehydrogenation of ethylbenzene to styrene using Pt, Mo, and Pt–Mo catalysts supported on clay nanocomposites

“…The monometallic 3Mo/TSM catalyst in the reduced form shows a high initial styrene yield (37%) but it drops off rapidly during the first minutes of reaction giving a final styrene yield of 18% after 30 min. However, the performance of this catalyst was much better than those reported for Mo supported over a natural (ST x -1) and pillared clays (10% conversion for the most active catalyst) [6], which presented low surface areas compared to the support used in this work, and thus resulting a poor metal dispersion. The unreduced 3Mo/TSM catalyst showed a marginal styrene yield.…”

“…It was found that the reaction was very limited and catalysts rapidly deactivated due to a weak thermal stability of the prepared materials whose structure collapsed after calcination at 500 • C for 4 h and a significant decrease of the surface area and mesoporosity which let the sintering of Ni after reaction. Therefore, it is believed that the low catalytic activity detected by Gonzalez and Moronta [5] and Moronta et al [6] in the ethylbenzene dehydrogenation is produced by these two effects.…”

“…The reaction rate was governed by the existence of acid sites well dispersed more than by accessibility to the gallery of ethylbenzene molecule or pore site distribution because all pillared clays possessed higher d-spacings and higher pore volume than the Co-impregnated clays, but the acidity of these materials was greater in natural impregnated clays. More recently, in another study [6] (ST x -1) in its natural and Al-pillared forms. In general, low conversions were obtained for all catalysts studied (10% for the most active one) and this was attributed to the low surface areas detected in all catalysts, which resulted in a poor metal phase dispersion.…”