Transformation of acetone over a 0.4PtHMFI(60) catalyst. Reaction scheme

• Published in: Journal of molecular catalysis. A, Chemical Chemical, 1997-10, Vol.124 (2), p.155-161
• Main Authors: Melo, L., Magnoux, P., Giannetto, G., Alvarez, F., Guisnet, M.
• Format: Article
• Language: English
• Subjects: Catalysis; Catalytic reactions; Chemistry; Exact sciences and technology; General and physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/S1381-1169(97)00073-3

The transformation of acetone was carried out over a 0.4 wt% PtHMFI catalyst ( Si Al = 60 ) under the following conditions: flow reactor, 160°C, pressures of acetone and hydrogen equal to 0.75 and 0.25 bar, respectively. Methylisobutylketone, propane and traces of mesityloxide are observed as primary products while the other main products: 2-methylpentane and diisobutylketone result from secondary transformation of methylisobutylketone. The reactivity of the reaction products and of probable intermediates: diacetone alcohol, isopropanol and propene was compared to that of acetone, which allows us to establish the complete scheme of acetone transformation. Acetone is competitively transformed through bifunctional catalysis into methylisobutylketone and into propane. The limiting step of methylisobutylketone formation is acetone aldolisation over the acid sites of the catalyst while that of propane formation is acetone hydrogenation over platinum sites. Methylisobutylketone undergoes the same competitive bifunctional transformations leading to diisobutylketone (limiting step: acid coaldolisation of acetone and of methylisobutylketone) and to 2-methylpentane (limiting step: hydrogenation of methylisobutylketone).