title: Ternary Ag/MgO-SiO2 catalysts for the conversion of ethanol into butadiene.
abstract: Ternary Ag/Magnesia-silica catalysts were tested in the direct synthesis of 1,3-butadiene from ethanol. The influence of the silver content and the type of silica source on catalytic performance has been studied. Prepared catalysts were characterized by (29) Si NMR, N2 sorption, small-angle X-ray scattering measurements, XRD, environmental scanning electron microscopy with energy dispersive X-ray analysis (ESEM/EDX), FTIR spectroscopy of adsorbed pyridine and CO2 , temperature-programmed desorption of CO2 and UV/Vis diffuse reflectance spectroscopy. Based on these characterization results, the catalytic performance of the catalysts in the 1,3-butadiene formation process was interpreted and a tentative model explaining the role of the different catalytically active sites was elaborated. The balance of the active sites is crucial to obtain an active and selective catalyst to form 1,3-butadiene from ethanol. The optimal silver loading is 1-2 wt% on a MgO-silica support with a molar Mg/Si ratio of 2. The silver species and basic sites (Mg−O pairs and basic OH groups) are of prime importance in the 1,3-butadiene production, catalyzing mainly the ethanol dehydrogenation and the aldol condensation, respectively.
authors.affiliation: Centre for Surface Chemistry and Catalysis, KU Leuven, Kasteelpark Arenberg 23, 3001 Leuven (Belgium), Fax: (+32) 1632-1998.
authors.forename: Wout
authors.initials: W
authors.lastname: Janssens
authors.forename: Ekaterina V
authors.initials: EV
authors.lastname: Makshina
authors.forename: Pieter
authors.initials: P
authors.lastname: Vanelderen
authors.forename: Filip
authors.initials: F
authors.lastname: De Clippel
authors.forename: Kristof
authors.initials: K
authors.lastname: Houthoofd
authors.forename: Stef
authors.initials: S
authors.lastname: Kerkhofs
authors.forename: Johan A
authors.initials: JA
authors.lastname: Martens
authors.forename: Pierre A
authors.initials: PA
authors.lastname: Jacobs
authors.forename: Bert F
authors.initials: BF
authors.lastname: Sels
mesh_terms: D002070:Butadienes / Q000737:chemistry*; D002384:Catalysis; D000431:Ethanol / Q000737:chemistry*; D008277:Magnesium Oxide / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013696:Temperature
chemical_list: D002070:Butadienes; D008277:Magnesium Oxide; D000431:Ethanol; D012834:Silver; D012822:Silicon Dioxide; C031763:1,3-butadiene
keywords: 1,3-butadiene; biomass; ethanol; heterogeneous catalysis; silver catalysts