6416-39-3Relevant articles and documents
An Eco-friendly Soft Template Synthesis of Mesostructured Silica-Carbon Nanocomposites for Acid Catalysis
Zhong, Ruyi,Peng, Li,De Clippel, Filip,Gommes, Cedric,Goderis, Bart,Ke, Xiaoxing,Van Tendeloo, Gustaaf,Jacobs, Pierre A.,Sels, Bert F.
, p. 3047 - 3058 (2015/09/22)
The synthesis of ordered mesoporous silica-carbon composites was explored by employing TEOS and sucrose as the silica and carbon precursor respectively, and the triblock copolymer F127 as a structure-directing agent via an evaporation-induced self-assembly (EISA) process. It is demonstrated that the synthesis procedures allow for control of the textural properties and final composition of these silica-carbon nanocomposites via adjustment of the effective SiO2/C weight ratio. Characterization by SAXS, N2 physisorption, HRTEM, TGA, and 13C and 29Si solid-state MAS NMR show a 2D hexagonal mesostructure with uniform large pore size ranging from 5.2 to 7.6 nm, comprising of separate carbon phases in a continuous silica phase. Ordered mesoporous silica and non-ordered porous carbon can be obtained by combustion of the pyrolyzed nanocomposites in air or etching with HF solution, respectively. Sulfonic acid groups can be readily introduced to such kind of silica-carbon nanocomposites by a standard sulfonation procedure with concentrated sulfuric acid. Excellent acid-catalytic activities and selectivities for the dimerization of styrene to produce 1,3-diphenyl-1-butene and dimerization of α-methylstyrene to unsaturated dimers were demonstrated with the sulfonated materials. Tintin and the sulfurous nanocatalysts: Sulfonic acid groups can be readily introduced to mesostructured silica-carbon nanocatalysts to reveal excellent acid-catalytic activities and selectivities for the dimerization of styrene to produce 1,3-diphenyl-1-butene and the dimerization of α-methylstyrene.
Codimerisation of styrene and α-methylstyrene in the presence of zeolites
Grigor'eva,Bubennov,Khalilov,Kutepov
experimental part, p. 85 - 90 (2012/07/13)
The reaction of styrene with α-methylstyrene has been studied over Y, Beta and ZSM-12 zeolites at 80-120 °C in the presence or absence of chlorobenzene. Homo- and codimers of styrene and α-methylstyrene were the main reaction products. The yield of dimers
FTIR and reaction studies of styrene and toluene over silica-zirconia-supported heteropoly acid catalysts
Bachiller-Baeza,Anderson
, p. 231 - 239 (2007/10/03)
The interactions of styrene and toluene with a sol-gel-prepared SiO2-ZrO2 mixed oxide and with two supported heteropolytungstic acid samples, i.e., a Keggin type (H3PW12O40) and a Dawson type (H6PW18O62) were studied by FTIR. Both supported heteropoly acids (HPA) were highly active, leading to styrene conversions of ≤ 94% after 4 hr, while the pure SiO2-ZrO2 support was almost inactive, with only 8% conversion after the safe reaction time. The Dawson catalyst showed higher activity than the supported Keggin. The catalysts differed in activity and in the product distribution, as reflected in the levels of conversion after equivalent reaction times. Toluene adsorption on HPA(K)/SiZr and HPA(D)/SiZr gave similar spectra, as observed for adsorption on the support alone. Increased pressures of styrene progressively demonstrated the adsorbed toluene, resulting in a typical spectrum of polymeric species on the catalysts, with maxima at 1601, 1583, 1494, 1478, 1450, and 1378/cm. The presence of zirconium in SiO2-ZrO2 mixed oxides led to the generation of Bronsted acid sites, which were otherwise absent in the single-component oxides. HPA addition to the SiO2-ZrO2 support led to an increase in the number of sites, which were available for the activation and subsequent reactions involving styrene, as confirmed by the increase activity in catalytic tests in the FTIR study.
