877-44-1Relevant articles and documents
Synthesis, characterization and application of MCM-22 zeolites via a conventional HMI route and temperature-controlled phase transfer hydrothermal synthesis
Xing, Enhui,Shi, Yanchun,Xie, Wenhua,Zhang, Fengmei,Mu, Xuhong,Shu, Xingtian
, p. 8514 - 8522 (2015/03/05)
With less environmental and economical impact, temperature-controlled phase transfer hydrothermal synthesis of MWW zeolites was realized with hexamethyleneimine as a structure-directing agent and aniline as a structure-promoting agent. MCM-22 zeolite, synthesized via temperature-controlled phase transfer hydrothermal synthesis, is nearly identical concerning chemical composition and structure, and possesses nearly identical properties with respect to porosity, Si/Al ratio, thermal behavior and catalytic activity at 200°C, compared with that made from conventional synthesis with hexamethyleneimine as the only template.
Kinetics and Mechanisms of Transalkylation and Disproportionation of meta-Diethylbenzene by Triflic Acid Catalyst
Al-Zahrani,Al-Kinany,Al-Humaizi,Al-Khowaiter
, p. 555 - 563 (2007/10/03)
The kinetics of transalkylation and isomerization of meta-diethylbenzene in the presence of benzene using triflic acid as a catalyst has been investigated. High catalytic activity of the triflic acid catalyst was observed in homogeneous liquid-phase reactions. On the basis of the product distribution obtained, transalkylation, disproportionation, and isomerization reactions have been considered and the main product of the reaction was ethylbenzene. These reactions are conducted in a closed liquid batch reactor with continuous stirring under dry nitrogen and atmospheric pressure over the temperature range of 288-308 K. The main transalkylation, disproportionation, and isomerization reactions occurred simultaneously and were considered as elementary reactions. The apparent activation energy of the transalkylation reaction was found to be 35.5 kj/mol, while that of disproportionation reaction was 42.3 kj/mol. The reproducibility of the experimental product distribution occurred with an average relative error of ±2%.
INTERMOLECULAR HYDROGEN TRANSFER IN UNSATURATED HYDROCARBONS INDUCED BY DIMERIC TITANOCENE
Mach, Karel,Petrusova, Lidmila,Antropiusova, Helena,Hanus, Vladimir,Turecek, Frantisek,Sedmera, Petr
, p. 2924 - 2936 (2007/10/02)
μ-(η5:η5-Fulvalene)-di-μ-hydrido-bis(η5-cyclopentadienyltitanium) and μ-(η5:η5-fulvalene)-μ-chloro-μ-hydrido-bis(cyclopentadienyltitanium) form a thermally stable complex which catalyzes the intermolecular hydrogen transfer in unsaturated hydrocarbons, in addition to isomerizations and cyclizations.Cyclic hydrocarbons disproportionate under catalysis to saturated and aromatic hydrocarbons, while linear olefins yield predominantly linear alkanes and high molecular weight tar.The catalyst enables the hydrocarbon system to approach the thermodynamicequilibrium through a series of substitution reactions between alkyl- and allyltitanocene-like species and olefins and dienes.The catalytic complex was characterized by UV and ESR spectra.About one half of overall titanium content could be converted to mononuclear η3-allyltitanocene-like species, stable up to 400 deg C.This exceptional thermal stability is ascribed to a firmly bound allyl containing ligand.
Studies in Trifluoromethanesulfonic Acid. 3. Kinetics and Mechanism of Transalkylation Reactions
Bakoss, H. J.,Roberts, R. M. G.,Sadri, A. R.
, p. 4053 - 4055 (2007/10/02)
Rates of disproportionation of ethylbenzene and m-diethylbenzene have been measured in the solvent trifluoromethanesulfonic acid (triflic acid).Ethylbenzene disproportionates very rapidly, whereas m-diethylbenzene reacts at a conveniently measurable rate.The reactions obey first-order kinetics over a wide range of concentration, and the results are interpreted as involving ethyl transfer to the triflate anion followed by alkylation via the ethyl triflate formed.
