3266-23-7Relevant articles and documents
2,3-Butanediol dehydration catalyzed by silica-supported alkali phosphates
Kim, Wooyoung,Shin, Wookyun,Lee, Kyoung Jun,Cho, YongSeok,Kim, Hyung Soon,Filimonov, Igor N.
, p. 148 - 163 (2018/11/26)
Characterization of acid-base centers and catalytic dehydration of 2,3-butanediol (BDO) was performed over a wide range of silica-supported alkali phosphates (M_P/SiO2; M = Na, K, Cs; M:P = 0.5–3 mol:mol). Selectivity to 1,3-butadiene (BD) and 3-butene-2-ol (3B2OL) formed by elimination correlates with the densities of conjugated acid-base pairs and increases in the order Na ??M+ moieties. Isolated Br?nsted acid centers are probably silica grafted phosphoric acid molecules at low M/P and –PO(OH)2 end groups of oligophosphates at M/P > 1.5. Deactivation rate increases with the increase of M/P ratio in order Na K Cs. Deactivation patterns imply that sites responsible for elimination are active in dehydrative epoxidation. Dehydration of 3B2OL smoothly proceeds to BD, but the catalysts deactivate faster compared to BDO dehydration.
A method for preparing epoxy butane
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Paragraph 0019; 0020, (2017/03/08)
The invention relates to a method for preparing epoxy butane, which comprises the following step: in an isopropyl benzene solution containing 25 wt% of cumene hydroperoxide solute, preparing epoxy butane from butylene oxide by using the cumene hydroperoxide solute as an oxidizer and a titanium-silicon molecular sieve with three-dimensional pore canal structure as a catalyst, wherein the fixed bed reaction conditions are as follows: the mole ratio of butylene to the cumene hydroperoxide solute is (5.0-12.0):1, the weight hourly space velocity of the cumene hydroperoxide is 1.0-5.0 h, the reaction pressure is 1.0-6.0 MPa, and the temperature is 60.0-120.0 DEG C. The catalyst is the titanium-silicon molecular sieve with three-dimensional pore canal structure; the molecular sieve has hysteresis loop on the low-temperature nitrogen adsorption and desorption isotherm; the average pore size is 2.0-8.0nm, and the specific area is 650.0-1100.0 m/g; and the catalyst has the advantages of favorable activity and high epoxy butane selectivity, and can be widely popularized and applied to industrial production of epoxy butane by butylene epoxidation.
Gas-phase dehydration of vicinal diols to epoxides: Dehydrative epoxidation over a Cs/SiO2 catalyst
Kim, Tae Yong,Baek, Jayeon,Song, Chyan Kyung,Yun, Yang Sik,Park, Dae Sung,Kim, Wooyoung,Han, Jeong Woo,Yi, Jongheop
, p. 85 - 99 (2015/09/28)
A novel type of dehydration reaction that produces epoxides from vicinal diols (dehydrative epoxidation) using a basic catalyst is reported. Epoxyethane, 1,2-epoxypropane, and 2,3-epoxybutane were produced from the dehydrative epoxidation of ethylene glycol, 1,2-propanediol, and 2,3-butanediol, respectively. Among a number of tested basic catalysts, the Cs/SiO2 catalyst showed outstanding performance for the dehydrative epoxidation of 2,3-butanediol and is considered to be the most promising catalyst for this type of reaction. In order to identify the superiority of the Cs/SiO2 catalyst and a mechanism of the reaction, structure-activity relationships were studied along with density functional theory (DFT) calculations. The following features are found to be responsible for the excellent activity of the Cs/SiO2 catalyst: i) strong basic sites formed by Cs+, ii) low penetration of Cs+ into SiO2 which permits basic sites to be accessible to the reactant, iii) stable basic sites due to the strong interactions between Cs+ and SiO2 surface, and iv) mildly acidic surface of SiO2 which is advantageous for the elimination to H2O. In addition, the dehydrative epoxidation involves an inversion of chirality (e.g. meso-2,3-butanediol (R,S) to trans-2,3-epoxybutane (R,R or S,S)), which is in agreement with DFT results that the reaction follows a stereospecific SN2-like mechanism.
