130983-70-9Relevant articles and documents
Impact of composition and structural parameters on the catalytic activity of MFI type titanosilicalites
Bruk, Lev,Chernyshev, Vladimir,Khramov, Evgeny,Kravchenko, Galina,Kustov, Aleksander,Kustov, Leonid,Kuz'Micheva, Galina,Markova, Ekaterina,Pastukhova, Zhanna,Pirutko, Larisa
, p. 3439 - 3451 (2022/03/14)
Titanosilicalite of the MFI type was obtained via a hydrothermal method. Its initial and annealed at 75 °C (TS-1P(75)) and 500 °C (TS-1P(500)) forms were studied by X-ray powder diffraction (PXRD), X-ray absorption spectroscopy (XAS-method), Fourier-transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), temperature-programmed ammonia desorption (TPD NH3), and pyridine adsorption (Py). The full-profile Rietveld method allowed us to observe the presence of the organic template tetrapropylammonium hydroxide (TPAOH) in the framework voids, as well as to determine the silicate module (Si/Ti = 73.5) and the distribution of Ti4+ ions over the MFI-type structure sites (Ti atoms replace Si ones in two positions: T1 and T6). The coordination numbers of titanium (CNTi = 4.6 for TS-1P and TS-1P(75), CNTi = 3.8 for TS-1P(500)) were established by the XAS-method. The catalytic activity of titanosilicalites was found in the reactions of nitrous oxide decomposition (the maximal decomposition rate is demonstrated for the TS-1P(75) sample), allyl chloride epoxidation to epichlorohydrin (the best combination of all indicators was exhibited for the TS-1P sample) and propane conversion (maximum propane conversion, and butadiene and propylene selectivity were observed in both TS-1P(75) and TS-1P(500) samples). Mechanisms for the catalytic processes are proposed. The relationship between the catalytic properties and the composition (Si/Ti), Ti4+ ion distribution over the MFI-type structure sites, the local environment of titanium ions, and the number of acid sites in the titanosilicalites are discussed.
Selective production of 1,3-butadiene from 1,3-butanediol over Y2Zr2O7 catalyst
Matsuda, Asami,Matsumura, Yoshitaka,Sato, Satoshi,Yamada, Yasuhiro
, p. 1651 - 1658 (2021/07/21)
The vapor-phase dehydration of 1,3-butanediol (1,3-BDO) to produce 1,3-butadiene (BD) was evaluated over yttrium zirconate, which was prepared through a hydrothermal aging process. 1,3-BDO was initially dehydrated to three unsaturated alcohols, namely 3-buten-2-ol, 3-buten-1-ol, and 2-buten-1-ol, followed by the further dehydration to BD. The catalytic activity of yttrium zirconate was greatly dependent on the calcination temperature. Also, the reaction temperature was one of the important factors to produce BD efficiently. The selectivity to BD was increased with increasing reaction temperature up to 375°C, while coke formation resulted in catalyst deactivation together with by-product formation at higher temperatures. Yttrium zirconate catalyst calcined at 900°C showed a high BD yield of 95% at 375°C and 10 hr on stream.
CATALYTIC CONVERSION OF ETHANOL TO 1-/2-BUTENES
-
Paragraph 0013-0022; 0026-0046, (2021/06/11)
Simple and economical conversion of aqueous ethanol feed streams into butenes by a single step method using transition metal oxides on a silica supports under preselected processing conditions. By directly producing a C4-rich olefin mixture from an ethanol containing stream various advantages are presented including, but not limited to, significant cost reduction in capital expenses and operational expenses.
