9003-17-2Relevant 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.
METHOD FOR PRERARING BUTADIENE
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Paragraph 0088-0131, (2021/10/17)
The present invention relates to a method for producing butadiene, comprising butenes, steam and oxygen (O). 2 The method according to S10, wherein the mixed gas stream comprising the inert diluent gas and inert diluent 1 gas is fed to the first reactor (step S). The catalyst of claim 1, wherein the mixed gas stream is passed through a catalytic bed containing MoBi or more selected from the group consisting of a ferritic and 1-series metal oxide catalyst in the first reactor. S20. The reaction product stream is fed into the reactor 2. The 2-series metal oxide catalyst in a MnCe-th reactor passes through a catalyst layer, and includes a step (S30) of removing the oxygen compound contained in the reaction product stream, wherein the operating temperature of the first reactor 1 150 is 250, and the operating temperature of the first reactor 550 °C is 350 °C 2.
SUPPORTED TANTALUM CATALYST FOR THE PRODUCTION OF 1,3-BUTADIENE
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Page/Page column 14-17, (2021/04/03)
The invention relates to a process for the production of 1,3-butadiene from a feed comprising ethanol and acetaldehyde in the presence of a supported tantalum catalyst obtainable by aqueous impregnation of the support with a water-soluble tantalum precursor. Furthermore, the present invention relates to a process for the production of a supported tantalum catalyst, and the supported tantalum catalyst. Finally, the invention relates to the use of the supported tantalum catalyst for the production of 1,3-butadiene from a feed comprising ethanol and acetaldehyde to increase one or both of selectivity and yield of the reaction.
Understanding Ta as an Efficient Promoter of MgO–SiO2 Catalyst for Conversion of the Ethanol–Acetaldehyde Mixture into 1,3-Butadiene
Gao, Qiang,Jiang, Angjiong,Jiang, Haoxi,Yang, Guochao,wang, Lingtao
, (2021/10/27)
In this work, Ta was firstly reported as an efficient promoter of MgO–SiO2 for the conversion of ethanol and acetaldehyde to 1,3-butadiene. The doping of Ta into MgO–SiO2 forms Ta–O–Si bonds and generates more strong Lewis acid sites, which not only promote the aldol condensation reaction but also significantly facilitate the Meerwein–Ponndorf–Verley reduction, the total conversion around 80% which drops to 65% after 24?h. In addition, the catalyst showed desirable stability in 24?h long-term stability evaluation, the selectivity remained stable at 80%. Graphic Abstract: [Figure not available: see fulltext.]
Effect of Steam–Air Treatment of Alumina–Chromia Dehydrogenation Catalysts on Their Physicochemical and Catalytic Characteristics
Nazimov,Klimov,Saiko,Noskov
, p. 1283 - 1291 (2021/12/29)
The effect of calcined alumina–chromia catalyst containing 13 wt.% Cr with additions of Na+ and Zr4+ in an air–water vapor atmosphere (from 0 to 80 vol % water vapor) at 750°С and a pressure of 1 bar on the physicochemical properties of the catalyst and its activity in n-butane dehydrogenation was evaluated. The steam treatment led to a slight decrease in the specific surface area (by up to 10%), partial decomposition of Cr(VI) compounds (up to 60%), and Cr2O3 crystallization. The catalytic activity decreased with an increase in the water vapor:air ratio. Low water vapor concentration (10 vol %) favored a remarkable decrease in the amount of the coke formed (by 60%) without considerably affecting alkene yield. Thus, the introduction of water vapor into the calcination atmosphere allowed control of the Cr(VI) amount and catalyst selectivity.
CATALYTIC HYDROCARBON DEHYDROGENATION
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Paragraph 0059; 0060; 0124; 0125, (2021/03/13)
A catalyst for dehydrogenation of hydrocarbons includes a support including zirconium oxide and Linde type L zeolite (L-zeolite). A concentration of the zirconium oxide in the catalyst is in a range of from 0.1 weight percent (wt. %) to 20 wt. %. The catalyst includes from 5 wt. % to 15 wt. % of an alkali metal or alkaline earth metal. The catalyst includes from 0.1 wt. % to 10 wt. % of tin. The catalyst includes from 0.1 wt. % to 8 wt. % of a platinum group metal. The alkali metal or alkaline earth metal, tin, and platinum group metal are disposed on the support.
Pt/TS-1 catalysts: Effect of the platinum loading method on the dehydrogenation of n-butane
Shao, Mingyuan,Hu, Chaoquan,Xu, Xuebing,Song, Yang,Zhu, Qingshan
, (2021/05/10)
A series of catalysts in which platinum was supported on the crystalline pure titanium silicalite (TS-1) were prepared using two different loading methods, namely, an ethylene glycol (EG) reduction method and the conventional incipient wetness impregnation (IM) technique. Various characterization techniques were used to study the effect of the loading method on the physicochemical and morphological properties of the prepared catalysts. Also the effect of the platinum-loading method on the dehydrogenation of n-butane was investigated in a fixed-bed reactor. The results show that the EG method favors the formation of a more-concentrated Pt dispersion, which results in much better catalytic activities for the selective formation of butenes and butadiene (> 97 %). This phenomenon is interpreted by carrying out density functional theory (DFT) calculations with focus on the relationship between the coverage of n-butane on Pt surface and the activation barrier for the first C[sbnd]H bond cleavage.
Oxidative dehydrogenation of n-butene to buta-1,3-diene with novel iron oxide-based catalyst: Effect of iron oxide crystalline structure
Kiyokawa, Takayasu,Ikenaga, Naoki
, (2021/04/19)
We investigate the effect of the crystalline structure of iron oxide catalysts on oxidative dehydrogenation (ODH) of n-butene. ODH reactions of n-butene were carried out with a fixed-bed flow reactor at 450 °C under a but-1-ene (1-C4H8) or cis-but-2-ene (cis-2-C4H8)(mL/min)/O2(mL/min) flow ratio of 5/2.5. Of the various iron oxide-based catalysts (α-, β-, γ-, ε-Fe2O3, Fe3O4, ZnFe2O4), ε-Fe2O3 showed the highest ODH activity. To the best of our knowledge, ε-Fe2O3 has never been used for the ODH of n-butene. Moreover, the catalytic performance of ε-Fe2O3 was improved by adding SiO2, which is related to the maintenance of its structure and improves its redox property. A high BD selectivity of 65 % and BD yield of 18 % were then obtained for 4 h without deactivation. This catalyst can be applied to the ODH of cis-2-C4H8 and is proposed as the noble high catalytic performance catalyst for the ODH of n-butene.
Chemoenzymatic Buta-1,3-diene Synthesis from Syngas Using Biological Decarboxylative Claisen Condensation and Zeolite-Based Dehydration
Balasubramaniam, Sivaraman,Badle, Sneh,Badgujar, Swati,Veetil, Vinod P.,Rangaswamy, Vidhya
, p. 705 - 711 (2020/12/01)
A method for producing buta-1,3-diene (1,3-BD) by an amalgamation of chemical and biological approaches with syngas as the carbon source is proposed. Syngas is converted to the central intermediate, acetyl-CoA, by microorganisms through a tetrahydrofolate metabolism pathway. Acetyl-CoA is subsequently converted to malonyl-CoA using a carbonyl donor in the presence of a carboxylase enzyme. A decarboxylative Claisen condensation of malonyl-CoA and acetaldehyde ensues in the presence of acyltransferases to form 3-hydroxybutyryl-CoA, which is subsequently reduced by aldehyde reductase to give butane-1,3-diol (1,3-BDO). An ensuing dehydration step converts 1,3-BDO to 1,3-BD in the presence of a chemical dehydrating reagent.
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.
