75-02-5Relevant articles and documents
PRODUCTION METHOD FOR FLUORO-ETHANE AND PRODUCTION METHOD FOR FLUORO-OLEFIN
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Paragraph 0087, (2021/10/15)
The production method according to the present disclosure comprises obtaining a product containing the fluoroethane from a fluoroethylene by a reaction in the presence of catalysts. Each catalyst is formed by supporting a noble metal on a carrier. A reactor for performing the reaction is filled with a catalyst having a noble metal concentration of C1 mass % based on the entire catalyst and a catalyst having a noble metal concentration of C2 mass % based on the entire catalyst to form an upstream portion and a downstream portion, respectively; and C1C2. The reaction is performed by bringing the fluoroethylene represented by formula (3) and hydrogen gas into contact with the upstream portion and the downstream portion in this order.
Thermally conductive SiC as support of aluminum fluoride for the catalytic dehydrofluorination reaction
Han, Wenfeng,Li, Ying,Liu, Bing,Liu, Yongnan,Lu, Jiaqin,Tang, Haodong,Yang, Hong,Yu, Wei
, (2020/05/18)
Aluminum fluoride (AlF3) is a typical catalyst for dehydrofluorination of hydrofluorocarbons (HFCs) to fluoroolefins with high heat of reaction. Consequently, heat supply and sintering are the key challenges for AlF3-based catalysts. Herein, SiC with high thermal conductivity and resistance to HF corrosion is suggested as a candidate support of AlF3 catalyst. The interaction between AlF3 and SiC leads to uniform distribution of the catalytic phase, and as a result of this, AlF3/SiC exhibits high catalytic activity and stability for the dehydrofluorination of 1,1-difluoroethane to vinyl fluoride. This study proposes a novel catalyst support (SiC) for strong endothermic catalytic reactions involving HFCs for the first time to the best of our knowledge.
Rational design of MgF2 catalysts with long-term stability for the dehydrofluorination of 1,1-difluoroethane (HFC-152a)
Tang, Haodong,Dang, Mingming,Li, Yuzhen,Li, Lichun,Han, Wenfeng,Liu, Zongjian,Li, Ying,Li, Xiaonian
, p. 23744 - 23751 (2019/08/13)
In this study, three different approaches, i.e. the sol-gel method, precipitation method and hardlate method, were applied to synthesize MgF2 catalysts with improved stability towards the dehydrofluorination of hydrofluorocarbons (HFCs); the in situ XRD technique was employed to investigate the relationship between the calcination temperature and the crystallite size of precursors to determine optimal calcination temperature for the preparation of the MgF2 catalysts. Moreover, the physicochemical properties of MgF2 catalysts were examined via BET, XRD, EDS and TPD of NH3 and compared. Undoubtedly, the application of different methods had a significant influence on the surface properties and catalytic performances of MgF2 catalysts. The surface areas of the catalysts prepared by the precipitation method, sol-gel method and template method were 120, 215 and 304 m2 g-1, respectively, upon calcination at 200 °C. However, the surface area of the MgF2 catalysts decreased significantly when the calcination temperatures of 300 and 350 °C were applied. The catalytic performance of these catalysts was evaluated via the dehydrofluorination of 1,1-difluoroethane (HFC-152a). The MgF2 catalyst prepared by the precipitation method showed the lowest catalytic activity among all the MgF2 catalysts. When the calcination temperature was above 300 °C, the MgF2 catalysts prepared via the template method demonstrated the highest catalytic conversion rate with catalytic activity following the order: MgF2-T (template method) > MgF2-S (sol-gel method) > MgF2-P (precipitation method). The conversion rate generally agreed with the total amount of acid on the surface of the catalysts, which was measured by the NH3-TPD technique. The MgF2-T catalysts were further examined for the dehydrofluorination of HFC-152a for 600 hours, and a conversion rate greater than 45% was maintained, demonstrating superior long-term stability of these catalysts.
Selective Copper Complex-Catalyzed Hydrodefluorination of Fluoroalkenes and Allyl Fluorides: A Tale of Two Mechanisms
Andrella, Nicholas O.,Xu, Nancy,Gabidullin, Bulat M.,Ehm, Christian,Baker, R. Tom
supporting information, p. 11506 - 11521 (2019/08/20)
The transition to more economically friendly small-chain fluorinated groups is leading to a resurgence in the synthesis and reactivity of fluoroalkenes. One versatile method to obtain a variety of commercially relevant hydrofluoroalkenes involves the catalytic hydrodefluorination (HDF) of fluoroalkenes using silanes. In this work it is shown that copper hydride complexes of tertiary phosphorus ligands (L) can be tuned to achieve selective multiple HDF of fluoroalkenes. In one example, HDF of the hexafluoropropene dimer affords a single isomer of heptafluoro-2-methylpentene in which five fluorines have been selectively replaced with hydrogens. DFT computational studies suggest a distinct HDF mechanisms for L2CuH (bidentate or bulky monodentate phosphines) and L3CuH (small cone angle monodentate phosphines) catalysts, allowing for stereocontrol of the HDF of trifluoroethylene.
Method for preparing vinyl fluoride by splitting 1,1-difluoroethane
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Paragraph 0022; 0024-0025, (2017/07/20)
The invention discloses a method for preparing vinyl fluoride by splitting 1,1-difluoroethane. The method comprises the following steps: in the presence of acetylene, under the effect of a catalyst, splitting 1,1-difluoroethan to obtain 1,1-difluoroethan. The method provided by the invention has the advantages of high raw material single-process conversion rate, low splitting reaction temperature, fewer impurities contained in vinyl fluoride, high selectivity and the like.
A polyvinylidene fluoride preparation method and its catalyst preparation method
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Paragraph 0031; 0032, (2017/08/25)
The invention discloses a preparation method of vinylidene fluoride and a preparation method of a catalyst used by the same. The preparation method of vinylidene fluoride comprises the following steps: mixing methane, oxygen and fluoroform or monochlorodifluoromethane or the mixed gas of fluoroform and monochlorodifluoromethane at any ratio or the mixed gas of multiple gases including fluoroform and monochlorodifluoromethane; adding O2 at a certain proportion, and reacting at a temperature of 550-1,050 DEG C under a total pressure of 1-10bar and at an air speed of 50-10,000h; and reacting in the presence of a catalyst to generate vinylidene fluoride. According to the method disclosed by the invention, the vinylidene fluoride with relatively high added value is generated under a catalytic action from several waste fluoroform raw materials which are cheap or need forced treatment, has relatively high added value, and brings good economic and social benefits.
METHOD FOR PRODUCING OLEFIN
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Paragraph 0150-0154; 0168-0171, (2017/11/01)
A method for producing at least one olefin compound selected from the group consisting of a compound of formula (51), a compound of formula (52), a compound of formula (53), and a compound of formula (54), the method including reacting an olefin compound of formula (21) with a olefin compound of formula (31) in the presence of at least one metal catalyst selected from the group consisting of a compound of formula (11), a compound of formula (12), a compound of formula (13), a compound of formula (14), and a compound of formula (15).
Compositions
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Paragraph 0119; 0120, (2013/09/12)
A composition comprising HCFO-1233xf and at least one additional compound selected from the group consisting of HCFO-1233zd, HCFO-1232xd, HCFO-1223xd, HCFC-253fb, HCFC-233ab, HFO-1234yf, HFO-1234ze, ethylene, HFC-23, CFC-13, HFC-143a, HFC-152a, HFO-1243zf, HFC-236fa, HCO-1130, HCO-1130a, HFO-1336, HCFC-244bb, HCFC-244db, HFC-245fa, HFC-245cb, HCFC-133a, HCFC-254fb, HCFC-1131, HCFO-1242zf, HCFO-1223xd, HCFC-233ab, HCFC-226ba, and HFC-227ca.
Titanium-catalyzed vinylic and allylic C-F bond activation-scope, limitations and mechanistic insight
Kuehnel, Moritz F.,Holstein, Philipp,Kliche, Meike,Krueger, Juliane,Matthies, Stefan,Nitsch, Dominik,Schutt, Joseph,Sparenberg, Michael,Lentz, Dieter
supporting information, p. 10701 - 10714 (2013/01/14)
The hydrodefluorination (HDF) of fluoroalkenes in the presence of a variety of titanium catalysts was studied with respect to scope, selectivity, and mechanism. Optimization revealed that the catalyst requires low steric bulk and high electron density; secondary silanes serve as the preferred hydride source. A broad range of substrates yield partially fluorinated alkenes, such as previously unknown (Z)-1,2-(difluorovinyl)ferrocene. Mechanistic studies indicate a titanium(III) hydride as the active species, which forms a titanium(III) fluoride by H/F exchange with the substrate. The HDF step can follow both an insertion/elimination and a σ-bond metathesis mechanism; the E/Z selectivity is controlled by the substrate. The catalysts' ineffieciency towards fluoroallenes was rationalized by studying their reactivity towards Group 6 hydride complexes. The broad application of the catalytic hydrofluorination of fluoroalkenes by the system [Cp2TiF 2]/silane is demonstrated. Isolated yields up to 79 % could be obtained for various substrates. Mechanistic studies indicate two competing reaction mechanisms. Copyright
Experimental and chemical kinetic study of the pyrolysis of trifluoroethane and the reaction of trifluoromethane with methane
Han, Wenfeng,Kennedy, Eric M.,Kundu, Sazal K.,MacKie, John C.,Adesina, Adesoji A.,Dlugogorski, Bogdan Z.
scheme or table, p. 751 - 760 (2010/09/04)
A detailed reaction mechanism is developed and used to model experimental data on the pyrolysis of CHF3 and the non-oxidative gas-phase reaction of CHF3 with CH4 in an alumina tube reactor at temperatures between 873 and 1173 K and at atmospheric pressure. It was found that CHF3 can be converted into C2F4 during pyrolysis and CH2=CF2 via reaction with CH4. Other products generated include C3F6, CH 2F2, C2H3F, C2HF 3, C2H6, C2H2 and CHF2CHF2. The rate of CHF3 decomposition can be expressed as 5.2×1013[s-1]e -295[kJmol-1]/RT. During the pyrolysis of CHF3 and in the reaction of CHF3 with CH4, the initial steps in the reaction involve the decomposition of CHF3 and subsequent formation of CF2 difluorocarbene radical and HF. It is proposed that CH4 is activated by a series of chain reactions, initiated by H radicals. The NIST HFC and GRI-Mech mechanisms, with minor modifications, are able to obtain satisfactory agreement between modelling results and experimental data. With these modelling analyses, the reactions leading to the formation of major and minor products are fully elucidated.
