Ordered Cr2O3 nanorods (Cr2O3-R) and Cr2O3 nanoparticles (Cr2O3-P) were prepared by a hard template method with SBA-15 and a deposition–precipitation method, respectively. These catalysts were tested for the fluorination of 2-chloro-1,1,1-trifluoroethane (HCFC-133a) to synthesize 1,1,1,2-tetrafluoroethane (HFC-134a). It was found that both catalysts were very selective, with a HFC-134a selectivity of 98 %. However, the Cr2O3-R catalyst had an area specific reaction rate of 0.012 μmol m−2 s−1 at 320 °C, which was much higher than that on the Cr2O3-P (0.005 μmol m−2 s−1). The enhanced activity of the Cr2O3-R was attributed to its higher content of Cr(VI) species compared to that in the Cr2O3-P, which was evidenced by the hydrogen temperature-programmed reduction and X-ray photoelectron spectroscopy results. Besides, the Cr2O3-R catalyst had a higher surface acid density (0.076 mmol m−2) than the Cr2O3-P (0.068 mmol m−2), which could be another reason for its better performance.

Morphological effects of ordered Cr2O3 nanorods and Cr2O3 nanoparticles on fluorination of 2-chloro-1,1,1-trifluoroethane

Co-production preparation method of 2-chloro-3,3,3-trifluoropropene and 2,3-dichloro-1,1-difluoro propylene

The invention discloses a method for synthesizing 3, 3, 3-trifluoro propene. The method is as follows: 1, 1, 1, 3-tetrachloropropane, catalyst and hydrofluoric acid are added in a high-pressure reactor used for deoxidization and dewatering, and are heated to a temperature of between 90 and 500 DEG C so as to carry out reaction for 0.5 to 3 hours, thereby obtaining 3, 3, 3-trifluoro propene product; moreover, the molar ratio between hydrofluoric acid and 1, 1, 1, 3-tetrachloropropane is between 3:1 and 300:1, and the mass ratio between catalyst and 1, 1, 1, 3-tetrachloropropane is between 0.005:1 and 10:1. The method can synthesize 3, 3, 3-trifluoro propene at high transformation efficiency and high selectivity with both the transformation efficiency and the selectivity reaching to more than 98 percent. Moreover, the method has the advantages of simple production equipment, short technological flow, long service life of catalyst, low price, high reaction transformation efficiency, ideal reaction selectivity and high product purity, etc.

Method for synthesizing 3,3,3-trifluoro propene

The invention discloses a catalyst for fluoridation, which is composed of a La2O3-NiO-Al2O3 compound oxide comprising, in mass fraction, 8% of La2O3, 2% of NiO and 90% of Al2O3, and Cr2O3, wherein the mass ratio of the La2O3-NiO-Al2O3 compound oxide to the Cr2O3 is (0.01 to 0.1): 1. The preparation method comprises the following steps of: preparing the La2O3-NiO-Al2O3 compound oxide at first, and then preparing Cr(OH)3; weighing the La2O3-NiO-Al2O3 compound oxide and Cr2O3 in a mass ratio of (0.01 to 0.1): 1; and adequately grinding and drying, and then roasting to prepare the catalyst. The catalyst is used for gas-phase fluorination synthesis for tetrafluoroethane from trichloroethylene or gas-phase fluorination synthesis for pentafluoroethane from tetrachloroethylene or gas-phase fluorination synthesis for tetrafluoropropene from tetrachloropropene, as well as is good in activity and selectivity.

Catalyst for fluoridation and preparation method for same

Preparation method for trifluoroethylene and tetrafluoroethane

The invention relates to a catalyst used for making tetrafluoromethane through gas-phase fluorination and a preparation method thereof, and aims at providing a catalyst used for making tetrafluoromethane through gas-phase fluorination characterized by high activity and high stability and a preparation method thereof in consideration of poor activity and low stability existing in the existing gas-phase fluorination catalyst. The preparation method of the catalyst of the invention is as follows: one or more than one compound of Y, compound of Cr, compound of magnesium, aluminum, indium, gallium, zinc, scandium, strontium, iron, cobalt, nickel and cadmium are measured according to a certain proportion; the precipitator adopts one among ammonia, sodium hydroxide, ammonium carbonate, sodium carbonate and potassium hydroxide, and sediments are obtained by a coprecipitation method, and the precursor of the catalyst is obtained by baking and roasting the sediments then the catalyst is obtained after being treated with anhydrous hydrogen fluoride.

Catalyst for producing tetrafluoromethane with gas-phase fluoridation and production method

The invention relates to a catalyst for fluorination, especially a catalyst for producing HFC-134a in gas phase fluorination and the manufacturing method. Aiming at the lack of prior technology, the invention provides a catalyst for producing HFC-134a in gas phase fluorination with high activity and high stability and the manufacturing method. The catalyst comprises carrier and active component. The carrier adopts Y compound and the active component adopts Cr compound. The preparing process for the catalyst for producing HFC-134a in gas phase fluorination is that soluble Cr and Y salts are taken to be dissolved by water according to the proportion; it is mixed in uniformity; precipitant is added to make them precipitate; then the filter solution is neural after centrifugal separation and washing; it is dried; the dried precipitate is formed by tablet mould; the precursor of fluorination catalyst is obtained by baking; after it is treated dry by nitrogen, it is treated by HF without water; finally the catalyst is obtained.

Vapor-phase fluorination catalysts for producing HFC-134a and the preparing method

The invention provides a gas phase fluorination catalyst and a method for preparing the same. The aim of the invention is to provide a gas phase fluorination catalyst with high activity and stability and a method for preparing the same so as to overcome the defects of poor activity and stability existing in the prior gas phase fluorination catalyst. The catalyst of the invention comprises a carrier and active components, wherein the carrier is a compound of Y, and the active components comprise a compound of chromium and one or more of compounds of magnesium, aluminum, indium, gallium and zinc. The method for preparing the catalyst comprises: according to a certain ratio, the compounds of Y and Cr and one or more of compounds of magnesium, aluminum, indium, gallium and zinc are weighed up, added with water, evenly mixed and added with a precipitator until the precipitation is finished, and the precipitate is separated and the solution washed until the filtrate is neutral, the precipitate is dried, formed and roasted to give the a precursor of the fluorination catalyst, and the precursor of the fluorination catalyst is added with anhydrous HF and treated at a certain temperature to give the gas phase fluorination catalyst.

Gas-phase fluorination catalyst and preparation method thereof

The invention relates to a catalyst used for fluoridation. Aiming at the deficiencies that the activity is worse and the stability is not high in the prior catalyst used for producing FC-14 through gas phase fluorination, the invention provides a catalyst used for producing tetrafluoromethane through the gas phase fluorination and possessed of high activity, high selectivity, high stability and low application temperature, as well as the preparation method thereof. The catalyst of the invention comprises a carrier and an active ingredient, wherein, the carrier adopts the compound of aluminum; and the active ingredient adopt the compound of chromium. The catalyst of the invention comprises the following preparation process: firstly, the compound of Al and the compound of Cr are weighed out according to a certain proportion, after water is added and the compounds are uniformly mixed, a precipitating agent is added until the compounds are completely precipitated, then separation and washing are carried out until the filtrate is neutral, and the precipitate is dried; secondly, the dried precipitate is calcined after being shaped, so as to obtain a fluorination catalyst precursor; and thirdly, the fluorination catalyst precursor is processed by HF, so as to obtain the catalyst of the invention.

Catalyst for producing tetrafluoromethane by gas-phase fluorination and preparation method thereof

The invention discloses a method for producing a tetrafluoromethane by gas phase catalysis. Aiming at the defects of high needed reaction temperature and low conversion per pass existing in the conventional process for producing FC-14 by gas phase fluorination, the invention provides an economic and high-efficient method for producing the tetrafluoromethane by gas phase catalysis, which has the advantages of low needed reaction temperature and high conversion per pass. The method for producing the tetrafluoromethane comprises the following step: reacting halohydrocarbon with hydrogen fluoride at the presence of a gas phase fluorination catalyst in a gas phase to produce the tetrafluoromethane, wherein the molar ratio of the halohydrocarbon to the hydrogen fluoride is 1:1-10; the halohydrocarbon is one or more of the tetrafluoromethane, trichloromonofluomethane, dichlorodifluoromethane and monochlorotrifluoromethane; the used gas phase fluorination catalyst adopts a chromium compound as an active component and an aluminum compound as a carrier; and the molar ratio of the chromium to the aluminum is 1:1-19. The method for producing the tetrafluoromethane has the characteristics of long service life and high percent conversion of the halohydrocarbon.

Method for producing tetrafluoromethane by gas phase catalysis

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