阅读说明：本技术 一种κ-AlF3催化剂的制备方法 (kappa-AlF3Process for preparing catalyst ) 是由 韩文锋 王海丽 俞威 刘永南 杨虹 刘兵 李西良 陆佳勤 唐浩东 李瑛� 于 2019-09-20 设计创作，主要内容包括：本发明公开了一种κ-AlF_3催化剂的制备方法,包括以下过程：将铝源溶于溶剂中形成混合溶液,再将氟源加入到该混合溶液中,搅拌溶解形成无色透明的溶液,然后置于水热釜中经水热反应,反应结束后冷却至室温,将反应液离心分离,离心分离得到的固体经乙醇水溶液洗涤后干燥,将干燥后的固体煅烧活化,制得所述κ-AlF_3催化剂。通过本发明的方法合成的κ-AlF_3催化剂,在催化含氟烷烃裂解脱HF制备含氟烯烃反应中具有较高的催化活性,且本发明制备的κ-AlF_3催化剂纯度很高,形貌规则且多样。(The invention discloses a kappa-AlF 3 The preparation method of the catalyst comprises the following steps: dissolving an aluminum source in a solvent to form a mixed solution, adding a fluorine source into the mixed solution, stirring and dissolving to form a colorless and transparent solution, then placing the solution in a hydrothermal kettle for hydrothermal reaction, cooling to room temperature after the reaction is finished, centrifugally separating the reaction liquid, washing the solid obtained by centrifugal separation with an ethanol water solution, drying, calcining and activating the dried solid to obtain the kappa-AlF 3 A catalyst. kappa-AlF synthesized by the method of the present invention 3 Catalyst for the catalysis of fluorine-containing alkanesHas higher catalytic activity in the reaction of preparing fluorine-containing olefin by cracking and removing HF, and the kappa-AlF prepared by the invention 3 The catalyst has high purity and regular and various appearance.)

1. kappa-AlF₃The preparation method of the catalyst is characterized by comprising the following steps: dissolving an aluminum source in a solvent to form a mixed solution, adding a fluorine source into the mixed solution, stirring and dissolving to form a colorless and transparent solution, then placing the solution in a hydrothermal kettle for hydrothermal reaction, cooling to room temperature after the reaction is finished, centrifugally separating the reaction liquid, washing the solid obtained by centrifugal separation with an ethanol water solution, drying, calcining and activating the dried solid to obtain the kappa-AlF₃A catalyst.

2. The kappa-AlF of claim 1₃The preparation method of the catalyst is characterized in that the aluminum source is any one or a mixture of more than one of aluminum nitrate, aluminum chloride, aluminum acetylacetonate, aluminum isopropoxide, aluminum sulfate, aluminum hydroxide and aluminum acetate, preferably any one or a mixture of more than one of aluminum nitrate, aluminum acetylacetonate, aluminum isopropoxide and aluminum hydroxide.

3. The kappa-AlF of claim 1₃The preparation method of the catalyst is characterized in that the fluorine source is NH₄BF₄、NH₄F、(NH₄)₂SiF₆、HF、HBF₄、NH₄HF₂Preferably NH, preferably₄BF₄、NH₄F、(NH₄)₂SiF₆One or a mixture of several of them.

4. The kappa-AlF of claim 1₃The preparation method of the catalyst is characterized in that the solvent is one or a mixture of DMF, ethanol, glycol, glycerol, isopropanol, acetic acid and deionized water.

5. The kappa-AlF of claim 1₃Process for the preparation of a catalyst, characterized in that the kappa-AlF₃In the preparation process of the catalyst, a surfactant is also added into a solution which is placed in a hydrothermal kettle for hydrothermal reaction; the surfactant is sodium dodecyl benzene sulfonate, cetyl trimethyl ammonium bromide, sodium oleate or polyvinylpyrrolidone.

6. The kappa-AlF of claim 1₃A process for producing a catalyst, characterized in that the molar ratio of the Al element in the aluminum source to the F element in the fluorine source is 3 to 15:1, preferably 5 to 10: 1.

7. The kappa-AlF of claim 1₃The preparation method of the catalyst is characterized in that the temperature of the hydrothermal reaction is 100-180 ℃, and the time of the hydrothermal reaction is 1-48 h.

8. The kappa-AlF of claim 1₃The preparation method of the catalyst is characterized in that the drying temperature is 50-120 ℃, and the drying time is 1-24 h.

9. The kappa-AlF of claim 1₃The preparation method of the catalyst is characterized in that the calcination activation temperature is 300-500 ℃, and the calcination activation time is 3-10 h.

Technical Field

The invention relates to a kappa-AlF₃A method for preparing the catalyst.

Background

Hydrofluoroalkanes (HFCs) are Cl-free and have an Ozone Depletion Potential (ODP) of 0 and do not cause damage to the ozone layer, but are greenhouse gases with relatively high green house effect potential (GWP) and a residence time in the atmosphere of up to 47 years, the presence of which poses a significant threat to the global environment. The gas which is prohibited to be discharged in the Jingdu protocol is a gas which causes certain harm to the environment when being used in large quantities. Such as HFC-134a (1, 1,1, 2-tetrafluoroethane), which is a refrigerant commonly used in automobile air conditioners, has a GWP of about CO₂1400 times the potential for the greenhouse effect. Hydrofluoroolefins (HFOs) have relatively low GWP values and have a residence time in the atmosphere of only about 10 days. Relative to each otherIt appears that the conversion of hydrofluoroalkanes into hydrofluoroolefins is a very environmentally friendly way, slowing down the greenhouse effect to a great extent, solving the present very serious environmental problem.

Moreover, HFOs have physicochemical properties similar to HFCs, are also widely used in refrigerants, blowing agents, cleaning agents, etc., and have very low GWP values (generally below 150), which are considered to be ideal substitutes for HFCs. Hydrofluoroolefin is also an important polymerization precursor, can generate some fluorine-containing monomers and fluorine-containing high molecular materials with high added values through polymerization and addition reaction, and is widely applied to aspects such as fluorine-containing resin, fluorine-containing rubber, fluorine-containing fiber, fluorine-containing surfactant and the like.

Chinese patent CN201710353517 reports prepared theta-AlF₃For the production of trifluoroethylene by dehydrohf of 1,1,1, 2-tetrafluoroethane at 450 ℃ with a conversion of 1,1,1, 2-tetrafluoroethane of around 30% and a selectivity for trifluoroethylene higher than 99% chinese patent CN106000428A used an OH group containing aluminium fluoride, an OH group containing P doped aluminium fluoride and an OH group containing zinc doped aluminium fluoride catalyst for the dehydrohf production of trifluoroethylene from 1,1,1, 2-tetrafluoroethane at 450 ~ 500 ℃ with a conversion of 1,1,1, 2-tetrafluoroethane of 20 ~ 60% and a selectivity for trifluoroethylene higher than 99% also reported in US5856593A₃When the catalyst is used as a catalyst for preparing trifluoroethylene by dehydrofluorination of HFC-134a, the conversion rate of 1,1,1, 2-tetrafluoroethane is about 35 percent by reaction at 600 ℃. European patent EP2170788A1 reports high specific surface area AlF prepared by sol-gel process₃As a catalyst for preparing trifluoroethylene by dehydrofluorination of HFC-134a, the conversion rate of HFC-134a is about 10% at 300 ℃.

AlF as described above₃Is an important inorganic material, is often used for preparing hydrofluoroolefin by removing HF from hydrofluoroalkane, and is also a main catalyst for F/Cl exchange, HF removal, HCl removal, fluorination reaction and replacement reaction. The specific surface area, crystal structure and surface acidity of the catalyst are all key factors influencing the catalytic activity. Current AlF₃The preparation method of the catalyst comprises a sol-gel method, a gas phase fluorination method, a precipitation method, an immersion method and the like. Some of the existing preparation methods use HF gas or HF solutionIs a fluorine source, the operation process is dangerous, and the prepared AlF₃Has lower specific surface area and no regular morphology. The most reported at present is mainly alpha-AlF₃、β- AlF₃、γ- AlF₃With respect to kappa-AlF₃There are few reports in the literature.

Disclosure of Invention

In view of the above technical problems in the prior art, the present invention aims to provide a kappa-AlF₃A method for preparing the catalyst.

The kappa-AlF₃The preparation method of the catalyst is characterized by comprising the following steps: dissolving an aluminum source in a solvent to form a mixed solution, adding a fluorine source into the mixed solution, stirring and dissolving to form a colorless and transparent solution, then placing the solution in a hydrothermal kettle for hydrothermal reaction, cooling to room temperature after the reaction is finished, centrifugally separating the reaction liquid, washing the solid obtained by centrifugal separation with an ethanol water solution, drying, calcining and activating the dried solid to obtain the kappa-AlF₃A catalyst.

The kappa-AlF₃The preparation method of the catalyst is characterized in that the aluminum source is any one or a mixture of more than one of aluminum nitrate, aluminum chloride, aluminum acetylacetonate, aluminum isopropoxide, aluminum sulfate, aluminum hydroxide and aluminum acetate, preferably any one or a mixture of more than one of aluminum nitrate, aluminum acetylacetonate, aluminum isopropoxide and aluminum hydroxide.

The kappa-AlF₃The preparation method of the catalyst is characterized in that the fluorine source is NH₄BF₄、NH₄F、(NH₄)₂SiF₆、HF、HBF₄、NH₄HF₂Preferably NH, preferably₄BF₄、NH₄F、(NH₄)₂SiF₆One or a mixture of several of them.

The kappa-AlF₃The preparation method of the catalyst is characterized in that the solvent is one or a mixture of DMF, ethanol, glycol, glycerol, isopropanol, acetic acid and deionized water.

The above-mentionedA kappa-AlF₃Process for the preparation of a catalyst, characterized in that the kappa-AlF₃In the preparation process of the catalyst, a surfactant is also added into a solution which is placed in a hydrothermal kettle for hydrothermal reaction; the surfactant is sodium dodecyl benzene sulfonate, cetyl trimethyl ammonium bromide, sodium oleate or polyvinylpyrrolidone.

The kappa-AlF₃A process for producing a catalyst, characterized in that the molar ratio of the Al element in the aluminum source to the F element in the fluorine source is 3 to 15:1, preferably 5 to 10: 1.

The kappa-AlF₃The preparation method of the catalyst is characterized in that the temperature of the hydrothermal reaction is 100-180 ℃, and the time of the hydrothermal reaction is 1-48 h.

The kappa-AlF₃The preparation method of the catalyst is characterized in that the drying temperature is 50-120 ℃, and the drying time is 1-24 h.

The kappa-AlF₃The preparation method of the catalyst is characterized in that the calcination activation temperature is 300-500 ℃, and the calcination activation time is 3-10 h.

Compared with the prior art, the invention has the following beneficial effects:

compared with the conventional AlF₃The preparation process of the catalyst needs a later fluorination process, and the invention prepares the kappa-AlF₃The catalyst is synthesized in one step and has short operation period. The source of the aluminum source is wide, cheap and easily available, and the fluorine source does not adopt the traditional HF but adopts NH₄BF₄And the like, which are safer to operate. Without harsh preparation conditions, a product with special morphology is obtained by hydrothermal reaction of a hydrothermal kettle and self-assembly of particles, and then the product is roasted to obtain rare kappa-AlF₃Catalyst, kappa-AlF₃The catalyst has good repeatability. kappa-AlF synthesized by the method of the present invention₃The catalyst has higher catalytic activity in the reaction of catalyzing the cracking of fluorine-containing alkane to remove HF to prepare fluorine-containing olefin, and the kappa-AlF prepared by the invention₃The catalyst has high purity and regular and various appearance.

Drawings

FIG. 1a is a SEM characterization of the aluminum fluoride catalyst prepared in example 1;

FIG. 1b is a SEM characterization of the aluminum fluoride catalyst prepared in example 2;

FIG. 1c is a SEM characterization of the aluminum fluoride catalyst prepared in example 3;

FIG. 1d is a SEM characterization of the aluminum fluoride catalyst prepared in example 4;

FIG. 1e is a SEM characterization of the aluminum fluoride catalyst prepared in example 5;

FIG. 1f is a SEM characterization of the aluminum fluoride catalyst prepared in example 6;

FIG. 1g is a SEM characterization of the aluminum fluoride catalyst prepared in example 7;

FIG. 1h is a SEM characterization of the aluminum fluoride catalyst prepared in example 8;

figure 2 is a comparison of XRD characterization results for the aluminum fluoride catalyst prepared in example 5 ~ 7.

Detailed Description

The present invention is further illustrated by the following examples, which should not be construed as limiting the scope of the invention.