阅读说明：本技术 一种纳米级氟氯化钡催化剂及其制备方法和应用 (Nano-scale barium fluochloride catalyst and preparation method and application thereof ) 是由 韩文锋 俞威 刘永南 刘兵 李西良 杨虹 陆佳勤 陈爱民 唐浩东 李瑛� 于 2019-10-30 设计创作，主要内容包括：本发明公开了一种纳米级氟氯化钡催化剂的制备方法和应用。所述催化剂的制备过程为：先将含钡化合物磨碎备用,再将氟化剂和氯化剂按一定摩尔比例混合研磨均匀得到氟化剂和氯化剂混合粉末,氟化剂和氯化剂混合粉末与磨碎的含钡化合物混合均匀,并不断研磨反应得到粘稠混合物；粘稠混合物在110～120℃下烘5-7小时、再在马弗炉或氮气气氛下的管式炉中300～700℃焙烧5-6小时,得到纳米级氟氯化钡催化剂,过筛得纳米级氟氯化钡催化剂。其具有制备简单、转化率高、选择性好、稳定性高和不易积碳等特点,本发明将纳米级氟氯化钡应用于含氟氯烷烃气相脱HCl制备含氟烯烃的反应中,纳米级氟氯化钡显示了极高的活性和稳定性。(The invention discloses a preparation method and application of a nano barium fluochloride catalyst. The preparation process of the catalyst comprises the following steps: grinding barium-containing compounds for later use, mixing and uniformly grinding a fluorinating agent and a chlorinating agent according to a certain molar ratio to obtain mixed powder of the fluorinating agent and the chlorinating agent, uniformly mixing the mixed powder of the fluorinating agent and the chlorinating agent with the ground barium-containing compounds, and continuously grinding and reacting to obtain a viscous mixture; and drying the viscous mixture at 110-120 ℃ for 5-7 hours, roasting in a muffle furnace or a tubular furnace under nitrogen atmosphere at 300-700 ℃ for 5-6 hours to obtain the nano-scale barium fluochloride catalyst, and sieving to obtain the nano-scale barium fluochloride catalyst. The method has the characteristics of simple preparation, high conversion rate, good selectivity, high stability, difficult carbon deposition and the like, and the nano barium chlorofluoride is applied to the reaction of preparing the fluorine-containing olefin by removing HCl from the fluorine-containing chloroalkane gas phase, and shows extremely high activity and stability.)

1. A preparation method of a nano-scale barium fluochloride catalyst is characterized by comprising the following steps:

1) grinding: grinding barium-containing compounds for later use, mixing and uniformly grinding a fluorinating agent and a chlorinating agent according to a certain molar ratio to obtain mixed powder of the fluorinating agent and the chlorinating agent, uniformly mixing the mixed powder of the fluorinating agent and the chlorinating agent with the ground barium-containing compounds, continuously grinding until ammonia gas with pungent smell is not smelled, and finishing the reaction to obtain a viscous mixture;

2) drying: drying the viscous mixture obtained in the step 1) at 110-120 ℃ for 5-7 hours to obtain a catalyst, preferably 6 hours;

3) roasting: roasting the dried mixture obtained in the step 2) in a muffle furnace or a tubular furnace under nitrogen atmosphere at the temperature of 300-700 ℃ for 5-6 hours to obtain a nano barium fluochloride catalyst;

4) screening: sieving the catalyst roasted in the step 3), and screening out particles of 20-40 meshes to obtain the nano barium fluochloride catalyst.

2. The method for preparing a nano-sized barium chlorofluoride catalyst according to claim 1, wherein the barium-containing compound is one of barium oxide, barium hydroxide and barium hydroxide octahydrate; the fluorinating agent is one of ammonium fluoride, ammonium bifluoride and ammonium hexafluorosilicate; the chlorinating agent is ammonium chloride.

3. The preparation method of the nanoscale barium chlorofluoride catalyst according to claim 1 or 2, wherein the fluorinating agent is ammonium fluoride, and the molar ratio of the fluorinating agent to the chlorinating agent is 1-19: 1, the molar ratio of the barium compound to the sum of the fluorinating agent and the chlorinating agent is 2: 1.

4. the preparation method of the nanoscale barium chlorofluoride catalyst according to claim 1 or 2, wherein the fluorinating agent is ammonium bifluoride or ammonium hexafluorosilicate, and the molar ratio of the fluorinating agent to the chlorinating agent is 1-19: and 2, the molar amount of the barium-containing compound is the sum of 1 time of the molar amount of the fluorinating agent and 2 times of the molar amount of the chlorinating agent.

5. The method for preparing a nano-scale barium chlorofluoride catalyst according to claim 1, wherein the fluorinating agent and the chlorinating agent are mixed and ground uniformly to obtain mixed powder of the fluorinating agent and the chlorinating agent, and then the mixed powder is added.

6. A nanoscale barium chlorofluoride catalyst prepared according to the process of claim 1.

7. The use of the nanoscale barium chlorofluoride catalyst of claim 6 in the preparation of fluorine-containing olefins by cracking fluorine-containing alkanes to remove HCl.

8. The application of claim 6, wherein the reaction temperature for preparing the fluorine-containing olefin by cracking the fluorine-containing alkane to remove HCl is 250-400 ℃, and the reaction pressure is normal pressure.

9. Use according to claim 6, characterized in that the fluorine-containing alkane is 1, 1-difluoro-1-chloroethane and the fluorine-containing alkene is 1, 1-difluoroethylene.

Technical Field

The invention belongs to the technical field of chemical catalysts, and particularly relates to a nano-scale barium fluochloride catalyst and a preparation method and application thereof.

Background

At present, VDF is produced by a method of empty-tube thermal cracking mainly in industry, the pyrolysis temperature is generally between 600 ℃ and 800 ℃, the conversion rate of HCFC-142b is about 80-100%, and the selectivity of VDF is about 85-95%. However, a large amount of carbon deposits are generated in the high-temperature tubular reactor and cause clogging of the pipeline, and therefore, in order to improve safety and reaction efficiency, the plant must be periodically stopped to remove the carbon deposits; furthermore, thermal cracking is particularly energy intensive and produces a large amount of by-products at high temperatures.

The catalyst can reduce the reaction temperature of thermal cracking, save a large amount of energy consumption and reduce the generation of carbon deposition. At present, most of catalysts used in the reaction are activated carbon, metal oxides and metal fluorides, and all of the catalysts have good catalytic activity. However, the activated carbon catalyst is not easily regenerated, and the metal oxide and metal fluoride catalysts are easily reacted with hydrogen chloride to be quickly deactivated, so that the development of a catalyst resistant to chlorine in the reaction is of great significance.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention aims to provide a nano barium fluochloride catalyst and a preparation method and application thereof. The method has the advantages of short preparation period, high yield, high conversion rate and simple operation. The catalyst synthesized by the method has higher catalytic activity and stability in the reaction of removing HCl from fluorine-containing chloroalkane to prepare fluorine-containing olefin.

The preparation method of the nano barium fluochloride catalyst is characterized by comprising the following steps:

1) grinding: grinding barium-containing compounds for later use, mixing and uniformly grinding a fluorinating agent and a chlorinating agent according to a certain molar ratio to obtain mixed powder of the fluorinating agent and the chlorinating agent, uniformly mixing the mixed powder of the fluorinating agent and the chlorinating agent with the ground barium-containing compounds, continuously grinding until ammonia gas with pungent smell is not smelled, and finishing the reaction to obtain a viscous mixture;

2) drying: drying the viscous mixture obtained in the step 1) at 110-120 ℃ for 5-7 hours to obtain a catalyst, preferably 6 hours;

3) roasting: roasting the dried mixture obtained in the step 2) in a muffle furnace or a tubular furnace under nitrogen atmosphere at the temperature of 300-700 ℃ for 5-6 hours to obtain a nano barium fluochloride catalyst;

4) screening: sieving the catalyst roasted in the step 3), and screening out particles of 20-40 meshes to obtain the nano barium fluochloride catalyst.

The preparation method of the nano barium fluochloride catalyst is characterized in that the barium-containing compound is one of barium oxide, barium hydroxide and barium hydroxide octahydrate; the fluorinating agent is one of ammonium fluoride, ammonium bifluoride and ammonium hexafluorosilicate; the chlorinating agent is ammonium chloride.

The preparation method of the nano-scale barium chlorofluoride catalyst is characterized in that the fluorinating agent is ammonium fluoride, and the molar ratio of the fluorinating agent to the chlorinating agent is 1-19: 1, the molar ratio of the barium compound to the sum of the fluorinating agent and the chlorinating agent is 2: 1.

the preparation method of the nano-scale barium chlorofluoride catalyst is characterized in that the fluorinating agent is ammonium bifluoride or ammonium hexafluorosilicate, and the molar ratio of the fluorinating agent to the chlorinating agent is 1-19: and 2, the molar amount of the barium-containing compound is the sum of 1 time of the molar amount of the fluorinating agent and 2 times of the molar amount of the chlorinating agent.

The preparation method of the nano-scale barium fluochloride catalyst is characterized in that a fluorinating agent and a chlorinating agent are mixed and ground uniformly to obtain mixed powder of the fluorinating agent and the chlorinating agent, and then the mixed powder is added.

The nano barium fluochloride catalyst prepared by the method.

The nanometer barium chlorofluoride catalyst is applied to the reaction of preparing fluorine-containing olefin by cracking fluorine-containing alkane and removing HCl.

The application is characterized in that the reaction temperature for preparing the fluorine-containing olefin by cracking and removing HCl from the fluorine-containing alkane is 250-400 ℃, and the reaction pressure is normal pressure.

The application is characterized in that the fluorine-containing alkane is 1, 1-difluoro-1-chloroethane, and the fluorine-containing alkene is 1, 1-difluoroethylene.

By adopting the technology, compared with the prior art, the invention has the following beneficial effects:

the nano barium fluochloride catalyst is prepared by grinding, drying, roasting and screening, and the method has the advantages of short preparation period, high yield and conversion rate and simple operation; the obtained barium chlorofluoride catalyst has higher catalytic activity and stability in the reaction of preparing the fluorine-containing olefin by removing HCl from the gas phase of the fluorine-containing chloroalkane, the service life is prolonged, the chlorination speed of the catalyst in the reaction is greatly reduced, and carbon deposition and inactivation are not easy to occur.

Detailed Description

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