阅读说明：本技术 R142b加热裂解制备VDF用高性能催化剂的制备方法 (Preparation method of high-performance catalyst for preparing VDF (vertical double-diffused fluoride) by heating and cracking R142b ) 是由 李佳琦 朱灵运 张健 钱易 于 2021-08-05 设计创作，主要内容包括：本发明公开了R142b加热裂解制备VDF用高性能催化剂的制备方法,其包括以下步骤:(1)采用去离子水配置溶质为ZrOCl-(2)·8H-(2)O、Cu(NO-(3))-(2)·3H-(2)O和Fe(NO-(3))-(3)·9H-(2)O的混合溶液；(2)采用去离子水配置氨水,在搅拌条件下加入到混合溶液中,沉淀反应完成后静置,然后进行真空抽滤获得沉淀物；(3)使用去离子水沉淀物进行洗涤后,置于烘箱中干燥,然后焙烧制得ZrO-(2)-CuO-Fe-(2)O-(3)；(4)使用硝酸钯溶液对ZrO-(2)-CuO-Fe-(2)O进行等体积浸渍,干燥,然后把催化剂前驱体焙烧,经机械处理后制得催化剂Pd/ZrO-(2)-CuO-Fe-(2)O-(3)；本发明的制备方法不仅保证了反应转化率和选择性在实现工业化生产时的可操作性,同时也较大幅度的降低了反应温度(350～400℃)。(The invention discloses a preparation method of a high-performance catalyst for VDF (vertical double-walled carbon fiber) prepared by heating and cracking R142b, which comprises the following steps of (1) preparing ZrOCl serving as solute by deionized water 2 ·8H 2 O、Cu(NO 3 ) 2 ·3H 2 O and Fe (NO) 3 ) 3 ·9H 2 A mixed solution of O; (2) preparing ammonia water by using deionized water, adding the ammonia water into the mixed solution under the condition of stirring, standing the mixed solution after the precipitation reaction is finished, and then carrying out vacuum filtration to obtain the catalystA precipitate; (3) washing the precipitate with deionized water, drying in a baking oven, and calcining to obtain ZrO 2 ‑CuO‑Fe 2 O 3 (ii) a (4) ZrO Using Palladium nitrate solution 2 ‑CuO‑Fe 2 Soaking O in the same volume, drying, roasting the catalyst precursor, and mechanically treating to obtain the catalyst Pd/ZrO 2 ‑CuO‑Fe 2 O 3 (ii) a The preparation method provided by the invention not only ensures the operability of reaction conversion rate and selectivity in industrial production, but also greatly reduces the reaction temperature (350-400 ℃).)

The preparation method of the high-performance catalyst for preparing VDF by heating and cracking R142b is characterized by comprising the following steps:

(1) preparing ZrOCl as solute by using deionized water₂·8H₂O、Cu(NO₃)₂·3H₂O and Fe (NO)₃)₃·9H₂Mixed solution of O, ZrOCl in the mixed solution₂0.5 to 8 mass percent of (C), Cu (NO)₃)₂0.5-12% by weight of Fe (NO)₃)₃The mass fraction of the solute is 1-30%, the ratio of the solute to the metal elements is n (Cu), n (Zr) is 1-10, n (Fe) is n (Cu) is 1-10;

(2) preparing ammonia water with the concentration of 4-10 mol/L by using deionized water, adding the ammonia water into the mixed solution under the stirring condition, standing the mixed solution after the precipitation reaction is finished, and then carrying out vacuum filtration to obtain a precipitate;

(3) washing the precipitate in the step (2) by using deionized water, drying in an oven, and roasting to obtain ZrO₂-CuO-Fe₂O₃；

(4) ZrO Using Palladium nitrate solution₂-CuO-Fe₂Soaking O in the same volume, drying in a drying oven, roasting the catalyst precursor to obtain solid matter, and mechanically treating to obtain the catalyst Pd/ZrO₂-CuO-Fe₂O₃。

2. The method for preparing the high-performance catalyst for preparing VDF from R142b through thermal cracking according to claim 1, wherein the method comprises the following steps: in the step (2), the pH value of the ammonia water in the process of adding the ammonia water into the mixed solution under the stirring condition is 7-10.

3. The method for preparing the high-performance catalyst for preparing VDF from R142b through thermal cracking according to claim 1, wherein the method comprises the following steps: in the step (2), the reaction mixture was allowed to stand for 6 hours after completion of the precipitation reaction.

4. The method for preparing the high-performance catalyst for preparing VDF from R142b through thermal cracking according to claim 1, wherein the method comprises the following steps: in the step (3), the drying temperature of the oven is 70-120 ℃, and the drying time is 12 hours.

5. The method for preparing the high-performance catalyst for preparing VDF from R142b through thermal cracking according to claim 1, wherein the method comprises the following steps: in the step (3), the roasting temperature is 400-800 ℃, and the roasting time is 3-10 h.

6. The method for preparing the high-performance catalyst for preparing VDF from R142b through thermal cracking according to claim 1, wherein the method comprises the following steps: in the step (4), the mass concentration of the palladium nitrate solution is 0.5-5%.

7. The method for preparing the high-performance catalyst for preparing VDF from R142b through thermal cracking according to claim 1, wherein the method comprises the following steps: in the step (4), the drying temperature of the solid matter after the impregnation is 70-120 ℃, and the solid matter is dried for 12 hours.

8. The method for preparing the high-performance catalyst for preparing VDF from R142b through thermal cracking according to claim 1, wherein the method comprises the following steps: in the step (4), the roasting temperature is 400-900 ℃, and the roasting time is 4-10 h.

9. The method for preparing the high-performance catalyst for preparing VDF from R142b through thermal cracking according to claim 1, wherein the method comprises the following steps: in the above-mentionedIn the step (4), the solid matter of the catalyst precursor after roasting is ground, tableted, crushed and sieved to prepare the 5-30-mesh catalyst Pd/ZrO₂-CuO-Fe₂O₃。

Technical Field

The invention relates to a preparation method of a high-performance catalyst for preparing VDF (vertical double-walled carbon fiber) by heating and cracking R142b, which is used for preparing the high-performance catalyst and is used for preparing the VDF by heating and cracking R142 b.

Background

VDF is one of the important monomers widely applied in the field of fluorine chemicals, and is the main raw material for synthesizing polyvinylidene fluoride (PVDF). Polyvinylidene fluoride is a fluoropolymer functional material with excellent comprehensive performance, has the advantages of strong high-temperature resistance, strong mechanical strength and the like due to stable chemical performance, and is widely applied to high-end scientific and technological fields such as lithium batteries, semiconductors, aerospace and the like. Currently, the worldwide production of vinylidene fluoride from fluoromonomers is second only to tetrafluoroethylene.

Worldwide research on the synthetic process of VDF begins in the beginning of the last century, and a plurality of synthetic processes have been formed and successfully applied to industrial mass production to date, wherein the process route for preparing VDF by R142b high-temperature air tube cracking is still the first choice of many production enterprises. The process has the advantages of simple preparation process, readily available reaction raw material R142b and good reaction selectivity, but the temperature in the reaction process is as high as 700-900 ℃, and the obvious defects of easy coking of a reaction tube section, high reaction energy consumption and the like exist. In recent years, the improvement and optimization of the process become research hotspots at home and abroad, and the most common optimization scheme is to add a catalyst in the reaction process to improve the activity of the R142b in the cracking reaction.

The patent document EP0461297A1 discloses a method for preparing VDF by high-temperature catalytic cracking R142b, namely Cr is adopted in the preparation process₂O₃/Al₂O₃As a catalyst for the reaction, the catalyst is prepared by using Al as a carrier₂O₃Soaking in soluble chromium salt solution, and performing subsequent treatment. Research shows that Cr is adopted in the reaction process₂O₃/Al₂O₃As a catalyst, at the reaction temperatureWhen the temperature is 400-550 ℃, the residence time of R142b in the reactor is 5-20 s, the conversion rate of R142b is 74-98%, but the selectivity of VDF generation is lower than 15%.

The patent document EP0407711A1 also discloses a process for preparing VDF by the high-temperature catalytic cracking of R142b, for NiF₂/AlF₃And NiCl₂/Al₂O₃The catalytic performance of the catalyst in the reaction process is studied. The former being Al₂O₃Hydrofluoric acid solution and NiCl₂Three substances are prepared, the latter is made of NiCl₂Loaded on gamma-Al₂O₃Is prepared by the above steps. When the two catalysts are respectively adopted in the reaction process, the reaction conversion rate is higher than 90% at the reaction temperature of 400-600 ℃, but the selectivity of the VDF is only 20% -50%.

It can be seen that although the addition of catalyst during the reaction of R142b pyrolysis to prepare VDF helps to lower the reaction temperature, the selectivity of VDF is not ideal, so it becomes crucial to develop a new high performance catalyst.

Disclosure of Invention

The invention aims to solve the technical problem of providing a preparation method of a high-performance catalyst for preparing VDF by heating and cracking R142b, and solving the problems of low activity, low VDF selectivity and the like in the reaction process.

In order to solve the technical problem, the preparation method of the high-performance catalyst for preparing VDF by heating and cracking R142b comprises the following steps:

(1) preparing ZrOCl as solute by using deionized water₂·8H₂O、Cu(NO₃)₂·3H₂O and Fe (NO)₃)₃·9H₂Mixed solution of O, ZrOCl in the mixed solution₂0.5 to 8 mass percent of (C), Cu (NO)₃)₂0.5-12% by weight of Fe (NO)₃)₃The mass fraction of the solute is 1-30%, the ratio of the solute to the metal element is n (Cu), n (Zr) is 1-10, n (Fe) is n (Cu) is 1-10.

(2) Preparing ammonia water with the concentration of 4-10 mol/L by using deionized water, adding the ammonia water into the mixed solution under the stirring condition, standing the mixed solution (for example, standing for 6 hours) after the precipitation reaction is finished, and then carrying out vacuum filtration to obtain a precipitate. Specifically, the pH value of the ammonia water in the process of adding the ammonia water into the mixed solution under the stirring condition is 7-10.

(3) Washing the precipitate in the step (2) by using deionized water, drying in a drying oven, and then roasting in a muffle furnace to obtain ZrO₂-CuO-Fe₂O₃. Preferably, the drying temperature of the oven is 70-120 ℃, the drying time is 12 hours, the roasting temperature in the muffle furnace is 400-800 ℃, and the roasting time is 3-10 hours.

(4) ZrO Using Palladium nitrate solution₂-CuO-Fe₂Soaking O in the same volume, drying in a drying oven, calcining the catalyst precursor in a muffle furnace to obtain solid matter, and mechanically treating to obtain the catalyst Pd/ZrO₂-CuO-Fe₂O₃. Preferably, the mass concentration of the palladium nitrate solution is 0.5-5%. And drying the solid matter after the impregnation at the drying temperature of 70-120 ℃ for 12 hours, wherein the roasting temperature in the muffle furnace is 400-900 ℃ and the roasting time is 4-10 hours.

Specifically, the solid matter of the catalyst precursor after roasting is ground, tableted, crushed and sieved to prepare the 5-30-mesh catalyst Pd/ZrO₂-CuO-Fe₂O₃。

The preparation method provided by the invention not only ensures the operability of reaction conversion rate and selectivity in industrial production, but also greatly reduces the reaction temperature (350-400 ℃).

Detailed Description

Example 1

Preparing ZrOCl as solute by using deionized water₂·8H₂O、Cu(NO₃)₂·3H₂O and Fe (NO)₃)₃·9H₂And the mass concentration of the mixed solution of O is 1 percent, 2 percent and 15 percent in sequence. Preparing 8mol/L ammonia water solution with deionized water, slowly adding into the solution under stirring, and controlling pH of the whole mixed solutionAround 8. Standing for 6 hours after the precipitate is completely precipitated, then carrying out vacuum filtration to obtain a precipitate, washing the precipitate for 3 times by using deionized water, then drying the precipitate in a drying oven at 100 ℃ for 12 hours, and roasting the dried precipitate in a muffle furnace at 600 ℃ for 7 hours to obtain ZrO₂-CuO-Fe₂O₃And (3) a solid. Adopts 1 percent of palladium nitrate to ZrO₂-CuO-Fe₂O₃Soaking the solid in the same volume, drying in an oven at 100 deg.C for 12 hr, calcining in a muffle furnace at 500 deg.C for 5 hr, grinding, tabletting, pulverizing, and sieving to obtain 10-mesh Pd/ZrO catalyst₂-CuO-Fe₂O₃。

The reactor type for preparing VDF by heating and catalytic cracking of R142b adopts a small fixed bed reaction device, and the catalyst is filled in a pure nickel tube of DN15, and the reaction pressure is normal pressure. When the reaction temperature is 400 ℃, the space velocity of the gas phase R142b is 700h^-1Then (c) is performed. According to the calculation of the gas chromatography detection result of the materials after the reaction is finished, the conversion rate of R142b is 65.1%, and the selectivity of VDF is 75.8%.

Example 2

Preparing ZrOCl as solute by using deionized water₂·8H₂O、Cu(NO₃)₂·3H₂O and Fe (NO)₃)₃·9H₂The mass concentration of the mixed solution of O is 2 percent, 5 percent and 18 percent in sequence. Deionized water is adopted to prepare an ammonia water solution with the concentration of 7mol/L, and the ammonia water solution is slowly added into the solution under the stirring condition, wherein the PH of the whole mixed solution needs to be controlled at about 8 in the process. Standing for 6 hours after the precipitate is completely precipitated, then carrying out vacuum filtration to obtain a precipitate, washing the precipitate for 3 times by using deionized water, then drying the precipitate in a drying oven at 100 ℃ for 12 hours, and roasting the dried precipitate in a muffle furnace at 550 ℃ for 7 hours to obtain ZrO₂-CuO-Fe₂O₃And (3) a solid. Adopts palladium nitrate with the mass concentration of 1.5 percent to ZrO₂-CuO-Fe₂O₃Soaking the solid in the same volume, drying in an oven at 100 deg.C for 12 hr, calcining in a muffle furnace at 500 deg.C for 5 hr, grinding, tabletting, pulverizing, and sieving to obtain 15-mesh catalystCatalyst Pd/ZrO₂-CuO-Fe₂O₃。

The reactor type for preparing VDF by heating and catalytic cracking of R142b adopts a small fixed bed reaction device, and the catalyst is filled in a pure nickel tube of DN15, and the reaction pressure is normal pressure. When the reaction temperature is 400 ℃, the space velocity of the gas phase R142b is 700h^-1Then (c) is performed. According to the calculation of the gas chromatography detection result of the materials after the reaction is finished, the conversion rate of R142b is 68.5%, and the selectivity of VDF is 82.2%.

Example 3

Preparing ZrOCl as solute by using deionized water₂·8H₂O、Cu(NO₃)₂·3H₂O and Fe (NO)₃)₃·9H₂The mass concentration of the mixed solution of O is 3 percent, 6 percent and 20 percent in sequence. Deionized water is adopted to prepare an ammonia water solution with the concentration of 8mol/L, and the ammonia water solution is slowly added into the solution under the stirring condition, wherein the PH of the whole mixed solution needs to be controlled at about 8 in the process. Standing for 6 hours after the precipitate is completely precipitated, then carrying out vacuum filtration to obtain a precipitate, washing the precipitate for 3 times by using deionized water, then drying the precipitate in a drying oven at 100 ℃ for 12 hours, and roasting the dried precipitate in a muffle furnace at 500 ℃ for 7 hours to obtain ZrO₂-CuO-Fe₂O₃And (3) a solid. Adopts palladium nitrate with the mass concentration of 1.5 percent to ZrO₂-CuO-Fe₂O₃Soaking the solid in the same volume, drying in an oven at 100 deg.C for 12 hr, calcining in a muffle furnace at 500 deg.C for 5 hr, grinding, tabletting, pulverizing, and sieving to obtain 15-mesh Pd/ZrO catalyst₂-CuO-Fe₂O₃。

The reactor type for preparing VDF by heating and catalytic cracking of R142b adopts a small fixed bed reaction device, and the catalyst is filled in a pure nickel tube of DN15, and the reaction pressure is normal pressure. When the reaction temperature is 400 ℃, the space velocity of the gas phase R142b is 750h^-1Then (c) is performed. According to the gas chromatography detection result of the materials after the reaction is finished, the conversion rate of R142b is 70.8%, and the selectivity of VDF is 84.6%.

Example 4

Using deionized waterThe solute is ZrOCl₂·8H₂O、Cu(NO₃)₂·3H₂O and Fe (NO)₃)₃·9H₂The mass concentration of the mixed solution of O is 4 percent, 6 percent and 20 percent in sequence. Deionized water is adopted to prepare an ammonia water solution with the concentration of 8mol/L, and the ammonia water solution is slowly added into the solution under the stirring condition, wherein the PH of the whole mixed solution needs to be controlled at about 8 in the process. Standing for 6 hours after the precipitate is completely precipitated, then carrying out vacuum filtration to obtain a precipitate, washing the precipitate for 3 times by using deionized water, then drying the precipitate in a drying oven at 100 ℃ for 12 hours, and roasting the dried precipitate in a muffle furnace at 600 ℃ for 7 hours to obtain ZrO₂-CuO-Fe₂O₃And (3) a solid. Adopts 2 percent palladium nitrate to ZrO₂-CuO-Fe₂O₃Soaking the solid in the same volume, drying in an oven at 100 deg.C for 12 hr, calcining in a muffle furnace at 500 deg.C for 5 hr, grinding, tabletting, pulverizing, and sieving to obtain 10-mesh Pd/ZrO catalyst₂-CuO-Fe₂O₃。

The reactor type for preparing VDF by heating and catalytic cracking of R142b adopts a small fixed bed reaction device, and the catalyst is filled in a pure nickel tube of DN15, and the reaction pressure is normal pressure. When the reaction temperature is 400 ℃, the space velocity of the gas phase R142b is 750h^-1Then (c) is performed. According to the gas chromatography detection result of the materials after the reaction is finished, the conversion rate of R142b is 71.8%, and the selectivity of VDF is 85.9%.

Example 5

Preparing ZrOCl as solute by using deionized water₂·8H₂O、Cu(NO₃)₂·3H₂O and Fe (NO)₃)₃·9H₂And the mass concentration of the mixed solution of O is 5 percent, 7 percent and 20 percent in sequence. Deionized water is adopted to prepare an ammonia water solution with the concentration of 7mol/L, and the ammonia water solution is slowly added into the solution under the stirring condition, wherein the PH of the whole mixed solution needs to be controlled at about 8 in the process. Standing for 6 hr after precipitation, vacuum filtering to obtain precipitate, washing with deionized water for 3 times, drying in 100 deg.C oven for 12 hr, and roasting in 650 deg.C muffle furnace for 7 hrThereby obtaining ZrO₂-CuO-Fe₂O₃And (3) a solid. Adopts 2 percent palladium nitrate to ZrO₂-CuO-Fe₂O₃Soaking the solid in the same volume, drying in an oven at 100 deg.C for 12 hr, calcining in a muffle furnace at 600 deg.C for 5 hr, grinding, tabletting, pulverizing, and sieving to obtain 10-mesh Pd/ZrO catalyst₂-CuO-Fe₂O₃。

The reactor type for preparing VDF by heating and catalytic cracking of R142b adopts a small fixed bed reaction device, and the catalyst is filled in a pure nickel tube of DN15, and the reaction pressure is normal pressure. When the reaction temperature is 450 ℃, the space velocity of the gas phase R142b is 750h^-1Then (c) is performed. According to the gas chromatography detection result of the materials after the reaction is finished, the conversion rate of R142b is 73.3%, and the selectivity of VDF is 86.8%.

Example 6

Preparing ZrOCl as solute by using deionized water₂·8H₂O、Cu(NO₃)₂·3H₂O and Fe (NO)₃)₃·9H₂And the mass concentration of the O mixed solution is 6 percent, 7 percent and 22 percent in sequence. Deionized water is adopted to prepare an ammonia water solution with the concentration of 7mol/L, the ammonia water solution is slowly added into the solution under the stirring condition, and the PH of the mixed solution needs to be controlled to be about 8 in the process. Standing for 6 hours after the precipitate is completely precipitated, then carrying out vacuum filtration to obtain a precipitate, washing the precipitate for 3 times by using deionized water, then drying the precipitate in a drying oven at 100 ℃ for 12 hours, and roasting the dried precipitate in a muffle furnace at 600 ℃ for 7 hours to obtain ZrO₂-CuO-Fe₂O₃And (3) a solid. Adopts 2 percent palladium nitrate to ZrO₂-CuO-Fe₂O₃Soaking the solid in the same volume, drying in an oven at 100 deg.C for 12 hr, calcining in a muffle furnace at 600 deg.C for 5 hr, grinding, tabletting, pulverizing, and sieving to obtain 20-mesh Pd/ZrO catalyst₂-CuO-Fe₂O₃。

The reactor type of R142b for preparing VDF by heating and catalytic cracking adopts a small fixed bed reaction device, and the catalyst is filled in DN15The reaction pressure in the pure nickel tube is normal pressure. When the reaction temperature is 400 ℃, the space velocity of the gas phase R142b is 750h^-1Then (c) is performed. According to the gas chromatography detection result of the materials after the reaction is finished, the conversion rate of R142b is 75.6%, and the selectivity of VDF is 88.9%.

Example 7

Preparing ZrOCl as solute by using deionized water₂·8H₂O、Cu(NO₃)₂·3H₂O and Fe (NO)₃)₃·9H₂The mass concentration of the O mixed solution is 6 percent, 7 percent and 18 percent in sequence. Deionized water is adopted to prepare an ammonia water solution with the concentration of 7mol/L, the ammonia water solution is slowly added into the solution under the stirring condition, and the PH of the mixed solution needs to be controlled to be about 8 in the process. Standing for 6 hours after the precipitate is completely precipitated, then carrying out vacuum filtration to obtain a precipitate, washing the precipitate for 3 times by using deionized water, then drying the precipitate in a drying oven at 100 ℃ for 12 hours, and roasting the dried precipitate in a muffle furnace at 550 ℃ for 7 hours to obtain ZrO₂-CuO-Fe₂O₃And (3) a solid. Adopts 2 percent palladium nitrate to ZrO₂-CuO-Fe₂O₃Soaking the solid in the same volume, drying in an oven at 100 deg.C for 12 hr, calcining in a muffle furnace at 500 deg.C for 5 hr, grinding, tabletting, pulverizing, and sieving to obtain 20-mesh Pd/ZrO catalyst₂-CuO-Fe₂O₃。

The reactor type for preparing VDF by heating and catalytic cracking of R142b adopts a small fixed bed reaction device, and the catalyst is filled in a pure nickel tube of DN15, and the reaction pressure is normal pressure. When the reaction temperature is 350 ℃, the space velocity of the gas phase R142b is 700h^-1Then (c) is performed. According to the gas chromatography detection result of the materials after the reaction is finished, the conversion rate of R142b is 71.8%, and the selectivity of VDF is 82.7%.

Example 8

Preparing ZrOCl as solute by using deionized water₂·8H₂O、Cu(NO₃)₂·3H₂O and Fe (NO)₃)₃·9H₂And the mass concentration of the O mixed solution is 7 percent, 8 percent and 22 percent in sequence.Deionized water is adopted to prepare an ammonia water solution with the concentration of 8mol/L, the ammonia water solution is slowly added into the solution under the stirring condition, and the PH of the mixed solution needs to be controlled to be about 8 in the process. Standing for 6 hours after the precipitate is completely precipitated, then carrying out vacuum filtration to obtain a precipitate, washing the precipitate for 3 times by using deionized water, then drying the precipitate in a drying oven at 100 ℃ for 12 hours, and roasting the dried precipitate in a muffle furnace at 550 ℃ for 7 hours to obtain ZrO₂-CuO-Fe₂O₃And (3) a solid. Adopts 3 percent palladium nitrate to ZrO₂-CuO-Fe₂O₃Soaking the solid in the same volume, drying in an oven at 100 deg.C for 12 hr, calcining in a muffle furnace at 500 deg.C for 5 hr, grinding, tabletting, pulverizing, and sieving to obtain 20-mesh Pd/ZrO catalyst₂-CuO-Fe₂O₃。

The reactor type for preparing VDF by heating and catalytic cracking of R142b adopts a small fixed bed reaction device, and the catalyst is filled in a pure nickel tube of DN15, and the reaction pressure is normal pressure. When the reaction temperature is 350 ℃, the space velocity of the gas phase R142b is 700h^-1Then (c) is performed. According to the calculation of the gas chromatography detection result of the materials after the reaction is finished, the conversion rate of R142b is 73.2%, and the selectivity of VDF is 83.6%.

Example 9

Preparing ZrOCl as solute by using deionized water₂·8H₂O、Cu(NO₃)₂·3H₂O and Fe (NO)₃)₃·9H₂And the mass concentration of the mixed solution of O is 8 percent, 10 percent and 25 percent in sequence. Deionized water is adopted to prepare an ammonia water solution with the concentration of 8mol/L, the ammonia water solution is slowly added into the solution under the stirring condition, and the PH of the mixed solution needs to be controlled to be about 8 in the process. Standing for 6 hours after the precipitate is completely precipitated, then carrying out vacuum filtration to obtain a precipitate, washing the precipitate for 3 times by using deionized water, then drying the precipitate in a drying oven at 100 ℃ for 12 hours, and roasting the dried precipitate in a muffle furnace at 550 ℃ for 7 hours to obtain ZrO₂-CuO-Fe₂O₃And (3) a solid. Adopts 2 percent palladium nitrate to ZrO₂-CuO-Fe₂O₃Soaking the solid in the same volume, and oven drying at 100 deg.CDrying for 12 hours, then roasting for 5 hours in a muffle furnace at 500 ℃, grinding, tabletting, crushing and sieving the obtained solid matter to obtain the 20-mesh catalyst Pd/ZrO₂-CuO-Fe₂O₃。

The reactor type for preparing VDF by heating and catalytic cracking of R142b adopts a small fixed bed reaction device, and the catalyst is filled in a pure nickel tube of DN15, and the reaction pressure is normal pressure. When the reaction temperature is 330 ℃, the space velocity of the gas phase R142b is 700h^-1Then (c) is performed. According to the gas chromatography detection result of the materials after the reaction is finished, the conversion rate of R142b is 67.4%, and the selectivity of VDF is 80.2%.

Example 10

Preparing ZrOCl as solute by using deionized water₂·8H₂O、Cu(NO₃)₂·3H₂O and Fe (NO)₃)₃·9H₂The mass concentration of the mixed solution of O is 8 percent, 12 percent and 25 percent in sequence. Deionized water is adopted to prepare an ammonia water solution with the concentration of 8mol/L, the ammonia water solution is slowly added into the solution under the stirring condition, and the PH of the mixed solution needs to be controlled to be about 8 in the process. Standing for 6 hours after the precipitate is completely precipitated, then carrying out vacuum filtration to obtain a precipitate, washing the precipitate for 3 times by using deionized water, then drying the precipitate in a drying oven at 100 ℃ for 12 hours, and roasting the dried precipitate in a muffle furnace at 600 ℃ for 7 hours to obtain ZrO₂-CuO-Fe₂O₃And (3) a solid. Adopts 2 percent palladium nitrate to ZrO₂-CuO-Fe₂O₃Soaking the solid in the same volume, drying in an oven at 100 deg.C for 12 hr, calcining in a muffle furnace at 500 deg.C for 5 hr, grinding, tabletting, pulverizing, and sieving to obtain 20-mesh Pd/ZrO catalyst₂-CuO-Fe₂O₃。

The reactor type for preparing VDF by heating and catalytic cracking of R142b adopts a small fixed bed reaction device, and the catalyst is filled in a pure nickel tube of DN15, and the reaction pressure is normal pressure. When the reaction temperature is 350 ℃, the space velocity of the gas phase R142b is 700h^-1Then (c) is performed. The conversion rate of R142b can be calculated according to the gas chromatography detection result of the materials after the reaction is finishedThe selectivity to VDF was 76.7% and 86.5%.

The experimental results of the examples 1 to 10 show that when the high-performance catalyst of the invention is used, the conversion rate and selectivity of the VDF prepared by heating and catalytic cracking R142b in a lower temperature range (350 to 400 ℃) can basically meet the industrial requirements.

The above embodiments do not limit the present invention in any way, and all technical solutions obtained by means of equivalent substitution or equivalent transformation fall within the protection scope of the present invention.