A Cu / HOF-Co catalyst for acetylene hydrochlorination reaction and its preparation method and application

Abstract

The present invention discloses a Cu / HOF-Co catalyst for acetylene hydrochlorination reaction, a preparation method and an application thereof. The Cu / HOF-Co catalyst comprises a carrier and a copper active component loaded on the carrier, wherein the carrier is a Co-doped hydrogen-bonded organic framework, denoted as HOF-Co. The present invention provides an application of the Cu / HOF-Co catalyst in the reaction of synthesizing vinyl chloride by acetylene hydrochlorination, which exhibits good catalytic activity and stability.

Description

Technical Field

[0001] The invention belongs to the technical field of catalysts, and in particular relates to a supported copper catalyst and a preparation method thereof, and application thereof in catalyzing acetylene hydrochlorination reaction. Background Art

[0002] In terms of metal active components, the most mature non-mercury catalysts in the industry are mainly precious metal catalysts, such as gold, palladium, ruthenium, etc. Although they have certain advantages in reaction activity, they are difficult to regenerate after deactivation and their high prices bring great cost pressure to the industrial production of vinyl chloride. Due to cost and other issues, there are still no reports of large-scale applications. Therefore, the development of non-precious metal catalysts represented by copper-based catalysts is imperative. Non-precious metal catalysts have the advantage of relatively low prices, but their activity and stability are far behind those of precious metal catalysts, and further optimization and development are needed.

[0003] In terms of catalyst carrier, most acetylene hydrochlorination catalysts use activated carbon as carrier, which has low mechanical strength and poor regeneration performance. Therefore, some researchers use molecular sieves, metal oxides, metal-organic framework compounds or hydrogen bonded organic frameworks (HOF) as carriers.

[0004] Among them, hydrogen-bonded organic framework (HOF) refers to an organic molecular skeleton composed of hydrogen bonds. Hydrogen bond is a weak interaction force, which refers to a non-covalent bond formed by the electronegativity difference between hydrogen atoms and adjacent atoms such as nitrogen, oxygen, and fluorine. Hydrogen bonds formed between or within molecules can affect the properties and structure of substances. Hydrogen-bonded organic frameworks have certain stability and rigidity, and can form a variety of stereo conformations and molecular combinations. Therefore, it has a wide range of applications in drug design and chemical reaction history. For example, hydrogen-bonded organic frameworks can be used to construct efficient chemical catalysts, prepare new drug molecules and functional materials, etc. The study of hydrogen-bonded organic frameworks is also a hot topic in the field of organic chemistry. People have explored new reaction modes and compounds through the study of different hydrogen bonds. At the same time, studying the structure and properties of hydrogen-bonded organic frameworks can also help people to deeply understand the laws of intermolecular interactions, and also provide us with ideas for the development of catalyst carriers in acetylene hydrochlorination reactions.

[0005] In domestic and foreign research, the mercury-free catalyst disclosed in patent CN201010248348.4 uses molecular sieves such as MCM-41 as carriers and precious metal ruthenium trichloride as an active component. The mercury-free catalyst disclosed in patent CN201110257696.2 uses HZSM-5, NaZSM-5, mordenite, Hβ and HY molecular sieves as carriers, and precious metal palladium halides and complexes as active components. The mercury-free catalyst disclosed in patent CN201310124706.4 uses molecular sieves, silica or alumina as carriers, Pt and Cu as main active components, and alkaline earth metals and alkaline earth metals as additives. The mercury-free catalyst disclosed in patent CN201910221548.1 uses metal organic framework materials with pyridine nitrogen as carriers, and pyridine nitrogen and copper ions as active components.

[0006] Patent CN201110040369.1 reports a mercury-free catalyst with activated carbon as a carrier and Cu2P-CuCl2 as an active component. Copper chloride and hypophosphite are prepared into a solution with deionized water at room temperature, and the solution is impregnated into the activated carbon carrier. The copper-based catalyst is obtained after drying and roasting. However, when the catalyst is used for acetylene hydrochlorination at 170°C, the acetylene conversion rate is only 64% and the vinyl chloride selectivity is 53%. The problem of low activity and selectivity has not been solved.

[0007] Patent CN201711154986.8 reported that FAU type silicon aluminum molecular sieve was used as the carrier, and the active component was CuCl2. Copper chloride was dissolved in deionized water or anhydrous ethanol; the copper chloride solution was impregnated on the molecular sieve according to the calculated ratio; and the prepared catalyst was placed in a 100-150℃ oven to dry to obtain the catalyst. However, since stannous chloride is very easy to volatilize and lose during the reaction, the stability of the catalyst is not strong and cannot meet the requirements of industrialization.

[0008] In summary, the activity and stability of mercury-free catalysts used in acetylene hydrochlorination reactions are still difficult to meet industrial requirements. Although methods such as adding metal additives, stabilizers, and using ionic liquids as impregnation liquids can improve activity, the stability problem is difficult to solve. In addition, most acetylene hydrochlorination catalysts use activated carbon as a carrier, which has low mechanical strength and poor regeneration performance. As a result, the catalyst pores will collapse and sinter during long-term use, resulting in catalyst loss and serious pollution to the environment. Therefore, it is of great industrial application value to develop a cheap, effective, durable and environmentally friendly non-precious metal catalyst to replace the existing acetylene hydrochlorination catalyst. Summary of the invention

[0009] The present invention aims to solve the problems of poor acetylene conversion rate and poor catalyst stability in acetylene hydrochlorination reaction of copper catalyst, and provide a Cu / HOF-Co catalyst and a preparation method thereof and application in acetylene hydrochlorination reaction to synthesize vinyl chloride. The application of the catalyst in acetylene hydrochlorination reaction to synthesize vinyl chloride shows good catalytic activity and stability.

[0010] In order to achieve the above-mentioned invention object, the present invention adopts the following technical scheme:

[0011] In a first aspect, the present invention provides a Cu / HOF-Co catalyst for acetylene hydrochlorination reaction, wherein the Cu / HOF-Co catalyst comprises a carrier and a copper active component loaded on the carrier, wherein the carrier is a Co-doped hydrogen-bonded organic framework, denoted as HOF-Co, and the specific synthesis method of the carrier is as follows:

[0012] Step 1: Add 4,4'-bipyridine, Na2S, and S into deionized water and mix thoroughly to form a mixed solution;

[0013] Step 2: Transfer the mixed solution obtained in step 1 to an autoclave with a polytetrafluoroethylene liner and perform hydrothermal treatment at 140-160° C. for 60-84 hours;

[0014] Step 3: Cool the mixed solution obtained in step 2 to 60-80°C and transfer it into a sealed glass bottle;

[0015] Step 4: Add the Co compound to the mixed solution obtained in step 3, stir for 1-3 hours and then filter;

[0016] Step 5: crystallize the filtrate obtained in step 4 at 20-40° C. for 10-12 hours in an air atmosphere or under vacuum conditions to obtain a crystal, which is a doped hydrogen-bonded organic framework HOF-Co.

[0017] Furthermore, in step 1, ultrasound is first applied followed by stirring to achieve uniform mixing to form a mixed solution.

[0018] Furthermore, in step 4, the Co compound is at least one of CoCl2, Co(NO3)2, CoSO4, and (NH4)2C2O4.

[0019] Furthermore, the molar ratio of 4,4'-bipyridine, Na2S, S, and Co compound is 2.23:2.53:2.53:2.25.

[0020] In the Cu / HOF-Co catalyst of the present invention, the copper active component can adopt the copper active component of the conventional supported copper catalyst used for acetylene hydrochlorination reaction, and the loading amount of the copper active component also uses the conventional loading amount, for example, the loading amount of the copper active component (calculated according to the feed mass ratio of copper element to carrier) is generally 0.2 to 10 wt%.

[0021] In a second aspect, the present invention provides a method for preparing a Cu / HOF-Co catalyst for acetylene hydrochlorination reaction, comprising the following steps: dissolving a divalent copper precursor in a solvent to obtain an active component solution; loading the divalent copper precursor onto a Co-doped hydrogen-bonded organic framework by a solution impregnation method, vacuum drying the solution, and then treating the solution with a glow discharge method to improve the dispersion of the Cu active component and inhibit its agglomeration, thereby obtaining a Cu / HOF-Co catalyst.

[0022] Preferably, the divalent copper precursor is selected from at least one of Cu(BF4)2, Cu(NO3)2, CuSO4, CuCl2, Cu3(PO4)2, and Cu2P2O7.

[0023] Preferably, the solvent is a mixture of one or more of deionized water, anhydrous ethanol, tetrahydrofuran, methanol, acetone, ether, cyclohexane, carbon tetrachloride and benzene.

[0024] Preferably, the solution impregnation method is a solution impregnation method, specifically, after the active component solution and the carrier are mixed, they are stirred for 1-2 hours, and the supernatant is removed by centrifugation to load the divalent copper precursor onto the carrier.

[0025] Preferably, the vacuum drying treatment conditions are: temperature of 120-300°C, time of 8-12 hours, and more preferably, the vacuum drying temperature is 120-150°C.

[0026] Preferably, the glow discharge plasma treatment conditions are: using a vacuum pump with a power of 500W to keep the system in a vacuum state, adjusting the air flow to keep the pressure of the plasma chamber at 100Pa, adjusting the discharge voltage value to adjust the plasma treatment intensity, applying a voltage of 80-300V, and a treatment time of 0.5-2h. As a further preference, the applied voltage is 80-200V, the treatment time is 1.5h, and most preferably the applied voltage is 160V, and the treatment time is 1.5h.

[0027] In a third aspect, the present invention provides the use of the Cu / HOF-Co catalyst in the reaction of synthesizing vinyl chloride by hydrochlorination of acetylene.

[0028] The application is specifically as follows: in a fixed bed reactor, the Cu / HOF-Co catalyst is loaded, raw gas HCl and C2H2 are introduced, the reaction temperature is 120-200°C, the reaction pressure is 0.01-2MPa, and vinyl chloride is obtained by reaction.

[0029] Preferably, the molar ratio of the raw gas is n(HCl):n(C2H2)=1:1-1.2:1, and the volumetric space velocity of acetylene is 5-500h -1 .

[0030] Compared with the prior art, the present invention has the following innovations and technical advantages:

[0031] (1) The present invention uses hydrogen-bonded organic framework materials HOF instead of traditional activated carbon as a catalyst carrier. HOF materials have the advantages of high crystallinity, large surface area and rich porosity. In catalytic reactions, compared with single-atom catalysts (SACs), transition metal macrocyclic HOFs also have clear active sites, providing an ideal model system for exploring structure-performance correlations. In addition, the HOF structure optimizes the molecular structure to promote intrinsic catalytic activity or constructs a porous framework to increase the surface exposure of active sites. As the preparation technology of HOF materials gradually matures and the cost gradually decreases, the present invention has a strong prospect for industrial application.

[0032] (2) The present invention dopes the HOF carrier with Co and further coordinates it with Cu, thereby enhancing the activity and stability of the Cu-based catalyst and increasing the dispersion and anti-carbon deposition capability of the Cu active component.

[0033] (3) The present invention adopts glow discharge plasma technology instead of traditional calcination treatment, which greatly enhances the dispersion of copper, helps to reduce its agglomeration, exposes more active sites on the inner and outer surfaces of the catalyst, exerts higher activity, and can remain stable during a long reaction process.

[0034] (4) The Cu / HOF-Co catalyst prepared by the present invention is applied to the acetylene hydrochlorination reaction, which can achieve high conversion rate and high selectivity for the acetylene hydrochlorination reaction, and has good stability, and has good economic applicability and industrial application value. DETAILED DESCRIPTION

[0035] The present invention is described below with specific examples. It is necessary to point out that the examples are only used to further illustrate the present invention, but cannot be understood as limiting the scope of protection of the present invention, and the present invention is not limited thereto in any way. Those skilled in the art in this field can make some non-essential improvements and adjustments based on the content of the above invention.

[0036] Example 1

[0037] (1) Synthesis of Co-doped hydrogen-bonded organic framework (HOF-Co): First, 4,4'-bipyridine (2.23 mmol), Na2S (2.53 mmol), and S (2.53 mmol) were added to 16.7 mL of deionized water, ultrasonically treated for 20 min, and then stirred at room temperature for 5 h in an electromagnetic stirrer with a magnetic field set to 100 T. The mixed solution was then added to a reactor lined with polytetrafluoroethylene and hydrothermally treated at 150 °C at a heating rate of 1 °C / min for 72 h. Then, the mixture was cooled to 70 °C at a cooling rate of 1 °C / min to obtain a pink solution of hydrogen-bonded organic framework product. After adding 2.25 mmol Co(NO3)2·6H2O to the above solution, the mixture was stirred at room temperature for 2 h in an electromagnetic stirrer with a magnetic field set to 100 T, filtered, and the obtained filtrate was crystallized at 30 °C in an air atmosphere for 12 h to obtain needle-shaped crystals, that is, the HOF-Co support material.

[0038] (2) Preparation of Cu / HOF-Co catalyst: 10 g of the HOF-Co material obtained in step (1) was added to a container. Then 1.75 g of 45% Cu(BF4)2 in acetonitrile solution was added, stirred for 2 hours, centrifuged, the supernatant was removed, vacuum dried at 120°C for 10 hours, and then glow discharge treated. A vacuum pump with a power of 500 W was used to keep the system in a vacuum state. The pressure in the plasma chamber was maintained at 100 Pa by adjusting the air flow rate. The plasma treatment intensity was adjusted by adjusting the discharge voltage value. The applied voltage was 80 V and the treatment time was 1.5 h. A Cu / HOF-Co catalyst with a Cu(II) loading of 2.13 wt% was obtained.

[0039] (3) The catalyst was tested for the acetylene hydrochlorination reaction in a fixed bed reactor under the following reaction conditions: temperature 150°C, reaction pressure 0.01 MPa, n(HCl):n(C2H2)=1:1, acetylene space velocity 30 h -1 At the initial stage of the reaction, the acetylene conversion rate was 97.36% and the vinyl chloride selectivity was 97.92%; after 800 hours of reaction, the acetylene conversion rate was 96.88% and the vinyl chloride selectivity was 97.57%.

[0040] Example 2

[0041] (1) HOF-Co prepared in the same manner as in Example 1.

[0042] (2) Preparation of Cu / HOF-Co catalyst: 10 g of the HOF-Co material in step (1) was added to a container. Then 2.75 g of 45% Cu2P2O7 ethanol solution was added, stirred for 2 hours, centrifuged, the supernatant was removed, vacuum dried at 120°C for 10 hours, and then glow discharged. A 500 W vacuum pump was used to keep the system in a vacuum state. The pressure in the plasma chamber was maintained at 100 Pa by adjusting the air flow rate. The plasma treatment intensity was adjusted by adjusting the discharge voltage value. The applied voltage was 100 V and the treatment time was 1.5 h. A Cu / HOF-Co catalyst with a Cu(Ⅱ) loading of 5.26 wt% was obtained.

[0043] (3) The catalyst was tested for the acetylene hydrochlorination reaction in a fixed bed reactor under the following reaction conditions: temperature 150°C, reaction pressure 0.01 MPa, n(HCl):n(C2H2)=1:1, acetylene space velocity 30 h -1 At the initial stage of the reaction, the acetylene conversion rate was 98.55% and the vinyl chloride selectivity was 98.88%; after 800 hours of reaction, the acetylene conversion rate was 98.09% and the vinyl chloride selectivity was 98.34%.

[0044] Example 3

[0045] (1) HOF-Co prepared in the same manner as in Example 1.

[0046] (2) Preparation of Cu / HOF-Co catalyst: 10 g of the HOF-Co material obtained in step (1) was added to a container. Then 2.0 g of 45% Cu3(PO4)2 ethanol solution was added, stirred for 2 hours, centrifuged, the supernatant was removed, vacuum dried at 120°C for 10 hours, and then glow discharge treated. A vacuum pump with a power of 500 W was used to keep the system in a vacuum state. The pressure in the plasma chamber was maintained at 100 Pa by adjusting the air flow rate. The plasma treatment intensity was adjusted by adjusting the discharge voltage value. The applied voltage was 120 V and the treatment time was 1.5 h. A Cu / HOF-Co catalyst with a Cu(Ⅱ) loading of 4.54 wt% was obtained.

[0047] (3) The catalyst was tested for the acetylene hydrochlorination reaction in a fixed bed reactor under the following reaction conditions: temperature 150°C, reaction pressure 0.01 MPa, n(HCl):n(C2H2)=1:1, acetylene space velocity 30 h -1 At the initial stage of the reaction, the acetylene conversion rate was 98.98% and the vinyl chloride selectivity was 98.99%; after 800 hours of reaction, the acetylene conversion rate was 98.37% and the vinyl chloride selectivity was 98.06%.

[0048] Example 4

[0049] (1) HOF-Co prepared in the same manner as in Example 1.

[0050] (2) Preparation of Cu / HOF-Co catalyst: 10 g of the HOF-Co material obtained in step (1) was added to a container. Then 1.5 g of 45% CuCl2 ethanol solution was added, stirred for 2 hours, centrifuged, the supernatant was removed, vacuum dried at 120°C for 10 hours, and then glow discharge treated. A vacuum pump with a power of 500 W was used to keep the system in a vacuum state. The pressure in the plasma chamber was maintained at 100 Pa by adjusting the air flow rate. The plasma treatment intensity was adjusted by adjusting the discharge voltage value. The applied voltage was 140 V and the treatment time was 1.5 h. A Cu / HOF-Co catalyst with a Cu(II) loading of 3.21 wt% was obtained.

[0051] (3) The catalyst was tested for the acetylene hydrochlorination reaction in a fixed bed reactor under the following reaction conditions: temperature 150°C, reaction pressure 0.01 MPa, n(HCl):n(C2H2)=1:1, acetylene space velocity 30 h -1 At the initial stage of the reaction, the acetylene conversion rate was 99.27% ​​and the vinyl chloride selectivity was 99.01%; after 800 hours of reaction, the acetylene conversion rate was 98.88% and the vinyl chloride selectivity was 98.74%.

[0052] Example 5

[0053] (1) HOF-Co prepared in the same manner as in Example 1.

[0054] (2) Preparation of Cu / HOF-Co catalyst: 10 g of the purified HOF material in step (1) was added to a container. Then 2.5 g of 45% Cu(BF4)2 ethanol solution was added, stirred for 2 hours, centrifuged, the supernatant was removed, vacuum dried at 120°C for 10 hours, and then glow discharge treated. A 500 W vacuum pump was used to keep the system in a vacuum state. The pressure in the plasma chamber was maintained at 100 Pa by adjusting the air flow rate. The plasma treatment intensity was adjusted by adjusting the discharge voltage value. The applied voltage was 160 V and the treatment time was 1.5 h. A Cu / HOF-Co catalyst with a Cu(II) loading of 3.04 wt% was obtained.

[0055] (3) The catalyst was tested for the acetylene hydrochlorination reaction in a fixed bed reactor under the following reaction conditions: temperature 150°C, reaction pressure 0.01 MPa, n(HCl):n(C2H2)=1:1, acetylene space velocity 30 h -1At the initial stage of the reaction, the acetylene conversion rate was 99.86% and the vinyl chloride selectivity was 99.82%; after 800 hours of reaction, the acetylene conversion rate was 99.49% and the vinyl chloride selectivity was 99.36%.

[0056] Example 6

[0057] (1) HOF-Co prepared in the same manner as in Example 1.

[0058] (2) Preparation of Cu / HOF-Co catalyst: 10 g of the HOF-Co material obtained in step (1) was added to a container. Then 1.75 g of 45% Cu(BF4)2 in acetonitrile solution was added, stirred for 2 hours, centrifuged, the supernatant was removed, vacuum dried at 120°C for 10 hours, and then glow discharge treated. A vacuum pump with a power of 500 W was used to keep the system in a vacuum state. The pressure in the plasma chamber was maintained at 100 Pa by adjusting the air flow rate. The plasma treatment intensity was adjusted by adjusting the discharge voltage value. The applied voltage was 180 V and the treatment time was 1.5 h. A Cu / HOF-Co catalyst with a Cu(II) loading of 2.13 wt% was obtained.

[0059] (3) The catalyst was tested for the acetylene hydrochlorination reaction in a fixed bed reactor under the following reaction conditions: temperature 150°C, reaction pressure 0.01 MPa, n(HCl):n(C2H2)=1:1, acetylene space velocity 30 h -1 At the initial stage of the reaction, the acetylene conversion rate was 98.84% and the vinyl chloride selectivity was 98.75%; after 800 hours of reaction, the acetylene conversion rate was 98.23% and the vinyl chloride selectivity was 98.16%.

[0060] Example 7

[0061] (1) HOF-Co prepared in the same manner as in Example 1.

[0062] (2) Preparation of Cu / HOF-Co catalyst: 10 g of the HOF-Co material obtained in step (1) was added to a container. Then 2.75 g of 45% Cu2P2O7 ethanol solution was added, stirred for 2 hours, centrifuged, the supernatant was removed, vacuum dried at 120°C for 10 hours, and then glow discharge treated. A vacuum pump with a power of 500 W was used to keep the system in a vacuum state. The pressure in the plasma chamber was maintained at 100 Pa by adjusting the air flow rate. The plasma treatment intensity was adjusted by adjusting the discharge voltage value. The applied voltage was 200 V and the treatment time was 1.5 h. A Cu / HOF-Co catalyst with a Cu(Ⅱ) loading of 5.26 wt% was obtained.

[0063] (3) The catalyst was tested for the acetylene hydrochlorination reaction in a fixed bed reactor under the following reaction conditions: temperature 150°C, reaction pressure 0.01 MPa, n(HCl):n(C2H2)=1:1, acetylene space velocity 30 h -1 At the initial stage of the reaction, the acetylene conversion rate was 97.48% and the vinyl chloride selectivity was 97.74%; after 800 hours of reaction, the acetylene conversion rate was 96.93% and the vinyl chloride selectivity was 97.13%.

[0064] Example 8

[0065] (1) HOF-Co prepared in the same manner as in Example 1.

[0066] (2) Preparation of Cu / HOF-Co catalyst: 10 g of the HOF-Co material obtained in step (1) was added to a container. Then 2.0 g of 45% Cu3(PO4)2 ethanol solution was added, stirred for 2 hours, centrifuged, the supernatant was removed, vacuum dried at 120°C for 10 hours, and then glow discharge treated. A vacuum pump with a power of 500 W was used to keep the system in a vacuum state. The pressure in the plasma chamber was maintained at 100 Pa by adjusting the air flow rate. The plasma treatment intensity was adjusted by adjusting the discharge voltage value. The applied voltage was 180 V and the treatment time was 1.5 h. A Cu / HOF-Co catalyst with a Cu(Ⅱ) loading of 4.54 wt% was obtained.

[0067] (3) The catalyst was tested for the acetylene hydrochlorination reaction in a fixed bed reactor under the following reaction conditions: temperature 150°C, reaction pressure 0.01 MPa, n(HCl):n(C2H2)=1:1, acetylene space velocity 30 h -1 At the initial stage of the reaction, the acetylene conversion rate was 98.74% and the vinyl chloride selectivity was 98.67%; after 800 hours of reaction, the acetylene conversion rate was 98.17% and the vinyl chloride selectivity was 98.08%.

[0068] Example 9

[0069] (1) HOF-Co prepared in the same manner as in Example 1.

[0070] (2) Preparation of Cu / HOF-Co catalyst: 10 g of the HOF-Co material obtained in step (1) was added to a container. Then 1.5 g of 45% CuCl2 ethanol solution was added, stirred for 2 hours, centrifuged, the supernatant was removed, vacuum dried at 120°C for 10 hours, and then glow discharge treated. A vacuum pump with a power of 500 W was used to keep the system in a vacuum state. The pressure in the plasma chamber was maintained at 100 Pa by adjusting the air flow rate. The plasma treatment intensity was adjusted by adjusting the discharge voltage value. The applied voltage was 180 V and the treatment time was 1.5 h. A Cu / HOF-Co catalyst with a Cu(II) loading of 3.21 wt% was obtained.

[0071] (3) The catalyst was tested for the acetylene hydrochlorination reaction in a fixed bed reactor under the following reaction conditions: temperature 150°C, reaction pressure 0.01 MPa, n(HCl):n(C2H2)=1:1, acetylene space velocity 30 h -1 At the initial stage of the reaction, the acetylene conversion rate was 98.63% and the vinyl chloride selectivity was 98.75%; after 800 hours of reaction, the acetylene conversion rate was 98.15% and the vinyl chloride selectivity was 98.27%.

[0072] Example 10

[0073] (1) Synthesis of Co-doped hydrogen-bonded organic framework (HOF-Co): First, 4,4'-bipyridine (2.23 mmol), Na2S (2.53 mmol), and S (2.53 mmol) were added to deionized water, ultrasonically treated for 20 min, and then stirred at room temperature for 5 h in an electromagnetic stirrer with a magnetic field set to 100 T. The mixed solution was then added to a reactor lined with polytetrafluoroethylene and hydrothermally treated at 150 °C at a heating rate of 1 °C / min for 72 h. The mixture was then cooled to 70 °C at a cooling rate of 1 °C / min to obtain a pink solution of hydrogen-bonded organic framework product. After adding 2.25 mmol Co(NO3)2·6H2O to the above solution, the mixture was stirred at room temperature for 2 h in an electromagnetic stirrer with a magnetic field set to 100 T, filtered, and the obtained filtrate was crystallized in a vacuum oven at 30 °C for 12 h to obtain needle-shaped crystals, i.e., the HOF-Co support material was obtained.

[0074] (2) Preparation of Cu / HOF-Co catalyst: 10 g of the HOF-Co material obtained in step (1) was added to a container. Then 1.75 g of 45% Cu(BF4)2 in acetonitrile solution was added, stirred for 2 hours, centrifuged, the supernatant was removed, vacuum dried at 120°C for 10 hours, and then glow discharge treated. A vacuum pump with a power of 500 W was used to keep the system in a vacuum state. The pressure in the plasma chamber was maintained at 100 Pa by adjusting the air flow rate. The plasma treatment intensity was adjusted by adjusting the discharge voltage value. The applied voltage was 80 V and the treatment time was 1.5 h. A Cu / HOF-Co catalyst with a Cu(II) loading of 2.13 wt% was obtained.

[0075] (3) The catalyst was tested for the acetylene hydrochlorination reaction in a fixed bed reactor under the following reaction conditions: temperature 150°C, reaction pressure 0.01 MPa, n(HCl):n(C2H2)=1:1, acetylene space velocity 30 h -1 At the initial stage of the reaction, the acetylene conversion rate was 98.77% and the vinyl chloride selectivity was 99.26%; after 800 hours of reaction, the acetylene conversion rate was 98.26% and the vinyl chloride selectivity was 98.98%.

[0076] Comparative Example 1

[0077] Comparative Example 1 is compared with Example 1 to illustrate the excellence of the hydrogen-bonded organic framework carrier material in terms of catalytic stability.

[0078] (1) Take 10g of activated carbon (Fujian Xinsen SAC) and add it to a container. Then add 1.75g ​​of 45% Cu(BF4)2 in acetonitrile solution, stir for 2 hours, centrifuge, remove the supernatant, vacuum dry at 120℃ for 10 hours, and then perform glow discharge treatment. Use a vacuum pump with a power of 500W to keep the system in a vacuum state. The pressure of the plasma chamber is maintained at 100Pa by adjusting the air flow rate. The plasma treatment intensity is adjusted by adjusting the discharge voltage value. The applied voltage is 80V and the treatment time is 1.5h. A copper-based catalyst with a Cu(Ⅱ) loading of 2.13wt% can be obtained.

[0079] (2) The catalyst was tested for the acetylene hydrochlorination reaction in a fixed bed reactor under the following reaction conditions: temperature 150°C, reaction pressure 0.01 MPa, n(HCl):n(C2H2)=1:1, acetylene space velocity 30 h -1 At the initial stage of the reaction, the acetylene conversion rate was 73.91% and the vinyl chloride selectivity was 90.65%; after 800 hours of reaction, the acetylene conversion rate was 56.37% and the vinyl chloride selectivity was 85.68%.

[0080] Comparative Example 2

[0081] Comparative Example 2 is compared with Example 2 to illustrate the superiority of the hydrogen-bonded organic framework carrier material in terms of catalytic stability.

[0082] (1) Take 10g of activated carbon fiber (Nantong Senyou SY-1000) and add it to a container. Then add 2.75g of 45% Cu2P2O7 ethanol solution, stir for 2 hours, centrifuge, remove the supernatant, vacuum dry at 120℃ for 10 hours, and then perform glow discharge treatment. Use a vacuum pump with a power of 500W to keep the system in a vacuum state. The pressure of the plasma chamber is maintained at 100Pa by adjusting the air flow rate. The plasma treatment intensity is adjusted by adjusting the discharge voltage value. The applied voltage is 100V and the treatment time is 1.5h. A copper-based catalyst with a Cu(Ⅱ) loading of 5.26wt% can be obtained.

[0083] (2) The catalyst was tested for the acetylene hydrochlorination reaction in a fixed bed reactor under the following reaction conditions: temperature 150°C, reaction pressure 0.01 MPa, n(HCl):n(C2H2)=1:1, acetylene space velocity 30 h -1 At the initial stage of the reaction, the acetylene conversion rate was 71.45% and the vinyl chloride selectivity was 91.62%; after 800 hours of reaction, the acetylene conversion rate was 55.34% and the vinyl chloride selectivity was 84.98%.

[0084] Comparative Example 3

[0085] Comparative Example 3 is compared with Example 3 to illustrate the irreplaceable role of glow discharge plasma in the catalyst preparation process.

[0086] (1) HOF-Co prepared in the same manner as in Example 1.

[0087] (2) Preparation of Cu-HOF catalyst: 10 g of the HOF-Co material obtained in step (1) was added to a container. Then 2.0 g of a 45% Cu3(PO4)2 ethanol solution was added, stirred for 2 hours, centrifuged, the supernatant was removed, and vacuum dried at 120°C for 10 hours to obtain a Cu / HOF-Co catalyst with a Cu(II) loading of 4.54 wt%.

[0088] (3) The catalyst was tested for the acetylene hydrochlorination reaction in a fixed bed reactor under the following reaction conditions: temperature 150°C, reaction pressure 0.01 MPa, n(HCl):n(C2H2)=1:1, acetylene space velocity 30 h -1 At the initial stage of the reaction, the acetylene conversion rate was 80.76% and the vinyl chloride selectivity was 94.72%; after 800 hours of reaction, the acetylene conversion rate was 61.58% and the vinyl chloride selectivity was 88.59%.

[0089] Comparative Example 4

[0090] (1) Synthesis of Fe and Co doped hydrogen bonded organic framework (HOF-Co0.5Fe0.5): First, 4,4'-bipyridine (2.23 mmol), Na2S (2.53 mmol), and S (2.53 mmol) were added to 16.7 ml of deionized water, ultrasonically treated for 20 min, and then stirred at room temperature for 5 h in an electromagnetic stirrer with a magnetic field set to 100 T. The mixed solution was then added to a reactor lined with polytetrafluoroethylene and hydrothermally treated at 150 °C at a heating rate of 1 °C / min for 72 h. Then cool to 70°C at a cooling rate of 1°C / min to obtain a hydrogen-bonded framework product of a pink solution. After adding a total of 2.25 mmol Co(NO3)2·6H2O and FeSO4·7H2O in a molar ratio of 0.5:0.5 to the above solution, stir at room temperature for 2 h in an electromagnetic stirrer with a magnetic field set to 100 T. Filter and crystallize the filtrate at 30°C for 12 h to obtain needle-shaped crystals, thereby obtaining the HOF-Co0.5Fe0.5 carrier material.

[0091] (2) Preparation of Cu / HOF-Co catalyst: 10 g of the HOF-Co0.5Fe0.5 material obtained in step (1) was added to a container. Then 1.75 g of 45% Cu(BF4)2 in acetonitrile solution was added, stirred for 2 hours, centrifuged, the supernatant was removed, vacuum dried at 120°C for 10 hours, and then glow discharge treated. A vacuum pump with a power of 500 W was used to keep the system in a vacuum state. The pressure in the plasma chamber was maintained at 100 Pa by adjusting the air flow rate. The plasma treatment intensity was adjusted by adjusting the discharge voltage value. The applied voltage was 80 V and the treatment time was 1.5 h. A Cu / HOF-Co0.5Fe0.5 catalyst with a Cu(II) loading of 2.13 wt% was obtained.

[0092] (3) The catalyst was tested for the acetylene hydrochlorination reaction in a fixed bed reactor under the following reaction conditions: temperature 150°C, reaction pressure 0.01 MPa, n(HCl):n(C2H2)=1:1, acetylene space velocity 30 h -1 At the initial stage of the reaction, the acetylene conversion rate was 90.77% and the vinyl chloride selectivity was 92.92%; after 800 hours of reaction, the acetylene conversion rate was 89.86% and the vinyl chloride selectivity was 91.67%.

Claims

1. A Cu / HOF-Co catalyst for acetylene hydrochlorination reaction, the Cu / HOF-Co catalyst comprising a carrier and a copper active component supported on the carrier, characterized in that: The carrier is a Co-doped hydrogen-bonded organic framework, denoted as HOF-Co. The specific synthesis method of the carrier is as follows: Step 1: Add 4,4'-bipyridine, Na2S, and S into deionized water and mix thoroughly to form a mixed solution; Step 2: Transfer the mixed solution obtained in step 1 to an autoclave with a polytetrafluoroethylene liner and perform hydrothermal treatment at 140-160° C. for 60-84 hours; Step 3: Cool the mixed solution obtained in step 2 to 60-80°C and transfer it into a sealed glass bottle; Step 4: Add the Co compound to the mixed solution obtained in step 3, stir for 1-3 hours and then filter; Step 5: crystallize the filtrate obtained in step 4 at 20-40° C. for 10-12 hours in an air atmosphere or under vacuum conditions to obtain a crystal, which is a doped hydrogen-bonded organic framework HOF-Co.

2. The Cu / HOF-Co catalyst for acetylene hydrochlorination according to claim 1, characterized in that: In step 4, the Co compound is at least one of CoCl2, Co(NO3)2, and CoSO4.

3. A method for preparing a Cu / HOF-Co catalyst for acetylene hydrochlorination as claimed in claim 1 or 2, characterized in that: The preparation method comprises the following steps: dissolving a divalent copper precursor in a solvent to obtain an active component solution; loading the divalent copper precursor onto a Co-doped hydrogen-bonded organic framework by a solution impregnation method, vacuum drying the solution, and then performing a glow discharge method to improve the dispersion of the Cu active component and inhibit its agglomeration, and finally obtaining a Cu / HOF-Co catalyst.

4. The preparation method according to claim 3, characterized in that: The divalent copper precursor is selected from at least one of Cu(BF4)2, Cu(NO3)2, CuSO4, CuCl2, Cu3(PO4)2, and Cu2P2O7.

5. The preparation method according to claim 4, characterized in that: The solvent is a mixture of one or more of deionized water, anhydrous ethanol, tetrahydrofuran, methanol, acetone, ether, cyclohexane, carbon tetrachloride and benzene.

6. The preparation method according to claim 3, characterized in that: The solution impregnation method is specifically as follows: after the active component solution and the carrier are mixed, they are stirred for 1-2 hours, and the supernatant is removed by centrifugation to load the divalent copper precursor onto the carrier.

7. The preparation method according to claim 3, characterized in that: The vacuum drying treatment conditions are: temperature of 120-300°C and time of 8-12 hours.

8. The preparation method according to claim 7, characterized in that: The vacuum drying temperature is 120-150°C.

9. The preparation method according to claim 3, characterized in that: The treatment conditions of the glow discharge method are: using a vacuum pump with a power of 500W to keep the system in a vacuum state, maintaining the pressure of the plasma chamber at 100Pa by adjusting the air flow, adjusting the plasma treatment intensity by adjusting the discharge voltage value, the applied voltage is 80 to 300V, and the treatment time is 0.5 to 2h.

10. The preparation method according to claim 9, characterized in that: In the treatment conditions of the glow discharge method, the applied voltage is 80-200V and the treatment time is 1.5h.

11. The preparation method according to claim 10, characterized in that: In the treatment conditions of the glow discharge method, the applied voltage is 160V and the treatment time is 1.5h.

12. Use of the Cu / HOF-Co catalyst as claimed in claim 1 or 2 in the reaction of synthesizing vinyl chloride from acetylene hydrochlorination.