Phosphorus-doped activated carbon loaded copper-based catalyst as well as preparation method and application thereof

Abstract

The invention discloses a phosphorus-doped activated carbon loaded copper-based catalyst. The catalyst is prepared from a copper-phosphorus complex impregnation liquid and a shell activated carbon carrier. The catalyst is high in catalytic activity and good in stability. All adopted phosphorus sources are common water treatment agents which are low in toxicity, low in harm, small in dosage, greener, more environmentally friendly and low in price; compared with the prior art that calcination and doping are conducted firstly and then coordination and loading are conducted, coordination and loading are conducted firstly and then high-temperature calcination is conducted, the method is simple, multiple times of dipping and drying treatment are not needed, and water and energy can be effectively saved in large-scale production; when the product is applied under industrial production conditions, the acetylene conversion rate and the vinyl chloride selectivity which are industrially required can be realized, and the product can be directly used on the basis of not changing the existing production equipment, is more easily accepted by enterprises and has a good application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of catalyst preparation, and specifically relates to a phosphorus-doped activated carbon-supported copper-based catalyst and a preparation method and application thereof. Background Art

[0002] Polyvinyl chloride (PVC) is one of the top five general-purpose plastics in the world. With its excellent physical and chemical properties, it is widely used in many fields such as medicine, construction, daily necessities, portable electronic devices, etc. Mercury is regarded as one of the top ten chemicals that threaten human health in the world. Mercuric chloride is even more harmful. 0.3g of mercuric chloride can cause death. As early as 2013, my country signed the Minamata Convention, which aims to control and reduce global mercury emissions. The convention proposes to eliminate the use of mercury in chlor-alkali production by 2025. The development of new green and environmentally friendly catalysts is imminent.

[0003] In recent years, researchers have made great progress in the study of acetylene hydrochlorination catalysts. Among them, Cu is favored by researchers because of its low price and good selectivity. Patent CN108993956B discloses a copper salt and organic phosphoric acid ligand complex catalyst and its preparation method: copper salt and organic phosphoric acid ligand are dissolved in deionized water or ethanol, mixed evenly, and then an activated carbon carrier is added, and then impregnated and dried. The obtained catalyst has good catalytic activity and selectivity, but the reaction temperature is high and is not suitable for the existing production conditions of the factory.

[0004] Patent CN115025790B uses activated carbon as a carrier and adds mercuric chloride as an active species, and uses selenium and sulfur dioxide as additives to prepare a low-mercury catalyst with high stability, but the mercuric chloride content of 3-5wt% is still relatively high. Patent CN113731460A uses ethylenediamine, melamine, etc. as nitrogen sources, and phosphoric acid, ammonium polyphosphate, etc. as phosphorus sources to prepare nitrogen and phosphorus co-doped activated carbon supported copper chloride catalyst, which has good stability and high catalytic efficiency, but has many steps and requires multiple impregnation, drying and calcination.

[0005] Therefore, it is necessary to develop a new acetylene hydrochlorination catalyst to solve the problems of low catalytic activity and poor stability of existing copper-based catalysts. Summary of the invention

[0006] The purpose of the present invention is to provide a phosphorus-doped activated carbon-supported copper-based catalyst, and providing a preparation method and application thereof is another purpose of the present invention. Studies have shown that the phosphorus-doped activated carbon-supported copper-based catalyst provided by the present invention is a new type of acetylene hydrochlorination catalyst, which has the characteristics of high catalytic activity, vinyl chloride selectivity and high stability.

[0007] In order to achieve the above-mentioned invention object, the present invention adopts the following technical solutions:

[0008] A phosphorus-doped activated carbon-supported copper-based catalyst is prepared from a copper-phosphorus complex impregnation solution and a fruit shell activated carbon carrier.

[0009] Preferably, the copper-phosphorus complex impregnation solution is prepared from anhydrous cupric chloride, a phosphorus-containing ligand, and a metal additive; the molar ratio of the anhydrous cupric chloride to the phosphorus-containing ligand is 1:(0.1-1); and the added amount of the metal additive is 1-5% of the mass of the fruit shell activated carbon carrier.

[0010] Preferably, the phosphorus-containing ligand is one or a mixture of two or more of aminotrimethylenephosphonic acid, ethylenediaminetetramethylenephosphonic acid, cyclohexanehexolhexaphosphoric acid, 2-hydroxyphosphonoacetic acid, and 2-phosphonobutane-1,2,4-tricarboxylic acid.

[0011] Preferably, the metal auxiliary agent is one of bismuth chloride, potassium chloride, cesium chloride, zinc chloride, and tin chloride, or a mixture of two or more thereof.

[0012] Preferably, the fruit shell activated carbon is one or a mixture of two or more of walnut shell activated carbon, coconut shell activated carbon and apricot shell activated carbon.

[0013] In a second aspect, the present invention provides a method for preparing the above-mentioned phosphorus-doped activated carbon-supported copper-based catalyst, comprising the following steps:

[0014] 1) preparing a copper-phosphorus complex impregnation solution: dissolving anhydrous cupric chloride in a dilute hydrochloric acid solution, and sequentially adding a phosphorus-containing ligand and a metal auxiliary agent to mix to obtain a copper-phosphorus complex impregnation solution;

[0015] 2) Preparation of phosphorus-doped activated carbon-supported copper-based catalyst: Add fruit shell activated carbon to the copper-phosphorus complex impregnation solution of step 1), perform equal volume impregnation treatment at room temperature, and obtain phosphorus-doped activated carbon-supported copper-based catalyst after drying and calcination.

[0016] Preferably, in step 1), when the phosphorus-containing ligand is one of aminotrimethylenephosphonic acid, cyclohexanehexol hexaphosphoric acid, 2-hydroxyphosphonoacetic acid, and 2-phosphonobutane-1,2,4-tricarboxylic acid, water is added to it before adding to prepare a phosphorus-containing ligand aqueous solution.

[0017] Preferably, in step 2), gradient drying is adopted, and the specific operation of gradient drying is: keeping warm at 55-65°C for 5-7h, keeping warm at 90-110°C for 1.5-2.5h, and keeping warm at 115-125°C in a vacuum oven for 1.5-2.5h.

[0018] Preferably, in step 2), a tubular furnace is used for calcination, and the specific operation is: in a nitrogen atmosphere, heating to 400-600° C. at a heating rate of 4-5° C. / min and calcining for 1.5-2.5 hours.

[0019] In a third aspect, the present invention also provides the use of the above phosphorus-doped activated carbon-supported copper-based catalyst in acetylene hydrochlorination.

[0020] The present invention coordinates copper chloride with phosphorus-containing ligands, adds metal additives to load on activated carbon carriers to improve the dispersion of copper chloride, and calcines it at high temperature to improve its stability and further improve its catalytic activity. Experiments show that when it is used as an acetylene hydrochlorination catalyst, it has the characteristics of high catalytic activity, vinyl chloride selectivity, high stability, etc.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The present invention not only solves the problem of low catalytic activity of traditional copper-based catalysts: by coordinating copper ions with P, the dispersion of copper ions is improved, the electron cloud distribution of copper ions is changed, and the catalytic activity of the catalyst is greatly improved; the present invention also solves the problem of poor stability of existing copper-based catalysts: at high temperatures, P forms a PO bond with the activated carbon carrier, firmly fixing the active species on the carrier, greatly improving the catalytic activity of the catalyst. Moreover, the addition of metal additives such as Bi, Sn, K, Cs, and Zn can play a synergistic role with Cu, significantly improving the catalytic activity and stability of copper-based catalysts;

[0023] 2. The phosphorus sources used in the present invention are all commonly used water treatment agents, which are low in toxicity and harm and are used in small amounts, are more environmentally friendly and inexpensive;

[0024] 3. Compared with the existing method of calcining doping first and then coordinating loading, the present invention first coordinates loading and then calcines at high temperature. The method is simple and does not require multiple impregnation and drying treatments. It can effectively save water and energy in large-scale production;

[0025] 4. The product of the present invention can be applied under industrial production conditions to achieve the acetylene conversion rate and vinyl chloride selectivity required by the industry, and can be directly used without changing the existing production equipment, which is more easily accepted by enterprises and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 is the acetylene conversion rate of the catalyst. Reaction conditions: 140-200℃, acetylene space velocity 30h -1 , the flow ratio of HCl to C2H2 is 1.2:1;

[0028] Figure 2 It is the VCM selectivity of the catalyst. Reaction conditions: 140-200℃, acetylene space velocity 30h -1 , the flow ratio of HCl to C2H2 is 1.2:1;

[0029] Figure 3 It is a long-term stability test of the catalyst. Test conditions: T = 180 ° C, CHSV (C2H2) = 180h -1 , the flow ratio of HCl to C2H2 is 1.2:1;

[0030] Figure 4 It is the chromatographic analysis diagram of the tail gas of acetylene hydrochlorination reaction;

[0031] Figure 5 are SEM images of activated carbon and catalysts obtained by different methods: a) activated carbon, b) 10Cu / AC, c) 10Cu-0.25ATMP / AC and d) 10Cu-0.25ATMP / AC@500;

[0032] Figure 6 are XRD analysis diagrams of 10Cu-0.25ATMP / AC, 10Cu-0.25ATMP / AC@500 and 10Cu-0.25ATMP / AC@800 catalysts;

[0033] Figure 7 are the FT-IR spectra of 10Cu / AC, 10Cu-0.25ATMP / AC, 0.25ATMP / AC@500, and 10Cu-0.25ATMP / AC@500 catalysts;

[0034] Figure 8 The effect of ligand to copper molar ratio on acetylene conversion of catalysts;

[0035] Fig. 9 These are the test results of the acetylene conversion rate of the catalyst at different calcination temperatures. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described below in conjunction with specific implementation methods.

[0037] The room temperature in the present invention refers to 20-30°C, preferably 25°C.

[0038] In this embodiment, the molecular weight of anhydrous cupric chloride is 135, the molecular weight of copper is 64, and the molecular weight of aminotrimethylenephosphonic acid is 299.

[0039] Example 1

[0040] The phosphorus-doped activated carbon-supported copper-based catalyst of this embodiment is prepared from a copper-phosphorus complex impregnation solution and a walnut shell activated carbon carrier. The preparation method thereof comprises the following steps:

[0041] 1) Preparation of copper-phosphorus complex impregnation solution:

[0042] 0.9375g of anhydrous copper chloride (0.0069mol) was dissolved in 5-6mL of 1mol / L dilute hydrochloric acid solution, and ultrasonicated for 10min. Then, 0.416g of aminotrimethylenephosphonic acid (ATMP) (0.00069mol) aqueous solution (50wt% inwater) was slowly added dropwise while ultrasonicating for 5min. Cesium chloride was added as a metal auxiliary agent, and ultrasonicated for 15min to obtain a copper-phosphorus complex impregnation solution. The molar ratio of anhydrous copper chloride to aminotrimethylenephosphonic acid was 1:0.1, and the amount of the metal auxiliary agent added was 1% of the mass of the activated carbon.

[0043] 2) Preparation of phosphorus-doped activated carbon-supported copper-based catalyst: The copper-phosphorus complex impregnation solution obtained in step 1) is slowly added dropwise to 4.4 g of walnut shell activated carbon and impregnated at equal volume at room temperature for 12 hours, and then gradient dried: 60°C for 6 hours, 100°C for 2 hours, and 120°C in a vacuum oven for 2 hours. In a tubular furnace, under a nitrogen atmosphere, the temperature is increased to 500°C at a rate of 5°C / min and calcined for 2 hours. After cooling to room temperature, a phosphorus-doped activated carbon-supported copper-based catalyst is obtained. For ease of marking, the phosphorus-doped activated carbon-supported copper-based catalyst obtained in the present invention is named xCu-nLigand / AC@T, where x is the mass percentage of copper Cu to activated carbon AC, n is the molar ratio of ligand to copper chloride, Ligand is the ligand, and T is the calcination temperature. Therefore, this embodiment 1 is marked as 10Cu-0.1ATMP / AC@500.

[0044] Example 2

[0045] The phosphorus-doped activated carbon-supported copper-based catalyst and its preparation method in this embodiment are the same as those in Example 1, except that:

[0046] Step 1) Preparation of copper-phosphorus complex impregnation solution:

[0047] 0.9375g of anhydrous cupric chloride is dissolved in 10-12mL of 1mol / L dilute hydrochloric acid solution, ultrasonicated for 10min, heated in a water bath to 90°C, 0.31g of ethylenediaminetetramethylenephosphonic acid (EDTMP) is added, stirred and dissolved, evaporated and concentrated to 5-6mL, and cesium chloride is added as a metal auxiliary to obtain a copper-phosphorus complex impregnation solution; the molar ratio of the anhydrous cupric chloride to the ethylenediaminetetramethylenephosphonic acid is 1:0.1, and the amount of the metal auxiliary added is 1% of the mass of the activated carbon.

[0048] The phosphorus-doped activated carbon-supported copper-based catalyst obtained in this example is named 10Cu-0.1EDTMP / AC@500.

[0049] Example 3

[0050] The phosphorus-doped activated carbon-supported copper-based catalyst and its preparation method in this embodiment are the same as those in Example 1, except that:

[0051] Step 1) Preparation of copper-phosphorus complex impregnation solution:

[0052] 0.9375g of anhydrous cupric chloride is dissolved in 5-6mL of 1mol / L dilute hydrochloric acid solution, ultrasonicated for 10min, then 0.92g of cyclohexanehexol hexaphosphate (IP6) aqueous solution (50wt% inwater) is slowly added dropwise while ultrasonicated for 5min, and cesium chloride is added as a metal auxiliary agent, and ultrasonicated for 15min to obtain a copper-phosphorus complex impregnation solution; the molar ratio of anhydrous cupric chloride to cyclohexanehexol hexaphosphate is 1:0.1, and the amount of the metal auxiliary agent added is 1% of the mass of the activated carbon.

[0053] The phosphorus-doped activated carbon-supported copper-based catalyst obtained in this example is named 10Cu-0.1IP6 / AC@500.

[0054] Example 4

[0055] The phosphorus-doped activated carbon-supported copper-based catalyst and its preparation method in this embodiment are the same as those in Example 1, except that:

[0056] Step 1) Preparation of copper-phosphorus complex impregnation solution:

[0057] 0.9375g of anhydrous cupric chloride is dissolved in 5-6mL of 1mol / L dilute hydrochloric acid solution, ultrasonicated for 10min, then 0.22g of 2-hydroxyphosphonoacetic acid (HPAA) aqueous solution (50wt% in water) is slowly added dropwise while ultrasonicated for 5min, and cesium chloride is added as a metal auxiliary agent, and ultrasonicated for 15min to obtain a copper-phosphorus complex impregnation solution; the molar ratio of the anhydrous cupric chloride to the 2-hydroxyphosphonoacetic acid is 1:0.1, and the amount of the metal auxiliary agent added is 1% of the mass of the activated carbon.

[0058] The phosphorus-doped activated carbon-supported copper-based catalyst obtained in this example is named 10Cu-0.1HPAA / AC@500.

[0059] Example 5

[0060] The phosphorus-doped activated carbon-supported copper-based catalyst and its preparation method in this embodiment are the same as those in Example 1, except that:

[0061] Step 1) Preparation of copper-phosphorus complex impregnation solution:

[0062] 0.9375g of anhydrous cupric chloride is dissolved in 5-6mL of 1mol / L dilute hydrochloric acid solution, ultrasonicated for 10min, then 0.3765g of 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) aqueous solution (50wt% inwater) is slowly added dropwise while ultrasonicated for 5min, and cesium chloride is added as a metal auxiliary agent, and ultrasonicated for 15min to obtain a copper-phosphorus complex impregnation solution; the molar ratio of the anhydrous cupric chloride to the 2-phosphonobutane-1,2,4-tricarboxylic acid is 1:0.1, and the amount of the metal auxiliary agent added is 1% of the mass of the activated carbon.

[0063] The phosphorus-doped activated carbon-supported copper-based catalyst obtained in this example is named 10Cu-0.1PBTCA / AC@500.

[0064] Example 6

[0065] The phosphorus-doped activated carbon-supported copper-based catalyst and its preparation method in this embodiment are the same as those in Example 1, except that:

[0066] 1) Preparation of copper-phosphorus complex impregnation solution:

[0067] 1.875g of anhydrous cupric chloride is dissolved in 5-6mL of 1mol / L dilute hydrochloric acid solution, ultrasonicated for 10min, then 2.08g of aminotrimethylenephosphonic acid (ATMP) aqueous solution (50wt% in water) is slowly added dropwise while ultrasonicated for 5min, and cesium chloride is added as a metal auxiliary agent, and ultrasonicated for 15min to obtain a copper-phosphorus complex impregnation solution; the molar ratio of the anhydrous cupric chloride to the aminotrimethylenephosphonic acid is 1:0.5; and the amount of the metal auxiliary agent added is 5% of the mass of the activated carbon.

[0068] The phosphorus-doped activated carbon-supported copper-based catalyst obtained in this example is named 20Cu-0.5ATMP / AC@500.

[0069] Example 7

[0070] The phosphorus-doped activated carbon-supported copper-based catalyst and its preparation method in this embodiment are the same as those in Example 1, except that:

[0071] 1) Preparation of copper-phosphorus complex impregnation solution:

[0072] 1.875g of anhydrous cupric chloride is dissolved in 10-12mL of 1mol / L dilute hydrochloric acid solution, ultrasonicated for 10min, heated in a water bath to 90°C, 0.775g of ethylenediaminetetramethylenephosphonic acid (EDTMP) is added, stirred and dissolved, evaporated and concentrated to 5-6mL, and cesium chloride is added as a metal auxiliary to obtain a copper-phosphorus complex impregnation solution; the molar ratio of the anhydrous cupric chloride to the ethylenediaminetetramethylenephosphonic acid is 1:0.25; and the amount of the metal auxiliary added is 5% of the mass of the activated carbon.

[0073] The phosphorus-doped activated carbon-supported copper-based catalyst obtained in this example is named 20Cu-0.25EDTMP / AC@500.

[0074] Example 8

[0075] The phosphorus-doped activated carbon-supported copper-based catalyst and its preparation method in this embodiment are the same as those in Example 1, except that:

[0076] 1) Preparation of copper-phosphorus complex impregnation solution:

[0077] 1.875g of anhydrous cupric chloride is dissolved in 5-6mL of 1mol / L dilute hydrochloric acid solution, ultrasonicated for 10min, then 2.3g of cyclohexanehexol hexaphosphate (IP6) aqueous solution (50wt% in water) is slowly added dropwise while ultrasonicated for 5min, and cesium chloride is added as a metal auxiliary agent, and ultrasonicated for 15min to obtain a copper-phosphorus complex impregnation solution; the molar ratio of anhydrous cupric chloride to cyclohexanehexol hexaphosphate is 1:0.25; the amount of the metal auxiliary agent added is 5% of the mass of the activated carbon.

[0078] The phosphorus-doped activated carbon-supported copper-based catalyst obtained in this example is named 20Cu-0.25IP6 / AC@500.

[0079] Example 9

[0080] The phosphorus-doped activated carbon-supported copper-based catalyst and its preparation method in this embodiment are the same as those in Example 1, except that:

[0081] 1) Preparation of copper-phosphorus complex impregnation solution:

[0082] 1.875g of anhydrous cupric chloride is dissolved in 5-6mL of 1mol / L dilute hydrochloric acid solution, ultrasonicated for 10min, then 1.1g of 2-hydroxyphosphonoacetic acid (HPAA) aqueous solution (50wt% in water) is slowly added dropwise while ultrasonicated for 5min, and cesium chloride is added as a metal auxiliary agent, and ultrasonicated for 15min to obtain a copper-phosphorus complex impregnation solution; the molar ratio of the anhydrous cupric chloride to the 2-hydroxyphosphonoacetic acid is 1:0.5; and the amount of the metal auxiliary agent added is 5% of the mass of the activated carbon.

[0083] The phosphorus-doped activated carbon-supported copper-based catalyst obtained in this example is named 20Cu-0.5HPAA / AC@500.

[0084] Example 10

[0085] The phosphorus-doped activated carbon-supported copper-based catalyst and its preparation method in this embodiment are the same as those in Example 1, except that:

[0086] 1) Preparation of copper-phosphorus complex impregnation solution:

[0087] 1.875g of anhydrous cupric chloride is dissolved in 5-6mL of 1mol / L dilute hydrochloric acid solution, ultrasonicated for 10min, then 0.9413g of 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) aqueous solution (50wt% inwater) is slowly added dropwise while ultrasonicated for 5min, and cesium chloride is added as a metal auxiliary agent, and ultrasonicated for 15min to obtain a copper-phosphorus complex impregnation solution; the molar ratio of the anhydrous cupric chloride to the 2-phosphonobutane-1,2,4-tricarboxylic acid is 1:0.25; and the amount of the metal auxiliary agent added is 5% of the mass of the activated carbon.

[0088] The phosphorus-doped activated carbon-supported copper-based catalyst obtained in this example is named 20Cu-0.25PBTCA / AC@500.

[0089] Embodiment 11

[0090] The phosphorus-doped activated carbon-supported copper-based catalyst and its preparation method in this embodiment are the same as those in Example 1, except that:

[0091] 1) Preparation of copper-phosphorus complex impregnation solution:

[0092] 0.9375g of anhydrous copper chloride (0.0069mol) was dissolved in 5-6mL of 1mol / L dilute hydrochloric acid solution, and ultrasonicated for 10min. Then, 4.16g of aminotrimethylenephosphonic acid (ATMP) (0.00069mol) aqueous solution (50wt% inwater) was slowly added dropwise while ultrasonicating for 5min. Cesium chloride was added as a metal auxiliary agent, and ultrasonicated for 15min to obtain a copper-phosphorus complex impregnation solution. The molar ratio of anhydrous copper chloride to aminotrimethylenephosphonic acid was 1:1, and the amount of the metal auxiliary agent added was 1% of the mass of the activated carbon.

[0093] This embodiment is marked as 10Cu-1ATMP / AC@500.

[0094] Example 12

[0095] The phosphorus-doped activated carbon-supported copper-based catalyst and its preparation method in this embodiment are the same as those in Example 1, except that:

[0096] Step 2) Preparation of copper-phosphorus complex impregnation solution:

[0097] The copper-phosphorus complex impregnation solution obtained in step 1) was slowly added dropwise to 5g of walnut shell activated carbon at room temperature and impregnated with equal volume for 12h, and then dried in a gradient manner: 60°C for 6h, 100°C for 2h, and 120°C in a vacuum oven for 2h. In a tubular furnace, under a nitrogen atmosphere, the mixture was heated to 400°C at a heating rate of 4°C / min and calcined for 2h, and then cooled to room temperature to obtain a phosphorus-doped activated carbon-supported copper-based catalyst.

[0098] The phosphorus-doped activated carbon-supported copper-based catalyst of this embodiment is named 10Cu-0.1ATMP / AC@400.

[0099] Embodiment 13

[0100] The phosphorus-doped activated carbon-supported copper-based catalyst and its preparation method in this embodiment are the same as those in Example 1, except that:

[0101] 2) Preparation of copper-phosphorus complex impregnation solution:

[0102] Preparation of phosphorus-doped activated carbon-supported copper-based catalyst: The copper-phosphorus complex impregnation solution obtained in step 1) was slowly added dropwise to 5g of walnut shell activated carbon and impregnated at equal volume at room temperature for 12 hours, and then dried in a gradient manner: 60°C for 6 hours, 100°C for 2 hours, and 120°C in a vacuum oven for 2 hours. In a tubular furnace, under a nitrogen atmosphere, the mixture was heated to 600°C at a heating rate of 6°C / min and calcined for 2 hours, and then cooled to room temperature to obtain a phosphorus-doped activated carbon-supported copper-based catalyst.

[0103] The phosphorus-doped activated carbon-supported copper-based catalyst of this embodiment is named 10Cu-0.1ATMP / AC@600.

[0104] In other embodiments, the molar ratio of anhydrous cupric chloride and ethylenediaminetetramethylenephosphonic acid is changed to 1:(0.1-1); the metal auxiliary agent is selected from any one of bismuth chloride, potassium chloride, cesium chloride, tin chloride, and zinc chloride, and the added amount is 1-5% of the mass of the fruit shell activated carbon carrier; during gradient drying, the temperature is kept at 55-65°C for 5-7h, 90-110°C for 1.5-2.5h, and the temperature is kept at 115-125°C in a vacuum oven for 1.5-2.5h; all of which can achieve the effects of the present invention.

[0105] Experimental Example 1

[0106] To illustrate the effect of the present invention, the phosphorus-doped activated carbon-supported copper-based catalyst prepared by the present invention was tested for acetylene conversion, VCM selectivity, long-term stability, chromatography and SEM, and no ligand was added as a control. The samples involved in the test were acetylene conversion and vinyl chloride selectivity: 10Cu-0.25ATMP / AC@500, 10Cu-0.25EDTMP / AC@500, 10Cu-0.25IP6 / AC@500, 10Cu-0.25HPAA / AC@500, 10Cu-0.25PBTCA / AC@500, 10Cu / AC; long-term stability: 10Cu-0.25ATMP / AC@500, 10Cu / AC, gas chromatography: 10Cu-0.25ATMP / AC@500; SEM: AC, 10Cu / AC, 10Cu-0.25ATMP / AC, 10Cu-0.25ATMP / AC@500; XRD: 10Cu-0.25ATMP / AC, 10Cu-0.25ATMP / AC@500, 10Cu-0.25ATMP / AC@800; IR spectrum: 10Cu-0.25ATMP / AC@500, 0.25ATMP / AC@500, 10Cu-0.25ATMP / AC, 10Cu / AC. Among them, the preparation method of samples 10Cu-0.25ATMP / AC@500, 10Cu-0.25IP6 / AC@500, 10Cu-0.25HPAA / AC@500, and 10Cu-0.25PBTCA / AC@500 is the same as that of Example 1, except that the ATMP ligand is replaced by IP6, HPAA, and PBTCA, and the molar ratio of anhydrous copper chloride to the ligand is 1:0.25. The preparation method of 10Cu-0.25EDTMP / AC@500 is the same as that of Example 2, except that the molar ratio of anhydrous copper chloride to the ligand is 1:0.25. The preparation of 10Cu-0.25ATMP / AC@800 refers to Example 1, except that the calcination temperature is replaced by 800°C from 500°C; 10Cu-0.25ATMP / AC and 10Cu / AC are both control groups that have not been calcined. Test results are shown in Figure 1-Figure 7 shown.

[0107] Figure 1 is the acetylene conversion rate of the catalyst. Reaction conditions: 140-200℃, acetylene space velocity 30h -1 , the flow ratio of HCl to C2H2 is 1.2:1. Figure 1 It can be seen from the results that, compared with the 10Cu / AC catalyst, the catalytic performance of the phosphorus-doped activated carbon-supported copper-based catalyst of the present invention has been significantly improved.

[0108] Figure 2It is the VCM selectivity of the catalyst. Reaction conditions: 140-200℃, acetylene space velocity 30h -1 , the flow ratio of HCl to C2H2 is 1.2:1. Figure 2 It can be seen that both the phosphorus-doped activated carbon-supported copper-based catalyst and the ordinary copper-based catalyst show excellent VCM selectivity, which is a significant advantage of the copper-based catalyst, indicating that the phosphorus-doped activated carbon-supported copper-based catalyst produces almost no by-products when producing vinyl chloride.

[0109] Figure 3 It is a long-term stability test of the catalyst. Test conditions: T = 180 ° C, CHSV (C2H2) = 180h -1 , the flow ratio of HCl to C2H2 is 1.2:1. Figure 3 The results show that at T = 180 ° C, CHSV (C2H2) = 180h -1 Under the test conditions of high temperature and high acetylene space velocity, compared with the ordinary catalyst of copper chloride supported on activated carbon, the catalytic activity and stability of the copper-based catalyst supported on phosphorus-doped activated carbon were significantly improved, and the catalytic activity did not show a significant decrease in the 30h test.

[0110] Figure 4 This is the chromatographic analysis diagram of the tail gas from the acetylene hydrochlorination reaction of 10Cu-0.25ATMP / AC@500. Figure 4 Among them, peak 2 belongs to the reactant acetylene, with an area accounting for 0.0760%, and peak 4 belongs to the product vinyl chloride, with an area accounting for 99.8%. It can be seen that the acetylene conversion rate and vinyl chloride selectivity of the catalyst of the present invention are both as high as 99.9%, indicating that the catalyst prepared by the present invention has very excellent catalytic performance.

[0111] Figure 5 The SEM images of activated carbon and catalysts obtained by different methods are: a) activated carbon, b) 10Cu / AC, c) 10Cu-0.25ATMP / AC and d) 10Cu-0.25ATMP / AC@500; Figure 5 b It can be seen that due to the large metal surface energy, pure copper chloride is easy to agglomerate when loaded on activated carbon, and is concentrated on the surface of activated carbon to form particles. After adding ATMP, the agglomeration of copper chloride is suppressed and the degree of dispersion is greatly improved ( Figure 5 c), but the introduction of ATMP will block the pores of activated carbon and is also not conducive to the catalytic reaction. After high-temperature calcination, the structure of ATMP is destroyed and the pore structure is exposed again. At this time, there is no obvious difference between the SEM image of the catalyst and the SEM image of activated carbon;

[0112] Figure 6The XRD analysis diagrams of 10Cu-0.25ATMP / AC, 10Cu-0.25ATMP / AC@500 and 10Cu-0.25ATMP / AC@800 catalysts are shown in Figure 1. XRD test is often used to analyze the crystal structure of materials. Figure 6 Regardless of the method used to obtain the catalyst, there are two broad diffraction peaks near 2θ=23.8° and 43°. These two peaks are the (002) and (101) crystal planes of amorphous carbon, respectively. There is a sharper peak at 26.5°, indicating that there are still a small amount of graphite crystals in the activated carbon. The 10Cu-0.25ATMP / AC and 10Cu-0.25ATMP / AC@500 catalysts have no other characteristic peaks, indicating that their Cu dispersion is good and the particle diameter is smaller than the detection limit of XRD. The 10Cu-0.25ATMP / AC@800 catalyst has characteristic peaks belonging to the copper (111) and (200) crystal planes at around 43.0° and 50.5°. This is because Cu agglomerates at high temperature to form larger crystals, which reduces the number of active sites of the catalyst and leads to lower catalytic activity. Therefore, the calcination temperature of the catalyst should not be too high. After testing, the catalyst has the best catalytic performance when calcined between 400°C and 600°C, and the acetylene conversion rate is above 99%.

[0113] Figure 7 FT-IR spectra of 10Cu / AC, 10Cu-0.25ATMP / AC, 0.25ATMP / AC@500 and 10Cu-0.25ATMP / AC@500 catalysts. Figure 7 As shown in Figure 2, the FT-IR spectra of 10Cu / AC, 10Cu-0.25ATMP / AC, 10ATMP / AC@500 and 10Cu-0.25ATMP / AC@500 catalysts have obvious similarities but also some differences. -1 The carbon-carbon double bond stretching vibration peaks of the activated carbon support can be observed around 1140 cm-1. The CO stretching vibration peaks of 10Cu / AC, 10Cu-0.25ATMP / AC, 0.25ATMP / AC@500 and 10Cu-0.25ATMP / AC@500 are at 1140 cm-1, -1 、1080cm -1 、1120cm -1 、1073cm -1 Around 10Cu-0.25ATMP / AC and 10Cu-0.25ATMP / AC@500, the CO stretching vibration peaks were blue-shifted to varying degrees compared with 10Cu / AC and 0.25ATMP / AC@500, indicating that the chemical environment of CO had changed, proving the formation of Cu-P complex.

[0114] Experimental Example 2

[0115] In order to explore the effect of the molar ratio of ligand to copper on the performance of the catalyst, the ATMP ligand was kept unchanged, and the molar ratio of aminotrimethylenephosphonic acid to anhydrous copper chloride was changed to 0.05, 0.1, 0.25, 0.5, 1.0, and 1.5, respectively. The other preparation methods were the same as in Example 1. The acetylene conversion rate of the obtained catalyst was tested, and the results are shown in Figure 8 shown.

[0116] from Figure 8 It can be seen that when the molar ratio of ligand to copper is less than 1, the acetylene conversion rate of 10Cu-xATMP / AC@500 increases with the increase of the molar ratio of ligand to copper, among which the highest conversion rate of 10Cu-0.10ATMP / AC@500 exceeds 99%, while the acetylene conversion rates of 10Cu-0.25ATMP / AC@500, 10Cu-0.50ATMP / AC@500 and 10Cu-1.00ATMP / AC@500 are always above 99%. When the molar ratio of ligand to copper is greater than 1, the acetylene conversion rate of the catalyst will decrease, which may be due to the carbonization of too many ligands to cover the active sites of copper ions.

[0117] Experimental Example 3

[0118] The ATMP ligand was kept unchanged, and the calcination temperature was changed to 300°C, 400°C, 500°C, 600°C, and 800°C. The other preparation methods were the same as in Example 1. The acetylene conversion rate of the obtained catalyst was tested, and the results are shown in FIG. Fig. 9 shown.

[0119] from Fig. 9 It can be seen that compared with 10Cu-0.25ATMP / AC, the acetylene conversion rate of 10Cu-0.25ATMP / AC@300 is only slightly improved because the ligand cannot be completely decomposed and carbonized under calcination at 300°C. When the calcination temperature is 800°C, the acetylene conversion rate of the catalyst decreases because the calcination temperature is too high and copper will agglomerate, resulting in a reduction in active sites. Therefore, the optimal calcination temperature of the catalyst is between 400-600°C.

[0120] The preferred embodiments of the present invention are specifically described above, but the present invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention, and these equivalent modifications or substitutions are all within the scope defined by the claims of this application. Those skilled in the art should regard the specification as a whole, and the technical solutions in the embodiments may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A phosphorus-doped activated carbon-supported copper-based catalyst, characterized in that: The catalyst is prepared from a copper-phosphorus complex impregnation solution and a fruit shell activated carbon carrier.

2. The phosphorus-doped activated carbon-supported copper-based catalyst according to claim 1, characterized in that: The copper-phosphorus complex impregnation solution is prepared from anhydrous copper chloride, phosphorus-containing ligands and metal additives; the molar ratio of the anhydrous copper chloride to the phosphorus-containing ligands is 1:(0.1-1); and the added amount of the metal additive is 1-5% of the mass of the fruit shell activated carbon carrier.

3. The phosphorus-doped activated carbon-supported copper-based catalyst according to claim 1, characterized in that: The phosphorus-containing ligand is one of aminotrimethylenephosphonic acid, ethylenediaminetetramethylenephosphonic acid, cyclohexanehexolhexaphosphoric acid, 2-hydroxyphosphonoacetic acid, and 2-phosphonobutane-1,2,4-tricarboxylic acid, or a mixture of two or more thereof.

4. The phosphorus-doped activated carbon-supported copper-based catalyst according to claim 1, characterized in that: The metal auxiliary agent is one of bismuth chloride, potassium chloride, cesium chloride, zinc chloride, and tin chloride, or a mixture of two or more thereof.

5. The phosphorus-doped activated carbon-supported copper-based catalyst according to claim 1, characterized in that: The fruit shell activated carbon is one or a mixture of two or more of walnut shell activated carbon, coconut shell activated carbon and apricot shell activated carbon.

6. The method for preparing a phosphorus-doped activated carbon-supported copper-based catalyst according to any one of claims 1 to 5, characterized in that: The following steps are involved: 1) preparing a copper-phosphorus complex impregnation solution: dissolving anhydrous cupric chloride in a dilute hydrochloric acid solution, and sequentially adding a phosphorus-containing ligand and a metal auxiliary agent to mix to obtain a copper-phosphorus complex impregnation solution; 2) Preparation of phosphorus-doped activated carbon-supported copper-based catalyst: Add fruit shell activated carbon to the copper-phosphorus complex impregnation solution of step 1), perform equal volume impregnation treatment at room temperature, and obtain phosphorus-doped activated carbon-supported copper-based catalyst after drying and calcination.

7. The method for preparing a phosphorus-doped activated carbon-supported copper-based catalyst according to claim 6, characterized in that: In step 1), when the phosphorus-containing ligand is one of aminotrimethylenephosphonic acid, cyclohexanehexol hexaphosphoric acid, 2-hydroxyphosphonoacetic acid, and 2-phosphonobutane-1,2,4-tricarboxylic acid, water is added to it before adding to prepare a phosphorus-containing ligand aqueous solution.

8. The method for preparing a phosphorus-doped activated carbon-supported copper-based catalyst according to claim 6, characterized in that: In step 2), gradient drying is adopted, and the specific operation of gradient drying is: keeping warm at 55-65°C for 5-7h, keeping warm at 90-110°C for 1.5-2.5h, and keeping warm at 115-125°C in a vacuum oven for 1.5-2.5h.

9. The method for preparing a phosphorus-doped activated carbon-supported copper-based catalyst according to claim 6, characterized in that: In step 2), a tubular furnace is used for calcination, and the specific operation is: in a nitrogen atmosphere, heating to 400-600° C. at a heating rate of 4-5° C. / min and calcining for 1.5-2.5 hours.

10. Use of the phosphorus-doped activated carbon-supported copper-based catalyst according to any one of claims 1 to 5 in acetylene hydrochlorination.

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