CuNi bimetallic ligand modified Au catalyst for acetylene hydrochlorination reaction

Abstract

The invention discloses a CuNi bimetallic ligand modified Au catalyst for acetylene hydrochlorination reaction. The CuNi bimetallic ligand modified Au catalyst comprises a carrier and an active component loaded on the carrier, the carrier is an activated carbon carrier; the active component is composed of compounds of a gold element, a copper element and a nickel element; the loading capacity of the gold element in the active component is 0.05-0.5 wt%, the molar ratio of the copper element to the gold element is (1-30): 1, and the molar ratio of the nickel element to the gold element is (0.1-10): 1. According to the Au catalyst, the structure of Au is modified through a CuNi bimetallic ligand, Au is located in the center of a catalytic chain formed by Cu and Ni, meanwhile, the adsorption performance of Au species to acetylene and hydrogen chloride is adjusted, the acetylene conversion rate is increased, the catalytic stability is improved, the excellent catalytic performance and stability can be achieved on the premise of low gold loading capacity, and the catalyst is suitable for industrial production. Therefore, the catalyst replaces a mercury catalyst to be widely applied to synthesis of vinyl chloride monomers, and green and efficient production is realized.

Description

Technical Field

[0001] The invention relates to the technical field of industrial catalysts, and in particular to a CuNi bimetallic ligand-modified Au catalyst for acetylene hydrochlorination reaction. Background Art

[0002] Polyvinyl chloride (PVC), a polymer made from vinyl chloride monomer (VCM), is the third most commonly used synthetic plastic in the world and is widely used in packaging, automotive, and construction industries. The preparation of VC monomer is a key step in the PVC production process.

[0003] In China, due to abundant coal resources and relatively limited oil reserves, the calcium carbide acetylene process has become the primary production method, accounting for 80% of the country's polyvinyl chloride production capacity. Currently, the industry still uses activated carbon loaded with mercuric chloride as a catalyst. Mercury chloride is a highly toxic substance that easily sublimates and escapes into the environment, causing ecological degradation and environmental pollution. Furthermore, my country's mercury resources are largely depleted, and catalyst production relies on imported mercury raw materials. Therefore, the development of green and efficient non-mercury catalysts has become a key research direction in this field.

[0004] Currently, extensive research has been conducted by scholars both domestically and internationally on non-mercury catalysts. This research focuses on two main areas: metallic non-mercury catalysts, including precious metals such as Au, Pd, Pt, Ir, Rh, and Ru, and non-precious metal catalysts such as Cu, Co, Bi, Zn, and Ni. Among these non-mercury catalysts, activated carbon-supported gold catalysts possess the highest catalytic activity and are considered the most promising alternative to mercuric chloride for the hydrochlorination of acetylene to vinyl chloride monomer.

[0005] However, the high cost of gold catalysts and their stability issues under reaction conditions greatly limit their industrial application. To overcome these challenges, a variety of strategies have been proposed, including support modification, ligand modification, and the introduction of metal promoters. Nevertheless, each method has its limitations. For example, complex process flows may hinder large-scale applications, and ligand modification has stability issues at high temperatures. Among them, metal promoters have attracted attention due to their high-temperature stability and environmental friendliness. Studies have shown that metal promoters can enhance catalytic activity through synergistic effects, improve the dispersion and stability of gold species, and reduce the amount of gold required. AuCu / AC is a typical catalyst. However, it should be noted that some metal promoters, especially copper, may cause strong acetylene adsorption and cause local carbon deposition, thereby worsening the situation.

[0006] Therefore, there is an urgent need for a Au catalyst for acetylene hydrochlorination that can balance the positive regulation of metal promoters with their potential negative effects, thereby obtaining a low gold loading, excellent catalytic ability and high stability, and can alleviate carbon deposition. Summary of the Invention

[0007] Purpose of the invention: In view of the defects of the prior art, the purpose of the present invention is to provide a CuNi bimetallic ligand modified Au catalyst for acetylene hydrochlorination reaction with low gold loading, excellent catalytic ability and high stability, and can alleviate carbon deposition.

[0008] Technical solution:

[0009] In one aspect, the present invention provides a CuNi bimetallic ligand-modified Au catalyst for acetylene hydrochlorination, comprising a carrier and an active component supported on the carrier;

[0010] The carrier is an activated carbon carrier;

[0011] The active component is composed of a compound of gold, copper and nickel;

[0012] The loading amount of the gold element in the active component is 0.05-0.5wt%, the molar ratio of the copper element to the gold element is 1-30:1, and the molar ratio of the nickel element to the gold element is 0.1-10:1.

[0013] The gold catalyst provided by the present invention, on the one hand, does not contain heavy metals such as mercury in its composition, which can achieve green and environmentally friendly industrial production. At the same time, it does not contain organic ligands in its composition, which can avoid the problem of catalyst deactivation caused by poor stability of organic ligands under high temperature conditions. On the other hand, its gold loading is only 0.05-0.5wt%, which not only greatly reduces the gold content in conventional gold catalysts and significantly reduces the cost of raw materials, but also enhances its catalytic performance through the synergistic effect of non-precious metals, so that it still has sufficient catalytic ability and stability.

[0014] Furthermore, the compound of gold element is selected from one of chloroauric acid, gold chloride or gold(II) chloride;

[0015] The copper compound is selected from at least one of copper chloride, copper nitrate, copper sulfate or copper acetate;

[0016] The nickel compound is selected from at least one of nickel chloride, nickel nitrate, nickel sulfate or nickel acetate.

[0017] In the catalyst provided by the present invention, the nickel component regulates the adsorption behavior of C2H2 and HCl, thereby enhancing HCl adsorption and moderately reducing C2H2 adsorption, creating a local HCl-rich environment, inhibiting the reduction effect of C2H2 on metals, and reducing carbon deposition, ultimately improving the stability and performance of the catalyst.

[0018] The preferred compound of gold is chloroauric acid, the preferred compound of copper is copper chloride, and the preferred compound of nickel is nickel chloride.

[0019] Furthermore, the activated carbon carrier is selected from one of fruit shell activated carbon, wood activated carbon, petroleum activated carbon or coal activated carbon, and its shape is selected from one of spherical, granular, flaky, strip or columnar.

[0020] Furthermore, the loading amount of gold element in the active component is 0.1-0.2 wt %, the molar ratio of copper element to gold element is 4-28:1, and the molar ratio of nickel element to gold element is 0.5-6:1.

[0021] For example, the loading amount of gold element in the active component can be 0.1%, 0.105%, 011%, 0.115%, 0.12%, 0.125%, 0.13%, 0.135%, 0.14%, 0.145%, 0.15%, 0.155%, 0.16%, 0.165%, 0.17%, 0.175%, 0.18%, 0.185%, 0.19%, 0.195%, or 0.2%.

[0022] The molar ratio of the copper element to the gold element can be (4:1), (8:1), (12:1), (16:1), (20:1), (24:1), or (28:1).

[0023] There is a significant synergistic effect between gold and copper. When the copper loading increases within a certain range, the catalyst performance is improved because copper increases the dispersion and oxidation state of gold, promotes adsorption, and effectively prevents C2H2 from converting Au to 3+ However, when the ratio of copper to gold is too high, the improvement of catalytic performance is limited and the stability is significantly reduced. The reason is that the excessive presence of copper will inhibit the gold species, reduce the number of active sites, and cause the exposed small amount of gold species to be over-oxidized, thereby affecting the desorption of C2H2 and promoting carbon deposition, ultimately leading to catalyst deactivation. Therefore, even if AuCu 16 / AC catalysts can show higher conversion rates, but their stability is still greatly insufficient.

[0024] The molar ratio of nickel element to gold element can be (0.5:1), (1:1), (2:1), (4:1), or (6:1).

[0025] The self-reconstructive properties of nickel allow the catalyst structure to reconfigure, protecting gold from excessive oxidation by copper while maintaining the dispersed oxidation of gold by copper. Therefore, the introduction of nickel can make the catalyst both efficient and stable.

[0026] After further optimizing the nickel loading, a key phenomenon emerged: at extremely low nickel loadings (0.045 wt%), nickel has a positive effect on catalyst stability; while increasing nickel loadings leads to decreased catalyst performance. This is because excessive nickel destroys the synergistic effect of gold and copper, thereby reducing catalyst efficiency.

[0027] In the gold catalyst provided by the present invention, gold, as the main active component, plays a core role in the catalyst performance. On this basis, there is a synergistic effect between gold and copper, and there is also an enhancement effect between Au-Ni and Cu-Ni. These directly contribute to the excellent catalytic performance of the CuNi bimetallic ligand-modified Au catalyst.

[0028] Furthermore, the molar ratio of copper element to gold element in the active component is 16:1, and the molar ratio of nickel element to gold element is 1:1.

[0029] As a preferred composition ratio, AuCu 16 Ni / AC catalyst has excellent catalytic performance and stability. When the C2H2 gas hourly space velocity (GHSV) is 540h -1 The catalyst showed excellent performance, achieving an acetylene conversion of 93.03% and a deactivation rate of only 0.12% h -1 .

[0030] Another aspect of the present invention provides a method for preparing any one of the above-mentioned CuNi bimetallic ligand-modified Au catalysts for acetylene hydrochlorination, comprising the following steps:

[0031] (1) dissolving a gold compound and a copper compound in an organic solvent, and adding an aqueous solution of a nickel compound to form a precursor solution;

[0032] (2) impregnating the precursor solution into the activated carbon support and allowing it to stand under heating conditions;

[0033] (3) drying the material after standing at high temperature to obtain the CuNi bimetallic ligand modified Au catalyst for acetylene hydrochlorination reaction.

[0034] Furthermore, the standing temperature in step (2) is 50-80° C. and the standing time is 2-6 hours.

[0035] Furthermore, the drying temperature in step (3) is 120-150° C. and the drying time is 6-12 hours.

[0036] Finally, the present invention also provides the use of any one of the above-mentioned CuNi bimetallic ligand-modified Au catalysts for acetylene hydrochlorination in the synthesis of vinyl chloride monomer.

[0037] Furthermore, the specific method of the application is: loading a catalyst into a reactor, introducing raw material gases HCl and C2H2, and reacting under heating conditions to produce vinyl chloride monomer;

[0038] The reaction temperature is 140-200°C, and the C2H2 space velocity is 300-1080h -1 , the volume ratio of HCl to C2H2 is 1.1-1.3:1.

[0039] Under high-temperature catalytic conditions, carbon dioxide (CH2) coking in the acetylene hydrochlorination reaction can cover and deactivate active sites, posing a key challenge that must be addressed in the development of acetylene hydrochlorination catalysts. Gold-only catalysts exhibit the highest carbon deposition during the reaction. The introduction of a copper component reduces carbon deposition due to enhanced metal dispersion, which enhances catalytic efficiency and inhibits acetylene polymerization. The catalyst modified with a copper-nickel bimetallic ligand exhibits the lowest carbon deposition under the same conditions. This significant reduction in carbon accumulation effectively prevents clogging of active sites, contributing to its excellent acetylene conversion and long-term catalytic stability.

[0040] Beneficial effects:

[0041] (1) The CuNi bimetallic ligand-modified Au catalyst for acetylene hydrochlorination provided by the present invention modifies the structure of Au with the CuNi bimetallic ligand so that Au is located at the center of the catalytic chain formed by Cu and Ni. At the same time, the adsorption performance of Au species for acetylene and hydrogen chloride is adjusted, thereby promoting the improvement of acetylene conversion rate and catalytic stability. Excellent catalytic performance and stability can be achieved under the premise of low gold loading, thereby replacing mercury catalysts and being widely used in the synthesis of vinyl chloride monomer to achieve green and efficient production.

[0042] (2) The CuNi bimetallic ligand modified Au catalyst for acetylene hydrochlorination provided by the present invention effectively balances the positive regulation of the metal promoter and its potential negative effect by controlling the ratio of gold, copper and nickel, thereby achieving performance with both high catalytic ability and stability. 16 Ni / AC catalyst components can be used at a C2H2 space velocity of 540h -1 When the acetylene conversion rate was 93.03%, the deactivation rate was only 0.12% h -1 .

[0043] (3) The CuNi bimetallic ligand-modified Au catalyst for acetylene hydrochlorination provided by the present invention, on the one hand, does not contain heavy metals such as mercury in its composition, which can realize green and environmentally friendly industrial production. At the same time, it does not contain organic ligands in its composition, which can avoid the problem of catalyst deactivation caused by poor stability of organic ligands under high temperature conditions; on the other hand, its gold loading is only 0.05-0.5wt%, which not only greatly reduces the gold content in conventional gold catalysts and significantly reduces the cost of raw materials, but also enhances its catalytic performance through the synergistic effect of non-precious metals, so that it still has sufficient catalytic ability and stability.

[0044] (4) The CuNi bimetallic ligand-modified Au catalyst for acetylene hydrochlorination provided by the present invention creates a local HCl-rich environment through the regulatory effect of the nickel component on the adsorption behavior of C2H2 and HCl, inhibits the reduction effect of C2H2 on the metal and reduces carbon deposition, effectively avoiding the blockage of active sites, thereby contributing to the excellent acetylene conversion rate and long-term catalytic stability of the catalyst. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The C2H2 conversion rate test diagram of different series of catalysts, including (A) AuCux / AC catalysts with different Cu contents; (B) AuCu doped with different transition metals (M) 16 M / AC catalyst; (C) AuCu with different nickel components (Ni content) 16 Ni y / AC catalyst; (D)AuCu 16 Each component of the Ni / AC catalyst was compared individually.

[0046] Figure 2 The selectivity test diagram of vinyl chloride monomer of different series of catalysts, among which (A) AuCu x / AC catalyst; (B) AuCu doped with different transition metals (M) 16 M / AC catalyst; (C) AuCu with different nickel components (Ni content) 16 Ni y / AC catalyst; (D)AuCu 16 Each component of the Ni / AC catalyst was compared individually.

[0047] Figure 3 AuCu 16 Stability test diagram of Ni / AC catalyst.

[0048] Figure 4 The performance test diagrams of the catalyst before and after the reaction, including (A) low-temperature nitrogen adsorption-desorption curve; (B) X-ray diffraction (XRD) pattern; (C) AuCu before and (D) after the reaction16 High-resolution transmission electron microscopy (HRTEM) images of Ni / AC catalyst; (E) Au / AC, (F) AuCu 16 / AC、(G)AuCu 16 Thermogravimetric analysis (TGA) of Ni / AC.

[0049] Figure 5 This is the temperature-programmed desorption-mass spectrum of the adsorption intensity of the catalyst to the reaction gas, where (A) HCl and (B) C2H2. DETAILED DESCRIPTION

[0050] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following examples are illustrative of the present invention and are intended only to illustrate the present invention and are not intended to limit the present invention. Other combinations and various modifications within the scope of the present invention may be made without departing from the spirit or scope of the present invention.

[0051] Example 1

[0052] The CuNi bimetallic ligand-modified Au catalyst for acetylene hydrochlorination was prepared by the following steps:

[0053] (1) HAuCl4 and CuCl2 were weighed and dissolved in isopropanol according to the composition and ratio of 0.15 wt% Au, Cu / Au molar ratio of 16:1, and Ni / Au molar ratio of 1:1. Nickel chloride NiCl2 aqueous solution was added and ultrasonically dispersed for 30 minutes.

[0054] (2) The product of step (1) was impregnated in Norit activated carbon, allowed to stand at 70°C for 6 hours, and dried at 120°C for 8 hours to obtain AuCu 16 Ni / AC catalyst;

[0055] (3) Adjust the Cu / Au molar ratio and Ni / Au molar ratio respectively to prepare AuCu x / AC series catalyst, AuNi y / AC series catalysts and AuCu 16 Ni y / AC series catalysts.

[0056] Comparative Example 1

[0057] The same as Example 1, except that nickel chloride is replaced with equal molar amounts of manganese chloride, tin chloride, zinc chloride, cobalt chloride, scandium chloride and gallium chloride to prepare AuCu doped with different transition metals (M). 16 M / AC series catalysts.

[0058] Comparative Example 2

[0059] The process is basically the same as Example 1, except that the active components in step (1) are changed to single components of Au, Cu and Ni to prepare single-component catalysts.

[0060] Comparative Example 3

[0061] Literature Au catalyst.

[0062] Performance Testing

[0063] 1. Conversion rate and selectivity test of different series of catalysts: The catalysts of each series in Examples and Comparative Examples 1-2 were respectively heated at T = 180 ° C, V (HCl) / V (C2H2) = 1.2 and GHSV (C2H2) = 540h -1 , the acetylene hydrochlorination reaction experiment was carried out under the conditions, and the C2H2 conversion rate and vinyl chloride monomer selectivity during the experiment were recorded. The test results are as follows Figure 1 and Figure 2 shown.

[0064] According to the test results, the CuNi bimetallic ligand-modified Au catalyst provided by the present invention has excellent conversion rate and selectivity. In addition, by adjusting the ratio between the active components, the present invention effectively balances the positive regulation of the metal promoter and its potential negative effects, thereby successfully obtaining an Au catalyst with low loading and excellent catalytic performance.

[0065] like Figure 1 A and Figure 2 As shown in Figure A, there is a significant synergistic effect between gold and copper. When the copper loading increases within a certain range, the catalyst performance improves; however, when the copper to gold ratio exceeds 16, the improvement in catalytic performance is limited and the stability decreases significantly.

[0066] like Figure 1 B and Figure 2 As shown in B, the introduction of transition metals significantly affects the catalyst performance, among which AuCu 16 The Ni / AC catalyst achieved a C2H2 conversion of 93.03%. Further optimization of the nickel loading revealed a key phenomenon: at very low nickel loadings (0.045 wt%), nickel had a positive effect on catalyst stability, while increasing nickel loadings led to a decrease in catalyst performance.

[0067] like Figure 1 As shown in Figure D, there are differences in the performance of different catalyst components. In terms of converting acetylene to vinyl chloride, Au / AC showed the highest conversion rate (52.3%), while Cu / AC and Ni / AC only reached 21.5% and 8.7%, respectively. These results highlight the central role of gold in the catalyst performance and illustrate the sharp drop in performance when the nickel loading is too high. As for the bimetallic catalyst, AuCu 16 / AC、Cu16 The conversion rates of Ni / AC and AuNi / AC were 90.8%, 29.3% and 69.3%, respectively. These results indicate that there is a synergistic effect between gold and copper, and there is also an enhancement effect between Au-Ni and Cu-Ni, which directly contributes to the AuCu 16 Excellent catalytic performance of Ni / AC catalyst.

[0068] 2.AuCu 16 Stability test of Ni / AC catalyst: AuCu 16 Ni / AC catalyst at T = 180 ° C, V (HCl) / V (C2H2) = 1.2 and GHSV (C2H2) = 540h -1 , a 100-hour acetylene hydrochlorination durability test was conducted under the conditions, and the changes in acetylene conversion rate during the experiment were recorded. The test results are as follows Figure 3 shown.

[0069] According to the test results, in the 100-hour durability test, the deactivation rate was observed to be 0.12% h -1 , corresponding to a decrease in acetylene conversion from 93.03% to 81.40%. Despite the decrease in conversion, the deactivation rate was relatively low, indicating that the catalyst remained highly stable throughout the test.

[0070] 3. Comparison of Au catalyst performance: various Au catalysts reported in the literature and AuCu 16 Acetylene hydrochlorination was carried out over the Ni / AC catalyst, and the acetylene conversion was recorded. The results are shown in Table 1 below.

[0071]

[0072] Table 1

[0073] According to the test results, compared with various existing metal catalysts, the catalyst provided by the present invention exhibits better catalytic performance and stability under conditions of lower metal loading. It not only greatly reduces the gold content in conventional gold catalysts and significantly reduces the cost of raw materials, but also enhances its catalytic performance through the synergistic effect of non-precious metals, so that it still has sufficient catalytic ability and stability and can be widely used in acetylene hydrochlorination reactions.

[0074] 4. Comparison of catalyst reaction before and after: record the catalyst at T = 180 ° C, V (HCl) / V (C2H2) = 1.2 and GHSV (C2H2) = 2160h -1 , low temperature nitrogen adsorption-desorption curves before and after the reaction under the condition of Time = 120h, X-ray diffraction patterns, AuCu before and after the reaction 16High-resolution transmission electron microscopy images and thermogravimetric analysis of Ni / AC catalyst. Figure 4 shown.

[0075] according to Figure 4 A, for Au / AC, AuCu 16 / AC and AuCu 16 BET surface area and pore size analysis of the Ni / AC catalyst before and after the reaction yielded the following key conclusions: The nitrogen adsorption-desorption isotherms exhibited typical Type I curves, indicating that the microporous structure was maintained during the reaction. These curves exhibited a significant increase in adsorption at very low relative pressures (P / P0), indicating enhanced interactions between the adsorbate and the confined micropores. These structural features facilitated the catalytic reaction by providing a large number of active sites within the confined space.

[0076] according to Figure 4 X-ray diffraction analysis of B, Au / AC, AuCu before reaction 16 / AC and AuCu 16 All three Ni / AC catalysts showed amorphous carbon characteristics, indicating that the metal components were evenly dispersed on the surface of activated carbon without significant agglomeration. 16 The / AC catalyst exhibits diffraction peaks at 38.2°, 44.4°, 64.6°, and 77.6°, corresponding to the (111), (200), (220), and (311) gold planes, respectively (PDF 04-0784). The agglomerated crystallite size was calculated using the Scherrer equation. The results are shown in Table 2.

[0077] 2θ(°) FWHM(°) β(rad) D(nm) Au / AC Used 38.18 0.19 0.0033 47.86 <![CDATA[AuCu 16 / AC Used]]> 38.18 0.23 0.0040 39.53

[0078] Table 2

[0079] Copper promoted the dispersion of gold species and suppressed their agglomeration by reducing the gold grain size from 47.86 nm to 39.53 nm. 16 After the introduction of trace nickel into the AuCu / AC catalyst, no crystal diffraction peak was observed after the reaction, and its diffraction pattern was consistent with that before the reaction. 16 Ni / AC has anti-sintering properties and can effectively inhibit metal agglomeration, thereby ensuring catalyst stability.

[0080] according to Figure 4 High-resolution transmission electron microscopy images of CD, AuCu 16 The Ni / AC catalyst showed no significant morphological changes before and after the reaction; no crystalline structure was observed. These observations suggest that the catalyst maintained high dispersion during the reaction, avoiding agglomeration of active sites. This further demonstrates the catalyst's structural stability and highlights its ability to maintain its morphology and elemental distribution under the reaction conditions.

[0081] 5. Catalyst Carbon Deposition Test: The amount of carbon deposition on the catalyst surface was tested by thermogravimetric analysis. The results are shown in Table 3 below.

[0082]

[0083]

[0084] Table 3

[0085] Note: T1 is 200℃, T2 is 450℃ for Au / AC, and T2 is 400℃ for AuCu16 / AC and AuCu16Ni / AC.

[0086] The coking behavior of the catalyst surface was studied by thermogravimetric analysis. Figure 4 As shown in EG and Table 3, the carbon deposition trends of different catalyst series showed significant differences. The Au / AC catalyst showed the highest carbon deposition (5.77 wt%). After the introduction of the copper component, the carbon deposition decreased by 32.4% to 3.90 wt%. It is worth noting that the ternary AuCu 16 The Ni / AC catalyst exhibited the lowest carbon deposition under the same conditions, at only 1.69 wt%. This significant reduction in carbon accumulation effectively avoided blockage of active sites, contributing to its excellent acetylene conversion and long-term catalytic stability.

[0087] 6. Test of adsorption strength of reaction gas: The adsorption strength of reaction gas on different catalysts was analyzed by temperature programmed desorption-mass spectrometry. Figure 5 Mass spectrometry analysis clearly confirmed the presence of C2H2 and HCl in the desorbed species, indicating that the catalyst effectively adsorbed the reaction gases.

[0088] In addition, the adsorption capacity of each catalyst can be quantitatively evaluated based on mass spectrometry measurements, and the results are shown in Table 4 below.

[0089] HCl (mmol / g) <![CDATA[C2H2(mmol / g)]]> Au / AC 0.072 0.044 <![CDATA[AuCu 16 / AM]]> 0.078 0.046 <![CDATA[AuCu 16 In / AC]]> 0.089 0.045

[0090] Table 4

[0091] AuCu 16 Comparing Au / AC with Au / AC, the former has improved adsorption capacity for C2H2 (0.046mmol / g vs. 0.044mmol / g) and HCl (0.078mmol / g vs. 0.072mmol / g). This enhanced adsorption performance directly explains the 16 / AC has a higher C2H2 conversion rate than Au / AC. When nickel components are introduced to form AuCu 16In the case of Ni / AC catalyst, the HCl adsorption capacity further increased to 0.089 mmol / g, while the C2H2 adsorption capacity slightly decreased to 0.045 mmol / g.

[0092] These results highlight the regulatory role of the nickel component on the adsorption behavior of the two reactants: by enhancing HCl adsorption and moderately reducing C2H2 adsorption, Ni creates a local HCl-rich environment, inhibits the reduction of acetylene to the metal and reduces carbon deposition, ultimately improving the stability and performance of the catalyst.

[0093] The above embodiments are only for illustrating the technical concept and features of the present invention. Its purpose is to enable people familiar with this technology to understand the content of the present invention and implement it. It cannot be used to limit the scope of protection of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A CuNi bimetallic ligand modified Au catalyst for acetylene hydrochlorination, characterized in that: It includes a carrier and an active component loaded on the carrier; The carrier is an activated carbon carrier; The active component is composed of a compound of gold, copper and nickel; The loading amount of the gold element in the active component is 0.05-0.5wt%, the molar ratio of the copper element to the gold element is 1-30:1, and the molar ratio of the nickel element to the gold element is 0.1-10:

1.

2. The CuNi bimetallic ligand modified Au catalyst for acetylene hydrochlorination according to claim 1, characterized in that: The gold compound is selected from one of chloroauric acid, gold chloride or gold(II) chloride; The copper compound is selected from at least one of copper chloride, copper nitrate, copper sulfate or copper acetate; The nickel compound is selected from at least one of nickel chloride, nickel nitrate, nickel sulfate or nickel acetate.

3. The CuNi bimetallic ligand modified Au catalyst for acetylene hydrochlorination according to claim 1, characterized in that: The activated carbon carrier is selected from one of fruit shell activated carbon, wood activated carbon, petroleum activated carbon or coal activated carbon, and its shape is selected from one of sphere, granule, sheet, strip or column.

4. The CuNi bimetallic ligand modified Au catalyst for acetylene hydrochlorination according to claim 1, characterized in that: The loading amount of the gold element in the active component is 0.1-0.2 wt %, the molar ratio of the copper element to the gold element is 4-28:1, and the molar ratio of the nickel element to the gold element is 0.5-6:

1.

5. The CuNi bimetallic ligand modified Au catalyst for acetylene hydrochlorination according to claim 4, characterized in that: The molar ratio of copper element to gold element in the active component is 16:1, and the molar ratio of nickel element to gold element is 1:

1.

6. The method for preparing the CuNi bimetallic ligand modified Au catalyst for acetylene hydrochlorination according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) dissolving a gold compound and a copper compound in an organic solvent, and adding an aqueous solution of a nickel compound to form a precursor solution; (2) impregnating the precursor solution into the activated carbon support and allowing it to stand under heating conditions; (3) drying the material after standing at high temperature to obtain the CuNi bimetallic ligand modified Au catalyst for acetylene hydrochlorination reaction.

7. The method for preparing the CuNi bimetallic ligand modified Au catalyst for acetylene hydrochlorination according to claim 6, characterized in that: The standing temperature in step (2) is 50-80° C. and the standing time is 2-6 hours.

8. The method for preparing the CuNi bimetallic ligand modified Au catalyst for acetylene hydrochlorination according to claim 6, characterized in that: The drying temperature in step (3) is 120-150° C. and the drying time is 6-12 hours.

9. Use of the CuNi bimetallic ligand modified Au catalyst for acetylene hydrochlorination according to any one of claims 1 to 5 in the synthesis of vinyl chloride monomer.

10. The use according to claim 9, characterized in that The specific application method is: loading a catalyst into a reactor, introducing raw material gases HCl and C2H2, and reacting under heating conditions to produce vinyl chloride monomer; The reaction temperature is 140-200°C, and the C2H2 space velocity is 300-1080h -1 , the volume ratio of HCl to C2H2 is 1.1-1.3:1.

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