A copper porphyrin catalyst for acetylene hydrochlorination reaction, a preparation method and application thereof

Abstract

The application discloses a copper porphyrin catalyst for acetylene hydrochlorination and a preparation method and application thereof. The catalyst is composed of copper chloride and tetra-p-chlorophenyl porphyrin and is prepared by adopting a dry impregnation method. The catalyst has the technical advantages of environmental non-pollution, high catalytic conversion rate, good selectivity and good thermal stability.

Description

Technical Field

[0001] This invention relates to the field of chemical catalysis technology, specifically to a copper porphyrin catalyst for the preparation of vinyl chloride from acetylene hydrochlorination, its preparation method, and its application. Background Technology

[0002] Vinyl chloride (VCM) is a crucial monomer in the production of polyvinyl chloride (PVC), and the acetylene hydrochlorination process is one of the main technologies for its production. The traditional catalyst for this process is a mercuric chloride / activated carbon (HgCl2 / AC) catalyst, which offers advantages such as high initial activity and low reaction temperature. However, mercury is a highly toxic substance that poses serious threats to the environment and human health during its production and use. With the entry into force of the Minamata Convention on Mercury, developing efficient, stable, and environmentally friendly non-mercury catalysts to replace mercuric chloride catalysts has become a research hotspot and an urgent need in this field.

[0003] Currently, research on non-mercury catalysts mainly includes noble metal catalysts (such as gold, ruthenium, and palladium) and non-noble metal catalysts (such as bismuth, antimony, copper, and tin). While noble metal catalysts exhibit high activity, their high cost and susceptibility to reduction and deactivation limit their industrial application. Non-noble metal catalysts, particularly copper-based catalysts, have attracted widespread attention due to their wide availability and low cost. However, single copper-based catalysts suffer from problems such as easy loss of active components, easy reduction to low-valence states or elemental copper leading to deactivation, and poor catalytic stability.

[0004] Porphyrins and their metal complexes are widely found in nature, possessing unique conjugated macrocyclic structures and excellent electronic regulation capabilities, showing great potential in catalysis, photochemistry, and biomedicine. Introducing porphyrin structures into catalyst design can utilize their macrocyclic coordination environment to stabilize the metal center and regulate the electron cloud density of the active metal center, potentially improving the catalyst's activity and stability.

[0005] Therefore, developing a novel acetylene hydrochlorination catalyst based on inexpensive metals that combines high activity and high stability is of great practical significance. Summary of the Invention

[0006] The purpose of this invention is to provide a copper porphyrin catalyst for the hydrochlorination reaction of acetylene, its preparation method, and its application.

[0007] The catalyst of this invention has the advantages of being environmentally friendly, highly dispersed, having a high catalytic conversion rate, high selectivity, and low cost.

[0008] To achieve the objectives of this invention, the technical solution is as follows:

[0009] A copper porphyrin catalyst for the hydrochlorination of acetylene, the catalyst comprising tetrachlorophenylporphyrin.

[0010] The catalyst consists of copper chloride and the ligand tetrachlorophenylporphyrin.

[0011] Preferably, the ratio of copper chloride to ligand tetrachlorophenylporphyrin is 5-40:5-25 by weight.

[0012] Preferably, by weight, every 100 parts of catalyst contains 5-40 parts of copper chloride, 5-25 parts of tetrachlorophenylporphyrin, and the remainder is activated carbon as a support.

[0013] Preferably, by weight, every 100 parts of catalyst contains 10-30 parts of copper chloride, 10-20 parts of tetrachlorophenylporphyrin, and the remainder is activated carbon as a support.

[0014] Based on the same inventive concept, the present invention also provides a method for preparing a copper porphyrin catalyst for the hydrochlorination of acetylene, comprising the following steps:

[0015] (a) Dissolve tetrachlorophenylporphyrin in chloroform to prepare a 10% tetrachlorophenylporphyrin chloroform solution, mix thoroughly, and obtain product A;

[0016] (b) Dissolve copper chloride in an aqueous hydrochloric acid solution with pH ≤ 3 to prepare an 8% copper chloride aqueous solution, thus obtaining product B;

[0017] (c) Impregnate product A with carrier activated carbon at 20-30℃ for 4-5 hours and then drain to obtain product C;

[0018] (d) Immerse product B in product C at 89-90℃ for 4-5 hours, then drain to obtain product D;

[0019] (e) D product was dried by step heating at 70°C, 80°C, 90°C and 100°C to evaporate hydrochloric acid and water, thus obtaining a copper porphyrin catalyst for acetylene hydrochlorination.

[0020] Preferably, in step (a), tetrachlorophenylporphyrin is dissolved in chloroform.

[0021] Preferably, product A is impregnated with activated carbon to obtain product C, and product B is then impregnated with product C to obtain product D.

[0022] Preferably, the copper porphyrin catalyst is used for the addition reaction of acetylene and hydrogen chloride.

[0023] Preferably, the tetrachlorophenylporphyrin is used in the field of catalysis for the preparation of acetylene hydrochlorination.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] ① Synergistic catalytic effect: This invention innovatively combines copper chloride with porphyrin compounds as active components. The electron-rich system of the porphyrin macrocycle can effectively regulate the electron cloud density of the copper center, making it easier for it to combine with reactants. At the same time, it may stabilize the valence state of copper ions during the reaction process and prevent them from being over-reduced, thereby significantly improving catalytic activity and stability.

[0026] ② The tetrachlorophenylporphyrin in the catalyst improves the adsorption capacity for the reactant hydrogen chloride, inhibits the formation of carbon deposits during the reaction, and extends the service life of the catalyst.

[0027] ③ High stability: Porphyrin molecules are anchored to the surface of activated carbon through coordination and interact with copper species to form more stable active centers, which effectively inhibits the loss and aggregation of active components during the reaction process and extends the service life of the catalyst.

[0028] ④ Environmentally friendly and low-cost: This invention completely avoids the use of toxic mercury, which is in line with the development trend of green chemistry. In addition, by using inexpensive copper as the main active metal and supplementing it with a small amount of porphyrin, the cost of the catalyst is effectively controlled while ensuring high performance, and it has good prospects for industrial application.

[0029] ⑤ Simple preparation method: The preparation process of the present invention adopts the conventional equal volume impregnation or excessive impregnation method, which is simple to operate, mild under mild conditions, and easy to achieve large-scale production. Detailed Implementation

[0030] The present invention will be further described below with reference to embodiments and comparative examples, but these are not intended to limit the present invention.

[0031] Example 1

[0032] A copper porphyrin catalyst for the hydrochlorination of acetylene, its preparation method and application, wherein the catalyst comprises, by weight, 20% copper chloride, 10% tetrachlorophenylporphyrin, and 70% activated carbon support.

[0033] The preparation method is as follows:

[0034] (a) Dissolve tetrachlorophenylporphyrin in chloroform to prepare a 10% tetrachlorophenylporphyrin chloroform solution, mix thoroughly, and obtain product A;

[0035] (b) Dissolve copper chloride in hydrochloric acid aqueous solution with pH=2 to prepare copper chloride aqueous solution with a mass fraction of 8% to obtain product B;

[0036] (c) Impregnate product A with carrier activated carbon at 20-30℃ for 4-5 hours and then drain to obtain product C;

[0037] (d) Immerse product B in product C at 89-90℃ for 4-5 hours, then drain to obtain product D;

[0038] (e) D product was dried by step heating at 70°C, 80°C, 90°C and 100°C to evaporate hydrochloric acid and water, thus obtaining a copper porphyrin catalyst for acetylene hydrochlorination.

[0039] This catalyst is used for the addition reaction of acetylene with hydrogen chloride. The conditions for the acetylene-hydrogen chloride addition reaction are: temperature 180℃, molar ratio of acetylene to hydrogen chloride 1:1.08, and acetylene space velocity 32. -1 The conversion rate of acetylene was 99.9%, and the selectivity of vinyl chloride was 99.9%.

[0040] Example 2

[0041] A copper porphyrin catalyst for the hydrochlorination of acetylene, its preparation method, and its application are disclosed. By weight, the catalyst comprises 15% copper chloride, 12% tetrachlorophenylporphyrin, and 73% activated carbon support. The catalyst was prepared according to the method described in Example 1. This catalyst is used for the addition reaction of acetylene with hydrogen chloride. The conditions for the acetylene-hydrogen chloride addition reaction are: temperature 190°C, molar ratio of acetylene to hydrogen chloride 1:1.1, and acetylene space velocity 33. -1 The conversion rate of acetylene was 99.7%, and the selectivity of vinyl chloride was 99.8%.

[0042] Example 3

[0043] A copper porphyrin catalyst for the hydrochlorination of acetylene, its preparation method, and its application are disclosed. By weight, the catalyst comprises 17% copper chloride, 10% tetrachlorophenylporphyrin, and 73% activated carbon support. The catalyst was prepared according to the method described in Example 1. This catalyst is used for the addition reaction of acetylene with hydrogen chloride. The conditions for the acetylene-hydrogen chloride addition reaction are: temperature 170°C, molar ratio of acetylene to hydrogen chloride 1:1.09, and acetylene space velocity 33. -1 The conversion rate of acetylene was 99.9%, and the selectivity of vinyl chloride was 99.8%.

Claims

1. A copper porphyrin catalyst for the hydrochlorination of acetylene, characterized in that, The catalyst contains tetrachlorophenylporphyrin.

2. The copper porphyrin catalyst for the hydrochlorination of acetylene according to claim 1, characterized in that, The catalyst consists of copper chloride and the ligand tetrachlorophenylporphyrin.

3. The copper porphyrin catalyst for the hydrochlorination of acetylene according to claim 2, characterized in that, The ratio of copper chloride to ligand tetrachlorophenylporphyrin is 5-40:5-25 by weight.

4. The copper porphyrin catalyst for the hydrochlorination of acetylene according to claim 3, characterized in that, By weight, every 100 parts of catalyst contains 5-40 parts of copper chloride, 5-25 parts of tetrachlorophenylporphyrin, and the remainder is activated carbon as a support.

5. The copper porphyrin catalyst for the hydrochlorination of acetylene according to claim 4, characterized in that, By weight, every 100 parts of catalyst contains 10-30 parts of copper chloride, 10-20 parts of tetrachlorophenylporphyrin, and the remainder is activated carbon as a support.

6. The method for preparing a copper porphyrin catalyst for the hydrochlorination of acetylene according to claims 1-5, characterized in that, Includes the following steps: (a) Dissolve tetrachlorophenylporphyrin in chloroform to prepare a 10% tetrachlorophenylporphyrin chloroform solution, mix thoroughly, and obtain product A; (b) Dissolve copper chloride in an aqueous hydrochloric acid solution with pH ≤ 3 to prepare an 8% copper chloride aqueous solution, thus obtaining product B; (c) Impregnate product A with carrier activated carbon at 20-30℃ for 4-5 hours and then drain to obtain product C; (d) Immerse product B in product C at 80-90℃ for 4-5 hours, then drain to obtain product D; (e) D product was dried by step heating at 70°C, 80°C, 90°C and 100°C to evaporate hydrochloric acid and water, thus obtaining a copper porphyrin catalyst for acetylene hydrochlorination.

7. The method for preparing the copper porphyrin catalyst for the hydrochlorination of acetylene according to claim 6, characterized in that, In step (a), tetrachlorophenylporphyrin is dissolved in chloroform.

8. The method for preparing the copper porphyrin catalyst for acetylene hydrochlorination according to claim 6, characterized in that, Product A is obtained by impregnating it with activated carbon on a carrier, and product C is obtained by impregnating product B with product C. Product D is obtained by impregnating product B with product C.

9. A copper porphyrin catalyst for the hydrochlorination of acetylene according to claims 1-6, characterized in that, Copper porphyrin catalysts are used in the addition reaction of acetylene and hydrogen chloride.

10. A copper porphyrin catalyst for the hydrochlorination of acetylene according to claims 1-6, characterized in that, Application of tetrachlorophenylporphyrin in the catalytic preparation of acetylene hydrochlorination.