Preparation method of catalyst for acetylene hydrochlorination reaction
By using nitrogen-rich supramolecular compounds to coat carbon materials in the acetylene hydrochlorination reaction, a supported catalyst was prepared, which solved the loss problem of activated carbon-supported mercuric chloride catalyst, improved the activity and stability of the catalyst, and achieved efficient vinyl chloride production.
Patent Information
- Application Number
- CN202510885387.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-30
- Publication Date
- 2025-10-10
AI Technical Summary
The activated carbon-supported mercuric chloride catalyst used in the existing acetylene hydrochlorination reaction has the problem that the active components are easily lost, causing environmental pollution, and the catalyst activity and stability are insufficient.
A nitrogen-rich supramolecular compound is used to coat a carbon material, and a carrier material is prepared by calcination. The metal is loaded as a catalyst to form a multi-tubular structure, thereby improving the activity and stability of the catalyst.
The catalyst has high activity, high vinyl chloride selectivity and high stability, and the process is simple, the raw materials are easily available and the pollution is small.
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Abstract
Description
Technical Field
[0001] The invention belongs to a method for preparing a catalyst, and in particular relates to a method for preparing a catalyst for acetylene hydrochlorination reaction. Background Art
[0002] Vinyl chloride is an important industrial chemical, primarily used as a monomer in the production of polyvinyl chloride (PVC). As the third-largest synthetic polymer produced globally, the widespread use of PVC has led to sustained demand for vinyl chloride. Since my country began large-scale vinyl chloride production in the 1950s, the calcium carbide acetylene process has been the primary production process. Due to my country's unique energy structure, characterized by abundant coal, limited oil, and limited natural gas, the annual production of vinyl chloride monomer (VCM) using this process has exceeded 13 million tons. Acetylene hydrochlorination is the core reaction unit of this process, traditionally using activated carbon-supported mercuric chloride (HgCl2 / AC) as a catalyst. However, mercury-based catalysts suffer from the problem of easy loss of active components, particularly mercury, which can cause serious environmental problems.
[0003] Therefore, it is necessary to develop a method for preparing a supported non-mercury metal catalyst to avoid the above problems existing in the prior art. Summary of the Invention
[0004] The present invention provides a method for preparing a catalyst for acetylene hydrochlorination reaction. The method utilizes a nitrogen-rich supramolecular compound to coat a carbon material, prepares a novel carrier material by calcination, and then loads a metal as a preparation method for the acetylene hydrochlorination reaction catalyst. The method is used to solve the problems of low activity and poor stability of metal catalysts in acetylene hydrochlorination reaction.
[0005] The purpose of the present invention is achieved through the following technical solutions: A method for preparing a catalyst for acetylene hydrochlorination reaction comprises the following steps: Dispersing the carbon material in a solution of compound 1; Compound 2 is added to the suspension in step 1) under stirring conditions, and compound 1 reacts with compound 2 to form a nitrogen-rich supramolecular compound. The generated supramolecular compound is in situ coated on the carbon material to form a hollow multi-tubular structure. The nitrogen-rich supramolecular compound also serves as a nitrogen source; Drying the suspension obtained in step 2) to obtain a catalyst support precursor; calcining the catalyst support precursor obtained in step 3) and grinding it to obtain the catalyst support; 5) impregnating the metal precursor onto the catalyst support obtained in step 4), drying and grinding the catalyst to obtain the acetylene hydrochlorination catalyst.
[0006] Preferably, in the method for preparing a catalyst for acetylene hydrochlorination, the nitrogen source is a supramolecular compound formed by acid-base reaction of cyanuric acid and melamine in a molar ratio of 1:1.
[0007] Preferably, in the method for preparing a catalyst for acetylene hydrochlorination, in step 4), the calcination temperature is 300-500° C., and the calcination time is 1-3 hours.
[0008] Preferably, in the method for preparing a catalyst for acetylene hydrochlorination, the nitrogen source is a supramolecular compound formed by acid-base reaction of cyanuric acid and melamine in a molar ratio of 1:1.
[0009] Preferably, in the method for preparing a catalyst for acetylene hydrochlorination, the carbon material is 24-48 mesh activated carbon.
[0010] Preferably, in the method for preparing a catalyst for acetylene hydrochlorination, the metal precursor is chloroauric acid, and aqua regia is the solvent used for impregnation.
[0011] The significant features and positive effects of the present invention are: In the present invention, a supramolecular compound formed by acid-base interactions between cyanuric acid and melamine is coated on a carbon material, resulting in a specific morphology and composition. Experiments have shown that the catalyst exhibits high activity, high vinyl chloride selectivity, and high stability when used in catalyzing acetylene hydrochlorination.
[0012] The invention has the advantages of simple process, readily available raw materials, easy operation, and little pollution. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 This is a comparison chart of the catalytic performance of Example 1 of the present invention and Comparative Example 1; Figure 2 The figure is a comparison of the catalytic performance of Example 2 of the present invention and Comparative Example 1. DETAILED DESCRIPTION
[0014] The following describes the embodiments of the present invention in detail with reference to the examples. Example 1
[0015] Weigh equal amounts of melamine and cyanuric acid and place them in container 1 and container 2, respectively. Add dimethyl sulfoxide solvent to container 1 and container 2, respectively, to prepare melamine and cyanuric acid solutions. Activated carbon was added to container 2, with a mass ratio of cyanuric acid to activated carbon of 0.3:10. The solution in container 1 was then poured into container 2. The activated carbon was pretreated with dilute hydrochloric acid before use. The specific steps of the activated carbon pretreatment are shown in step 2 of the following comparative example 1); The suspension in container 2 was stirred uniformly and then ultrasonically dispersed for 30 minutes, and then dried at 80°C for 12 hours; After drying, the catalyst support was obtained by calcining at 400°C in a nitrogen atmosphere for 2 hours; Take a certain amount of chloroauric acid solution and quickly add it to the newly prepared aqua regia; The aqueous chloroauric acid regia solution was added to the support obtained in step 4), followed by heating at 60° C. for 4 hours and drying in a vacuum drying oven at 100° C. for about 10 hours. The obtained catalyst was designated as Au / MCA3-400-2. Example 2
[0016] Weigh equal amounts of melamine and cyanuric acid and place them in container 1 and container 2, respectively. Add dimethyl sulfoxide solvent to container 1 and container 2 to prepare melamine and cyanuric acid solutions. Activated carbon was added to container 2 at a mass ratio of cyanuric acid to activated carbon of 1:10, and the solution in container 1 was then poured into container 2. The activated carbon was pretreated with dilute hydrochloric acid before use. The specific steps of the activated carbon pretreatment are shown in step 2 of the following comparative example 1); The suspension in container 2 was stirred uniformly and then ultrasonically dispersed for 30 minutes, and then dried at 80°C for 12 hours; After drying, calcination was carried out at 500 °C in a nitrogen atmosphere for 2 hours; Take a certain amount of chloroauric acid solution and quickly add it to the newly prepared aqua regia; The aqueous chloroauric acid regia solution was added to the support obtained in step 4), followed by heating at 60° C. for 4 hours and drying in a vacuum drying oven at 100° C. for about 10 hours. The obtained catalyst was designated as Au / MCA1-500-2.
[0017] Comparative Example 1 Without introducing supramolecular compounds, activated carbon is directly used as a catalyst support; Before use, the activated carbon was pretreated with dilute hydrochloric acid solution at 70°C for 5 hours, then repeatedly washed with deionized water until the pH remained constant, then filtered and dried for later use; Take a certain amount of chloroauric acid solution and quickly add it to the newly prepared aqua regia; The above aqueous chloroauric acid regia solution was added to the activated carbon treated in step 2), followed by heating at 60°C for 4 hours and then drying in a vacuum drying oven at 100°C for about 10 hours. The obtained catalyst was recorded as Au / AC.
[0018] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.
Claims
1. A method for preparing a catalyst for acetylene hydrochlorination, characterized in that: The method comprises the following preparation steps: dispersing the carbon material in a solution of compound 1; Compound 2 is added to the suspension of step 1) under stirring conditions, and compound 1 reacts with compound 2 to form a nitrogen-rich supramolecular compound. The generated supramolecular compound is in situ coated on the carbon material to form a hollow multi-tubular structure. The nitrogen-rich supramolecular compound also serves as a nitrogen source; Drying the suspension obtained in step 2) to obtain a catalyst support precursor; calcining the catalyst support precursor obtained in step 3) and grinding it to obtain the catalyst support; The metal precursor is impregnated onto the catalyst support obtained in step 4), and the catalyst for acetylene hydrochlorination is obtained after drying and grinding.
2. A method for preparing a catalyst for acetylene hydrochlorination according to claim 1, characterized in that: In the steps 1) and 2), compound 1 and compound 2 are cyanuric acid and melamine, respectively, and the supramolecular compound is generated in situ in the suspension by the action of melamine and cyanuric acid through acid-base interaction.
3. A method for preparing a catalyst for acetylene hydrochlorination according to claim 1, characterized in that: In the step 2), the mass ratio of the supramolecular compound to the carbon material nitrogen source to the carbon material is between 1:5 and 1:
25.
4. The method for preparing a catalyst for acetylene hydrochlorination according to claim 1, wherein: In the step 4), the calcination temperature is 300-500° C., and the calcination time is 1-3 hours.
5. The method for preparing a catalyst for acetylene hydrochlorination according to claim 1, wherein: The nitrogen source is a supramolecular compound formed by acid-base action of cyanuric acid and melamine in a molar ratio of 1:
1.
6. The method for preparing a catalyst for acetylene hydrochlorination according to claim 1, wherein: The carbon material is 24-48 mesh activated carbon.
7. The method for preparing a catalyst for acetylene hydrochlorination according to claim 1, wherein: The metal precursor is chloroauric acid, and aqua regia is the solvent used for impregnation.