Copper bismuth composite salt non-noble metal catalyst for acetylene hydrochlorination reaction and preparation method thereof
By preparing a copper-bismuth composite salt catalyst, the problems of mercury pollution and resource shortage in the acetylene hydrochlorination process were solved, and a highly efficient and environmentally friendly acetylene hydrochlorination reaction was achieved. The catalyst exhibited excellent catalytic performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XINJIANG UNIVERSITY
- Filing Date
- 2021-05-25
- Publication Date
- 2026-08-04
AI Technical Summary
The mercuric chloride/activated carbon catalysts used in the existing acetylene hydrochlorination process suffer from severe mercury pollution, resource shortages, and restrictions imposed by the Mercury Ban Treaty. Furthermore, existing non-precious metal catalysts have insufficient activity and are difficult to replace.
Copper-bismuth composite salt non-precious metal catalysts were prepared by in-situ deposition, co-precipitation, hydrothermal/microwave and ultrasonic-assisted impregnation methods. Carbon and silicate materials were used as supports and copper bismuthate was used as the active component to achieve green and environmentally friendly catalysts with high efficiency.
The catalyst exhibits high acetylene conversion rate and high vinyl chloride selectivity, realizing an environmentally friendly and economical acetylene hydrochlorination reaction, solving the problems of mercury pollution and resource shortage, and meeting the requirements of clean production.
Abstract
Description
Technical Field
[0001] This invention relates to the field of non-precious metal catalyst preparation technology, and in particular to a copper-bismuth composite salt non-precious metal catalyst for the acetylene hydrochlorination reaction. Background Technology
[0002] Polyvinyl chloride (PVC) is the world's second most widely used resin material, and is widely used in various industries. Vinyl chloride is an important monomer for the synthesis of PVC. Given my country's resource characteristics of scarce petroleum resources and abundant coal resources, the acetylene hydrochlorination process, which uses coal as the main raw material, has become the main process for the industrial production of PVC in my country. However, the mercuric chloride / activated carbon catalyst used in this process has a series of problems: (1) Severe mercury pollution: A large amount of mercuric chloride consumed by the acetylene hydrochlorination process flows into the environment, which harms human health and the natural ecology. (2) Mercury resource shortage: At present, the mercury consumption of my country's PVC industry accounts for half of the country's mercury consumption, and the large amount of mercury consumption leads to a shortage of mercury resources in my country. (3) Restrictions of the Mercury Ban Treaty: On March 14, 2010, the Ministry of Industry and Information Technology of my country issued the "Notice on Issuing the Clean Production Technology Promotion Plan for 17 Key Industries including Polyvinyl Chloride", and proposed that my country should increase its support to help the research and development of mercury-free catalysts, prevent and reduce the generation of pollutants from the source, and achieve the fundamental way of clean development. In 2017, 17 central government departments jointly issued the "Announcement on the Entry into Force of the Minamata Convention on Mercury," which proposed a complete ban on the development of primary mercury mines from August 16, 2032. Therefore, to promote the sustainable development of the chlor-alkali industry, the development and research of environmentally friendly and economically sustainable mercury-free catalysts has become particularly important.
[0003] In recent years, researchers have conducted extensive studies on non-precious metal catalysts. However, most of these studies focus on single-component non-precious metals, whose activity is lower than that of mercury and precious metal catalysts. Zhou et al. studied a Cu / Bi / H3PO4 catalyst supported on silica gel, achieving an activity of 70% under certain conditions. This study only demonstrated a certain synergistic effect between Bi and Cu on the silica gel support, but did not clarify the existence forms of Bi and Cu. Deng Guocai's research group prepared a Sn / Bi / Cu ternary non-precious metal composite catalyst and found that, compared to a single metal active component, the synergistic effect between multiple metals can improve the acetylene hydrochlorination performance of the catalyst. Therefore, addressing the problems of single-component catalysts, research on bimetallic or multimetallic non-precious metal catalysts may be an effective strategy to improve the performance of single-component non-precious metal catalysts.
[0004] Copper bismuthate is a bimetallic oxide containing two non-noble metals, Bi and Cu. It possesses good thermal stability and low chemical affinity, making it widely used in various catalytic fields such as photocatalysis and electrocatalysis. By selecting different preparation methods (in-situ deposition, co-precipitation, hydrothermal / microwave method, and ultrasonic-assisted impregnation), copper and bismuth sources, the type / concentration of precipitant, and the support, copper bismuthate nanomaterials with different morphologies can be synthesized, thereby affecting the catalytic performance of copper bismuthate in various catalytic reactions. Summary of the Invention
[0005] Based on the above background, this invention addresses the environmental and human health hazards caused by the absence of mercury catalysts in existing acetylene hydrochlorination reactions, and provides a green and environmentally friendly copper-bismuth composite salt non-precious metal catalyst and its preparation method.
[0006] The copper-bismuth composite salt catalyst studied in this invention comprises an active component and a support. The active component is copper bismuthate, accounting for 1-60 wt% of the catalyst mass. The copper source includes one of copper chloride, copper nitrate, and copper sulfate, accounting for 50-100 wt% of the active component mass. The bismuth source includes one of bismuth chloride, bismuth nitrate, and bismuth sulfate, accounting for 0-50 wt% of the active component mass. The support is one of carbon materials (such as activated carbon, carbon nanotubes, and biomass) or non-carbon materials (such as molecular sieves, halloysite, and bentonite, etc., silicate materials).
[0007] The catalyst preparation methods in this invention employ in-situ deposition, co-precipitation, hydrothermal / microwave methods, and ultrasonic-assisted impregnation. The implementation steps are as follows: A. In-situ deposition: The pre-prepared support is immersed in an acidic solution containing copper and bismuth sources treated with a precipitant. The support is completely impregnated using methods such as ultrasound, microwave, stirring, and reflux. The resulting mixture is filtered, washed, and dried to obtain a copper-bismuth composite salt catalyst; B. Co-precipitation: The pre-prepared support is immersed in an acidic solution containing copper and bismuth sources. A precipitant is added to the solution to form an insoluble precipitate. The resulting mixture is filtered, washed, and dried to obtain a copper-bismuth composite salt catalyst; C. Hydrothermal... / Microwave method: In a reaction vessel / polytetrafluoroethylene digestion tank, an aqueous solution is used as the reaction medium. A certain mass of copper source and bismuth source are dissolved in an acid solution. A support and precipitant are added to the solution. The solution is subjected to hydrothermal treatment or microwave treatment. The resulting mixture is filtered, washed, and dried to obtain a copper-bismuth composite salt catalyst. D. Ultrasonic-assisted impregnation method: The pre-prepared support is immersed in an acid solution containing copper source and bismuth source. Ultrasonic assistance is used to ensure complete impregnation. The resulting mixture is filtered, washed, and dried to obtain a copper-bismuth composite salt catalyst.
[0008] The advantages of this invention are: the catalyst is green and environmentally friendly, low in cost, simple to prepare, and has excellent performance.
[0009] The catalyst prepared by the present invention can achieve an acetylene conversion rate of 91.60% and maintain a vinyl chloride selectivity of 99.20%. Detailed Implementation
[0010] The specific solutions are described in detail through the following examples to facilitate evaluation of the invention by those skilled in the art. However, the examples given are not intended to limit the invention.
[0011] Example 1: A copper-bismuth composite salt non-noble metal catalyst for the hydrochlorination of acetylene was prepared by in-situ deposition. The steps are as follows: 4.1780 g of Bi(NO3)3·5H2O was weighed and dissolved in 20 mL of 3 mol / L HNO3 solution at room temperature to form a Bi(NO3)3·5H2O solution. Subsequently, 1.0450 g of Cu(NO3)2·3H2O was added to the above solution to obtain a catalyst containing Bi... + Cu 2+ A nitric acid aqueous solution (Bi:Cu molar ratio 1:2) was prepared. Then, 80 ml of 6 mol / L NaOH was added dropwise to the above solution to adjust the pH to neutral. Next, 6 g of USY molecular sieve was added to the solution, and the mixture was magnetically stirred for 12 h at 1000 r / min at room temperature. The treated USY molecular sieve was then filtered through a microporous membrane, washed with distilled water until neutral, and then... o After drying with C, the CuBi2O4 / USY catalyst prepared by in-situ deposition method was obtained.
[0012] The above catalyst was packed into a fixed-bed reactor for reaction. The feed gas ratio was V(HCl):V(C2H2) = 1.29, and the gas space velocity was 120 h⁻¹. -1 The reaction temperature is 160°C. o The activity of the catalyst in the acetylene hydrochlorination reaction was evaluated under C conditions. The acetylene conversion rate reached 79.29%, and the selectivity of vinyl chloride was maintained at 98.61%.
[0013] Example 2: A copper-bismuth composite salt non-noble metal catalyst for the hydrochlorination of acetylene was prepared by co-precipitation. The steps are as follows: 1.3591 g of BiCl3 was weighed and dissolved in 10 mL of 3 mol / L HCl solution at room temperature to form a BiCl3 solution. Then, 3 g of carbon nanotubes (CNTs) were added to the above solution, and the mixture was magnetically stirred for 6 h at 1000 r / min to form a homogeneous mixed solution. Next, 0.3683 g of CuCl2·2H2O was added to the above solution, and the mixture was magnetically stirred for 12 h at 1000 r / min to form a BiCl3-containing catalyst. + Cu 2+ A hydrochloric acid aqueous solution was prepared, followed by dropwise addition of 40 ml of 6 mol / L NaOH solution. The treated carbon nanotubes (CNTs) were then filtered through a microporous membrane, washed with distilled water until neutral, and then... o After drying, the CuBi2O4 / CNTs catalyst prepared by the co-precipitation method was obtained.
[0014] The above catalyst was applied by filling 4 mL into a fixed-bed reactor. The feed gas ratio was V(HCl):V(C2H2) = 1.29, and the gas space velocity was 120 h⁻¹. -1 The reaction temperature is 160°C. o The activity of the catalyst in the acetylene hydrochlorination reaction was evaluated under C conditions. The acetylene conversion rate reached 62.36%, and the selectivity of vinyl chloride was maintained at 98.25%.
[0015] Example 3: A copper-bismuth composite salt non-noble metal catalyst for the hydrochlorination of acetylene was prepared by an ultrasonic-assisted impregnation method. The steps are as follows: 4.1780 g of Bi(NO3)3·5H2O was weighed and dissolved in 20 ml of a 3 mol / L HNO3 solution at room temperature to form a Bi(NO3)3·5H2O solution. Subsequently, 1.0405 g of CuCl2·2H2O was added to the above solution to obtain a catalyst containing Bi... + Cu 2+ A nitric acid aqueous solution (Bi:Cu molar ratio 1:2) was prepared. Then, 80 ml of 6 mol / L NaOH solution was added dropwise to the above solution, and the mixture was magnetically stirred for 12 h at 1000 r / min. The resulting mixture was then filtered through a microporous membrane at 120 °C. o After drying at C, CuBi₂O₄ was obtained. A certain amount of CuBi₂O₄ was weighed and prepared into a precursor solution of a certain concentration at room temperature, ensuring that the loading of CuBi₂O₄ in the catalyst was 20%. The precursor solution was added dropwise to 6 g of activated carbon to completely impregnate it. The mixture was ultrasonically impregnated for 1 h at room temperature, allowed to stand at room temperature for 10 h, and then subjected to further treatment at 120°C. oAfter drying with C, CuBi2O4 / activated carbon catalyst prepared by ultrasonic-assisted impregnation method was obtained.
[0016] The above catalyst was applied by filling 4 mL into a fixed-bed reactor. The feed gas ratio was V(HCl):V(C2H2) = 1.29, and the gas space velocity was 120 h⁻¹. -1 The reaction temperature is 160°C. o The activity of the catalyst in the acetylene hydrochlorination reaction was evaluated under C conditions. The acetylene conversion rate reached 91.60%, and the selectivity of vinyl chloride was maintained at 99.20%.
Claims
1. The application of copper-bismuth composite salt non-precious metal catalyst in the acetylene hydrochlorination reaction, characterized in that... The reaction conditions are: atmospheric pressure, reaction temperature of 90~300℃, and feed gas space velocity of 30~3000h. -1 Raw material gas V(C2H2):V(HCl) = 1.0~2.0; The catalyst includes an active component and a support; The active component is copper bismuthate; The catalyst is prepared by one of the following methods: in-situ deposition and hydrothermal / microwave method. The in-situ deposition method involves immersing a pre-prepared support in an acidic solution containing copper and bismuth sources treated with a precipitant. The support is then completely impregnated using ultrasonic, microwave, stirring, or reflux methods. The resulting mixture is then filtered, washed, and dried to obtain a copper-bismuth composite salt catalyst. The hydrothermal / microwave method involves using an aqueous solution as the reaction medium in a reaction vessel / polytetrafluoroethylene digestion tank. A certain mass of copper and bismuth sources are dissolved in an acid solution. A carrier and a precipitant are added to the solution. The solution is then subjected to hydrothermal or microwave treatment. The resulting mixture is filtered, washed, and dried to obtain a copper-bismuth composite salt catalyst.