A method for preparing P-Cu / Fe2O3 bimetallic composite material and its application

Abstract

This invention relates to a method for preparing a P-Cu / Fe2O3 bimetallic composite material and its application, belonging to the field of materials preparation technology. The method employs a hydrothermal synthesis of a phosphorus-doped bimetallic hydroxide precursor, followed by calcination under a H2 atmosphere to obtain the P-Cu / Fe2O3 bimetallic composite material. Using the P-Cu / Fe2O3 material as an electrocatalyst, it can efficiently electrocatalyze CO2 and NO3. ‑ This invention selectively prepares urea through a reaction. Compared with existing technologies, it has advantages such as high catalytic activity, simple preparation, readily available raw materials, and high activity in the electrocatalytic reaction of CO2 and NO3. ‑ It has significant industrial application prospects in the synthesis of urea.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation, specifically relating to a method for preparing a P-Cu / Fe2O3 bimetallic composite material and its application, particularly to a method for preparing a P-Cu / Fe2O3 bimetallic composite material and its application in the electrocatalysis of CO2 and NO3. - Applications in the synthesis of urea. Background Technology

[0002] Urea, an organic chemical with a nitrogen content as high as 46%, has wide applications in chemical, dye, and fertilizer industries, and is of great significance to global agricultural and social development. Currently, industrial urea production mainly relies on the Haber-Bosch process, which involves the reaction between ammonia and carbon dioxide under harsh conditions (150–200°C and 150–250 bar). This process is energy-intensive and produces large amounts of CO2 emissions, exacerbating global warming. With increasing societal emphasis on sustainable development, developing a clean urea production technology under milder conditions has become a future trend in industrial production. This involves using electrocatalysis to react CO2 and NO3 at room temperature and in atmospheric conditions. - Synthetic urea is a technology that aligns with sustainable development principles. Electrocatalytic urea synthesis is a series reaction, first involving nitrate reduction and carbon dioxide reduction to remove NO3. - The reduction of CO2 to the *NO intermediate and CO2 to the *CO intermediate are both steps involving electron transfer and proton coupling, and are important reaction processes in the urea synthesis pathway.

[0003] Currently, research on electrocatalytic urea synthesis mainly focuses on the development of novel catalysts to improve the selectivity and efficiency of urea synthesis. Although some breakthroughs have been achieved, problems such as insufficient activity, low selectivity, or poor stability still exist in the electrocatalytic urea synthesis process. Therefore, developing an electrocatalyst with high activity, high selectivity, and high stability is of great significance for the practical application of electrocatalytic urea synthesis technology. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing P-Cu / Fe2O3 bimetallic composite materials and their applications. The method involves a simple hydrothermal and calcination process to prepare the P-Cu / Fe2O3 bimetallic composite material. This catalyst electrocatalyzes the reaction of CO2 and NO3. - The coupling reaction enables the efficient electrosynthesis of urea.

[0005] Another objective of this invention is to provide a P-Cu / Fe2O3 bimetallic composite material and its application.

[0006] The specific technical solution to achieve the purpose of this invention is as follows: using different copper and iron salts as raw materials, a precursor is obtained through hydrothermal reaction, followed by calcination to obtain a P-Cu / Fe2O3 bimetallic composite material, including the following steps:

[0007] Step 1: Dissolve 4 mmol of copper salt and 2 mmol of iron salt in 10 mL of deionized water and stir for 1 hour until completely dissolved; add 15 mmol of sodium phosphate to the above solution, then add deionized water to 50 mL and continue stirring for 24 hours.

[0008] Step 2: Transfer the obtained solution to a 100 mL stainless steel high-pressure reactor and carry out a hydrothermal reaction at 160 °C; after the reaction is completed, separate the precipitate by centrifugation, wash it 5 times with deionized water and ethanol, and dry it at 60 °C for 24 hours to obtain powder.

[0009] Step 3: The powder obtained in Step 2 above is subjected to high-temperature calcination under H2 atmosphere to obtain the final P-Cu / Fe2O3 catalyst.

[0010] Furthermore, in the preparation method of P-Cu / Fe2O3 bimetallic composite material, the copper salt and iron salt solutions in step 1 can be any one of acetate, nitrate, or sulfate.

[0011] Furthermore, in the preparation method of P-Cu / Fe2O3 bimetallic composite material, the hydrothermal reaction time in step 2 is 8 hours.

[0012] Furthermore, in the preparation method of P-Cu / Fe2O3 bimetallic composite material, in step 3, the temperature is increased to 300℃ at a heating rate of 3℃ / min under H2 atmosphere and then reacted for 2 hours.

[0013] P-Cu / Fe2O3 bimetallic composite material was prepared according to the above preparation method.

[0014] This invention also provides a P-Cu / Fe2O3 bimetallic composite material as a catalyst for the electrocatalytic reaction of CO2 and NO3. - Applications in the synthesis of urea.

[0015] One of the objectives of this invention is to provide the application of the P-Cu / Fe2O3 bimetallic composite material prepared according to the method provided by this invention in the field of electrocatalysis, particularly in the electrocatalysis of CO2 and NO3. - Applications in the synthesis of urea.

[0016] The advantages of the method for preparing P-Cu / Fe2O3 bimetallic composite materials provided by this invention are as follows:

[0017] This invention proposes a novel method for preparing P-Cu / Fe2O3 bimetallic composite materials. This method uses a mixed solution of widely available and cost-effective copper and iron salts as starting materials, and is simple and efficient.

[0018] The resulting P-Cu / Fe2O3 bimetallic composite material exhibits excellent electrocatalytic performance in the preparation of urea, which gives it a particularly prominent advantage in the field of electrosynthesis applications. Attached Figure Description

[0019] Figure 1 This is a SEM image of the P-Cu / Fe2O3 bimetallic composite material prepared in Example 1;

[0020] Figure 2 The X-ray diffraction (XRD) pattern of the P-Cu / Fe2O3 bimetallic composite material prepared in Example 1;

[0021] Figure 3 The P-Cu / Fe2O3 bimetallic composite material prepared in Example 1 is used for the electrocatalysis of CO2 and NO3. - Performance diagram of synthetic urea. Detailed Implementation

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the present invention is not limited to the following embodiments.

[0023] Example 1

[0024] 4 mmol of copper acetate and 2 mmol of ferric acetate were dissolved in 10 mL of deionized water and stirred for 1 hour until completely dissolved. 15 mmol of sodium phosphate was added to the solution, followed by deionized water to a final volume of 50 mL, and stirring continued for 24 hours. The resulting solution was transferred to a 100 mL stainless steel autoclave and subjected to a hydrothermal reaction at 160 °C. After the reaction, the precipitate was separated by centrifugation, washed five times with deionized water and ethanol, and dried at 60 °C for 24 hours to obtain a powder. The powder obtained in the above steps was then heated to 300 °C at a rate of 3 °C / min under a H2 atmosphere and reacted for 2 hours to obtain the final P-Cu / Fe2O3 bimetallic composite material.

[0025] Figure 1 The image shows a SEM image of the P-Cu / Fe2O3 bimetallic composite material obtained in Example 1. Figure 1 It can be seen that the P-Cu / Fe2O3 bimetallic composite material exhibits a porous structure formed by the stacking of nanoparticles, which are approximately 50 nanometers in size. Figure 2The image shows the XRD pattern of the P-Cu / Fe2O3 bimetallic composite material obtained in Example 1. The crystal structure of the catalyst was analyzed from the image, confirming the phases of Cu and Fe2O3.

[0026] Example 2

[0027] 4 mmol of copper nitrate and 2 mmol of ferric nitrate were dissolved in 10 mL of deionized water and stirred for 1 hour until completely dissolved. 15 mmol of sodium phosphate was added to the solution, followed by deionized water to a final volume of 50 mL, and stirring continued for 24 hours. The resulting solution was transferred to a 100 mL stainless steel autoclave and subjected to a hydrothermal reaction at 160 °C. After the reaction, the precipitate was separated by centrifugation, washed five times with deionized water and ethanol, and dried at 60 °C for 24 hours to obtain a powder. The powder obtained in the above steps was then heated to 300 °C at a rate of 3 °C / min under a H2 atmosphere and reacted for 2 hours to obtain the final P-Cu / Fe2O3 bimetallic composite material.

[0028] Example 3

[0029] 4 mmol of copper sulfate and 2 mmol of ferric sulfate were dissolved in 10 mL of deionized water and stirred for 1 hour until completely dissolved. 15 mmol of sodium phosphate was added to the solution, followed by deionized water to a final volume of 50 mL, and stirring continued for 24 hours. The resulting solution was transferred to a 100 mL stainless steel autoclave and subjected to a hydrothermal reaction at 160 °C. After the reaction, the precipitate was separated by centrifugation, washed five times with deionized water and ethanol, and dried at 60 °C for 24 hours to obtain a powder. The powder obtained in the above steps was then heated to 300 °C at a rate of 3 °C / min under a H2 atmosphere and reacted for 2 hours to obtain the final P-Cu / Fe2O3 bimetallic composite material.

[0030] Example 4

[0031] All corresponding electrochemical tests were performed on the Shanghai Chenhua Electrochemical Workstation (CHI 6081E). Electrolysis tests were conducted in an H-type electrolytic cell using a three-electrode system, including a working electrode (P-Cu / Fe₂O₃ bimetallic composite material), a Pt electrode as the counter electrode, and Ag / AgCl as the reference electrode. During electrolysis, the cathode and anode chambers were separated by a proton exchange membrane. The electrolytes in the cathode and anode chambers were 0.1 M KNO₃ and 0.1 M K₂SO₄, respectively. Electrolysis was performed for 1 hour at each potential under constant potential mode, and gaseous and liquid products were collected.

[0032] The components of the obtained product were directly detected and quantitatively analyzed using gas chromatography (Agilent 8890), nuclear magnetic resonance spectroscopy (1H NMR, Bruker Ascend 500MHz), and the diacetyl monooxime method. For example... Figure 3 As shown, the P-Cu / Fe2O3 bimetallic composite material exhibits a Faradaic efficiency of 73.81% and a production rate of 62.74 mmol / h for urea at an electrolysis potential of -0.68 V vs. RHE. -1 g -1 cat. .

[0033] The applicant hereby declares that the specific embodiments of the present invention have been described in detail above, but this is only for illustrative purposes and not for limiting the scope of the present invention. For those skilled in the art, any equivalent modifications or substitutions to the present invention should be considered to fall within the protection scope of the present invention. Therefore, all equivalent transformations and adaptive adjustments implemented without departing from the basic concept and protection limits of the present invention are within the scope of the present invention.

Claims

1. A method for preparing a P-Cu / Fe2O3 bimetallic composite material, characterized in that, The specific steps include the following: Step 1: Dissolve 4 mmol of copper salt and 2 mmol of iron salt in 10 mL of deionized water and stir for 1 hour until completely dissolved; add 15 mmol of sodium phosphate to the above solution, then add deionized water to 50 mL and continue stirring for 24 hours. Step 2: Transfer the obtained solution to a 100 mL stainless steel high-pressure reactor and carry out a hydrothermal reaction at 160 °C; after the reaction is completed, separate the precipitate by centrifugation, wash it 5 times with deionized water and ethanol, and dry it at 60 °C for 24 hours to obtain powder. Step 3: The powder obtained in Step 2 is subjected to high-temperature calcination under H2 atmosphere to obtain the final P-Cu / Fe2O3 bimetallic composite material.

2. The method for preparing the P-Cu / Fe2O3 bimetallic composite material according to claim 1, characterized in that, The copper and iron salts in step 1 can be any one of acetate, nitrate, or sulfate.

3. The method for preparing the P-Cu / Fe2O3 bimetallic composite material according to claim 1, characterized in that, The hydrothermal reaction time in step 2 is 8 hours.

4. The method for preparing the P-Cu / Fe2O3 bimetallic composite material according to claim 1, characterized in that, In step 3, the temperature is increased to 300°C at a rate of 3°C / min under H2 atmosphere, and then reacted for 2 hours.

5. The P-Cu / Fe2O3 bimetallic composite material is prepared by the preparation method according to any one of claims 1-4.

6. The P-Cu / Fe2O3 bimetallic composite material of claim 5 as a catalyst for the electrocatalytic reaction of CO2 and NO3. - Applications in the synthesis of urea.

Images