Process for the preparation of a foamed copper-based composite organic compound layer catalytic material

Abstract

This invention provides a method for preparing a foamed copper-based composite organic compound layer catalytic material, comprising the following steps: forming 8-hydroxyquinoline molybdenum (Mo(C)) on the surface of a foamed copper matrix. 9 H 6 NO) 4 Organic compound layer; 8-hydroxyquinoline molybdenum (Mo(C)) 9 H 6 NO) 4 The organic compound layer is converted into phthalimide 8-hydroxyquinoline molybdenum (C). 8 H 4 NO 2 ) 2 (C 9 H 6 NO) 2 ; Phthalimide 8-hydroxyquinoline molybdenum Mo(C) 8 H 4 NO 2 ) 2 (C 9 H 6 NO) 2 Conversion to copper phthalimide / 8-hydroxyquinoline molybdenum Cu(C) 8 H 4 NO 2 ) 2 / Mo(C 9 H 6 NO) 2 The foamed copper-based composite organic compound layer catalytic material is finally obtained. The catalytic material prepared by the method of this invention can effectively improve the Faradaic efficiency, ammonia selectivity, production rate, and nitrate removal rate of the electrochemical reduction of nitrate to ammonia technology.

Description

Preparation method of copper foam-based composite organic compound layer catalytic material Technical Field

[0001] This invention relates to the field of organic compound catalytic materials, and in particular to a method for preparing a foamed copper-based composite organic compound layer catalytic material. Background Technology

[0002] Ammonia is not only an important raw material for the preparation of various agricultural nitrogen fertilizers, but also an energy carrier and a carbon-free fuel. Currently, ammonia is synthesized using the traditional Haber-Bosch process, which is not only complex in equipment and demanding in process conditions and energy consumption, but also has a significant impact on the environment and human health due to the emission of substances such as carbon dioxide.

[0003] Furthermore, with socio-economic development, the use and emission of nitrogen compounds in industry, agriculture, medicine, and household life have led to the generation of large amounts of nitrate-containing wastewater. NO3 in nitrate-containing wastewater... - It has high solubility and is difficult to separate and remove, which not only pollutes the environment but also poses a serious threat to human health.

[0004] Electrochemical catalytic reduction of NO3 - Ammonia conversion is an environmentally friendly process with zero emissions and simple equipment and process requirements. It is also an ideal method for treating nitrate-containing wastewater. However, the electrochemical reduction of NO3... - The ammonia conversion process involves eight electron transfer reactions, including not only the competing hydrogen evolution reduction (HER) process, but also the process involving the key intermediate NO2. - The high free energy of the intermediate product *NOH leads to difficulties in the electrochemical reduction of NO3. - The Faradaic efficiency, production rate, and nitrate removal rate of ammonia conversion are far from meeting practical requirements. Therefore, developing appropriate electrochemical catalytic materials to improve the Faradaic efficiency, production rate, and nitrate removal rate of electrochemical catalytic reduction of nitrate to ammonia is of great significance. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides a method for preparing a foamed copper-based composite organic compound layer catalytic material. The catalytic material prepared by this method can effectively improve the Faradaic efficiency, ammonia selectivity, production rate, and nitrate removal rate of the electrochemical reduction of nitrate to ammonia technology.

[0006] The technical solution adopted by this invention to solve its technical problem is:

[0007] This invention provides a method for preparing a foamed copper-based composite organic compound layer catalytic material, comprising the following steps performed in sequence:

[0008] Step [1]: An organic compound layer of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 is formed on the surface of the copper foam substrate;

[0009] Step [2] converts the organic compound layer of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 into phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2;

[0010] Step [3] converts phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 into phthalimide copper / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2, and finally obtains the foamed copper-based composite organic compound layer catalytic material.

[0011] Preferably, step [1] specifically includes the following operations:

[0012] a1. Prepare a dilute sulfuric acid solution by adding 98.3% concentrated sulfuric acid to deionized water; mix anhydrous ethanol with the prepared dilute sulfuric acid solution to form a base solution; add o-aminophenol, 8-hydroxyquinoline, ammonium tetrathiomolybdate, molybdenum trisulfide, and ammonium sulfide to the base solution and mix evenly to form a synthetic solution;

[0013] a2. Immerse the foamed copper metal in the synthesis solution and react at 40-65°C for 5-8 hours to form an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of the foamed copper metal.

[0014] Preferably, the mass fraction of the dilute sulfuric acid solution in step a1 is 4-12%; the volume ratio between anhydrous ethanol and dilute sulfuric acid solution in the base solution is 1-3:5-9; and the concentrations of o-aminophenol, 8-hydroxyquinoline, ammonium tetrathiomolybdate, molybdenum trisulfide, and ammonium sulfide in the synthesis solution are 20g / L-35g / L, 240g / L-290g / L, 140g / L-170g / L, 230g / L-260g / L, and 40g / L-70g / L.

[0015] Preferably, the weight of the copper foam immersed in each liter of the synthetic solution is 190-240g.

[0016] Preferably, step [2] specifically includes the following operations:

[0017] b1. Add phthalimide, ammonium bicarbonate, ammonium molybdate, and potassium ethoxide to deionized water and mix thoroughly to form a mother liquor; add molybdenum dialkyldithiocarbamate to ethanol to form an additive solution; mix a certain amount of the additive solution and the mother liquor to form the first conversion solution;

[0018] b2. Immerse copper foam with an organic compound layer of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 on its surface into the first conversion solution and react at room temperature for 7 to 11 hours to complete the conversion of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 into phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2.

[0019] Preferably, in step b1, the concentrations of phthalimide, ammonium bicarbonate, ammonium molybdate, and potassium ethoxide in the mother liquor are 60 g / L-100 g / L, 15 g / L-40 g / L, 100 g / L-130 g / L, and 40 g / L-80 g / L, respectively; the concentration of molybdenum dialkyldithiocarbamate in the additive solution is 75 g / L-140 g / L; and the volume ratio between the additive solution and the mother liquor in the first conversion solution is 2-3:5-7.

[0020] Preferably, in step b2, the weight of the copper foam with an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on its surface immersed in each liter of the first conversion solution is 270-310g.

[0021] Preferably, step [3] specifically includes the following operations:

[0022] c1. Add aminosulfonic acid, phthalimide, copper sulfate, potassium ethoxide, and urea to deionized water and mix well to form the second conversion solution;

[0023] c2. Immerse copper foam with phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on its surface into the second conversion solution and use it as the cathode. Use metallic copper as the anode and carry out an electrochemical conversion reaction at room temperature to convert the phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on the surface of the copper foam into phthalimide copper / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2, and finally obtain the copper foam-based composite organic compound layer catalytic material.

[0024] Preferably, in step c1, the concentrations of aminosulfonic acid in the second conversion solution are 30 g / L-55 g / L, phthalimide concentration is 170 g / L-215 g / L, copper sulfate concentration is 60 g / L-130 g / L, potassium ethoxide concentration is 20 g / L-35 g / L, and urea concentration is 40 g / L-60 g / L.

[0025] Preferably, in step c2, the weight of the copper foam with phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on its surface immersed in each liter of the second conversion liquid is 210-270g; the electrochemical voltage of the electrochemical conversion reaction is 0.4-0.8V, and the electrochemical conversion reaction time is 0.5-2 hours.

[0026] The positive effects of this invention are as follows: The foamed copper-based composite organic compound catalytic material prepared by the method described in this invention is an organic compound catalytic material with phthalimide copper / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2 formed on the surface of the foamed copper base. Its structural features are as follows: the organic compound phthalimide copper Cu(C8H4NO2)2 is composed of one copper ion and two phthalimide ions. The nitrogen atom of the phthalimide ion forms a chemical bond with ionic properties with the p-π electron clouds of the two carbonyl groups and the copper ion; the organic compound 8-hydroxyquinoline molybdenum Mo(C9H6NO)2 is composed of one molybdenum ion and two 8-hydroxyquinoline ions. The 8-hydroxyquinoline molybdenum contains delocalized π bonds, which can increase the electron transfer rate in the electrochemical reduction of nitrate to ammonia. The catalytic material prepared in this invention utilizes the low electron density of nitrogen atoms in copper phthalimide Cu(C8H4NO2)2 to reduce competition for hydrogen evolution reduction (HER) during the electrochemical reduction of nitrate to ammonia. Furthermore, the copper ions in Cu(C8H4NO2)2 can reduce the amount of *NO2 produced as a key intermediate during the electrochemical reduction of nitrate to ammonia. - The free energy for the formation of the intermediate product *NOH indicates that Cu(C8H4NO2)2 can not only inhibit the hydrogen evolution process but also improve the yield of electrochemical reduction of nitrate to ammonia. The molybdenum ion of 8-hydroxyquinoline molybdenum Mo(C9H6NO)2 has high activity, and the interfacial electron movement structure between 8-hydroxyquinoline molybdenum Mo(C9H6NO)2 and phthalimide copper Cu(C8H4NO2)2 lowers the barrier for electrochemical reduction of nitrate to ammonia, which can effectively improve the Faradaic efficiency, production rate and nitrate removal rate of the electrochemical reduction of nitrate to ammonia process. Attached Figure Description

[0027] Figure 1 is a schematic diagram of the preparation process of the foamed copper-based composite organic compound layer catalytic material of the present invention;

[0028] Figure 2a shows the formation of ammonia (NH4) during the electrochemical reduction of nitrate in Example 1 of the present invention. + ), nitrogen, NO2 - Faraday efficiency;

[0029] Figure 2b shows the formation of ammonia (NH4) during the electrochemical reduction of nitrate in Comparative Example 1 of this invention. + ), nitrogen, NO2- Faraday efficiency;

[0030] Figure 2c shows the formation of ammonia (NH4) during the electrochemical reduction of nitrate in Comparative Example 2 of this invention. + ), nitrogen, NO2 - Faraday efficiency;

[0031] Figure 3a shows the electrochemical reduction of nitrate ions to ammonia (NH4) in Example 1 of the present invention. + The average production rate;

[0032] Figure 3b shows the electrochemical reduction of nitrate ions to ammonia (NH4) in Comparative Example 1 of this invention. + The average production rate;

[0033] Figure 3c shows the electrochemical reduction of nitrate ions to ammonia (NH4) in Comparative Example 2 of this invention. + The average production rate;

[0034] Figure 4a shows the average nitrate removal rate in the electrochemical reduction of nitrate to ammonia process of Example 1 of the present invention.

[0035] Figure 4b shows the average nitrate removal rate in the electrochemical reduction of nitrate to ammonia process of Comparative Example 1 of the present invention.

[0036] Figure 4c shows the average nitrate removal rate in the electrochemical reduction of nitrate to ammonia process of Comparative Example 2 of the present invention. Detailed Implementation

[0037] Referring to Figure 1, the present invention provides a method for preparing a foamed copper-based composite organic compound layer catalytic material, comprising the following steps performed in sequence:

[0038] Step [1] involves forming an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of the copper foam substrate, specifically including the following operations:

[0039] a1. Prepare a 4-12% dilute sulfuric acid solution by adding 98.3% concentrated sulfuric acid to deionized water; mix anhydrous ethanol with the prepared dilute sulfuric acid solution at a volume ratio of 1-3:5-9 to form a base solution; add o-aminophenol, 8-hydroxyquinoline, ammonium tetrathiomolybdate, molybdenum trisulfide, and ammonium sulfide to the base solution and mix evenly to form a synthesis solution with o-aminophenol concentration of 20g / L-35g / L, 8-hydroxyquinoline concentration of 240g / L-290g / L, ammonium tetrathiomolybdate concentration of 140g / L-170g / L, molybdenum trisulfide concentration of 230g / L-260g / L, and ammonium sulfide concentration of 40g / L-70g / L;

[0040] a2. Immerse the foamed copper metal in the synthesis solution (the weight of the foamed copper immersed in each liter of the synthesis solution is 190-240g) and react at 40-65°C for 5-8 hours to form an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of the foamed copper metal.

[0041] The structural formula of the 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 is:

[0042]

[0043] Step [2] converts the organic compound layer of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 into phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2, specifically including the following operations:

[0044] b1. Add phthalimide, ammonium bicarbonate, ammonium molybdate, and potassium ethoxide to deionized water and mix thoroughly to form a mother liquor with a phthalimide concentration of 60 g / L-100 g / L, an ammonium bicarbonate concentration of 15 g / L-40 g / L, an ammonium molybdate concentration of 100 g / L-130 g / L, and a potassium ethoxide concentration of 40 g / L-80 g / L; add molybdenum dialkyldithiocarbamate to ethanol to form an additive solution with a molybdenum dialkyldithiocarbamate concentration of 75 g / L-140 g / L; mix the additive solution and the mother liquor at a volume ratio of 2-3:5-7 to form the first conversion solution;

[0045] b2. Immerse copper foam with an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on its surface into the first conversion solution (the weight of copper foam with an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on its surface immersed in each liter of the first conversion solution is 270-310 g), and react at room temperature for 7-11 hours to complete the conversion of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 into phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2.

[0046] The structural formula of the phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 is as follows:

[0047]

[0048] Step [3] converts phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 into phthalimide copper / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2, specifically including the following operations:

[0049] c1. Add aminosulfonic acid, phthalimide, copper sulfate, potassium ethoxide, and urea to deionized water and mix thoroughly to form a second conversion solution with aminosulfonic acid concentration of 30g / L-55g / L, phthalimide concentration of 170g / L-215g / L, copper sulfate concentration of 60g / L-130g / L, potassium ethoxide concentration of 20g / L-35g / L, and urea concentration of 40g / L-60g / L.

[0050] c2. Immerse copper foam with phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on its surface into the second conversion solution (the weight of copper foam with phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 immersed in each liter of the second conversion solution is 210-270g) and use it as the cathode, with metallic copper as the anode, and carry out an electrochemical conversion reaction at room temperature, wherein the voltage is 0.4-0.8V and the electrochemical conversion reaction time is 0.5-2 hours, so that the phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on the surface of the copper foam is converted into phthalimide copper / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2, and finally obtain the copper foam-based composite organic compound layer catalytic material.

[0051] The structural formula of the copper phthalimide / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2 is as follows:

[0052]

[0053] The preferred embodiments of the present invention will be described below by way of example.

[0054] Example 1

[0055] Preferred embodiment 1 of the present invention provides a method for preparing a foamed copper-based composite organic compound layer catalytic material, comprising the following steps performed in sequence:

[0056] Step [1] involves forming an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of the copper foam substrate, specifically including the following operations:

[0057] a1. Prepare a 10% dilute sulfuric acid solution by adding 98.3% concentrated sulfuric acid to deionized water; mix anhydrous ethanol with the prepared dilute sulfuric acid solution at a volume ratio of 2:7 to form a base solution; add o-aminophenol, 8-hydroxyquinoline, ammonium tetrathiomolybdate, molybdenum trisulfide, and ammonium sulfide to the base solution and mix thoroughly to form a synthesis solution with o-aminophenol concentration of 30 g / L, 8-hydroxyquinoline concentration of 280 g / L, ammonium tetrathiomolybdate concentration of 160 g / L, molybdenum trisulfide concentration of 252 g / L, and ammonium sulfide concentration of 60 g / L;

[0058] a2. Immerse the foamed copper metal in the synthesis solution (the weight of the foamed copper immersed in each liter of the synthesis solution is 230g) and react at 60°C for 7 hours to form an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of the foamed copper metal.

[0059] Step [2] converts the organic compound layer of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 into phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2, specifically including the following operations:

[0060] b1. Add phthalimide, ammonium bicarbonate, ammonium molybdate, and potassium ethoxide to deionized water and mix thoroughly to form a mother liquor with a phthalimide concentration of 90 g / L, an ammonium bicarbonate concentration of 30 g / L, an ammonium molybdate concentration of 120 g / L, and a potassium ethoxide concentration of 70 g / L; add molybdenum dialkyldithiocarbamate to ethanol to form an additive solution with a molybdenum dialkyldithiocarbamate concentration of 130 g / L; mix the additive solution and the mother liquor at a volume ratio of 3:5 to form the first conversion solution;

[0061] b2. Immerse copper foam with an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on its surface into the first conversion solution (the weight of copper foam with an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on its surface immersed in each liter of the first conversion solution is 300g), and react at room temperature for 10 hours to complete the conversion of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 into phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2.

[0062] Step [3] converts phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 into phthalimide copper / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2, specifically including the following operations:

[0063] c1. Add aminosulfonic acid, phthalimide, copper sulfate, potassium ethoxide, and urea to deionized water and mix thoroughly to form a second conversion solution with aminosulfonic acid concentration of 50 g / L, phthalimide concentration of 210 g / L, copper sulfate concentration of 120 g / L, potassium ethoxide concentration of 30 g / L, and urea concentration of 50 g / L.

[0064] c2. A copper foam with phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on its surface is immersed in the second conversion solution (the weight of copper foam with phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 immersed in each liter of the second conversion solution is 260g) and used as the cathode. With metallic copper as the anode, an electrochemical conversion reaction is carried out at room temperature, wherein the voltage is 0.6V and the electrochemical conversion reaction time is 1 hour, so that the phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on the surface of the copper foam is converted into phthalimide copper / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2, and finally the copper foam-based composite organic compound layer catalytic material is obtained, which is referred to as Example 1.

[0065] Comparative Example 1

[0066] Comparative Example 1 provides a method for preparing a copper foam-based 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 catalytic material, which includes the step of forming an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of a copper foam substrate, specifically including the following operations:

[0067] a1. Prepare a 5% sulfuric acid solution by adding 98.3% concentrated sulfuric acid to deionized water; mix anhydrous ethanol with the prepared dilute sulfuric acid solution at a volume ratio of 2:5 to form a base solution; add o-aminophenol, 8-hydroxyquinoline, ammonium tetrathiomolybdate, molybdenum trisulfide, and ammonium sulfide to the base solution and mix evenly to form a synthesis solution with o-aminophenol concentration of 25 g / L, 8-hydroxyquinoline concentration of 249 g / L, ammonium tetrathiomolybdate concentration of 150 g / L, molybdenum trisulfide concentration of 240 g / L, and ammonium sulfide concentration of 50 g / L.

[0068] a2. Immerse copper foam in the synthesis solution (200g of copper foam is immersed in each liter of the synthesis solution) and react at 60°C for 6 hours to form an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of the copper foam, and finally obtain the copper foam-based 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 catalytic material, referred to as Comparative Example 1.

[0069] Comparative Example 2

[0070] Comparative Example 2 provides a method for preparing a foamed copper-based phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 catalytic material, comprising the following steps performed in sequence:

[0071] Step [1] involves forming an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of the copper foam substrate, specifically including the following operations:

[0072] a1. Prepare an 8% sulfuric acid solution by adding 98.3% concentrated sulfuric acid to deionized water; mix anhydrous ethanol with the prepared dilute sulfuric acid solution at a volume ratio of 3:5 to form a base solution; add o-aminophenol, 8-hydroxyquinoline, ammonium tetrathiomolybdate, molybdenum trisulfide, and ammonium sulfide to the base solution and mix thoroughly to form a synthesis solution with o-aminophenol concentration of 30 g / L, 8-hydroxyquinoline concentration of 260 g / L, ammonium tetrathiomolybdate concentration of 160 g / L, molybdenum trisulfide concentration of 246 g / L, and ammonium sulfide concentration of 60 g / L.

[0073] a2. Immerse the foamed copper metal in the synthesis solution (the weight of the foamed copper immersed in each liter of the synthesis solution is 210g) and react at 55°C for 7 hours to form an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of the foamed copper metal.

[0074] Step [2] converts the organic compound layer of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 into phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2, specifically including the following operations:

[0075] b1. Add phthalimide, ammonium bicarbonate, ammonium molybdate, and potassium ethoxide to deionized water and mix thoroughly to form a mother liquor with a phthalimide concentration of 70 g / L, an ammonium bicarbonate concentration of 20 g / L, an ammonium molybdate concentration of 110 g / L, and a potassium ethoxide concentration of 50 g / L; add molybdenum dialkyldithiocarbamate to ethanol to form an additive solution with a molybdenum dialkyldithiocarbamate concentration of 80 g / L; mix the additive solution and the mother liquor at a volume ratio of 3:7 to form the first conversion solution;

[0076] b2. A copper foam with an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on its surface was immersed in the first conversion solution (the weight of the copper foam with an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer immersed in each liter of the first conversion solution was 280 g). The reaction was carried out at room temperature for 9 hours to complete the conversion of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 to phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2, and finally the copper foam-based phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 catalytic material was obtained, which was referred to as Comparative Example 2.

[0077] To compare and analyze the conversion products and catalytic characteristics (Faraday efficiency, selectivity, production rate, and nitrate removal rate) of nitrate reduction in Examples 1, 1 (Example), and 2 (Comparative Example), Example 1, 1 (Example), and 2 (Comparative Example) were used as the cathode working electrode, platinum as the auxiliary electrode, and a saturated calomel electrode as the reference electrode. An H-type electrolytic cell was used, with the cathode and anode chambers separated by a Nafion membrane. Electrochemical reduction of nitrate was tested in 0.1M NaNO3 solution with applied voltages of 0.2V, -0.3V, -0.4V, -0.5V, -0.6V, and -0.7V for 4 hours. The concentration of ammonia (NH4+) in the solution during the 4-hour electrochemical reduction of nitrate was quantitatively calculated and analyzed using a UV-Vis spectrophotometer. + ), nitrite (NO2) - ) and nitrate (NO3) - The concentration of nitrogen gas produced during the electrochemical reduction of nitrate was determined by gas chromatography.

[0078] Ammonia (NH4) was generated in Examples 1, Comparative Examples 1 and 2 after 4 hours of electrochemical reduction under different applied voltages. + ), nitrogen, NO2 - The Faraday efficiency test results are shown in Figures 2a-c. In Example 1, ammonia (NH4) was generated under applied voltages of -0.4V, -0.5V, and -0.6V. + With a Faraday efficiency exceeding 90%, ammonia (NH4) is generated when the applied voltage is -0.6V. + The Faraday efficiency can reach up to 93.28%; Comparative Example 1 produces ammonia (NH4). + The highest Faraday efficiency was only 11.26% (at an applied voltage of -0.3V), while Comparative Example 2 showed the highest ammonia formation efficiency (NH4). + The high-efficiency Faraday reduction was 21.29% (at an applied voltage of -0.4V). Clearly, Example 1 exhibits excellent electrochemical reduction efficiency for the conversion of nitrate ions to ammonia (NH4). + Faraday efficiency and selectivity.

[0079] After 4 hours of electrochemical reduction under different applied voltages, Examples 1, Comparative Examples 1 and 2 showed that nitrate ions were converted into ammonia (NH4+) by electrochemical reduction in 0.1M NaNO3 solution. + The average production rate results are shown in Figures 3a-c. In Example 1, the electrochemical reduction of nitrate ions to ammonia (NH4) was carried out at applied voltages of -0.2V, -0.3V, -0.4V, -0.5V, -0.6V, and -0.7V. + The average production rate is higher than 500 mg / h. -1 ·mg -1 The average production rate can reach a maximum of 674 mg·h when the applied voltage is -0.3V. -1 ·mg -1 Comparative Example 1 produces ammonia (NH4). + The highest average production rate was only 9.87 mg·h -1 ·mg -1 (When the applied voltage is -0.4V), ammonia (NH4) is generated in Comparative Example 2. + The highest average production rate was 28.85 mg / h. -1 ·mg -1 (When the applied voltage is -0.5V).

[0080] Figures 4a-c show the average removal rates of nitrate in 0.1M NaNO3 solution for 4 hours of electrochemical reduction under different applied voltages for Examples 1, Comparative Example 1, and Comparative Example 2. In Example 1, the average removal rate of nitrate during the electrochemical reduction process to ammonia conversion was higher than 77% at applied voltages of -0.2V, -0.3V, -0.4V, -0.5V, -0.6V, and -0.7V, with the highest removal rate reaching 82.31% at -0.4V. In Comparative Example 1, the highest average nitrate removal rate was only 15.51% (at -0.4V), and in Comparative Example 2, the highest average nitrate removal rate was 22.58% (at -0.6V).

[0081] The above experimental results show that the catalytic material prepared according to the method of the present invention can effectively improve the Faraday efficiency, ammonia selectivity, production rate and nitrate removal rate of the electrochemical reduction of nitrate to ammonia technology.

[0082] To illustrate this further in detail, three more embodiments are provided below.

[0083] Example 2

[0084] Preferred embodiment 2 of the present invention provides a method for preparing a foamed copper-based composite organic compound layer catalytic material, comprising the following steps performed in sequence:

[0085] Step [1] involves forming an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of the copper foam substrate, specifically including the following operations:

[0086] a1. Prepare a 4% sulfuric acid solution by adding 98.3% concentrated sulfuric acid to deionized water; mix anhydrous ethanol with the prepared dilute sulfuric acid solution at a volume ratio of 1:3 to form a base solution; add o-aminophenol, 8-hydroxyquinoline, ammonium tetrathiomolybdate, molybdenum trisulfide, and ammonium sulfide to the base solution and mix evenly to form a synthesis solution with o-aminophenol concentration of 20 g / L, 8-hydroxyquinoline concentration of 240 g / L, ammonium tetrathiomolybdate concentration of 170 g / L, molybdenum trisulfide concentration of 260 g / L, and ammonium sulfide concentration of 70 g / L.

[0087] a2. Immerse the foamed copper metal in the synthesis solution (the weight of the foamed copper immersed in each liter of the synthesis solution is 190g) and react at 40°C for 8 hours to form an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of the foamed copper metal.

[0088] Step [2] converts the organic compound layer of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 into phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2, specifically including the following operations:

[0089] b1. Add phthalimide, ammonium bicarbonate, ammonium molybdate, and potassium ethoxide to deionized water and mix thoroughly to form a mother liquor with a phthalimide concentration of 100 g / L, an ammonium bicarbonate concentration of 40 g / L, an ammonium molybdate concentration of 100 g / L, and a potassium ethoxide concentration of 40 g / L; add molybdenum dialkyldithiocarbamate to ethanol to form an additive solution with a molybdenum dialkyldithiocarbamate concentration of 140 g / L; mix the additive solution and the mother liquor at a volume ratio of 2:5 to form the first conversion solution;

[0090] b2. Immerse copper foam with an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on its surface into the first conversion solution (the weight of copper foam with an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on its surface immersed in each liter of the first conversion solution is 310 g), and react at room temperature for 11 hours to complete the conversion of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 into phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2.

[0091] Step [3] converts phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 into phthalimide copper / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2, specifically including the following operations:

[0092] c1. Add aminosulfonic acid, phthalimide, copper sulfate, potassium ethoxide, and urea to deionized water and mix thoroughly to form a second conversion solution with aminosulfonic acid concentration of 30 g / L, phthalimide concentration of 170 g / L, copper sulfate concentration of 130 g / L, potassium ethoxide concentration of 35 g / L, and urea concentration of 60 g / L.

[0093] c2. A copper foam with phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on its surface is immersed in the second conversion solution (the weight of copper foam with phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 immersed in each liter of the second conversion solution is 210g) and used as the cathode, with metallic copper as the anode, and an electrochemical conversion reaction is carried out at room temperature, wherein the voltage is 0.8V and the electrochemical conversion reaction time is 0.5 hours, so that the phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on the surface of the copper foam is converted into phthalimide copper / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2, and finally the copper foam-based composite organic compound layer catalytic material is obtained.

[0094] Example 3

[0095] Preferred embodiment 3 of the present invention provides a method for preparing a foamed copper-based composite organic compound layer catalytic material, comprising the following steps performed in sequence:

[0096] Step [1] involves forming an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of the copper foam substrate, specifically including the following operations:

[0097] a1. Prepare a 12% sulfuric acid solution by adding 98.3% concentrated sulfuric acid to deionized water; mix anhydrous ethanol with the prepared dilute sulfuric acid solution at a volume ratio of 3:5 to form a base solution; add o-aminophenol, 8-hydroxyquinoline, ammonium tetrathiomolybdate, molybdenum trisulfide, and ammonium sulfide to the base solution and mix evenly to form a synthesis solution with o-aminophenol concentration of 35 g / L, 8-hydroxyquinoline concentration of 290 g / L, ammonium tetrathiomolybdate concentration of 140 g / L, molybdenum trisulfide concentration of 230 g / L, and ammonium sulfide concentration of 40 g / L.

[0098] a2. Immerse the foamed copper metal in the synthesis solution (the weight of the foamed copper immersed in each liter of the synthesis solution is 240g) and react at 65°C for 5 hours to form an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of the foamed copper metal.

[0099] Step [2] converts the organic compound layer of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 into phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2, specifically including the following operations:

[0100] b1. Add phthalimide, ammonium bicarbonate, ammonium molybdate, and potassium ethoxide to deionized water and mix thoroughly to form a mother liquor with a phthalimide concentration of 60 g / L, an ammonium bicarbonate concentration of 15 g / L, an ammonium molybdate concentration of 130 g / L, and a potassium ethoxide concentration of 80 g / L; add molybdenum dialkyldithiocarbamate to ethanol to form an additive solution with a molybdenum dialkyldithiocarbamate concentration of 75 g / L; mix the additive solution and the mother liquor at a volume ratio of 3:7 to form the first conversion solution;

[0101] b2. Immerse copper foam with an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on its surface into the first conversion solution (the weight of copper foam with an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on its surface immersed in each liter of the first conversion solution is 270 g), and react at room temperature for 7 hours to complete the conversion of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 into phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2.

[0102] Step [3] converts phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 into phthalimide copper / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2, specifically including the following operations:

[0103] c1. Add aminosulfonic acid, phthalimide, copper sulfate, potassium ethoxide, and urea to deionized water and mix thoroughly to form a second conversion solution with aminosulfonic acid concentration of 55 g / L, phthalimide concentration of 215 g / L, copper sulfate concentration of 60 g / L, potassium ethoxide concentration of 20 g / L, and urea concentration of 40 g / L.

[0104] c2. A copper foam with phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on its surface is immersed in the second conversion solution (the weight of copper foam with phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 immersed in each liter of the second conversion solution is 270g) and used as the cathode. With metallic copper as the anode, an electrochemical conversion reaction is carried out at room temperature, wherein the voltage is 0.4V and the electrochemical conversion reaction time is 2 hours, so that the phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on the surface of the copper foam is converted into phthalimide copper / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2, and finally the copper foam-based composite organic compound layer catalytic material is obtained.

[0105] Example 4

[0106] Preferred embodiment 4 of the present invention provides a method for preparing a foamed copper-based composite organic compound layer catalytic material, comprising the following steps performed in sequence:

[0107] Step [1] involves forming an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of the copper foam substrate, specifically including the following operations:

[0108] a1. Prepare an 8% sulfuric acid solution by adding 98.3% concentrated sulfuric acid to deionized water; mix anhydrous ethanol with the prepared dilute sulfuric acid solution at a volume ratio of 3:8 to form a base solution; add o-aminophenol, 8-hydroxyquinoline, ammonium tetrathiomolybdate, molybdenum trisulfide, and ammonium sulfide to the base solution and mix thoroughly to form a synthesis solution with o-aminophenol concentration of 28 g / L, 8-hydroxyquinoline concentration of 270 g / L, ammonium tetrathiomolybdate concentration of 155 g / L, molybdenum trisulfide concentration of 245 g / L, and ammonium sulfide concentration of 55 g / L.

[0109] a2. Immerse the foamed copper metal in the synthesis solution (the weight of the foamed copper immersed in each liter of the synthesis solution is 215g) and react at 55°C for 6 hours to form an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of the foamed copper metal.

[0110] Step [2] converts the organic compound layer of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 into phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2, specifically including the following operations:

[0111] b1. Phthalimide, ammonium bicarbonate, ammonium molybdate, and potassium ethoxide are added to deionized water and mixed thoroughly to form a mother liquor with a phthalimide concentration of 80 g / L, an ammonium bicarbonate concentration of 26 g / L, an ammonium molybdate concentration of 115 g / L, and a potassium ethoxide concentration of 60 g / L; molybdenum dialkyldithiocarbamate is added to ethanol to form an additive solution with a molybdenum dialkyldithiocarbamate concentration of 108 g / L; the additive solution and the mother liquor are mixed at a volume ratio of 2.5:6 to form the first conversion solution;

[0112] b2. Immerse copper foam with an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on its surface into the first conversion solution (the weight of copper foam with an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on its surface immersed in each liter of the first conversion solution is 290 g), and react at room temperature for 9 hours to complete the conversion of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 into phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2.

[0113] Step [3] converts phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 into phthalimide copper / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2, specifically including the following operations:

[0114] c1. Add aminosulfonic acid, phthalimide, copper sulfate, potassium ethoxide, and urea to deionized water and mix thoroughly to form a second conversion solution with aminosulfonic acid concentration of 42 g / L, phthalimide concentration of 195 g / L, copper sulfate concentration of 95 g / L, potassium ethoxide concentration of 29 g / L, and urea concentration of 50 g / L.

[0115] c2. A copper foam with phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on its surface is immersed in the second conversion solution (the weight of copper foam with phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 immersed in each liter of the second conversion solution is 240g) and used as the cathode, with metallic copper as the anode, and an electrochemical conversion reaction is carried out at room temperature, wherein the voltage is 0.6V and the electrochemical conversion reaction time is 1.5 hours, so that the phthalimide-8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on the surface of the copper foam is converted into phthalimide copper / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2, and finally the copper foam-based composite organic compound layer catalytic material is obtained.

[0116] The above description is only a preferred embodiment of the present invention. It should be understood that the above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention, and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, etc. made within the idea and principle of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a foamed copper-based composite organic compound layer catalytic material, characterized in that, The process includes the following steps performed in sequence: Step [1] forming an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of a copper foam substrate; Step [2] converting the 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer into phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2; Step [3] converting phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 into phthalimide copper / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2, and finally obtaining the copper foam composite organic compound layer catalytic material.

2. The method for preparing a foamed copper-based composite organic compound layer catalytic material according to claim 1, characterized in that, The steps [1] specifically include the following operations: a1. Add concentrated sulfuric acid with a mass fraction of 98.3% to deionized water to prepare a dilute sulfuric acid solution; mix anhydrous ethanol with the prepared dilute sulfuric acid solution to form a base solution; add o-aminophenol, 8-hydroxyquinoline, ammonium tetrathiomolybdate, molybdenum trisulfide, and ammonium sulfide to the base solution and mix evenly to form a synthesis solution; a2. Immerse the foamed copper metal in the synthesis solution and react at 40-65°C for 5-8 hours to form an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on the surface of the foamed copper metal.

3. The method for preparing a foamed copper-based composite organic compound layer catalytic material according to claim 2, characterized in that: The mass fraction of the dilute sulfuric acid solution in step a1 is 4-12%; the volume ratio of anhydrous ethanol to dilute sulfuric acid solution in the base solution is 1-3:5-9; the concentration of o-aminophenol in the synthesis solution is 20g / L-35g / L, the concentration of 8-hydroxyquinoline is 240g / L-290g / L, the concentration of ammonium tetrathiomolybdate is 140g / L-170g / L, the concentration of molybdenum trisulfide is 230g / L-260g / L, and the concentration of ammonium sulfide is 40g / L-70g / L.

4. The method for preparing a foamed copper-based composite organic compound layer catalytic material according to claim 2, characterized in that: The weight of the copper foam immersed in each liter of the synthetic solution is 190-240g.

5. The method for preparing a foamed copper-based composite organic compound layer catalytic material according to claim 1, characterized in that, The steps [2] specifically include the following operations: b1. Add phthalimide, ammonium bicarbonate, ammonium molybdate and potassium ethoxide to deionized water and mix evenly to form a mother liquor; add molybdenum dialkyl dithiocarbamate to ethanol to form an additive solution; mix a certain amount of additive solution and mother liquor to form a first conversion solution; b2. Immerse copper foam with an organic compound layer of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 on its surface into the first conversion solution and react at room temperature for 7 to 11 hours to complete the conversion of 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 to phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2.

6. The method for preparing a foamed copper-based composite organic compound layer catalytic material according to claim 5, characterized in that: In step b1, the mother liquor contains phthalimide at a concentration of 60 g / L-100 g / L, ammonium bicarbonate at a concentration of 15 g / L-40 g / L, ammonium molybdate at a concentration of 100 g / L-130 g / L, and potassium ethoxide at a concentration of 40 g / L-80 g / L; the additive solution contains molybdenum dialkyldithiocarbamate at a concentration of 75 g / L-140 g / L; and the volume ratio between the additive solution and the mother liquor in the first conversion solution is 2-3:5-7.

7. The method for preparing a foamed copper-based composite organic compound layer catalytic material according to claim 5, characterized in that: In step b2, the weight of the foamed copper with an 8-hydroxyquinoline molybdenum Mo(C9H6NO)4 organic compound layer on its surface immersed in each liter of the first conversion solution is 270-310g.

8. The method for preparing a foamed copper-based composite organic compound layer catalytic material according to claim 1, characterized in that, The steps [3] specifically include the following operations: c1. Add aminosulfonic acid, phthalimide, copper sulfate, potassium ethoxide and urea to deionized water and mix evenly to form a second conversion solution; c2. Immerse the foamed copper with phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on its surface into the second conversion solution and use it as the cathode. Use metallic copper as the anode and carry out an electrochemical conversion reaction at room temperature so that the phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on the surface of the foamed copper base is converted into phthalimide copper / 8-hydroxyquinoline molybdenum Cu(C8H4NO2)2 / Mo(C9H6NO)2, and finally obtain the foamed copper base composite organic compound layer catalytic material.

9. The method for preparing a foamed copper-based composite organic compound layer catalytic material according to claim 8, characterized in that: In step c1, the concentrations of aminosulfonic acid in the second conversion solution are 30 g / L-55 g / L, phthalimide concentration is 170 g / L-215 g / L, copper sulfate concentration is 60 g / L-130 g / L, potassium ethoxide concentration is 20 g / L-35 g / L, and urea concentration is 40 g / L-60 g / L.

10. The method for preparing a foamed copper-based composite organic compound layer catalytic material according to claim 8, characterized in that: In step c2, the weight of the copper foam with phthalimide 8-hydroxyquinoline molybdenum Mo(C8H4NO2)2(C9H6NO)2 on its surface immersed in each liter of the second conversion solution is 210-270g; the electrochemical voltage of the electrochemical conversion reaction is 0.4-0.8V, and the electrochemical conversion reaction time is 0.5-2 hours.

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