A method for preparing copper-based noble metal nanomaterial

Abstract

The present invention relates to the technical field of metal materials, and discloses a method for preparing a copper-based noble metal nanomaterial. The copper-based noble metal nanomaterial is prepared by the following steps: copper oxide and a noble metal salt solution are evenly ground in a mortar until they become viscous, and a copper oxide / noble metal salt precursor is obtained after drying. Silane, acetonitrile, and water are then added to a photocatalytic reactor, dispersed evenly, and a solution system is obtained. An in-situ reconstruction strategy is then adopted, and the above-mentioned precursor is added to the above-mentioned solution system for light irradiation reaction, and finally a copper / noble metal nanomaterial is obtained. The preparation process of the copper-based noble metal nanomaterial of the present invention is simple and novel, the reaction conditions are mild, the time consumption is short, and it can be prepared in large quantities at low cost. Therefore, the synthesis method of the copper-based bimetallic catalyst has important application value in large-scale industrial practical applications.

Description

Technical Field

[0001] The present invention relates to the technical field of catalysts, and in particular to a method for preparing a copper-based noble metal nanomaterial. Background Art

[0002] Promoting the efficient conversion of carbon dioxide into high-value-added multi-carbon products is a key approach to achieving an artificial carbon cycle and a promising solution to reducing our dependence on fossil fuels, improving environmental issues, and addressing future global energy transitions. Producing abundant multi-carbon products through clean, renewable CO2 electrocatalytic reduction has garnered considerable research interest. Multi-carbon products (such as ethanol, ethylene, and propane) are widely used in pesticides, gasoline additives, daily chemicals, and pharmaceuticals due to their high energy density and economic value. Currently, copper nanomaterials, owing to their relaxed d-electron structure and moderate adsorption strength for carbonaceous intermediates, have become the leading catalysts for the electroreduction of CO2 to multi-carbon products with high activity and high Faradaic efficiency. However, under operating conditions, the constant changes in the electrocatalytic microenvironment (pH, reaction medium, etc.) can lead to poisoning of the active surface of the catalyst, leading to its deactivation. Furthermore, the long-term stability of these catalysts at high currents remains a bottleneck hindering their large-scale industrial application. Therefore, there is a need for economical and effective alternative catalysts, and the search for cost-effective and scalable preparation methods to efficiently synthesize copper-based catalysts is of great significance and faces major challenges for the high selectivity and high stability of carbon dioxide reduction to multi-carbon products.

[0003] With in-depth research, it has been discovered that copper nanomaterials can be combined with trace amounts of precious metals to construct high-performance precious metal nanomaterial catalysts. This strategy is one of the effective solutions to overcome the problem of catalytic stability and can achieve high catalytic performance and high selectivity for multi-carbon products. Currently reported methods for preparing copper-based precious metal materials mainly include solvothermal method, in-situ reduction method, hot injection method, physical mixing method and mechanical ball milling method. However, the above methods are usually time-consuming, the yield of synthetic catalysts is small, and they require high temperature, high pressure and complex and harsh reaction conditions; more importantly, the catalytic performance and long-term stability of the obtained copper-based precious metal materials for preparing multi-carbon products still need to be improved.

[0004] In response to the above problems, the present invention proposes a method for rapidly and massively preparing high-efficiency copper-based precious metal nanomaterials. The preparation process is simple and novel, the reaction conditions are mild, and the cost is low. Summary of the Invention

[0005] In order to solve the technical problems raised in the background technology, the present invention provides a method for quickly and massively preparing high-efficiency copper-based precious metal nanomaterials.

[0006] The present invention is implemented by the following technical solution: A method for preparing a copper-based noble metal nanomaterial comprises the following steps:

[0007] The copper oxide / noble metal salt precursor is synthesized by physical mixing method, and then the copper oxide / noble metal salt is converted into copper / noble metal nanomaterials by in situ reconstruction strategy, as follows:

[0008] Step (1) Grind the copper oxide and noble metal salt solution in a mortar until they are evenly viscous, and then dry them at 80-100° C. for 1-2 hours to obtain a copper oxide / noble metal salt precursor.

[0009] Step (2) adding silane, acetonitrile and water into a photocatalytic reactor and dispersing them evenly to obtain a solution system.

[0010] Step (3) adopts an in-situ reconstruction strategy, by adding the precursor in the above step (1) to the solution system in the above step (2) for light reaction, thereby converting the precursor in the above step (1) into copper / noble metal nanomaterials.

[0011] Step (4) The copper / noble metal nanomaterial obtained in step (3) is centrifuged, washed, dried, and stored under an inert atmosphere.

[0012] In the above preparation method, preferably, the copper oxide is one of powdered copper oxide, nano copper oxide, etc.

[0013] In the above preparation method, preferably, the noble metal salt includes one of silver nitrate, palladium chloride, chloroplatinic acid, chloroauric acid, etc.

[0014] In the above preparation method, preferably, the solvent used to prepare the noble metal salt solution is a 20-30% ethanol aqueous solution.

[0015] In the above preparation method, preferably, the precious metal includes one of silver, palladium, platinum, gold, etc.

[0016] In the above preparation method, preferably, the physical mixing method adopted in step (1) can be mixed by grinding, and more preferably, the grinding is performed uniformly in a mortar.

[0017] In the above preparation method, preferably, the molar ratio of copper oxide to precious metal salt used in step (1) is 1000:1 to 30:1.

[0018] In the above preparation method, preferably, the silane in step (2) includes one of triethylsilane, triphenylsilane, 1,4-bis(dimethylsilyl)benzene, etc.

[0019] In the above preparation method, preferably, the molar ratio of silane, acetonitrile and water used in step (2) is 1:40:50 to 2:20:25.

[0020] In the above preparation method, preferably, in step (2), the silane, acetonitrile, and water are uniformly dispersed in the photocatalytic reactor by stirring. More preferably, the stirring is magnetic stirring, and the speed of the magnetic stirring is 300-600 rpm, and the stirring time is 20-60 minutes. Further preferably, the silane, acetonitrile, and water are first added to the photocatalytic reactor and uniformly dispersed (stirring or ultrasonic dispersion can be selected), and then the precursor in step (1) is added and uniformly dispersed by magnetic stirring.

[0021] In the above preparation method, preferably, a xenon lamp can be selected as the light source for the illumination reaction in step (3), and more preferably, the xenon lamp is a Perfil constant current xenon lamp, and the current intensity of the Perfil constant current xenon lamp is 10-20A.

[0022] In the above preparation method, preferably, in the centrifugal washing in step (4), the centrifugal speed can be selected to be 8000-12000 rpm, and the centrifugation time can be 3-5 minutes. The solvent that can be selected for washing is one of ethanol, acetone, acetonitrile, etc.

[0023] In the above preparation method, preferably, the inert gas in step (4) can be selected from argon, nitrogen, etc.

[0024] Compared with the existing technology, the beneficial effect of the present invention lies in: synthesizing copper oxide / precious metal salt precursors by a physical mixing method, and then converting copper oxide / precious metal salts into copper / precious metal nanomaterials through an in situ reconstruction strategy. This method uses silane as a reducing agent to prepare a series of copper-based precious metal nanomaterials with uniform morphology and uniform element distribution.

[0025] The present invention uses conventional copper oxide powder and precious metal salts as raw materials, acetonitrile as a solvent, silane as a reducing agent, and water as an oxidant to synthesize copper-based precious metal nanomaterials under light conditions. The preparation process is simple and novel, with mild reaction conditions, short reaction time, and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a flow chart of the method for preparing the copper-based noble metal nanomaterial proposed by the present invention;

[0027] Figure 2 This is a macro-synthetic photograph of a copper oxide / silver nitrate precursor according to the present invention;

[0028] Figure 3The present invention relates to a scanning electron microscope (SEM) image of copper oxide powder;

[0029] Figure 4 is an X-ray diffraction (XRD) pattern of the copper / noble metal nanomaterial prepared by the present invention;

[0030] Figure 5 is the X-ray diffraction (XRD) pattern of the copper / silver nanomaterial prepared by using different silanes in the present invention;

[0031] Figure 6 This is a transmission electron microscope (STEM-EDS) image of the copper / silver nanomaterial prepared by the present invention;

[0032] Figure 7 X-ray photoelectron spectroscopy (XPS) of the copper / silver nanomaterial prepared by the present invention;

[0033] Figure 8 This is a transmission electron microscope (STEM-EDS) image of the copper / palladium nanomaterial prepared by the present invention;

[0034] Figure 9 X-ray photoelectron spectroscopy (XPS) of the copper / palladium nanomaterial prepared by the present invention;

[0035] Figure 10 This is a transmission electron microscope (STEM-EDS) image of the copper / platinum nanomaterial prepared by the present invention;

[0036] Figure 11 X-ray photoelectron spectroscopy (XPS) of the copper / platinum nanomaterial prepared by the present invention;

[0037] Figure 12 This is a transmission electron microscope (STEM-EDS) image of the copper / gold nanomaterial prepared by the present invention;

[0038] Figure 13 X-ray photoelectron spectroscopy (XPS) diagram of the copper / gold nanomaterial prepared by the present invention. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0040] Example 1:

[0041] This embodiment adopts the following technical solution to achieve: a method for preparing copper-based precious metal nanomaterials, comprising the following steps:

[0042] Step 1: Dissolve 0.5 mmol of silver nitrate in 20 mL of 30% ethanol aqueous solution and shake thoroughly to mix well.

[0043] Step 2: Grind 1 mL of silver nitrate solution with 5 mmol of copper oxide, and dry in an oven at 100° C. for 120 minutes to obtain a copper oxide / silver nitrate precursor.

[0044] Step 3: Take another 20 mg of the precursor and disperse it evenly in a system of 2 mL of acetonitrile, 1 mL of water and 2 mmol of triethylsilane by ultrasonication.

[0045] Step 4: Under the conditions of irradiation with a xenon lamp and stirring, in-situ reconstruction is performed for 20 minutes, and the mixture is taken out for cleaning, centrifugation, vacuum drying at room temperature, and then stored in a N2 atmosphere to obtain copper / silver nanomaterials.

[0046] Example 2

[0047] This embodiment adopts the following technical solution to achieve: a method for preparing copper-based precious metal nanomaterials, comprising the following steps:

[0048] Step 1: Dissolve 0.5 mmol of silver nitrate in 20 mL of 30% ethanol aqueous solution and shake thoroughly to mix well.

[0049] Step 2: Grind 1 mL of silver nitrate solution with 5 mmol of copper oxide, and dry in an oven at 100°C for 120 minutes to obtain a copper oxide / silver nitrate precursor.

[0050] Step 3: Take another 20 mg of the precursor and disperse it evenly in a system of 2 mL of acetonitrile, 1 mL of water and 2 mmol of triphenylsilane by ultrasonication.

[0051] Step 4: Under the conditions of irradiation with a xenon lamp and stirring, in-situ reconstruction is performed for 20 minutes, and the mixture is taken out for cleaning, centrifugation, vacuum drying at room temperature, and then stored in a N2 atmosphere to obtain copper / silver nanomaterials.

[0052] Example 3

[0053] This embodiment adopts the following technical solution to achieve: a method for preparing copper-based precious metal nanomaterials, comprising the following steps:

[0054] Step 1: Dissolve 0.5 mmol of silver nitrate in 20 mL of 30% ethanol aqueous solution and shake thoroughly to mix well.

[0055] Step 2: Grind 1 mL of silver nitrate solution with 5 mmol of copper oxide, and dry in an oven at 100° C. for 120 minutes to obtain a copper oxide / silver nitrate precursor.

[0056] Step 3: Take another 20 mg of the precursor and disperse it evenly in a system of 2 mL of acetonitrile, 1 mL of water and 2 mmol of 1,4-bis(dimethylsilyl)benzene by ultrasonication.

[0057] Step 4: Under the conditions of irradiation with a xenon lamp and stirring, in-situ reconstruction is performed for 20 minutes, and the mixture is taken out for cleaning, centrifugation, vacuum drying at room temperature, and then stored in a N2 atmosphere to obtain copper / silver nanomaterials.

[0058] Example 4

[0059] This embodiment adopts the following technical solution to achieve: a method for preparing copper-based precious metal nanomaterials, comprising the following steps:

[0060] Step 1: Dissolve 0.5 mmol of palladium chloride in 20 mL of 30% ethanol aqueous solution and shake thoroughly to mix well.

[0061] Step 2: Grind 1 mL of palladium chloride solution with 5 mmol of copper oxide, and dry in an oven at 100° C. for 120 minutes to obtain a copper oxide / palladium chloride precursor.

[0062] Step 3: Take another 20 mg of the precursor and disperse it evenly in a system of 2 mL of acetonitrile, 1 mL of water and 2 mmol of triethylsilane by ultrasonication.

[0063] Step 4: Under the conditions of irradiation with a xenon lamp and stirring, in-situ reconstruction is performed for 30 minutes, and the mixture is taken out for cleaning, centrifugation, vacuum drying at room temperature, and then stored in a N2 atmosphere to obtain copper / palladium nanomaterials.

[0064] Example 5

[0065] This embodiment adopts the following technical solution to achieve: a method for preparing copper-based precious metal nanomaterials, comprising the following steps:

[0066] Step 1: Dissolve 0.5 mmol of chloroplatinic acid in 20 mL of 30% ethanol aqueous solution and shake thoroughly to mix well.

[0067] Step 2: Grind 1 mL of chloroplatinic acid solution with 5 mmol of copper oxide, and dry in an oven at 100° C. for 120 minutes to obtain a copper oxide / chloroplatinic acid precursor.

[0068] Step 3: Take another 20 mg of the precursor and disperse it evenly in a system of 2 mL of acetonitrile, 1 mL of water and 2 mmol of triethylsilane by ultrasonication.

[0069] Step 4: Under the conditions of irradiation with a xenon lamp and stirring, in-situ reconstruction is performed for 30 minutes, and the mixture is taken out for cleaning, centrifugation, vacuum drying at room temperature, and then stored in a N2 atmosphere to obtain copper / platinum nanomaterials.

[0070] Example 6

[0071] This embodiment adopts the following technical solution to achieve: a method for preparing copper-based precious metal nanomaterials, comprising the following steps:

[0072] Step 1: Dissolve 0.5 mmol of chloroauric acid in 20 mL of 30% ethanol aqueous solution and shake thoroughly to mix well.

[0073] Step 2: Grind 1 mL of chloroauric acid solution with 5 mmol of copper oxide, and dry in an oven at 100° C. for 120 minutes to obtain a copper oxide / chloroauric acid precursor.

[0074] Step 3: Take another 20 mg of the precursor and disperse it evenly in a system of 2 mL of acetonitrile, 1 mL of water and 2 mmol of triethylsilane by ultrasonication.

[0075] Step 4: Under the conditions of irradiation with a xenon lamp and stirring, in-situ reconstruction is performed for 40 minutes, and the mixture is taken out for cleaning, centrifugation, vacuum drying at room temperature, and then stored in a N2 atmosphere to obtain copper / gold nanomaterials.

[0076] This method innovatively selects different silanes as reducing agents to prepare a series of copper-based precious metal nanomaterials doped with different precious metals with uniform morphology and uniform element distribution.

[0077] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A method for preparing a copper-based noble metal nanomaterial, comprising the following steps: The copper oxide / noble metal salt precursor is synthesized by physical mixing method, and then the copper oxide / noble metal salt is converted into copper / noble metal nanomaterials by in situ reconstruction strategy, as follows: Step (1) Grinding copper oxide and noble metal salt solution in a mortar until uniform and viscous, and then drying at 80-100° C. for 1-2 hours to obtain a copper oxide / noble metal salt precursor; Step (2) adding silane, acetonitrile and water into a photocatalytic reactor and dispersing them uniformly to obtain a solution system; Step (3) adopting an in-situ reconstruction strategy, by adding the precursor in the above step (1) to the solution system in the above step (2) for light reaction, thereby converting the precursor in the above step (1) into copper / noble metal nanomaterials; Step (4) The copper / noble metal nanomaterial obtained in the above step (3) is centrifuged, washed, dried, and stored under an inert atmosphere; The physical mixing method used in step (1) is a grinding method for mixing, and the grinding is performed uniformly on a mortar; The silane in step (2) includes one of triethylsilane, triphenylsilane, and 1,4-bis(dimethylsilyl)benzene.

2. The method for preparing a copper-based noble metal nanomaterial according to claim 1, wherein the copper oxide is one of powdered copper oxide and nano copper oxide, and the noble metal comprises one of silver, palladium, platinum, and gold.

3. The method for preparing a copper-based noble metal nanomaterial according to claim 1, wherein the noble metal salt comprises one of silver nitrate, palladium chloride, chloroplatinic acid, and chloroauric acid.

4. The method for preparing a copper-based noble metal nanomaterial according to claim 1, wherein the solvent used to prepare the noble metal salt solution is a 20-30% ethanol aqueous solution.

5. The method for preparing a copper-based noble metal nanomaterial according to claim 1, wherein a xenon lamp is selected as the light source for the illumination reaction in step (3), and the xenon lamp is a Perfil constant current xenon lamp, and the current intensity of the Perfil constant current xenon lamp is 10-20 A.

6. The method for preparing a copper-based noble metal nanomaterial according to claim 1, wherein the molar ratio of copper oxide to noble metal salt in step (1) is 1000:1 to 30:

1.

7. The method for preparing a copper-based noble metal nanomaterial according to claim 1, wherein the molar ratio of silane, acetonitrile, and water in step (2) is 1:40:50 to 2:20:

25.

8. The method for preparing a copper-based noble metal nanomaterial according to claim 1, wherein in step (2), silane, acetonitrile, and water are uniformly dispersed in a photocatalytic reactor by stirring, the stirring is magnetic stirring, and the magnetic stirring speed is 300-600 rpm, and the stirring time is 20-60 minutes. Silane, acetonitrile, and water are first added to the photocatalytic reactor and uniformly dispersed, and then the precursor in step (1) is added and uniformly dispersed by magnetic stirring.

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