Method for preparing nano-metal catalyst through ultra-fast hydrocarbon combustion at normal temperature and pressure and application of nano-metal catalyst
Synthesis of nanometallic catalysts by hydrocarbon combustion method under normal temperature and pressure solved the problems of harsh synthetic conditions and difficult phase separation, and achieved efficient mass production and high catalytic activity, which were suitable for green chemistry and sustainable energy fields.
Patent Information
- Application Number
- CN202510449567.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-11
- Publication Date
- 2025-07-11
AI Technical Summary
The existing nanometal catalyst synthesis methods are harsh, and phase separation is difficult after synthesis, and it is difficult to mass-scale rapid batch synthesis. The traditional high-temperature synthesis technology has high energy consumption.
The hydrocarbon combustion method is adopted at normal temperature and pressure to form a precursor by mixing the metal source with the hydrocarbon, ignite it and burn it in the combustion chamber. The residue is collected by mechanical devices, and the nanometal catalyst is obtained after vacuum drying.
It realizes efficient batch synthesis of nanometal catalysts under normal temperature and pressure, avoids high-energy phase separation, improves production efficiency, has high catalytic activity, and can form high entropy alloys. It is suitable for green chemistry, sustainable energy and environmental protection fields.
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Figure CN120291130A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of novel functional materials, and particularly relates to a method for preparing a nano-metal catalyst by ultra-fast combustion of hydrocarbons at normal temperature and pressure and its application. Background Art
[0002] Nano-metal catalysts are a class of metal materials prepared at the nanoscale, with the ability to regulate reaction rates and selectivities in chemical reactions. Due to their high surface area, abundant surface active sites, and size effects, nano-metal catalysts exhibit great application potential in fields such as energy conversion, environmental protection, chemical synthesis, and biomedicine. Nano-metal catalysts can serve as catalytic active centers in catalytic reactions, promoting reactions by providing surface reaction sites and changing the activation energy of catalytic reactions. In addition, metal nano-catalysts can also be custom-designed for catalytic performance by adjusting their shape, size, composition, and surface modification, thereby optimizing reaction efficiency and product selectivity. Therefore, nano-metal catalysts play an important role in promoting the development of fields such as green chemistry, sustainable energy, and environmental protection, and their research and application in the field of nanoscience have attracted widespread interest.
[0003] Common methods for synthesizing nano-metal catalysts include wet chemical synthesis, plasma etching, high-temperature migration, movable printing, laser scanning stripping, and carbothermal shock methods. However, the above classical methods for synthesizing nano-metal catalysts have many technical difficulties and problems, which hinder the large-scale promotion and application of this material. For example, the large differences in physical and chemical properties and thermodynamic properties between various metals make it difficult to synthesize a catalyst in a stable phase state; phase separation is difficult during the synthesis process, resulting in high energy consumption during the purification process; the synthesis conditions are harsh, posing high hardware requirements for the reactor. To solve these problems, in recent years, some researchers have developed a rapid heating shock synthesis technology, which avoids the high-energy-consuming phase separation process through the construction of a non-equilibrium environment, but this technology still needs to be implemented at a high temperature of 2000K. Summary of the Invention
[0004] Aiming at the key technical problems that the synthesis conditions of nano-metal catalysts are harsh, and phase separation is difficult after synthesis, resulting in difficulty in large-scale, rapid and batch synthesis, the present invention provides a preparation method for rapidly batch-synthesizing nano-metal catalysts under normal temperature and pressure. Specifically, this method mixes a metal source with a hydrocarbon to obtain a highly dispersed precursor, and then ignites the precursor. The hydrocarbon and the metal precursor are instantly evaporated by the high temperature of combustion, and the evaporated metal precursor reacts instantly with oxygen in the environment to form gaseous metal oxides. By adjusting the process conditions, different types of metal nano-catalysts such as high-entropy alloys and metal nanoparticles can be synthesized. The nano-metal catalysts prepared by this method can have excellent performance in the fields of green chemistry, sustainable energy, and environmental protection.
[0005] The present invention is realized through the following technical solutions:
[0006] A method for preparing nano-metal catalysts by ultra-rapid hydrocarbon combustion under normal temperature and pressure and its application, comprising the following steps:
[0007] (1) Preparation of a mixed precursor of a metal source and a hydrocarbon: Add the metal source to absolute ethanol and ultrasonically dissolve it to obtain a metal source ethanol solution; heat the hydrocarbon to improve its fluidity; then add the above metal source ethanol solution to the hydrocarbon and mix well by mechanical stirring to obtain a precursor of the metal source and the hydrocarbon mixed.
[0008] (2) Combustion synthesis of the mixed precursor: Add the precursor of the metal source and the hydrocarbon mixture obtained in step (1) to the combustion chamber, add a small amount of ignition material and then ignite it. Then place a mechanical rotary continuous collector above the flame until the precursor is completely burned out.
[0009] (3) Collection of the metal nano-catalyst: Use a mechanical device composed of a motor and a disc to collect the residue after combustion in step (2); then vacuum-dry the collected material to remove the residual hydrocarbon.
[0010] As a further preference of the present invention, in step (1), the concentration of the metal source in absolute ethanol is 0.5 - 2 mmol / L.
[0011] As a further preference of the present invention, the metal source in step (1) includes metal acetylacetonate salts, inorganic metal salts, phenyl metal salts, and ferrocene metal salts.
[0012] As a further preference of the present invention, the hydrocarbons in step (1) include paraffin, gasoline, diesel, kerosene, pulverized coal, graphite powder, and flour.
[0013] As a further preference of the present invention, the mechanical stirring duration in step (1) is 1 to 3 hours.
[0014] As a further preference of the present invention, the combustion chamber in step (2) includes: when the hydrocarbon is paraffin wax, a high-temperature resistant concrete combustion chamber is used; when the hydrocarbon is gasoline, diesel or kerosene, a combustion torch is used as the combustion chamber; when the hydrocarbon is pulverized coal, graphite powder or flour, it is mixed in a solid material mixing tank, and after powder spraying through a nozzle, it is ignited.
[0015] As a further preference of the present invention, the ignition material in step (2) includes: when the hydrocarbon is paraffin wax, the ignition material is a 2-mm diameter all-cotton thread; when the hydrocarbon is gasoline, diesel, kerosene, graphite powder or flour, the ignition material is an electric spark generator.
[0016] As a further preference of the present invention, the collection device in step (3) includes: when the hydrocarbon is paraffin wax, gasoline, diesel or kerosene, a mechanical rotary continuous collector is used; when the hydrocarbon is graphite powder or flour, a crawler continuous collector is used.
[0017] The metal nano-catalyst prepared by the present invention has high catalytic activity and can accelerate the progress of various catalytic reactions.
[0018] Technical principle of the present invention:
[0019] During the evaporation of the solvent, supersaturation occurs in the gas-phase metal oxide inside the tiny droplets, which promotes nucleation or the formation of metal clusters. These multi-metal nuclei or clusters have sufficient size and structure to serve as seeds for nano-particles and continue to grow by aggregation and sintering. This process makes the growth of nano-particles more orderly and controllable, resulting in highly crystallized and uniform nano-materials. By adjusting different synthesis parameters, we can further optimize the size, shape and structure of the nano-particles, thereby achieving precise regulation and customization of the material properties. This provides a new approach for the synthesis of nano-materials and also provides an important experimental platform for us to better understand and master the material formation process at the nano-scale.
[0020] Compared with the prior art, the advantages of the present invention are as follows:
[0021] (1) During the combustion process of the hydrocarbon, the combustion temperature can be conveniently controlled within 1800 - 2200K, enabling batch, continuous and large-scale preparation of metal nano-catalysts.
[0022] (2) The metal nano-catalyst prepared by the combustion method proposed by the present invention is a non-equilibrium preparation method. During the combustion process, it can instantaneously reach 1800 - 2200K, and then the product is obtained by rapid quenching, thus avoiding phase separation between incompatible elements.
[0023] (3) The existence of a high dispersion of multiple metals in hydrocarbons easily forms a high-entropy mixture, increasing the possibility of forming a high-entropy alloy.
[0024] (4) Compared with traditional batch production, the continuous production proposed by the present invention can greatly improve production efficiency.
[0025] (5) The metal nano-catalyst prepared by the present invention has excellent catalytic activity. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 It is a diagram of the mixed combustion mechanism of the metal source and hydrocarbons.
[0027] Figure 2 It is a diagram of the flame temperature distribution during the combustion process.
[0028] Figure 3 It is an element distribution diagram of the continuous production of metal nano-catalysts.
[0029] Figure 4 Electrocatalytic performance diagrams of metal nano-catalysts obtained under different process conditions.
[0030] Figure 5 Catalytic stability diagram of the metal nano-catalyst. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0031] The following further describes the present invention in conjunction with the drawings and embodiments, but the scope of protection required by the present invention is not limited to the scope protected by the embodiments.
[0032] Example 1
[0033] (1) Preparation of the metal source and hydrocarbon mixed precursor: First, Fe(NO3)3·9H2O, Co(NO3)2·6H2O, NiCl2·6H2O, Cu(NO3)2·3H2O, and Pd(NO3)2 were added to 20 mL of absolute ethanol according to a molar ratio of 1:1:1:1:1, and stirred and dispersed to obtain solution A; solution A was ultrasonically treated for 30 min; 60 g of paraffin was placed in a crucible and heated to melt to obtain liquid hydrocarbons B; then solution A was added to solution B, and the liquid mixture was heated to maintain its form and mechanically stirred for 1 h to obtain the precursor of the metal source and paraffin mixture.
[0034] (2) Combustion synthesis of the mixed precursor: Transfer the precursor obtained by mixing the above metal source and paraffin to a concrete combustion chamber; then insert a 2-mm-diameter cotton thread into it and introduce a fire source to ignite it; subsequently, place a mechanical rotary continuous collector above the flame until the precursor is completely burned out.
[0035] (3) Collection of the metal nanocatalyst: Fix a 3-cm-wide stainless-steel scraper under the mechanical rotary table. After waiting for the mechanical rotary table to rotate for 10 min, collect the material on the scraper; then place the material in an oven at 150 °C for vacuum drying to remove unreacted paraffin in the composition, and the obtained high-entropy alloy is denoted as FeCoNiCuPd.
[0036] Example 2
[0037] (1) Preparation of the mixed precursor of the metal source and hydrocarbon: First, add Rh(NO3)3, Ir(NO3)3, Cd(acac)2, Sn(acac)2, Cu(acac)2 to 10 mL of absolute ethanol according to a molar ratio of 1:1:1:1:1, stir and disperse to obtain solution A; ultrasonically treat solution A for 30 min; place 50 g of paraffin in a crucible and heat it to melt to obtain liquid hydrocarbon B; then add solution A to solution B, heat to maintain the form of the liquid mixture, and mechanically stir for 1.5 h to obtain the precursor of the metal source and paraffin mixture.
[0038] (2) Combustion synthesis of the mixed precursor: Transfer the precursor obtained by mixing the above metal source and paraffin to a concrete combustion chamber; then insert a 2-mm-diameter cotton thread into it and introduce a fire source to ignite it; subsequently, place a mechanical rotary continuous collector above the flame until the precursor is completely burned out.
[0039] (3) Collection of the metal nanocatalyst: Fix a 3-cm-wide stainless-steel scraper under the mechanical rotary table. After waiting for the mechanical rotary table to rotate for 15 min, collect the material on the scraper; then place the material in an oven at 150 °C for vacuum drying to remove unreacted paraffin in the composition, and the obtained high-entropy alloy is denoted as RhIrCdSnCu.
[0040] Example 3
[0041] (1) Preparation of the mixed precursor of the metal source and hydrocarbon: First, add CuCl2, Fe(NO3)3·9H2O to 10 mL of absolute ethanol according to a molar ratio of 1:5, stir and disperse to obtain solution A; ultrasonically treat solution A for 15 min; heat 20 mL of gasoline to 40 °C and denote it as B; then add solution A to solution B and mechanically stir for 0.5 h to obtain the precursor of the metal source and gasoline mixture.
[0042] (2) Combustion synthesis of the mixed precursor: Transfer the precursor obtained by mixing the above metal source with gasoline into a combustion torch; then adjust the flow rate of the combustion torch to 2 mL / s and ignite it using an electric spark generator; subsequently, place a mechanical rotary continuous collector above the flame until all the liquid in the torch has burned out.
[0043] (3) Collection of the metal nanocatalyst: Fix a 3-cm-wide stainless-steel scraper under the mechanical rotary table. After waiting for the mechanical rotary table to rotate for 10 minutes, collect the material on the scraper; then place the material in an oven at 150 °C for vacuum drying to remove unreacted gasoline, obtaining Cu-doped Fe nanoparticles.
[0044] Example 4
[0045] (1) Preparation of the metal source and hydrocarbon mixed precursor: First, add PdCl3 and Cu(NO3)2·3H2O to 10 mL of absolute ethanol according to a molar ratio of 0.01:1, stir and disperse to obtain solution A; subject solution A to ultrasonic treatment for 50 minutes; slowly add solution A dropwise to 20 g of graphite powder to obtain a mixed viscous liquid B; then transfer B to a mechanical ball mill tank and ball mill for 20 minutes to promote uniform mixing, obtaining the precursor of the metal source and graphite powder mixture.
[0046] (2) Combustion synthesis of the mixed precursor: Transfer the precursor of the metal source and graphite powder mixture to a solid material mixing tank; then set the powder spraying flow rate at the outlet of the mixing tank to 5 cm 3 / s and ignite it using an electric spark generator; subsequently, place a crawler-type continuous collector above the flame until all the materials in the solid material mixing tank are exhausted.
[0047] (3) Collection of the metal nanocatalyst: Fix a 3-cm-wide stainless-steel scraper under the crawler-type continuous collector. After waiting for the mechanical rotary table to rotate for 30 minutes, collect the material on the scraper; then transfer the material to a 50-mL centrifuge tube, set the rotation speed to 8000 rpm / min, and centrifuge for 10 minutes to remove unreacted graphite powder, obtaining Pd-doped Cu single-atom catalysts.
[0048] Example 5
[0049] (1) Preparation of metal source and hydrocarbon mixed precursor: First, Sr(acac)2, Zr(acac)4, Ru(acac)3, Rh(acac)3, and In(acac)3 were added to 10 mL of absolute ethanol according to a molar ratio of 1:1:1:1:1 and stirred for dispersion. Then, 0.1 mmol of trifluoromethoxyaniline was added to obtain solution A. Solution A was ultrasonically treated for 60 min. 25 g of paraffin was placed in a crucible and heated to melt to obtain liquid hydrocarbon B. Then, solution A was added to solution B, and heating was maintained to keep the liquid mixture in a liquid state, followed by mechanical stirring for 0.5 h to obtain a precursor of metal source and paraffin mixture.
[0050] (2) Combustion synthesis of the mixed precursor: The above-mentioned precursor of metal source and paraffin mixture was transferred to a concrete combustion chamber. Then, a 2-mm-diameter cotton thread was inserted into it, and a fire source was introduced to ignite it. Subsequently, a mechanical rotary continuous collector was placed above the flame until the precursor was completely burned out.
[0051] (3) Collection of metal nanocatalyst: A 3-cm-wide stainless-steel scraper was fixed below the mechanical rotary table. After waiting for the mechanical rotary table to rotate for 10 min, the material on the scraper was collected. Subsequently, the material was placed in an oven at 150 °C for vacuum drying to remove unreacted paraffin in the composition, and the obtained high-entropy fluoride was denoted as F-SrZrRuRhIn.
[0052] Material property testing
[0053] The nano-metal catalyst prepared by ultra-fast hydrocarbon combustion under normal temperature and pressure in Example 2 of the present invention was characterized and analyzed. The following are the characterization results and specific analysis of Example 2. A brief description of the test instruments and the drawing description part.
[0054] (1) Schematic diagram of the synthesis route of the nano-metal catalyst prepared by ultra-fast hydrocarbon combustion under normal temperature and pressure.
[0055] (2) During the synthesis of the nano-metal catalyst prepared by ultra-fast hydrocarbon combustion under normal temperature and pressure (Example 2), temperature analysis and characterization of the paraffin fuel were carried out.
[0056] (3) EMS mapping characterization test of the nano-metal catalyst prepared by ultra-fast hydrocarbon combustion under normal temperature and pressure (Example 2).
[0057] The elemental distribution of the nano-metal catalyst was analyzed and tested using a scanning transmission electron microscope of Hitachi, Japan. The results are as Figure 3 shown. It can be seen from the figure that various metal elements are evenly distributed in the catalyst structure.
[0058] (IV) The electrocatalytic activity of the H2O2 generated by oxygen reduction was quantitatively measured using RRDE, and the results are as Figure 4 shown. It can be seen from the figure that the current density of the nanometal catalyst exceeds 1 mA cm -2 at most, and the selectivity is close to 100%, showing excellent electrocatalytic performance.
[0059] (V) The stability of the H2O2 generated by oxygen reduction was quantitatively measured using RRDE, and the results are as Figure 5 shown. It can be seen from the figure that after 150 hours of testing, no obvious decrease in the activity and selectivity of the catalyst was observed, and a high Faraday efficiency was maintained.
Claims
1. A method for preparing a nano metal catalyst by ultra-fast combustion of hydrocarbons under normal temperature and pressure and its application, characterized in that, It includes the following steps: (1) Preparation of the metal source and hydrocarbon mixed precursor: Add the metal source to absolute ethanol and dissolve it by ultrasonic to obtain a metal source ethanol solution; heat the hydrocarbon to improve its fluidity; Subsequently, add the above metal source ethanol solution to the hydrocarbon and mix evenly by mechanical stirring to obtain a precursor of the metal source and hydrocarbon mixture; (2) Combustion synthesis of the mixed precursor: Add the precursor of the metal source and hydrocarbon mixture obtained in step (1) to the combustion chamber, add a small amount of ignition material and then ignite it. Subsequently, place a mechanical rotary continuous collector above the flame until the precursor is completely burned out; (3) Collection of the metal nanocatalyst: Use a mechanical device composed of a motor and a disc to collect the residue after combustion in step (2); Subsequently, vacuum-dry the collected material to remove the residual hydrocarbon to obtain the metal nanocatalyst.
2. The method for preparing a nano metal catalyst by ultra-fast combustion of hydrocarbons under normal temperature and pressure according to claim 1, characterized in that, In step (1), the concentration of the metal source in absolute ethanol is 0.5 - 2 mmol / L.
3. The method for preparing a nano-metal catalyst by ultra-fast combustion of hydrocarbons at normal temperature and pressure according to claim 1, characterized in that, The metal source described in step (1) includes metal acetylacetonate salts, inorganic metal salts, phenylmetal salts, and metallocene metal salts.
4. The method for preparing a nano metal catalyst by ultra-fast combustion of hydrocarbons at normal temperature and pressure according to claim 1, characterized in that In step (1), the hydrocarbons include paraffin, gasoline, diesel, kerosene, pulverized coal, graphite powder, and flour.
5. The method for preparing a nano-metal catalyst by ultra-fast combustion of hydrocarbons at normal temperature and pressure according to claim 1, characterized in that, In step (1), the mechanical stirring time is 1 - 3 hours.
6. The method for preparing a nano metal catalyst by ultra-fast combustion of hydrocarbons under normal temperature and pressure according to claim 1, characterized in that, The combustion chamber described in step (2) includes: when the hydrocarbon is paraffin, use a high-temperature-resistant concrete combustion chamber; when the hydrocarbon is gasoline, diesel, or kerosene, use a combustion torch as the combustion chamber; when the hydrocarbon is pulverized coal, graphite powder, or flour, use a solid material mixing tank to mix, spray powder through a nozzle and then ignite.
7. The method for preparing a nano-metal catalyst by ultra-fast combustion of hydrocarbons at normal temperature and pressure according to claim 1, characterized in that, The ignition material described in step (2) includes: when the hydrocarbon is paraffin, the ignition material is a 2-mm-diameter all-cotton thread; when the hydrocarbon is gasoline, diesel, kerosene, graphite powder, or flour, the ignition material is an electric spark generator.
8. The method for preparing a nano metal catalyst by ultra-fast combustion of hydrocarbons at normal temperature and pressure according to claim 1, characterized in that, The collection device described in step (3) includes: when the hydrocarbon is paraffin, gasoline, diesel, or kerosene, use a mechanical rotary continuous collector; when the hydrocarbon is graphite powder or flour, use a crawler-type continuous collector.
9. The method for preparing a nano-metal catalyst by ultra-fast combustion of hydrocarbons under normal temperature and pressure according to claim 1, characterized in that, The metal nanocatalyst described in step (3) includes high-entropy alloys, single-atom catalysts, and metal nanoparticles.
10. The method for preparing a nano metal catalyst by ultra-fast combustion of hydrocarbons under normal temperature and pressure according to claim 1, characterized in that, The metal content in the metal nanocatalyst described in step (3) is 0.1 - 25%.