A reverse water-gas reaction catalyst based on electromagnetic induction heating, preparation method and application thereof

Abstract

The present invention provides a reverse water-gas reaction catalyst based on electromagnetic induction heating, a preparation method, and its application. The preparation method comprises: S1, dissolving a soluble copper salt and a soluble cobalt salt in water at a molar ratio of 0.05 to 1 to form a precursor solution; S2, mixing the precursor solution with a carrier and drying in an oven to obtain a solid catalyst precursor; S3, reducing the solid catalyst precursor at high temperature in a hydrogen atmosphere to obtain a CoCu alloy catalyst; S4, oxidizing at 450°C to 700°C in an oxidizing atmosphere for 1 to 4 hours to obtain an oxidized Co@Cu catalyst; S5, further reducing the solid catalyst at high temperature in a hydrogen atmosphere to obtain a reverse water-gas reaction catalyst. The preparation method of the present invention is simple and easy to prepare in large quantities. The prepared catalyst can effectively respond to an alternating electromagnetic field to generate the high temperature required for the reverse water-gas reaction, and exhibits stable and efficient catalytic activity, selectivity, and stability in the reverse water-gas reaction.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical catalysts, and in particular relates to a reverse water-gas reaction catalyst based on electromagnetic induction heating, a preparation method and applications thereof. Background Art

[0002] Using non-carbon energy to generate electricity, then using that electricity to replace coal, oil, and gas for industrial use, and achieving electrification and energy-saving reengineering of production processes are key means of achieving carbon neutrality in industry. In traditional industrial catalysis, a flame furnace or resistance furnace is typically used to directly heat the reactor, which is then transferred to the catalyst and reactants for reaction. This process not only suffers significant heat transfer losses but also produces exhaust and soot. Electromagnetic induction heating is 30% to 50% more efficient than flame furnaces and 20% to 30% more efficient than resistance furnaces. It also produces no open flames, exhaust, or soot. More importantly, electromagnetic induction heating directly acts on the catalyst within the reactor, avoiding the heat losses associated with the heat transfer process. This energy-saving, environmentally friendly, and safe "green heating" method has significant potential for application in industrial catalysis.

[0003] The reverse water gas reaction (H2+CO2→CO+H2O) can utilize green hydrogen to convert CO2 to CO with high selectivity and is considered one of the most promising pathways for large-scale CO2 conversion. Among non-precious metal catalysts, Cu-based catalysts offer the advantages of low cost and high selectivity. Patent CN107497439A discloses a mesoporous Cu / CeO2 catalyst prepared by a silica sol method. Cu nanoparticles are highly dispersed within the mesoporous CeO2, and its reverse water gas reaction activity and stability are far superior to those of Cu-based catalysts prepared by traditional impregnation methods. Patent CN109621963A discloses a Cu / MgO / Al2O3 reverse water gas catalyst prepared using CuMgAl-LDH as a precursor. The catalyst exhibits high dispersion of active metal nanoparticles and excellent reaction activity. Patent CN111545203A discloses a spherical Cu-based Al2O3-supported catalyst with uniform particle size and a preparation method thereof. This catalyst exhibits high catalytic activity at lower temperatures for the reverse water gas reaction. CN116060009A discloses a MgO-supported CuFe alloy catalyst prepared by a nucleation crystallization isolation method. Fe can effectively inhibit the sintering and aggregation of Cu and performs well in the reverse water-gas reaction.

[0004] To date, the Cu-based reverse water-gas reaction catalysts reported in patent literature are all traditional heating types, and no catalysts that can be heated based on electromagnetic induction are involved. It is urgent to develop a high-performance Cu-based reverse water-gas reaction catalyst that can efficiently respond to electromagnetic external field induction heat generation. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the object of the present invention is to provide a reverse water-gas reaction catalyst based on electromagnetic induction heating, a preparation method and its application, so as to solve the problem in the prior art that the reverse water-gas reaction catalyst cannot efficiently respond to electromagnetic induction heating.

[0006] To achieve the above-mentioned and other related purposes, the present invention provides a method for preparing a reverse water-gas reaction catalyst based on electromagnetic induction heating, the preparation method comprising the following steps:

[0007] S1, dissolving a soluble copper salt and a soluble cobalt salt in water at a molar ratio of 0.05 to 1 to form a precursor solution;

[0008] S2, mixing the precursor solution with a carrier, and then placing it in an oven for drying to obtain a solid catalyst precursor;

[0009] S3, reducing the solid catalyst precursor at high temperature under a hydrogen atmosphere to obtain a CoCu alloy catalyst;

[0010] S4, oxidizing the CoCu alloy catalyst at 450° C. to 700° C. under an oxidizing atmosphere for 1 h to 4 h to obtain an oxidized Co@Cu catalyst;

[0011] S5. Reducing the oxidized Co@Cu catalyst again at high temperature in a hydrogen atmosphere to obtain a reverse water gas reaction catalyst.

[0012] Preferably, the soluble copper salt in step S1 includes one or a combination of copper nitrate, copper chloride, copper sulfate, and copper acetate.

[0013] Preferably, the soluble cobalt salt in step S1 includes one or a combination of cobalt nitrate, cobalt chloride, cobalt sulfate, and cobalt acetate.

[0014] Preferably, in step S1, the molar ratio between the soluble copper salt and the soluble cobalt salt is 0.1 to 0.2.

[0015] Preferably, the carrier in step S2 comprises one or a combination of aluminum oxide, zirconium oxide, silicon oxide, titanium oxide, lanthanum oxide, and magnesium oxide.

[0016] Preferably, the drying temperature in step S2 is 60-150° C., and the drying time is 6 hours to 24 hours.

[0017] Preferably, in step S3, the temperature for high-temperature reduction of the solid catalyst precursor in a hydrogen atmosphere is 500-800° C., and the time for high-temperature reduction is 1 h to 2 h.

[0018] Preferably, the oxidizing atmosphere in step S4 includes one or a combination of air, oxygen, water vapor, and carbon dioxide.

[0019] Preferably, in step S5, the temperature for the high-temperature reduction of the oxidized Co@Cu catalyst under a hydrogen atmosphere is 500-800° C., and the time for the high-temperature reduction is 1 h to 2 h.

[0020] Preferably, the reverse water-gas reaction catalyst obtained in step S5 comprises a CoCu component and a carrier, wherein the mass percentage of the CoCu component in the reverse water-gas reaction catalyst is 5% to 30%.

[0021] The present invention also provides a reverse water-gas reaction catalyst based on electromagnetic induction heating, wherein the reverse water-gas reaction catalyst is prepared by adopting the above-mentioned method for preparing the reverse water-gas reaction catalyst based on electromagnetic induction heating.

[0022] The present invention also provides an application of a reverse water-gas reaction catalyst based on electromagnetic induction heating, wherein the reverse water-gas reaction catalyst is applied to a reverse water-gas catalytic reaction driven by electromagnetic induction heating, wherein the reverse water-gas reaction catalyst is prepared by the above-mentioned preparation method.

[0023] As described above, the electromagnetic induction heating-based reverse water-gas reaction catalyst, preparation method, and application of the present invention have the following beneficial effects:

[0024] The preparation method of the reverse water gas reaction catalyst of the present invention comprises the following steps: dissolving a soluble copper salt and a soluble cobalt salt in water, loading the salts on a carrier, and then subjecting the catalyst to high-temperature hydrogen reduction to obtain a CoCu alloy catalyst; inducing the Cu component to migrate to the alloy surface under a high-temperature oxidizing atmosphere, so that the Cu component in the CoCu alloy particles migrates to the surface and is enriched, thereby forming Co@Cu nanoparticles with a core-shell structure having Co as a core and Cu as a shell; and further subjecting the catalyst to high-temperature hydrogen reduction to obtain a reverse water gas reaction catalyst. The preparation method of the present invention is simple, easy to prepare on a large scale, and the core-shell structure can be precisely controlled by the reaction atmosphere components and temperature, thus being simple and easy to implement and conducive to large-scale production.

[0025] The catalyst of the present invention is composed of a carrier, an induction heat generating component Co and a catalytically active component Cu coated on its surface. The catalyst can be directly heated to a high temperature through induction heating based on the principle of electromagnetic induction, avoiding the energy consumption and generation of waste gas and dust in traditional heating and heat transfer processes, and providing technical support for the green and low-carbonization of industrial catalysis. When applied to the reverse water-gas catalytic reaction driven by electromagnetic induction heating, the catalyst can effectively respond to the alternating electromagnetic field to generate the high temperature required for the reverse water-gas reaction, exhibit stable and efficient catalytic activity, selectivity and stability in the reverse water-gas reaction, can make the CO selectivity close to 100%, and can work stably for 100 hours without deactivation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This diagram shows the reaction results when the reverse water-gas reaction catalyst prepared in Example 2 of the present invention is applied to the reverse water-gas catalytic reaction driven by electromagnetic induction heating.

[0027] Figure 2 This figure shows the reaction results when the traditional Cu-based reverse water-gas reaction catalyst prepared in Comparative Example 1 of the present invention is applied to the reverse water-gas catalytic reaction driven by electromagnetic induction heating.

[0028] Figure 3 This figure shows the reaction results when the CoCu alloy reverse water-gas reaction catalyst prepared in Comparative Example 2 of the present invention is applied to the reverse water-gas catalytic reaction driven by electromagnetic induction heating.

[0029] Figure 4a Shown is a spherical aberration electron microscopy surface scanning energy spectrum of the reverse water-gas reaction catalyst prepared in Example 1.

[0030] Figure 4b Shown is a spherical aberration electron microscope line scanning energy spectrum of the reverse water gas reaction catalyst prepared in Example 1.

[0031] Figure 5a Shown is the spherical aberration electron microscopy surface scanning energy spectrum of the CoCu alloy reverse water gas reaction catalyst prepared in Comparative Example 2.

[0032] Figure 5b Shown is a spherical aberration electron microscope line scanning energy spectrum of the CoCu alloy reverse water gas reaction catalyst prepared in Comparative Example 2. DETAILED DESCRIPTION

[0033] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0034] The present invention provides a method for preparing a reverse water-gas reaction catalyst based on electromagnetic induction heating, the preparation method comprising the following steps:

[0035] S1. Dissolving a soluble copper salt and a soluble cobalt salt in water at a molar ratio of 0.05 to 1 to form a precursor solution; wherein the molar ratio between the soluble copper salt and the soluble cobalt salt may include values within any range such as 0.05, 0.1, 0.3, 0.5, 0.7, 0.9, and 1, and may be adjusted according to actual conditions;

[0036] S2, mixing the precursor solution with the carrier, and then placing it in an oven to dry, to obtain a solid catalyst precursor;

[0037] S3, reducing the solid catalyst precursor at high temperature under a hydrogen atmosphere to obtain a CoCu alloy catalyst;

[0038] S4. Oxidizing the CoCu alloy catalyst at 450° C. to 700° C. under an oxidizing atmosphere for 1 h to 4 h to obtain an oxidized Co@Cu catalyst; wherein the oxidation temperature may include values within any range such as 450° C., 500° C., 550° C., 600° C., 650° C., 700° C., and may be adjusted according to actual conditions; and the oxidation time may include values within any range such as 1 h, 2 h, 3 h, 4 h, and may be adjusted according to actual conditions;

[0039] S5. The oxidized Co@Cu catalyst is reduced again at high temperature in a hydrogen atmosphere to obtain a reverse water gas reaction catalyst.

[0040] Specifically, in a specific embodiment of the present invention, a soluble copper salt and a soluble cobalt salt are dissolved in water according to a certain molar ratio, then mixed with a carrier and dried, and the obtained solid catalyst precursor is reduced at high temperature in a hydrogen atmosphere to obtain a CoCu alloy catalyst, which is then oxidized at high temperature in an oxidizing atmosphere to induce the Cu component to migrate to the alloy surface, and finally reduced again in a hydrogen atmosphere to obtain a reverse water gas reaction catalyst. The catalyst consists of a carrier, an induction heat generating component Co and a catalytically active component Cu coated on its surface.

[0041] Furthermore, based on the technical problems to be solved by the prior art, the present invention needs to be able to solve two problems when preparing a reverse water-gas reaction catalyst based on electromagnetic induction heating. On the one hand, when the reaction temperature exceeds the Curie temperature of the ferromagnetic metal, the hysteresis thermal effect will disappear, resulting in the loss of the heating ability of the ferromagnetic metal; on the other hand, the inductive metal particles may promote the occurrence of side reactions, which may cause the selectivity of the prepared catalyst to decrease or even become inactivated; therefore, in a specific embodiment of the present invention, when preparing a reverse water-gas reaction catalyst based on electromagnetic induction heating, it is necessary to ensure that the catalyst contains not only the active component Cu, but also magnetic metal particles for electromagnetic induction heat generation.

[0042] In a specific embodiment of the present invention, the induction heating component is selected as Co, which has a Curie temperature of 1130°C, which is much higher than the temperature of 500-600°C required for the reverse water gas reaction, thereby solving the problem of high-temperature demagnetization. In addition, since Co promotes the methanation side reaction (4H2+CO2→CH4+2H2O) to produce CH4, resulting in a decrease in CO selectivity, it is necessary to cover the surface of the Co particles with the active component Cu. The present invention uses an oxidizing atmosphere to induce alloy structure transformation, causing the Cu component in the CoCu alloy particles to migrate and enrich to the surface, forming Co@Cu nanoparticles with a core-shell structure with Co as the core and Cu as the shell, thereby suppressing the methanation side reaction on the surface of the Co particles and solving the problem of product selectivity.

[0043] As an example, the soluble copper salt in step S1 includes one or a combination of copper nitrate, copper chloride, copper sulfate, and copper acetate.

[0044] As an example, the soluble cobalt salt in step S1 includes one or a combination of cobalt nitrate, cobalt chloride, cobalt sulfate, and cobalt acetate.

[0045] As an example, the molar ratio between the soluble copper salt and the soluble cobalt salt in step S1 is 0.1 to 0.2.

[0046] Specifically, the molar ratio between the soluble copper salt and the soluble cobalt salt in step S1 may include a value within any range such as 0.1, 0.12, 0.14, 0.16, 0.18, 0.2, etc., and may be adjusted according to actual conditions. By adjusting the molar ratio of Cu and Co, a Cu shell layer having a suitable thickness is obtained, which is beneficial for the catalyst finally prepared to maintain a high electromagnetic induction heat generation capacity and high selectivity in the reverse water gas reaction. In a specific embodiment of the present invention, the catalyst finally prepared in step S5 includes a Co@Cu component and a carrier of a core-shell structure. The Co@Cu component of the core-shell structure has Co as the core and Cu as the shell, but the thickness of the shell is less than 2 nm.

[0047] As an example, the carrier in step S2 includes one or a combination of aluminum oxide, zirconium oxide, silicon oxide, titanium oxide, lanthanum oxide, and magnesium oxide.

[0048] Specifically, loading the CoCu component on the carrier is beneficial to stabilizing the CoCu component, so that the prepared catalyst has good thermal stability.

[0049] Preferably, the carrier is alumina, which has a high specific surface area and thermal stability, and can effectively inhibit the sintering of CoCu particles at high temperatures. The acidity of the alumina surface is also conducive to the activation of CO2.

[0050] As an example, the drying temperature in step S2 is 60 to 150° C., and the drying time is 6 hours to 24 hours.

[0051] Specifically, the drying temperature in step S2 may include a value within any range such as 60°C, 80°C, 100°C, 120°C, 140°C, 150°C, etc., and may be adjusted according to actual conditions; the drying time may include a value within any range such as 6h, 12h, 18h, 24h, etc., and may be adjusted according to actual conditions.

[0052] As an example, in step S3 , the temperature for high-temperature reduction of the solid catalyst precursor in a hydrogen atmosphere is 500-800° C., and the time for high-temperature reduction is 1 h to 2 h.

[0053] Specifically, the temperature for high-temperature reduction of the solid catalyst precursor under a hydrogen atmosphere in step S3 may include any value within a range of 500°C, 600°C, 700°C, 800°C, etc., which can be adjusted according to actual conditions; the time for high-temperature reduction may include any value within a range of 1h, 1.2h, 1.4h, 1.6h, 1.8h, 2h, etc., which can be adjusted according to actual conditions.

[0054] As an example, the oxidizing atmosphere in step S4 includes one or a combination of air, oxygen, water vapor, and carbon dioxide.

[0055] Specifically, the high-temperature oxidation process of the CoCu alloy catalyst in an oxidizing atmosphere is actually a process of inducing a structural transformation of the alloy, causing the Cu component to migrate and enrich to the surface, forming Co@Cu nanoparticles with Co as the core and Cu as the shell, thereby inhibiting the methanation side reaction on the surface of the Co particles and solving the problem of product selectivity; and the core-shell structure formed is precisely controlled by the composition and temperature of the oxidizing atmosphere.

[0056] Preferably, the oxidizing atmosphere is carbon dioxide, and the CoCu alloy catalyst is oxidized in the carbon dioxide atmosphere at 600° C. for 1 hour.

[0057] As an example, in step S5, the temperature of the high-temperature reduction of the oxidized Co@Cu catalyst under a hydrogen atmosphere is 500-800° C., and the time of the high-temperature reduction is 1 h to 2 h.

[0058] Specifically, the temperature for the high-temperature reduction of the oxidized Co@Cu catalyst under a hydrogen atmosphere in step S5 may include any value within a range of 500°C, 600°C, 700°C, 800°C, etc., which can be adjusted according to actual conditions; the time for high-temperature reduction may include any value within a range of 1h, 1.2h, 1.4h, 1.6h, 1.8h, 2h, etc., which can be adjusted according to actual conditions.

[0059] As an example, the reverse water-gas reaction catalyst obtained in step S5 includes a CoCu component and a carrier supported by the CoCu component, wherein the mass percentage of the CoCu component in the reverse water-gas reaction catalyst is 5% to 30%.

[0060] Specifically, in the reverse water-gas reaction catalyst, the mass percentage of the CoCu component can include values within any range, such as 5%, 10%, 15%, 20%, 25%, 30%, etc., and can be adjusted according to actual conditions. By adjusting the loading amount of the CoCu component, a reverse water-gas reaction catalyst with a suitable particle size is obtained to ensure that it has high efficiency in inducing electromagnetic fields while obtaining more catalytic active sites. The particle size of the reverse water-gas reaction catalyst is 10nm to 40nm.

[0061] Preferably, in the reverse water gas reaction catalyst, the mass percentage of the CoCu component is 10% to 20% (such as 10%, 12%, 14%, 16%, 18%, 20%, etc.).

[0062] The present invention also provides a reverse water-gas reaction catalyst based on electromagnetic induction heating, which is prepared by adopting the above-mentioned method for preparing the reverse water-gas reaction catalyst based on electromagnetic induction heating.

[0063] Specifically, the reverse water-gas reaction catalyst based on electromagnetic induction heating includes a heat-generating component and an active component. The heat-generating component is Co and the active component is Cu. The reverse water-gas reaction catalyst has a core-shell structure with Co as the core and Cu as the shell, thereby suppressing the methanation side reaction on the surface of the Co particles and solving the problem of product selectivity.

[0064] In addition, the present invention also provides an application of a reverse water-gas reaction catalyst based on electromagnetic induction heating, and applies the reverse water-gas reaction catalyst to a reverse water-gas catalytic reaction driven by electromagnetic induction heating.

[0065] Specifically, an electromagnetic induction heating reactor is used to carry out the reverse water gas reaction. Before the reaction, a reverse water gas reaction catalyst is placed in the electromagnetic induction heating reactor, and then a mixed gas of H2, CO2, and N2 is introduced for reaction. The reaction conditions are: 50 mg of reverse water gas reaction catalyst, 60,000 mL / gh space velocity, 2:1:1 volume ratio of H2, CO2, and N2, electromagnetic heating frequency of 100 kHz, and current of 35 A.

[0066] In order to better understand the reverse water-gas reaction catalyst based on electromagnetic induction heating, its preparation method and its application in the present invention, the reverse water-gas reaction catalyst based on electromagnetic induction heating, its preparation method and its application in the present invention are described below with reference to specific examples. It should be noted that these examples are merely descriptive and do not limit the present invention in any way.

[0067] Example 1

[0068] This embodiment provides a method for preparing a reverse water-gas reaction catalyst based on electromagnetic induction heating, the preparation method comprising the following steps:

[0069] S1. Dissolve 0.043 g of copper nitrate (Cu(NO3)2·3H2O) and 0.69 g of cobalt nitrate (Co(NO3)2·6H2O) in water to form a precursor solution; wherein the molar ratio of copper nitrate to cobalt nitrate is 0.075;

[0070] S2. Mix the precursor solution with 0.85 g of an alumina support, and then dry it in an oven at 140° C. for 6 h to obtain a solid catalyst precursor;

[0071] S3, reducing the solid catalyst precursor at 500° C. in a hydrogen atmosphere for 2 h to obtain a CoCu alloy catalyst;

[0072] S4, oxidizing the CoCu alloy catalyst in air atmosphere at 500°C for 4 h to obtain an oxidized Co@Cu catalyst;

[0073] S5. Reducing the oxidized Co@Cu catalyst again under a hydrogen atmosphere at 500° C. for 1 h to obtain a reverse water gas reaction catalyst, wherein the mass percentage of the CoCu component in the reverse water gas reaction catalyst is 15%.

[0074] This embodiment further provides a reverse water-gas reaction catalyst based on electromagnetic induction heating. The reverse water-gas reaction catalyst is prepared by the preparation method of this embodiment. The mass percentage of the CoCu component in the prepared reverse water-gas reaction catalyst is 15%.

[0075] This embodiment also provides an application of a reverse water-gas reaction catalyst based on electromagnetic induction heating. The reverse water-gas reaction catalyst prepared in this embodiment is applied to a reverse water-gas catalytic reaction driven by electromagnetic induction heating. Specifically, an electromagnetic induction heating reactor is used for the reverse water-gas reaction. Before the reaction, the reverse water-gas reaction catalyst is placed in the electromagnetic induction heating reactor, and then a mixed gas of H2, CO2, and N2 is introduced for reaction. The reaction conditions are: 50 mg of the reverse water-gas reaction catalyst, 60,000 mL / gh of the air velocity, 2:1:1 of the volume ratio of H2, CO2, and N2, 100 kHz of the electromagnetic heating frequency, and 35 A of the current.

[0076] The test showed that the reverse water gas reaction catalyst prepared in this example showed good catalytic activity under electromagnetic induction heating conditions, with a CO2 conversion rate of nearly 40% and a CO selectivity of nearly 98%. Figure 4a 、 Figure 4b They are respectively the spherical aberration electron microscopy surface scanning energy spectrum and line scanning energy spectrum of the reverse water gas reaction catalyst prepared in this embodiment, wherein, Figure 4a The numbers 1 and 2 in Figure 4b The scanning lines 1 and 2 in FIG. 3 correspond to each other. As can be seen from the figure, in the reverse water-gas reaction catalyst prepared in this embodiment, Cu covers the Co surface.

[0077] Example 2

[0078] This embodiment provides a method for preparing a reverse water-gas reaction catalyst based on electromagnetic induction heating, the preparation method comprising the following steps:

[0079] S1. Dissolve 0.062 g of copper nitrate (Cu(NO3)2·3H2O) and 0.67 g of cobalt nitrate (Co(NO3)2·6H2O) in water to form a precursor solution; wherein the molar ratio of copper nitrate to cobalt nitrate is 0.11;

[0080] S2. Mix the precursor solution with 0.85 g of an alumina support, and then dry it in an oven at 120° C. for 12 h to obtain a solid catalyst precursor;

[0081] S3, reducing the solid catalyst precursor at 600° C. in a hydrogen atmosphere for 1 h to obtain a CoCu alloy catalyst;

[0082] S4, oxidizing the CoCu alloy catalyst at 600°C in a carbon dioxide atmosphere for 1 h to obtain an oxidized Co@Cu catalyst;

[0083] S5. Reducing the oxidized Co@Cu catalyst again in a hydrogen atmosphere at 600° C. for 1 h to obtain a reverse water gas reaction catalyst, wherein the mass percentage of the CoCu component in the reverse water gas reaction catalyst is 15%.

[0084] This embodiment further provides a reverse water-gas reaction catalyst based on electromagnetic induction heating. The reverse water-gas reaction catalyst is prepared by the preparation method of this embodiment. The mass percentage of the CoCu component in the prepared reverse water-gas reaction catalyst is 15%.

[0085] This embodiment also provides an application of a reverse water-gas reaction catalyst based on electromagnetic induction heating. The reverse water-gas reaction catalyst prepared in this embodiment is applied to a reverse water-gas catalytic reaction driven by electromagnetic induction heating. The specific method is the same as that in Example 1 and will not be repeated here.

[0086] See Figure 1 This is a diagram showing the reaction results when the reverse water-gas reaction catalyst prepared in this example is applied to the reverse water-gas catalytic reaction driven by electromagnetic induction heating. The results show that the reverse water-gas reaction catalyst prepared in this example exhibits good catalytic activity under electromagnetic induction heating conditions, with a CO2 conversion rate of nearly 40% and a CO selectivity of nearly 100%. Moreover, the activity of the catalyst is not deactivated even after the reaction is carried out for more than 100 hours.

[0087] Example 3

[0088] This embodiment provides a method for preparing a reverse water-gas reaction catalyst based on electromagnetic induction heating, the preparation method comprising the following steps:

[0089] S1. Dissolve 0.124 g of copper nitrate (Cu(NO3)2·3H2O) and 0.59 g of cobalt nitrate (Co(NO3)2·6H2O) in water to form a precursor solution; wherein the molar ratio of copper nitrate to cobalt nitrate is 0.25;

[0090] S2. Mix the precursor solution with 0.85 g of an alumina support, and then dry in an oven at 100° C. for 24 h to obtain a solid catalyst precursor;

[0091] S3, reducing the solid catalyst precursor at 650° C. in a hydrogen atmosphere for 2 h to obtain a CoCu alloy catalyst;

[0092] S4, oxidizing the CoCu alloy catalyst in a water vapor atmosphere at 650°C for 4 h to obtain an oxidized Co@Cu catalyst;

[0093] S5. Reducing the oxidized Co@Cu catalyst again in a hydrogen atmosphere at 650° C. for 1 h to obtain a reverse water gas reaction catalyst, wherein the mass percentage of the CoCu component in the reverse water gas reaction catalyst is 15%.

[0094] This embodiment further provides a reverse water-gas reaction catalyst based on electromagnetic induction heating. The reverse water-gas reaction catalyst is prepared by the preparation method of this embodiment. The mass percentage of the CoCu component in the prepared reverse water-gas reaction catalyst is 15%.

[0095] This embodiment also provides an application of a reverse water-gas reaction catalyst based on electromagnetic induction heating. The reverse water-gas reaction catalyst prepared in this embodiment is applied to a reverse water-gas catalytic reaction driven by electromagnetic induction heating. The specific method is the same as that in Example 1 and will not be repeated here.

[0096] According to tests, the reverse water gas reaction catalyst prepared in this embodiment exhibits good catalytic activity under electromagnetic induction heating conditions, with a CO2 conversion rate of approximately 32% and a CO selectivity close to 100%.

[0097] Example 4

[0098] This embodiment provides a method for preparing a reverse water-gas reaction catalyst based on electromagnetic induction heating, the preparation method comprising the following steps:

[0099] S1. Dissolve 0.186 g of copper nitrate (Cu(NO3)2·3H2O) and 0.52 g of cobalt nitrate (Co(NO3)2·6H2O) in water to form a precursor solution; wherein the molar ratio of copper nitrate to cobalt nitrate is 0.43;

[0100] S2. Mix the precursor solution with 0.85 g of an alumina support, and then dry it in an oven at 120° C. for 24 h to obtain a solid catalyst precursor;

[0101] S3, reducing the solid catalyst precursor at 650° C. in a hydrogen atmosphere for 2 h to obtain a CoCu alloy catalyst;

[0102] S4, oxidizing the CoCu alloy catalyst in air atmosphere at 650°C for 4 h to obtain an oxidized Co@Cu catalyst;

[0103] S5. Reducing the oxidized Co@Cu catalyst again at 650° C. in a hydrogen atmosphere for 2 h to obtain a reverse water gas reaction catalyst, wherein the mass percentage of the CoCu component in the reverse water gas reaction catalyst is 15%.

[0104] This embodiment further provides a reverse water-gas reaction catalyst based on electromagnetic induction heating. The reverse water-gas reaction catalyst is prepared by the preparation method of this embodiment. The mass percentage of the CoCu component in the prepared reverse water-gas reaction catalyst is 15%.

[0105] This embodiment also provides an application of a reverse water-gas reaction catalyst based on electromagnetic induction heating. The reverse water-gas reaction catalyst prepared in this embodiment is applied to a reverse water-gas catalytic reaction driven by electromagnetic induction heating. The specific method is the same as that in Example 1 and will not be repeated here.

[0106] The test showed that the reverse water gas reaction catalyst prepared in this example showed good catalytic activity under electromagnetic induction heating conditions, with a CO2 conversion rate of about 23% and a CO selectivity close to 100%.

[0107] Example 5

[0108] This embodiment provides a preparation method for a reverse water-gas reaction catalyst based on electromagnetic induction heating. The difference between this preparation method and Example 2 is that: in step S2, 0.186g of copper nitrate (Cu(NO3)2·3H2O) and 0.52g of cobalt nitrate (Co(NO3)2·6H2O) are dissolved in water to form a precursor solution; wherein the molar ratio between copper nitrate and cobalt nitrate is 0.43; other methods and steps are the same as those in Example 2 and are not repeated here.

[0109] This embodiment further provides a reverse water-gas reaction catalyst based on electromagnetic induction heating. The reverse water-gas reaction catalyst is prepared by the preparation method of this embodiment. The mass percentage of the CoCu component in the prepared reverse water-gas reaction catalyst is 15%.

[0110] This embodiment also provides an application of a reverse water-gas reaction catalyst based on electromagnetic induction heating. The reverse water-gas reaction catalyst prepared in this embodiment is applied to a reverse water-gas catalytic reaction driven by electromagnetic induction heating. The specific method is the same as that in Example 2 and will not be repeated here.

[0111] The test showed that the reverse water gas reaction catalyst prepared in this example showed good catalytic activity under electromagnetic induction heating conditions, with a CO2 conversion rate of about 23% and a CO selectivity close to 100%.

[0112] Comparative Example 1

[0113] This comparative example provides a method for preparing a conventionally heated Cu-based reverse water-gas reaction catalyst, the method comprising the following steps:

[0114] A1. Dissolve 1.7 g of copper nitrate (Cu(NO3)2·3H2O) in water to form a precursor solution;

[0115] A2. Mix the precursor solution with 2.55 g of alumina support and dry in an oven at 120° C. for 12 h to obtain a solid catalyst precursor;

[0116] A3. The solid catalyst precursor was calcined in air at 450°C for 4 hours, and then reduced in a hydrogen atmosphere at 450°C for 2 hours to obtain a supported Cu / Al2O3 reverse water-gas reaction catalyst, wherein the weight percentage of the Cu component in the supported Cu / Al2O3 reverse water-gas reaction catalyst was 15%.

[0117] This comparative example also provides an application of a conventionally heated Cu-based reverse water-gas reaction catalyst, which is applied to a reverse water-gas catalytic reaction driven by electromagnetic induction heating. The specific method is the same as that in Example 1 and will not be repeated here.

[0118] See Figure 2 This is a reaction result diagram of the traditional Cu-based reverse water-gas reaction catalyst prepared in Comparative Example 1 when applied to the reverse water-gas catalytic reaction driven by electromagnetic induction heating. The traditional Cu-based reverse water-gas catalyst cannot sense the electromagnetic field and has no reaction activity.

[0119] Comparative Example 2

[0120] This comparative example provides a method for preparing a CoCu alloy reverse water-gas reaction catalyst, which comprises the following steps:

[0121] B1. Dissolve 0.062 g of copper nitrate (Cu(NO3)2·3H2O) and 0.67 g of cobalt nitrate (Co(NO3)2·6H2O) in water to form a precursor solution; wherein the molar ratio of copper nitrate to cobalt nitrate is 0.11;

[0122] B2. Mix the precursor solution with 0.85 g of an alumina support, and then dry it in an oven at 120° C. for 12 h to obtain a solid catalyst precursor;

[0123] B3. Reducing the solid catalyst precursor at 600° C. in a hydrogen atmosphere for 1 h to obtain a CoCu alloy catalyst, wherein the mass percentage of the CoCu component in the CoCu alloy reverse water gas reaction catalyst is 15%.

[0124] This comparative example also provides an application of a conventionally heated Cu-based reverse water-gas reaction catalyst, which is applied to a reverse water-gas catalytic reaction driven by electromagnetic induction heating. The specific method is the same as that in Example 1 and will not be repeated here.

[0125] See Figure 3 The CoCu alloy reverse water-gas reaction catalyst prepared in this comparative example is used in the reverse water-gas catalytic reaction driven by electromagnetic induction heating. The CO selectivity is less than 85%. Figure 5a 、 Figure 5bThey are respectively the spherical aberration electron microscopy surface scanning energy spectrum and line scanning energy spectrum of the CoCu alloy reverse water gas reaction catalyst prepared in this comparative example, wherein, Figure 5a The numbers 1 and 2 in Figure 5b Scan line 1 and scan line 2 in the figure correspond to each other. It can be seen from the figure that Cu in the CoCu alloy reverse water gas reaction catalyst prepared in this comparative example is not covered on the surface of the Co particles. The catalyst is an alloy structure in which CoCu is uniformly mixed. Therefore, although the catalyst prepared in this comparative example can induce electromagnetic field to generate heat, since it has not undergone the oxidation induction process, Cu is not covered on the surface of the Co particles and cannot effectively inhibit the methanation side reaction.

[0126] In summary, the preparation method of the reverse water gas reaction catalyst in the present invention is to dissolve a soluble copper salt and a soluble cobalt salt in water, load them on a carrier, and then reduce them at high temperature with hydrogen to obtain a CoCu alloy catalyst, and then induce the Cu component to migrate to the alloy surface under a high temperature oxidizing atmosphere, so that the Cu component in the CoCu alloy particles migrates to the surface and is enriched, forming Co@Cu nanoparticles with a core-shell structure in which Co is the core and Cu is the shell, and then reduce them at high temperature with hydrogen to obtain a reverse water gas reaction catalyst. The preparation method of the present invention is simple, easy to prepare in large quantities, and the core-shell structure can be precisely controlled by the reaction atmosphere components and temperature, which is simple and easy to implement and conducive to scale. Chemical production; The catalyst in the present invention is composed of a carrier, an induction heat generating component Co and a catalytically active component Cu coated on its surface. The catalyst can be directly heated to a high temperature by induction based on the principle of electromagnetic induction, avoiding the energy consumption and the generation of waste gas and dust in the traditional heating and heat transfer process, and providing technical support for the green and low-carbonization of industrial catalysis; it is applied to the reverse water-gas catalytic reaction driven by electromagnetic induction heating. The catalyst can effectively respond to the alternating electromagnetic field to generate the high temperature required for the reverse water-gas reaction, and exhibits stable and efficient catalytic activity, selectivity and stability in the reverse water-gas reaction, making the CO selectivity close to 100%, and working stably for 100 hours without deactivation. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0127] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for preparing a reverse water-gas reaction catalyst based on electromagnetic induction heating, characterized in that: The preparation method comprises the following steps: S1, dissolving a soluble copper salt and a soluble cobalt salt in water at a molar ratio of 0.05 to 1 to form a precursor solution; S2, mixing the precursor solution with a carrier, and then placing it in an oven for drying to obtain a solid catalyst precursor; S3, reducing the solid catalyst precursor at high temperature under a hydrogen atmosphere to obtain a CoCu alloy catalyst; S4, oxidizing the CoCu alloy catalyst at 450° C. to 700° C. under an oxidizing atmosphere for 1 to 4 hours to obtain an oxidized Co@Cu catalyst; the oxidizing atmosphere comprises one or a combination of air, oxygen, water vapor, and carbon dioxide; S5. Reducing the oxidized Co@Cu catalyst again at high temperature under a hydrogen atmosphere to obtain a reverse water gas reaction catalyst, wherein the reverse water gas reaction catalyst comprises a Co@Cu component with a core-shell structure and a carrier, wherein the Co@Cu component with a core-shell structure has Co as a core and Cu as a shell.

2. The preparation method according to claim 1, wherein: Step S1 includes one or a combination of the following conditions: The soluble copper salt includes one or a combination of copper nitrate, copper chloride, copper sulfate, and copper acetate; The soluble cobalt salt includes one or a combination of cobalt nitrate, cobalt chloride, cobalt sulfate, and cobalt acetate.

3. The preparation method according to claim 1, wherein: In step S1, the molar ratio between the soluble copper salt and the soluble cobalt salt is 0.1-0.

2.

4. The preparation method according to claim 1, wherein: Step S2 includes one or a combination of the following conditions: The carrier comprises one or a combination of alumina, zirconia, silicon oxide, titanium oxide, lanthanum oxide, and magnesium oxide; The drying temperature is 60-150° C., and the drying time is 6 hours to 24 hours.

5. The preparation method according to claim 1, wherein: In step S3, the solid catalyst precursor is subjected to high-temperature reduction in a hydrogen atmosphere at a temperature of 500-800° C., and the high-temperature reduction time is 1 h-2 h.

6. The preparation method according to claim 1, wherein: In step S5, the temperature of the high-temperature reduction of the oxidized Co@Cu catalyst under a hydrogen atmosphere is 500-800° C., and the time of the high-temperature reduction is 1 h to 2 h.

7. The preparation method according to claim 1, wherein: The reverse water-gas reaction catalyst obtained in step S5 includes a CoCu component and a carrier, wherein the mass percentage of the CoCu component in the reverse water-gas reaction catalyst is 5% to 30%.

8. A reverse water-gas reaction catalyst based on electromagnetic induction heating, characterized by: The reverse water-gas reaction catalyst is prepared by the preparation method of the reverse water-gas reaction catalyst based on electromagnetic induction heating according to any one of claims 1 to 7.

9. An application of a reverse water-gas reaction catalyst based on electromagnetic induction heating, characterized in that: The reverse water-gas reaction catalyst is applied to a reverse water-gas catalytic reaction driven by electromagnetic induction heating, wherein the reverse water-gas reaction catalyst is prepared by the preparation method according to any one of claims 1 to 7.

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