A magnetic heat heterojunction catalyst capable of realizing confined transient heat and a preparation method and application thereof

Abstract

The application relates to the technical field of catalysis of thermochemical reaction, and discloses a magnetic-thermal heterojunction catalyst capable of realizing limited transient heat and a preparation method and application thereof, which is composed of conductive porous material with eddy current heat effect and nano-catalytic material with superparamagnetic or ferromagnetic properties, the nano-catalytic material is loaded on the material surface outside and inside the pores of the conductive porous material; under an alternating magnetic field: the conductive porous material realizes transient heat generation through the eddy current heat effect, excites non-equilibrium hot electrons, the non-equilibrium hot electrons are transferred to the nano-catalytic material through the interface electron overflow channel between the interface of the conductive porous material and the nano-catalytic material; the nano-catalytic material simultaneously has electron-rich sites and electron-deficient sites, the non-equilibrium hot electrons are directionally relayed to the electron-rich sites under the driving of the electronegativity difference of the nano-catalytic material, and the nano-catalytic material enhances the activation effect. The magnetic-thermal heterojunction catalyst can significantly improve the rate of thermochemical reaction and the conversion rate of reactants.

Description

Technical Field

[0001] This invention relates to the field of thermochemical reaction catalysis technology. Specifically, it relates to a magnetocaloric heterojunction catalyst capable of achieving confined instantaneous heating, its preparation method, and its applications. Background Technology

[0002] Thermochemical reactions (such as methane conversion, carbon dioxide conversion, reforming, cracking, and hydrodehydrogenation) are core processes in energy conversion and resource utilization, and their reaction efficiency highly depends on the synergistic matching of "heat supply" and "catalytic activity." Traditional thermochemical reactions primarily rely on external heat sources (such as electric resistance furnaces or gas heating). Heat must be transferred to the catalytic system through the reactor wall, resulting in significant heat loss, slow heating rates, and uneven temperature distribution. This leads to delayed reaction start-up, low energy utilization efficiency, and limitations on improving feedstock conversion rates and product selectivity. Furthermore, utilizing renewable energy has become an essential path for energy utilization; however, the inherent intermittency of renewable energy makes it difficult to integrate with traditional heating methods due to their slow heating rates. Catalysts are the core of efficient thermochemical reactions. However, traditional thermochemical catalysts still have the following shortcomings in terms of heat utilization and reaction efficiency improvement: existing catalysts do not have the ability to actively generate heat and rely entirely on external heat sources to provide the heat required for the reaction, which further aggravates heat loss and energy consumption problems; at the same time, factors such as the dispersion of the active components of the catalyst and the thermal conductivity of the support also affect the catalytic reaction efficiency. Some catalysts also have problems such as poor high-temperature stability and easy carbon deposition and deactivation, which further limit the industrialization process of thermochemical reactions.

[0003] To address the problems of low heat utilization efficiency and slow reaction start-up in traditional heating methods, as well as the insufficient catalytic efficiency of existing catalysts, there is an urgent need in this field to develop novel catalysts that can achieve efficient heat utilization, rapid catalytic reaction start-up, and significantly improve the conversion rate of thermochemical reactions. Based on the magnetocaloric effect and eddy current heating principle, if magnetocaloric properties can be combined with catalytic properties to design a magnetocaloric heterojunction catalyst that can generate heat itself through the eddy current effect under an alternating magnetic field, enabling rapid temperature rise and efficient catalytic reaction on the catalyst surface, it is expected to significantly improve energy utilization efficiency and catalytic reaction efficiency, while improving the temperature control responsiveness of the reaction, providing a new technical path for efficient and low-energy thermochemical reactions. Therefore, the development of a magnetocaloric heterojunction catalyst for thermochemical reactions, its preparation method, and its application have significant practical significance and application value.

[0004] Currently, achieving controllable volumetric hot electron generation under extreme thermal conditions is particularly challenging for thermochemical reaction systems. This is due to rapid heat dissipation, low energy transfer efficiency, and the stringent requirement to maintain multi-step reactions at high gas space-time velocities (GHSV). Therefore, further optimization of electrochemical catalytic systems is necessary to address issues such as high thermal inertia, high energy consumption, easy degradation of catalyst activity, poor compatibility with renewable energy sources with unstable output, and low conversion efficiency of existing catalytic reaction systems. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to provide a magnetocaloric heterojunction catalyst capable of confined instantaneous heating, its preparation method and application, so as to solve the problems of low catalytic reaction efficiency and energy utilization efficiency caused by the limitations of existing thermochemical reactions due to factors such as catalyst and heating method, as well as poor compatibility with renewable energy with "unstable output".

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A magnetocaloric heterojunction catalyst capable of confined instantaneous heating comprises a conductive porous material with eddy current heating effect and a superparamagnetic or ferromagnetic nanocatalyst. The nanocatalyst is loaded on the outer surface of the conductive porous material and on the surface of the pores inside the conductive porous material. Under the action of an alternating magnetic field, the conductive porous material achieves instantaneous heat generation through the eddy current heating effect, which excites non-equilibrium hot electrons. These non-equilibrium hot electrons are transferred to the nanocatalyst through the interfacial electron overflow channel between the conductive porous material and the nanocatalyst. The nanocatalyst simultaneously contains electron-rich sites and electron-deficient sites. Driven by the electronegativity difference of the nanocatalyst, the non-equilibrium hot electrons are directionally transferred to the electron-rich sites, thereby synergistically enhancing the activation effect on reactants and reaction intermediates. In existing technologies, for chemical reactions that require heating to a certain temperature to proceed rapidly, the slow heating rate during the initial reaction results in a long heating time. Furthermore, renewable energy sources are intermittent, making it impossible to apply them industrially to thermochemical reactions. The magnetocaloric heterojunction catalyst of this invention, under the action of an alternating magnetic field, not only achieves instantaneous heat generation and excites non-equilibrium hot electrons, but also allows these non-equilibrium hot electrons to transfer through interfacial electron overflow channels to the electron enrichment sites of the nanocatalytic material. This enables the chemical reaction to be initiated at any time, matching the intermittent nature of renewable energy and making it possible to use renewable energy industrially for thermochemical reactions.

[0008] The aforementioned magnetocaloric heterojunction catalyst capable of confined instantaneous heating comprises a conductive porous material, a carbon felt with a three-dimensional porous network structure formed by conductive carbon fibers, and a superparamagnetic or ferromagnetic nanocatalyst material, high-entropy alloy nanoparticles formed by five metal elements: iron, cobalt, copper, nickel, and ruthenium. The high-entropy alloy nanoparticles are loaded on the surface of the carbon felt and on the surface of conductive carbon fibers inside the carbon felt. In the high-entropy alloy nanoparticles, the binding energy of nickel and ruthenium shows a negative shift, and the electron density of nickel and ruthenium increases to form electron-rich Ni–Ru dual active sites, while the binding energy of iron, cobalt, and copper shows a positive shift, and the electron density of iron, cobalt, and copper is lacking to form electron-deficient sites.

[0009] In this invention, conductive porous materials achieve instantaneous heating in an alternating magnetic field, while nanocatalytic materials produce almost no thermal effect. Since the two materials generate heat in different ways, this invention defines the catalyst composed of these two materials as a magnetocaloric heterojunction catalyst. Furthermore, under the action of an alternating magnetic field, the magnetocaloric heterojunction catalyst of this invention generates high temperatures on the surface of the conductive porous material due to the skin effect of eddy currents. This excites non-equilibrium hot electrons on the surface of the conductive porous material, thus forming an electron overflow at the interface between the conductive porous material and the nanocatalytic material. This is defined as interfacial electron overflow. This interfacial electron overflow is transferred to the nanocatalytic material through the interfacial electron overflow channel, thereby enhancing the catalytic effect of the nanocatalytic material and thus facilitating the thermochemical reaction catalyzed by the magnetocaloric heterojunction catalyst. In addition, using carbon felt composed of conductive carbon fibers as the conductive porous material, under the alternating magnetic field of 100-300A and 200-500kHz of this invention, instantaneous heating can be achieved through the skin effect and eddy current effect. Moreover, the carbon fibers inside the carbon felt all exhibit the skin effect, which can ensure uniform heating inside the conductive porous material and avoid the temperature gradient generated by the magnetocaloric heterojunction catalyst as a heating medium from affecting the catalytic reaction efficiency.

[0010] In this process, the magnetic field acts as a switch, activating the electron spillover at the catalyst interface, leading to electron enrichment at active sites and dynamic reconfiguration of the electron distribution within the catalyst. Compared to the closed state, i.e., the traditional resistance furnace heating mode, activating this "switch" allows the catalyst to dynamically adapt to complex multi-electron transfer processes, thereby significantly improving reaction performance, with efficiency up to 1.8 times higher than the thermodynamic equilibrium state. Under switch-activated conditions, eddy currents on the carbon fibers (CFs) in the magnetocaloric heterostructure generate non-equilibrium hot electrons. These hot electrons are transferred to high-entropy alloy nanoparticles (HEANPs) through the interfacial electron spillover channel, and then, driven by the electronegativity difference, are transferred to the Ni–Ru dual active sites. Finally, through an electron relay mechanism, the non-equilibrium hot electrons are directionally transferred from the carbon fibers to the reactants, thereby synergistically enhancing the activation of both reactants and key intermediates.

[0011] A method for preparing a magnetocaloric heterojunction catalyst capable of confined instantaneous heating includes the following steps:

[0012] Step (1): Add acetylacetone iron, acetylacetone cobalt, acetylacetone nickel, acetylacetone copper, acetylacetone ruthenium and ascorbic acid to oleylamine, mix evenly and sonicate. After sonication, a mixed dispersion is obtained.

[0013] Step (2): The mixed dispersion is heated to the reaction temperature under magnetic stirring and isothermal reaction is carried out; after the isothermal reaction is completed, the solid product obtained by centrifugation is washed with cyclohexane or anhydrous ethanol, stored in cyclohexane and subjected to ultrasonic treatment to obtain high entropy alloy nanoparticle precursor dispersion.

[0014] Step (3): Calcine the carbon felt composed of conductive carbon fibers in an argon atmosphere to obtain a pretreated carbon felt; drop a high-entropy alloy nanoparticle precursor dispersion onto the pretreated carbon felt to obtain a high-entropy alloy nanoparticle precursor-carbon felt mixture; dry the high-entropy alloy nanoparticle precursor-carbon felt mixture to obtain a high-entropy alloy nanoparticle-magnetocaloric heterojunction precursor; the core function of drying is to gradually remove cyclohexane or anhydrous ethanol from the surface and pores of the precursor by gentle heating at a temperature lower than the boiling point or flash point of the organic solvent, so as to avoid its violent phase change and reaction during the high-temperature calcination stage, thereby ensuring the quality of the product;

[0015] Step (4): The high-entropy alloy nanoparticle-magnetothermal heterojunction precursor is subjected to a two-step calcination treatment to obtain a high-entropy alloy nanoparticle-magnetothermal heterojunction intermediate; then the high-entropy alloy nanoparticle-magnetothermal heterojunction intermediate is subjected to a reduction treatment under a reducing atmosphere. After the reduction treatment, a magnetocaloric heterojunction catalyst composed of conductive porous material with eddy current thermal effect and superparamagnetic or ferromagnetic nanocatalyst material is obtained. The high-entropy alloy nanoparticles are loaded as nanocatalyst material on the surface of carbon felt, which is conductive porous material, and on the surface of conductive carbon fiber inside the carbon felt. Under the action of alternating magnetic field: the conductive porous material achieves instantaneous heat generation through eddy current thermal effect and excites non-equilibrium hot electrons. The non-equilibrium hot electrons are transferred to the nanocatalyst material through the interfacial electron overflow channel between the conductive porous material and the nanocatalyst material. There are both electron enrichment sites and electron deficiency sites on the nanocatalyst material. The non-equilibrium hot electrons are directionally transferred to the electron enrichment sites under the drive of the electronegativity difference of the nanocatalyst material, thereby synergistically enhancing the activation effect on reactants and reaction intermediates by the nanocatalyst material.

[0016] In the preparation method of the above-mentioned magnetocaloric heterojunction catalyst capable of confined instantaneous heating, in step (1), the molar ratio of the five components of acetylacetone iron, acetylacetone cobalt, acetylacetone nickel, acetylacetone copper, and acetylacetone ruthenium is (15-20):(20-25):(28-32):(22-28):(5-8); the ratio of the total mass of acetylacetone iron, acetylacetone cobalt, acetylacetone nickel, acetylacetone copper, and acetylacetone ruthenium to the mass of ascorbic acid is 1:(2-4); the total mass volume concentration of acetylacetone iron, acetylacetone cobalt, acetylacetone nickel, acetylacetone copper, and acetylacetone ruthenium in the mixed dispersion is 1-3 mg / mL; the ultrasonic treatment conditions are: ultrasonic power of 200-600 W and ultrasonic time of 60-120 min.

[0017] In the above-mentioned method for preparing magnetocaloric heterojunction catalysts capable of confined instantaneous heating, in step (2), the magnetic stirring rate is 3500-4500 rpm (if the stirring rate is too low, the particle size of the generated alloy nanoparticles will increase and affect the catalytic performance), the heating rate is 8-12℃ / min, the isothermal reaction temperature is 200-250℃, and the isothermal reaction time is 3-5h; the ultrasonic treatment conditions are: ultrasonic power is 200-600W, ultrasonic time is 30-60min; and the mass volume concentration of high-entropy alloy nanoparticle precursor in the high-entropy alloy nanoparticle precursor dispersion is 1-3mg / mL.

[0018] In the above-mentioned method for preparing a magnetocaloric heterojunction catalyst capable of confined instantaneous heating, in step (3), the diameter of the conductive carbon fiber constituting the carbon felt is 10-15 μm and the length is 2-5 mm; the calcination conditions are: calcination temperature 800-1000℃, calcination time 2-4 h, which can effectively remove impurities; the mass ratio of high-entropy alloy nanoparticle precursor to pretreated carbon felt in the high-entropy alloy nanoparticle precursor-carbon felt mixture is 1:(5-15); the drying conditions are: drying temperature 70-90℃, drying time 20-28 h.

[0019] The above-mentioned method for preparing a magnetocaloric heterojunction catalyst capable of confined instantaneous heating includes a two-step calcination process in step (4): first, calcining at 200-300℃ for 30-80 min at a heating rate of 8-12℃ / min in an argon atmosphere, and then calcining at 500-700℃ for 30-80 min at a heating rate of 8-12℃ / min; the reduction process is as follows: under a reducing atmosphere of hydrogen and argon in a volume ratio of (5-10):1, heating at a heating rate of 8-12℃ / min to a reduction temperature of 500-700℃, reducing for 1-3 h, and then naturally cooling to room temperature.

[0020] The two-step calcination process employed in this invention is a necessary step for the precise formation of magnetocaloric heterojunctions. The method is as follows: the first calcination process can efficiently remove residual impurities in the precursor and stabilize the interface between the high-entropy alloy nanoparticle precursor and the conductive carbon fiber, providing favorable conditions for the construction of the magnetocaloric heterojunction; the second calcination process promotes the formation of a magnetocaloric heterojunction with a uniform structure and tight interfacial bonding between the high-entropy alloy nanoparticle precursor and the conductive carbon fiber, thereby enabling the generation of interfacial electron overflow channels between the conductive carbon fiber and the high-entropy alloy nanoparticle interface under the action of an alternating magnetic field, ensuring the magnetocaloric performance and catalytic stability of the catalyst.

[0021] In the preparation method of the above-mentioned magnetocaloric heterojunction catalyst, in step (1), the total mass ratio of iron acetylacetone, cobalt acetylacetone, nickel acetylacetone, copper acetylacetone, and ruthenium acetylacetone to ascorbic acid is 1:3; in the mixed dispersion, the total mass volume concentration of iron acetylacetone, cobalt acetylacetone, nickel acetylacetone, copper acetylacetone, and ruthenium acetylacetone is 2 mg / mL; the ultrasonic treatment conditions are: ultrasonic power of 500 W and ultrasonic time of 90 min.

[0022] In step (2), the magnetic stirring speed is 4000 rpm, the heating rate is 10℃ / min, the constant temperature reaction temperature is 230℃, and the constant temperature reaction time is 3.5h; the ultrasonic treatment conditions are: ultrasonic power is 500W, ultrasonic time is 30min; the mass volume concentration of high entropy alloy nanoparticle precursor in the high entropy alloy nanoparticle precursor dispersion is 2mg / mL.

[0023] In step (3), the diameter of the conductive carbon fiber is 10-15 μm and the length is 3 mm; the calcination conditions are: calcination temperature 900℃, calcination time 3h; the mass ratio of high entropy alloy nanoparticle precursor to pretreated carbon felt in the high entropy alloy nanoparticle precursor-carbon felt mixture is 1:10; the drying conditions are: drying temperature 80℃, drying time 24h.

[0024] In step (4), the two-step calcination treatment method is as follows: first, calcining at 250℃ for 60 min at a heating rate of 10℃ / min in an argon atmosphere, and then calcining at 600℃ for 60 min at a heating rate of 10℃ / min. After calcination, the temperature is naturally cooled to room temperature. The reduction treatment method is as follows: under a reducing atmosphere of hydrogen and argon mixed gas with a volume ratio of 5:1, the temperature is raised to the reduction temperature of 600℃ at a heating rate of 10℃ / min, and the reduction treatment is carried out for 2 h. Then, the temperature is naturally cooled to room temperature. In the obtained magnetocaloric heterojunction catalyst, the molar ratio of Fe:Co:Cu:Ni:Ru is 18:21:30:25:6.

[0025] An application of a magnetocaloric heterojunction catalyst, using the aforementioned magnetocaloric heterojunction catalyst or the magnetocaloric heterojunction catalyst prepared by the aforementioned method as a catalyst for thermochemical reactions, employs a magnetic induction-confined instantaneous heating enhanced thermochemical reaction system for thermochemical reactions. Specifically, electromagnetic induction is used as the heating method, and the magnetocaloric heterojunction catalyst is located within an alternating magnetic field generated by electromagnetic induction. Under electromagnetic induction heating, the magnetocaloric heterojunction catalyst is instantly heated to the thermochemical reaction temperature, which can be well matched with the intermittent nature of renewable energy sources. The thermochemical reaction occurs on the material surface outside the magnetocaloric heterojunction catalyst or on the material surface of its internal pores. The thermochemical reaction is a methane conversion reaction, a carbon dioxide conversion reaction, a reforming reaction, a cracking reaction, or a hydrodehydrogenation reaction.

[0026] In this invention, magnetically induction-confined instantaneous heating (IECH) refers to the following: In the thermochemical reaction system of this invention, the conductive porous material in the confined instantaneous heating reaction bed generates heat only at the catalytic reaction interface (i.e., the pore surface of the confined instantaneous heating reaction bed) due to the eddy current effect and skin effect in the alternating magnetic field generated by the electromagnetic induction coil. Other parts of the thermochemical reactor do not consume energy; this is the "confined" aspect. Furthermore, the conductive porous material, under the skin effect induced by the eddy current effect of the alternating magnetic field controlled by a frequency converter, can achieve instantaneous high-temperature driving at the thermochemical reaction interface; this is the instantaneous heating aspect. This invention utilizes the magnetically induction-confined instantaneous heating characteristic of the confined instantaneous heating reaction bed made of conductive porous material loaded with thermochemical reaction catalytically active components. This effectively avoids overall temperature rise inside the thermochemical reactor. Moreover, by controlling the on / off state of the frequency converter, the confined instantaneous heating reaction bed can achieve transient heating and cooling during power-on and power-off processes, thereby significantly improving the catalytic efficiency and selectivity of the thermochemical reaction and reducing system energy consumption.

[0027] The application of the aforementioned magnetocaloric heterojunction catalyst is based on a magnetically induction-confined instantaneous heating enhanced thermochemical reaction system comprising a frequency converter, an electromagnetic induction coil, a thermochemical reactor, and a confined instantaneous heating reaction bed. The confined instantaneous heating reaction bed is arranged within the thermochemical reactor, and the electromagnetic induction coil is arranged around the thermochemical reactor. The confined instantaneous heating reaction bed comprises the aforementioned magnetocaloric heterojunction catalyst or a magnetocaloric heterojunction catalyst prepared using the aforementioned method. The frequency converter controls the electromagnetic induction coil to generate an alternating magnetic field, and the confined instantaneous heating reaction bed is located within the region of the alternating magnetic field generated by the electromagnetic induction coil.

[0028] The skin depth is controlled to be less than or equal to 3 mm (3 mm is the gas diffusion depth of the thermochemical reaction) by controlling the radius of the thermochemical reactor, the frequency of the alternating magnetic field, the magnetic permeability of the conductive porous material, and the electrical conductivity of the conductive porous material; the formula for calculating the skin depth is:

[0029] (1);

[0030] In equation (1), δ is the skin depth, σ is the conductivity of the conductive porous material, f is the frequency of the alternating magnetic field, and μ is the permeability of the conductive porous material.

[0031] Along the axial direction of the thermochemical reactor: the ratio of the length of the confined instantaneous heating reaction bed to the length of the alternating magnetic field region is 1:5 to 10; the thermochemical reactor is a quartz tube reactor; the length of the confined instantaneous heating reaction bed along the axial direction of the thermochemical reactor is 10 mm, and the diameter of the confined instantaneous heating reaction bed is 18 mm; the electromagnetic induction coil is made of a copper tube with a diameter of 5 mm, the inner diameter of the electromagnetic induction coil is 40 mm, and the number of turns of the electromagnetic induction coil is 5 turns; the frequency of the alternating magnetic field is 100 to 1000 kHz, and the frequency converter is a power system that generates electricity from renewable energy sources (including wind power, solar power, etc.).

[0032] In the application of the above-mentioned magnetocaloric heterojunction catalyst, the thermochemical reaction is a methane ultra-dry reforming reaction, the catalytic reaction temperature is 650-800℃, the gas space velocity is 500-700 L g⁻¹ h⁻¹, the carbon dioxide flow rate is 10-20 mL / min, and the carbon dioxide to methane feed volume ratio is (1-3):1; the frequency of the alternating magnetic field is 200-500 kHz, and the alternating current is 100-300 A; preferably, the frequency of the alternating magnetic field is 300 kHz, and the alternating current is 100 A; the catalytic reaction temperature is 700℃, the gas space velocity is 600 L g⁻¹ h⁻¹, the carbon dioxide flow rate is 14 mL / min, and the carbon dioxide to methane volume feed ratio is 3:1.

[0033] The technical solution of the present invention achieves the following beneficial technical effects:

[0034] 1. The magnetocaloric heterojunction catalyst of the present invention comprises a superparamagnetic or ferromagnetic nanocatalytic material that mainly plays a catalytic role, while a conductive porous material mainly plays a role in heating to drive the thermochemical reaction. Furthermore, under the alternating magnetic field of the present invention, the non-equilibrium hot electrons in the conductive porous material migrate to the surface of the conductive porous material due to the skin effect, and are excited into non-equilibrium hot electrons at high temperature to form an interfacial electron spillover. The interfacial electron spillover transfers to the superparamagnetic or ferromagnetic nanocatalytic material to further increase the electronegativity of its active sites and reduce the activation energy barrier of the reactants, thereby improving the catalytic reaction efficiency.

[0035] 2. The preparation method of the magnetocaloric heterojunction catalyst of this invention selects acetylacetone salts of iron, cobalt, nickel, copper and ruthenium as raw materials, ascorbic acid as a reducing agent, and oleylamine as a reaction solvent. A FeCoNiCuRu high-entropy alloy nanoparticle precursor is prepared by controlling the hydrothermal reduction reaction conditions. Then, using a carbon felt composed of conductive carbon fibers as a carrier, the FeCoNiCuRu high-entropy alloy nanoparticle precursor is impregnated onto the carbon felt composed of conductive carbon fibers using a wet impregnation method. Finally, a two-step calcination method is used, and the heating rate, calcination temperature and calcination time of the two calcinations are controlled to obtain the high-entropy alloy. Alloy nanoparticles-magnetic-thermochromic heterojunction intermediates were transformed into a catalyst with a magnetic-thermochromic heterojunction through reduction treatment with controlled reduction atmosphere, heating rate, reduction temperature, and reduction time. This process increased the electron density of nickel and ruthenium, forming electron-rich Ni–Ru dual active sites, and positively shifted the binding energies of iron, cobalt, and copper, while eliminating electron density loss sites in iron, cobalt, and copper. This enabled highly efficient ultra-dry methane reforming catalysis with near-complete conversion in a single pass (CH4 93.0%, CO2 97.0%), significantly simplifying traditional multi-stage cascade reaction processes. Furthermore, the magnetic-thermochromic heterojunction catalyst exhibited a methane reduction activity as high as 2.99 mol CO2 / mol CH4, 1.8 times higher than the thermodynamic equilibrium value, setting a new record for the highest CO2 reduction per mole of CH4. Both theoretical calculations and experimental results demonstrate that the synergistic effect between the electron-enriched Ni–Ru dual active sites and the magnetically induced hot electrons in the magnetocaloric heterojunction catalyst significantly enhances the intrinsic activity of ultradry methane reforming. This invention opens a new pathway for electrified endothermic reactions and lays the foundation for future energy-saving industrial applications.

[0036] 3. This invention relates to a reaction system for enhancing thermochemical reactions based on magnetic induction confinement and instantaneous heating. By setting up a confined instantaneous heating reaction bed made of conductive porous material loaded with thermochemical catalytic active components within the thermochemical reactor, the conductive porous material generates heat only at the catalytic reaction interface due to the eddy current effect and accompanying skin effect of the alternating magnetic field. This achieves instantaneous high-temperature driving at the thermochemical reaction interface, effectively avoiding overall temperature rise inside the thermochemical reactor. Furthermore, by controlling the on and off states of the variable frequency power supply, the confined instantaneous heating reaction bed can achieve transient heating and cooling during power-on and power-off processes, thereby significantly improving the catalytic efficiency and selectivity of the thermochemical reaction and reducing system energy consumption.

[0037] 4. The magnetocaloric heterojunction catalyst of this invention is used in a methane ultra-dry reforming process based on magnetic induction heating. By inducing eddy currents in an alternating magnetic field driven by renewable energy, and using conductive carbon carbon fibers loaded with high-entropy alloy nanoparticles with gradient electronegativity, the challenge of achieving controllable volumetric hot electron generation under extreme thermal conditions can be effectively solved. This invention utilizes induced eddy currents generated by magnetic induction to drive the methane ultra-dry reforming process, achieving a relatively ideal conversion rate at 700℃: even at a high rate of 600 L g... -1 h -1 Under GHSV conditions, the conversion rate of methane (CH4) still reached 84.6%, the conversion rate of carbon dioxide (CO2) reached 90.6%, and the methane reaction rate reached 3.52 mol / g. cat / h is 4 to 25 times that of the most advanced existing level. Attached Figure Description

[0038] Figure 1 Low-magnification scanning electron microscope image of HEA-MtH in an embodiment of the present invention;

[0039] Figure 2 HEA-MtH transmission electron microscope image in an embodiment of the present invention;

[0040] Figure 3 HAADF-STEM image and elemental energy spectrum of HEA-MtH in the embodiments of the present invention;

[0041] Figure 4 A schematic diagram of the relative energy distribution and electronegativity ranking of each element in Ni-MtH, Ru-MtH and HEA-MtH in the embodiments of the present invention;

[0042] Figure 5 The k-edge XANES spectra of Ru in Ru HEA-MtH, Ru Foil, and Ru-MtH in the embodiments of the present invention;

[0043] Figure 6 Ni k-edge XANES spectra in Ni HEA-MtH, Ni Foil, and Ni-MtH in the embodiments of the present invention;

[0044] Figure 7 FT-EXAFS spectra of Ru HEA-MtH, Ru-MtH, and Ru Foil in the embodiments of the present invention;

[0045] Figure 8 WT-EXAFS spectra of Ni in Ni HEA-MtH and Ni-MtH in the embodiments of the present invention;

[0046] Figure 9The test and evaluation system based on magnetic induction confinement instantaneous heating technology in this embodiment of the invention, wherein (a) is a physical picture and (b) is a schematic diagram;

[0047] Figure 10 A schematic diagram of the fluctuation-adaptive electrified methane-carbon dioxide upgrade process in an embodiment of the present invention;

[0048] Figure 11 The CH4 and CO2 conversion rates of different samples under IECH and RFH driving conditions (GHSV=600 L g⁻¹ h⁻¹) in the embodiments of the present invention at 650, 700, 750 and 800 °C;

[0049] Figure 12 Arrhenius plots of the reaction rates of HEA-MtH with CO2 and CH4 under IECH and RFH conditions at different temperatures in this invention embodiment;

[0050] Figure 13 The following is a comparison of the mass specific activity of HEA-MtH with other typical SDRM reaction catalysts in this embodiment of the invention; 1 represents the research results in Nature Energy (2020), 2 represents the research results in Nature Communications (2023), 3 represents the research results in Advanced Functional Materials (2024), 4 represents the research results in Journal of the American Chemical Society (2020), 5 represents the research results in Science (2020), 6 represents the research results in Nature Communications (2019), 7 represents the research results in Advanced Energy Materials (2024), 8 represents the research results in Applied Catalysis B: Environmental (2022), 9 represents the research results in ACS "Cataly." represents ACS Catalysis (2021), and "10" represents the findings in Applied Catalysis B: Environmental (2018).

[0051] Figure 14The figure shows the test results of H2 / CO and CH4 reducibility of HEA-MtH under IECH driving conditions at 750°C under different CO2 / CH4 feed volume ratios (1, 2, 3) in the embodiments of the present invention.

[0052] Figure 15 In this embodiment of the invention, HEA-MtH was subjected to stability testing at 700℃;

[0053] Figure 16 Infrared thermograms of HEA-MtH under IECH conditions in this embodiment of the invention;

[0054] Figure 17 PPMS analysis results of high-entropy alloy nanoparticle precursors in this embodiment of the invention;

[0055] Figure 18 Eddy current curves of HEA-MtH under IECH energized / de-energized conditions in this embodiment of the invention;

[0056] Figure 19 A schematic diagram of the magnetocaloric heterojunction catalyst prepared in this embodiment of the invention under an alternating magnetic field;

[0057] Figure 20 The magnetocaloric heterojunction catalyst prepared in the embodiments of the present invention is shown in different states of the magnetic switch, wherein (a) is a schematic diagram of the magnetic switch being closed and (b) is a schematic diagram of the magnetic switch being open.

[0058] Figure 21 The graph shows the CH4 conversion rate and CO2 conversion rate of HEA-MtH at 250, 300, 350, 400 and 450 °C under IECH and RFH conditions in this embodiment of the invention.

[0059] Figure 22 The d-orbital density of states (DOS) of Ni in the HEA-MtH and Ni-MtH systems in this embodiment of the invention;

[0060] Figure 23 The d-orbital density of states (DOS) of Ru in the HEA-MtH and Ru-MtH systems in this embodiment of the invention;

[0061] Figure 24 Charge density difference maps of CO2 on HEA-MtH (1 1 1), Ru-MtH (0 0 1) and Ni-MtH (1 11) in embodiments of the present invention;

[0062] Figure 25 The total density of states of CO2 in the free state in the embodiments of the present invention, and the total density of states after adsorption on HEA-MtH in the ground state and excited state;

[0063] Figure 26 Transition state energy barrier diagrams of methane activation and carbon dioxide dissociation on the HEA (1 1 1) surface in the ground state and excited state in the embodiments of the present invention;

[0064] Figure 27 The flow model diagram of mass and energy flow in the SDRM process is realized through IECH and combustion heating in this embodiment of the invention;

[0065] Figure 28 The comparison chart of SEC values ​​of H2 production in the embodiments of this invention with existing research results (PH-plasma heating, JH-joule heating, MWH-microwave heating; SMR: steam methane reforming, OCRM: O-CO2 methane reforming, BRM: CH4 dual reforming, SDRM: CH4 dry reforming).

[0066] Figure 29 Cost breakdown diagram of IECH-driven dry reforming technology in this embodiment of the invention (S) feed (Raw material costs, CAPEX: Capital expenditures, Electricity: Electricity costs, OPEX: Fixed operating expenses)

[0067] Figure 30 In this embodiment of the invention, an IECH-driven HEA-MtH is used to realize a statistical chart of ultra-dry heavy integration gas production costs. Detailed Implementation

[0068] 1. Preparation of magnetocaloric heterojunction catalysts.

[0069] (1) Preparation of high-entropy alloy nanoparticle precursors.

[0070] The preparation method of the FeCoNiCuRu high-entropy alloy nanoparticle precursor in this embodiment is as follows:

[0071] (1.1) 2.085 mg of iron(III) acetylacetone (Fe(acac)3), 2.453 mg of cobalt(III) acetylacetone (Co(acac)3), 2.527 mg of nickel(II) acetylacetone (Ni(acac)2), 2.146 mg of copper(II) acetylacetone (Cu(acac)2), and 0.789 mg of ruthenium(III) acetylacetone (Ru(acac)3) were mixed with 30 mg of ascorbic acid and 5 mL of oleylamine in a 25 mL colorimetric tube and sonicated (500 W for 90 min) to ensure homogeneity and obtain a mixed dispersion.

[0072] (1.2) The mixed dispersion was heated to 230°C in the flask under magnetic stirring at 4000 rpm and a heating rate of 10°C / min, and the reaction was kept at 230°C for 3.5 h. After the reaction was completed, the mixture was centrifuged, and the obtained black solid product was washed three times with cyclohexane to obtain the high-entropy alloy nanoparticle precursor. Finally, the prepared high-entropy alloy nanoparticle precursor was stored in cyclohexane and subjected to ultrasonic treatment (ultrasonic power of 500 W, ultrasonic time of 30 min) to obtain a high-entropy alloy nanoparticle precursor dispersion for subsequent use. The mass-volume concentration of the high-entropy alloy nanoparticle precursor in the high-entropy alloy nanoparticle precursor dispersion was 2 mg / mL.

[0073] Using the same method described above, Ni nanoparticles, Ru nanoparticles, NiRu nanoparticles, NiRuCo nanoparticles, and FeCoCu nanoparticles were prepared by changing the type of corresponding metal acetylacetonate complexes used.

[0074] (2) Preparation of magnetothermal heterojunction catalyst.

[0075] This embodiment employs a wet impregnation method to prepare a magnetocaloric heterojunction catalyst (i.e., HEA-MtH). The specific preparation method is as follows:

[0076] (2.1) The carbon felt composed of conductive carbon fibers was calcined at 900°C for 3 hours in an argon atmosphere to obtain pretreated carbon felt, so as to effectively remove impurities. The conductive carbon fibers used in this embodiment have a diameter of 10-15 μm and a length of 3 mm. Then, 20 mg of high entropy alloy nanoparticle precursor was dispersed in 10 mL of cyclohexane to form a dispersion, which was ultrasonically treated (500 W) for 30 minutes to ensure uniform distribution, and a HEA nanoparticle precursor dispersion was obtained. Then, the HEA nanoparticle precursor dispersion was added dropwise to the pretreated carbon felt composed of 200 mg of conductive carbon fibers using a pipette to obtain a high entropy alloy nanoparticle precursor-carbon felt mixture. Then, the high entropy alloy nanoparticle precursor-carbon felt mixture was dried at 80°C for 24 hours to obtain a high entropy alloy nanoparticle-magnetic-thermal heterojunction precursor.

[0077] (2.2) The obtained high-entropy alloy nanoparticle-magnetothermal heterojunction precursor was subjected to the following two-step calcination treatment: first, it was heated to 250℃ for 1h in an argon atmosphere at a heating rate of 10℃ / min, and then heated to 600℃ for 1h at a heating rate of 10℃ / min. After the two-step calcination, the high-entropy alloy nanoparticle-magnetothermal heterojunction intermediate was obtained. Finally, the high-entropy alloy nanoparticle-magnetothermal heterojunction intermediate was reduced to 600℃ for 2h in a reducing atmosphere of hydrogen and argon mixed gas with a volume ratio of 5:1 at a heating rate of 10℃ / min. After the reduction treatment, it was naturally cooled to room temperature to prepare HEA-MtH (i.e., magnetocaloric heterojunction catalyst, hereinafter referred to as HEA-MtH, where HEA represents high-entropy alloy and MtH represents magnetocaloric heterojunction).

[0078] The high-entropy alloy nanoparticle precursor in the above preparation method was replaced with Ni nanoparticles, Ru nanoparticles, NiRu nanoparticles, NiRuCo nanoparticles and FeCoCu nanoparticles, and Ni-MtH catalyst, Ru-MtH catalyst, NiRu-MtH catalyst, NiRuCo-MtH catalyst and FeCoCu-MtH catalyst were synthesized respectively using the same process as above.

[0079] 2. Structural characterization of HEA-MtH.

[0080] HEA-MtH exhibits three significant diffraction peaks at 2θ = 43°, 51°, and 75°, corresponding to the (111), (200), and (220) crystal planes of the face-centered cubic (fcc) phase, respectively. No independent XRD peaks for Fe, Co, Ni, Cu, Ru, or metal oxides were detected, indicating the formation of a single-phase HEA. Figure 1 Field emission scanning electron microscopy (SEM) images show that interwoven carbon fibers with diameters of 10 to 15 micrometers form a three-dimensional porous network. Transmission electron microscopy (TEM) images ( Figure 2 High-entropy alloy nanoparticles with a homogeneous distribution are uniformly anchored on the carbon fiber surface, with an average particle size of approximately 15 ± 0.2 nm. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) was used to observe these nanoparticles. Figure 3Energy dispersive X-ray spectroscopy (EDS) imaging confirmed that the five elements in HEA nanoparticles were uniformly distributed and fully mixed, with no obvious component segregation, consistent with the XRD results. The elemental contents of HEA-MtH were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES), and the atomic ratio of Fe:Co:Cu:Ni:Ru was calculated to be 18:21:30:25:6. [It should be noted that the feeding ratio was not based on the exact molar ratio of Fe:Co:Cu:Ni:Ru (18:21:30:25:6). This is because it was found in experiments that when the feeding ratio of iron acetylacetone, cobalt acetylacetone, nickel acetylacetone, copper acetylacetone, and ruthenium acetylacetone was (15–20):(20–25):(28–32):(22–28):(5–8), the final magnetocaloric heterojunction catalyst with the Fe:Co:Cu:Ni:Ru atomic ratio was 18:21:30:25:6.] These results provide evidence for the successful synthesis of HEA-MtH. Furthermore, the morphology of Ni-MtH, Ru-MtH, NiRu-MtH, NiRuCo-MtH and FeCoCu-MtH was characterized by transmission electron microscopy (TEM) and high-angle scattering transmission electron microscopy (HAADF-STEM) combined with energy dispersive spectroscopy (EDS mapping). The results showed that all of the above nanoparticles were uniformly dispersed on the carbon fiber support.

[0081] The chemical composition and electronic properties of Ru-MtH, Ni-MtH, NiRu-MtH, NiRuCo-MtH, FeCoCu-MtH, and HEA-MtH were investigated using X-ray photoelectron spectroscopy (XPS). The Ru 3p spectrum of Ru-MtH showed double peaks at 461.8 and 484.3 eV, corresponding to the Ru 3p3 / 2 and Ru 3p1 / 2 orbitals of Ru0, respectively. The Ni 2p spectrum of Ni-MtH showed two strong peaks at 852.7 and 870.1 eV, respectively, characteristic of metallic Ni. Furthermore, the binding energies at 855.3, 872.5, 858.2, and 875.6 eV were attributed to the oxidation states of Ni 2p3 / 2 and Ni 2p1 / 2, respectively. In contrast, the Ru 3p XPS spectrum of HEA-MtH shows only the presence of metallic Ru (Ru 3p3 / 2 and Ru 3p1 / 2 at 460.9 eV and 482.7 eV, respectively), while the Ni 2p3 / 2 and 2p1 / 2 peaks of Ni0 are located at 850.8 eV and 867.9 eV, respectively. The binding energy (BE) of HEA-MtH with metal foils and nanoparticles was compared (…). Figure 4(Above), it was found that the binding energies of Ni and Ru in HEA-MtH exhibit a negative shift, while those of iron (Fe), cobalt (Co), and copper (Cu) show a positive shift. This phenomenon indicates an increase in electron density in Ni and Ru, while Fe, Co, and Cu lack electron density, leading to the formation of electron-rich Ni–Ru dual active sites due to electronegativity differences. Figure 4 (See below). On the other hand, compared with metal foils and nanoparticles, the Ni binding energy in NiRu-MtH shows a positive shift, while the Ru binding energy shows a negative shift, indicating that Ni is in an electron-deficient state and Ru is in an electron-rich state in NiRu-MtH. Furthermore, compared with metal foils and nanoparticles, the Ni binding energy shift in NiRuCo-MtH is basically consistent with that in Ni-MtH, the Co binding energy shows a positive shift, and the Ru binding energy shows a negative shift. This indicates that there are no electron-rich Ni–Ru dual active sites in NiRuCo-MtH, and it can be explained that high-entropy alloys containing multiple 3d elements are crucial for the formation of electron-rich Ni–Ru dual active sites.

[0082] To gain a deeper understanding of the local electronic structure characteristics, this embodiment uses X-ray absorption fine structure spectroscopy (XAFS) to characterize Ru-MtH, Ni-MtH, and HEA-MtH samples, with a metal foil as a reference. Figure 5 and Figure 6 X-ray absorption near-edge structure (XANES) spectra of three samples at the Ru K-edge and Ni K-edge are presented. The significant shifts in the absorption edges of Ni and Ru indicate changes in local electron density, consistent with XPS analysis results. Compared to metal foils and nanoparticles, the K-edge XANES spectra of Ni and Ru show a negative shift, confirming a rearrangement of electron density within the HEA-MtH due to differences in metal electronegativity. In HEA-MtH, the electronic configuration and local electron configurations of the Ni and Ru components are finely tuned, which may enhance catalytic efficiency compared to other metal nanoparticles. Further analysis of the extended X-ray absorption fine structure (EXAFS) results using Fourier transform (FT) spectral fitting reveals the coordination structure of the five elements in HEA-MtH. Figure 7 Experiments were demonstrated using HEA-MtH, Ru-MtH, and Ru foil at the Ru K-edge. 3Weighted EXAFS curves and their corresponding fitted curves. The average coordination numbers of the first shells of Ni and Ru metals in HEA-MtH are almost identical, confirming that these five metal elements form a solid solution in HEA-MtH (i.e., a pentagonal metal alloy is formed, but no binary, ternary, or quaternary metal alloys are formed), and no elemental segregation is observed. The average bond length of the Ru–M bond in HEA-MtH (2.53 Å) differs significantly from that in Ru-MtH (2.66 Å) and Ru foil (2.67 Å), indicating the presence of multiple metal species (Fe, Co, Ni, and Cu) around Ru. As for Ni FT-EXAFS, since the distances and amplitudes of the Fe, Co, Ni, and Cu absorbers are the same, the bond lengths of Ni–M / Ru (2.49 Å) and Ni–Ni (2.47 Å) are almost equal. From this, it can be inferred that the 3d transition metals have the same local atomic structure and are randomly mixed in HEA-MtH. Unlike the Fourier Transform (FT), the Wavelet Transform (WT) can simultaneously acquire EXAFS signals in both the R-space and k-space domains; therefore, the WT transform was further employed to reveal the coordination information of the Ni–Ru dual centers in the HEA-MtH. The Ru peak in the HEA-MtH is located at R ~ 2.53 Å and k ~ 9.55 Å. -1 At this location, there are significant differences compared to Ru-MtH and Ru Foil, which is attributed to the presence of Ru–M bonds. For example... Figure 8 As shown, the Ni–M / Ru scattering path in HEA-MtH is located in the k~9.30 Å region. -1 At that location, Ni-MtH (k ~ 9.55 Å) -1 ) and Ni Foil (k ~ 9.55 Å) -1 The significant differences in the Ni–Ni scattering pathway in HEA-MtH further confirm the presence of Ni–Ru dual active sites.

[0083] 3. SDRM performance of HEA-MtH driven by magnetic induction confinement instantaneous heating technology.

[0084] After successfully synthesizing different catalysts, the activity of Ni-MtH, Ru-MtH, and HEA-MtH samples for ultra-dry methane reforming was tested at atmospheric pressure and high gas space velocity (GHSV) of up to 600 L g⁻¹ h⁻¹ using both induction-confined instantaneous heating (IECH) and conventional resistance furnace heating (RFH) methods (both with 100% carbon balance). The catalytic reaction temperature was 650–800 °C, the gas space velocity was 600 L g⁻¹ h⁻¹, the carbon dioxide flow rate was 14 mL / min, and the carbon dioxide to methane feed volume ratio was (1–3):1. The alternating magnetic field frequency was 300 kHz, and the alternating current was 100 A. The efficiency of the ultra-dry methane reforming reaction was compared and evaluated. The SDRM performance testing system using the induction-confined instantaneous heating (IECH) method is shown below. Figure 9 and Figure 10 As shown, specifically in this embodiment, the reaction system based on magnetic induction-confined instantaneous heating to enhance thermochemical reactions includes a frequency converter, an electromagnetic induction coil, a thermochemical reactor, and a confined instantaneous heating reaction bed. The confined instantaneous heating reaction bed is arranged in the thermochemical reactor, and the electromagnetic induction coil is arranged around the thermochemical reactor. The confined instantaneous heating reaction bed is a cylinder made of a conductive porous material loaded with thermochemical reaction catalytically active components. The frequency converter controls the electromagnetic induction coil to generate an alternating magnetic field, and the confined instantaneous heating reaction bed is located within the region of the alternating magnetic field generated by the electromagnetic induction coil. In some other embodiments, the frequency converter is a solar or wind power generation system.

[0085] The skin depth is controlled to be less than or equal to 3 mm by adjusting the radius of the thermochemical reactor, the frequency of the alternating magnetic field, the magnetic permeability of the conductive porous material, and the electrical conductivity of the conductive porous material; the formula for calculating the skin depth is:

[0086] (1);

[0087] In equation (1), δ is the skin depth, σ is the conductivity of the conductive porous material, f is the frequency of the alternating magnetic field, and μ is the permeability of the conductive porous material. In the simulation experiment of this embodiment, the relative permeability of the conductive porous material is 1, the conductivity of the conductive porous material is 7000 S / m, and the frequency of the alternating magnetic field is 300 kHz. According to the calculation, the skin depth of the confined instantaneous thermal reaction bed in this embodiment is 0.563 mm.

[0088] In this embodiment, the thermochemical reactor is a quartz tube reactor with a diameter of 22 mm and a length of 50 mm. The diameter of the thermochemical reactor also affects the skin depth. The confined instantaneous reaction bed is a cylinder made of a magnetocaloric heterojunction catalyst, with a length of 10 mm and a diameter of 18 mm along the axial direction of the thermochemical reactor. The electromagnetic induction coil is made of a copper tube with a diameter of 5 mm, an inner diameter of 40 mm, and 5 turns. Along the axial direction of the thermochemical reactor, the ratio of the length of the confined instantaneous reaction bed to the length of the alternating magnetic field region is 1:5 to 10.

[0089] In this embodiment, the magnetic induction confinement instantaneous heating technology (IECH) refers to the following: HEA-MtH is made into a uniform porous medium cylinder. Due to the eddy current effect and skin effect in the alternating magnetic field generated by the electromagnetic induction coil, heat is generated only on the surface of the catalytic reaction interface, while other parts of the thermochemical reactor do not consume energy, which is called "confinement". On the material surface outside the carbon felt and the material surface inside the pores, under the eddy current effect and skin effect of the alternating magnetic field controlled by the frequency converter, the thermochemical reaction interface can be driven by instantaneous high temperature, which is called instantaneous heating.

[0090] like Figure 11 As shown, compared with Ru-MtH and Ni-MtH, HEA-MtH exhibited significantly higher activity in both IECH and RFH modes, highlighting the indispensable role of HEA-MtH with its gradient electronegativity in the activation of CH4 and CO2. Furthermore, the performance of the catalyst in the direct reduction of methane was further analyzed through CH4-temperature controlled surface reaction (TPSR) experiments. Among Ni-MtH, Ru-MtH, and NiRu-MtH, HEA-MtH exhibited the lowest CH4 consumption and H2 formation onset temperature, highlighting its high activation ability for CH4. For all three catalysts, the conversion rates of CH4 and CO2 under IECH conditions were higher than those under RFH heating conditions at 650°C. In addition, this example also evaluated the performance of the SDRM reaction driven by IECH under different magnetic field amplitudes (corresponding to 700–800°C). o The temperature range (C) was compared with that of an SDRM driven by RFH heating at the same temperature. In the IECH-driven SDRM reaction, all performance metrics, including conversion rate (…), were compared. Figure 11 The reaction rate and selectivity were consistently higher than those of the SDRM reaction driven by RFH at the same temperature, indicating the existence of an activation pathway beyond thermocatalysis under IECH conditions. Therefore, it is reasonable to speculate that IECH has a dual role: providing heat to drive the SDRM reaction and introducing a hot electron-related pathway to lower the activation energy barrier.

[0091] Furthermore, the activity of NiRu-MtH, NiRuCo-MtH, and FeCoCu-MtH samples was tested under atmospheric pressure using IECH, and it was found that HEA-MtH exhibited activity in the range of 650–800 °C. o The conversion rates of CH4 and CO2 were most significant under IECH conditions at C, highlighting the superior intrinsic SDRM activity of HEA. Furthermore, at 500, 550, and 600 °C, the conversion rates were also significantly improved. o The SDRM performance of HEA-MtH was evaluated under low-temperature conditions (C). The results showed that even under IECH conditions at 500℃, HEA-MtH maintained high CO2 and CH4 conversion rates. Overall, HEA-MtH and IECH synergistically improved the SDRM performance. The apparent activation energy (E0) of SDRM on HEA-MtH under IECH and RFH conditions was [not specified in the original text]. a The values ​​were calculated to be 34.6 and 49.9 kJ / mol, respectively. −1 ( Figure 12 This indicates that IECH plays a crucial role in reducing kinetics. Furthermore, under RFH conditions, SDRM's E on HEA-MtH... a The efficiency is far lower than that of the traditional thermocatalytic method (74 kJ / mol), highlighting the excellent intrinsic activity of HEA-MtH in the SDRM reaction.

[0092] This embodiment summarizes the research results on SDRM catalysts in recent years; see details below. Figure 13 . Figure 13In this table, 1 represents "Nat.Energy" (2020), 2 represents "Nat.Commun." (2023), 3 represents "Adv.Funct.Mater" (2024), 4 represents "J.Am.Chem.Soc" (2020), 5 represents "Science" (2020), 6 represents "Nat.Commun" (2019), 7 represents "Adv.Energy.Mater" (2024), 8 represents "Appl.Cata.B" (2022), and 9 represents "ACS Catal." (ACS Catalysis). (2021), 10 represents the research results from Applied Catalysis B: Environmental (2018), which states that HEA-MtH exhibits ideal conversion rates (CH4 84.6%, CO2 90.6%) at 700 °C, with a CH4 reaction rate of 3.52 mol / g. cat It has a high H2 / CO ratio of 0.82, which significantly surpasses existing advanced catalysts.

[0093] To evaluate the application potential of this strategy in various carbon dioxide-containing fluids, we further tested the catalytic performance of HEA-MtH under IECH conditions at CO2 / CH4 volume feed ratios of 2 and 3. With increasing CO2 / CH4 feed volume ratio, the CO2 reaction rate and conversion rate increased accordingly, reaching 4.01 mol CO2 / g at a CO2 / CH4 volume ratio of 3. cat / h and 97.0%. Furthermore, by adjusting the CO2 / CH4 feed ratio, syngas with an adjustable H2 / CO ratio can be customized, allowing for flexible adjustment of the syngas composition to meet specific process requirements. Impressively, within a single reactor, at 750 oAt temperature C, as the CO2 / CH4 ratio increased to 1, 2, and 3, the reducing power of CH4 increased to 1.00, 1.95, and 2.99 mol CO2 / mol CH4, respectively. Figure 14 Notably, at a feed volume ratio of 3, the methane reduction activity reached 2.99 mol CO2 / mol CH4, exceeding not only the reported values ​​for traditional multi-stage cascade reactors but also surpassing the thermodynamic equilibrium value by 1.8 times. To further highlight the superiority of HEA-MtH under IECH conditions, we compared its performance with previous studies. HEA-MtH simultaneously achieved high CH4 reducibility and significant CO2 conversion in a single reactor, outperforming current state-of-the-art catalysts. These results highlight the crucial role of MtH in generating non-equilibrium hot electrons under IECH conditions, transferring them to HEA via the interfacial electron overflow channel between MtH and HEA, and then being directionally relayed to electron-rich sites driven by the electronegativity difference of HEA, thus significantly enhancing catalytic performance. In addition to the significant improvement in activity, stability is also crucial for the application of IECH-driven HEA-MtH. Long-term test results show that the CH4 and CO2 conversion rates of HEA-MtH remained almost unchanged during continuous 100h operation. Figure 15 Furthermore, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and mass spectrometry (PPMS) analyses confirmed that the structure of HEA-MtH after use did not show significant changes compared to the new sample, indicating that it has high cycling stability.

[0094] To gain a deeper understanding of IECH technology, this embodiment first investigated the temperature change of HEA-MtH under an alternating magnetic field. HEA-MtH rapidly heated to 800°C within 90 seconds. o C, After the alternating magnetic field is turned off, the temperature immediately returns to room temperature. Figure 16 This fully demonstrates the perfect match between flexible start-stop functionality and intermittent renewable energy. For significant temperature increases (>500°C)... o In case C), this type of external magnetic field energy conversion mainly involves two electromagnetic heating phenomena: hysteresis heating and eddy current heating, the occurrence of which depends on the material properties. Therefore, a Physical Property Measurement System (PPMS) equipped with a vibrating sample magnetometer (VSM) was used to probe the magnetism of the high-entropy alloy nanoparticle precursor. For example... Figure 17As shown, the magnetization versus magnetic field (M / H) curve at 300 K exhibits a coercive S-shaped hysteresis loop, indicating that the high-entropy alloy nanoparticle precursor possesses superparamagnetism. Furthermore, the zero hysteresis loop area indicates that the conversion of magnetic energy into heat under an alternating magnetic field is negligible in the high-entropy alloy nanoparticle precursor. Infrared spectroscopy verifies this conclusion, ruling out the possibility of local hot spots (<1 °C) in HEA-MtH. The infrared thermometer reading is consistent with the thermocouple reading, with a temperature difference of less than 1 °C. o C, and has no significant effect on catalytic activity. Therefore, in this embodiment, the transient magnetocurrent response of HEA-MtH was studied using a magnetoelectrochemical testing system. Figure 18 As shown, the current in the sample rises rapidly when the alternating magnetic field is turned on and falls back to the initial state rapidly when it is turned off, exhibiting a consistent pattern in each consecutive cycle. These results indicate that the HEA-MtH sample generates eddy currents under the action of an alternating magnetic field, thereby forming a high-temperature hot zone through the Joule effect. This hot zone possesses the thermodynamic conditions required to drive the SDRM reaction. In contrast, the high-entropy alloy nanoparticle precursor, due to its paramagnetism, does not exhibit a significant thermal effect. Based on these characteristics, we define this type of structure exhibiting a significant heating effect under the action of an alternating magnetic field as a magnetocaloric heterojunction (MtH). Figure 19 This heating mode is called IECH. Due to the skin effect generated by eddy currents, electrons in CFs preferentially accumulate on the surface; at high temperatures, some of these electrons can be excited into non-equilibrium hot electrons. These hot electrons can then migrate to HEA NPs through interfacial electron overflow channels, driven by the electronegativity difference between elements, and are directionally transferred to the Ni–Ru dual active sites. Through this electron relay mechanism, non-equilibrium hot electrons from carbon fibers are directionally transferred to the reactants, thereby lowering the activation energy barrier for CH4–CO2 conversion, which will be elaborated in detail in the mechanism section. In fact, the alternating magnetic field acts as a switch to activate interfacial electron overflow in the magnetocaloric heterojunction catalyst, which can promote the enrichment of electrons at active sites and dynamically reconstruct the electron distribution inside the catalyst. Figure 20 (b) of the text. This is in contrast to the off state, i.e., the traditional resistance furnace heating mode (RFH). Figure 20 Compared to (a) in [the previous description], activating this "switch" enables the catalyst to dynamically adapt to complex multi-electron transfer processes, thereby significantly improving reaction performance, with an efficiency even 1.8 times higher than that of the thermodynamic equilibrium state. Under switch-activated conditions, eddy currents on the carbon fibers (CFs) in the magnetocaloric heterostructure generate non-equilibrium hot electrons. These hot electrons are transferred to HEA NPs through interfacial electron overflow channels, and then transferred to the Ni–Ru dual active sites driven by electronegativity differences. Finally, through an electron relay mechanism, the non-equilibrium hot electrons are directionally transferred from the carbon fibers to the reactants [the following text is incomplete and requires further context to translate accurately]. Figure 20[b], thereby synergistically enhancing the activation of reactants and key intermediates. Furthermore, to gain a deeper understanding of the mechanism of action of thermally non-equilibrium electrons, the onset temperatures of HEA-MtH under IECH-driven and RFH-driven conditions were tested. Under RFH-driven conditions, HEA-MtH required heating to 350°C to initiate CH4 and CO2 conversion; while under IECH-driven conditions, the catalyst only required 250°C to activate the reactants, significantly reducing the onset temperature by 100°C, highlighting the crucial role of IECH in lowering the activation energy. Figure 21 To further investigate the influence of carbon carrier properties, the temperature rise of different carbon carriers, including graphite, carbon nanotubes, graphene, and amorphous carbon, under an alternating magnetic field was tested. These materials showed only a slight temperature rise under the influence of the alternating magnetic field, indicating that their inherently low conductivity leads to insufficient eddy current intensity and a negligible Joule effect.

[0095] 4. HEA-MtH's enhanced SDRM mechanism under IECH driving.

[0096] To elucidate the intrinsic mechanism of the superior performance of HEA-MtH, density functional theory (DFT) calculations were performed. To minimize the bias caused by differences in local atomic arrangement, four randomly selected HEA-MtH configurations containing Ni–Ru coordination structures were analyzed. The results showed that the adsorption capacity of all HEA-MtH (111) surfaces for CO2 and CH3 was significantly stronger than that of Ni-MtH (111) and Ru-MtH (001) surfaces. These results indicate that the adsorption behavior of HEA-MtH is not affected by its atomic arrangement. Based on this, the HEA-MtH configuration with the lowest energy was selected for all subsequent DFT calculations. Furthermore, to reveal the intrinsic reasons for the enhanced adsorption performance of HEA-MtH, density of states projection (PDOS) analysis was conducted. Compared to Ni-MtH (111) and Ru-MtH (001), in HEA-MtH (111), Ru atoms and Ni atoms rarely have near-neighbor structures of the same element, resulting in a significant weakening of the d-d coupling between Ru–Ru and between Ni–Ni. Conversely, the local coordination structure of Ru atoms and Ni atoms in HEA-MtH is occupied by Fe / Co / Cu atoms, which in turn broadens the d-bands of Ni and Ru elements (W). d Narrowing Figure 22 , Figure 23 It is worth noting that, although the differences in electronegativity between different elements affect the d-band filling degree (f... d ) has improved, but is affected by the widening of the d-band (W) d The narrowing effect of the compensation mechanism affects the d-band centers (ɛ) of Ni and Ru elements in HEA-MtH. d), and the d-band center (ɛ) in metal nanoparticles (NPs) d ) basically remain consistent ( Figure 22 , Figure 23 In summary, as Figure 22 , Figure 23 As shown, the d-band broadening (W) in HEA-MtH d The narrowing effect of electrons causes electronic states to concentrate in the Fermi level (E). f Near the vicinity, it ultimately effectively enhanced CO2 and CH4. x The adsorption performance (x=1–4) was studied. To further verify the underlying reasons for the above-mentioned adsorption enhancement effect, Bader charge analysis was conducted, and the results are as follows: Figure 24 As shown, CO2 molecules chemisorbed on the HEA-MtH (111) surface accept 0.62|e| of charge. This charge transfer is significantly higher than that of CO2 molecules adsorbed on Ru-MtH (001), Ni-MtH (111), and NiRuCo-MtH (111) surfaces. This result further demonstrates that the interaction between HEA-MtH and the adsorbate is significantly enhanced. Consistent with existing related research conclusions, the above DFT calculation results of this invention clearly emphasize the broadening of the narrowed d-band in HEA-MtH (W). d It can directly enhance the bonding between the metal and the adsorbate, thereby reducing the activation energy barrier of the reactants and promoting the efficient activation of the reactants.

[0097] Furthermore, this invention investigates the enhancing effect of non-equilibrium hot electrons generated by electron spillover at the MtH interface on reactant activation. In stark contrast to the interactions between Ru–Ru and Ni–Ni, strong d–d orbital coupling exists among the five elements in HEA-MtH. This coupling is confirmed by the degree of d orbital overlap and the small integral crystal orbital Hamiltonian population (ICOHP), which not only lowers the energy barrier for directed electron transfer but also stabilizes the electron-rich Ni–Ru dual active sites. To further elucidate the superiority of the electron relay mechanism in enhancing the activation of reactants and key intermediates, this invention introduces additional electrons into the aforementioned density functional theory (DFT) calculation system to simulate the electron enrichment phenomenon induced by electron spillover on HEA-MtH under IECH conditions. It is worth noting that during CO2 adsorption, the non-equilibrium hot electrons enriched on the Ni–Ru dual sites on the HEA-MtH surface are injected into the π* antibonding orbitals of the CO2 molecule; specifically, the Ni–Ru dual active sites inject electrons into the π* orbitals of CO2, causing its antibonding orbitals to be almost completely filled and reduced to below the Fermi level. Figure 25 This effectively weakens the C–O bonds in the CO2 molecule, promoting CO2 conversion. Similarly, for CH4… xFor intermediates (x=1,2,3,4), the aforementioned additional non-equilibrium hot electrons can effectively promote the breaking of C–H bonds in subsequent dehydrogenation steps, thereby significantly improving the reducibility of CH4. In summary, under the combined effect of the HEA-MtH interface electron spillover effect and enhanced metal-adsorbate interaction, the activation performance of reactants and key intermediates is significantly improved. Specifically, in the HEA-MtH system, under the synergistic effect of interface electron spillover and enhanced metal-adsorbate interaction, the activation barrier for CH4 dissociation decreases from 0.77 eV to 0.45 eV, and the activation barrier for CO2 dissociation decreases from 0.66 eV to 0.47 eV. These changes in activation barriers correspond to IECH and RFH conditions, respectively. Figure 26 This further demonstrates the intrinsic mechanism of HEA-MtH's excellent catalytic performance, providing theoretical support for its practical application.

[0098] This invention, through the results obtained from the aforementioned density functional theory (DFT) calculations, clearly elucidates, from a mechanistic perspective, how HEA-MtH achieves a trade-off between high CO2 conversion and strong CH4 reducing power. Specifically, the narrowed d-band broadening (W) in HEA-MtH... d This process effectively enhances the adsorption performance of reactants and key intermediates. Simultaneously, the magnetocaloric response mismatch between HEA NPs and CFs induces eddies on the CFs surface, generating non-equilibrium hot electrons. These non-equilibrium hot electrons are transferred to HEA NPs through the interfacial electron overflow channel at the HEA NPs / CFs interface. Driven by the electronegativity difference between different elements within HEA NPs, these non-equilibrium hot electrons migrate directionally to the Ni–Ru dual active sites in HEA-MtH via an electron relay mechanism. The non-equilibrium hot electrons accumulated at the Ni–Ru dual active sites after the adsorption of reactants and key intermediates, combined with enhanced metal-adsorbate interactions, significantly enhance the adsorption of CO2 molecules and CH4 through the d–π* electron injection effect. x The activation properties of the intermediate effectively promote the dehydrogenation reaction of CH4 molecules and the efficient utilization of CO2.

[0099] 5. Economic analysis.

[0100] Based on these experimental results, a process model was established, and a techno-economic analysis (TEA) was conducted on the IECH-driven SDRM process to assess its performance potential for expanding industrial applications. Figure 27For reactors heated by magnetic induction confinement instantaneous heating, an energy efficiency of approximately 90% was considered in the analysis. In the proposed model, the unit energy consumption for hydrogen production via SDRM driven by IECH is approximately 2.05 kWh / standard cubic meter, significantly lower than other studies employing electric heating technologies (including plasma heating, Joule heating, and microwave heating). Figure 28 The technical and economic assessment (TEA) of this model, based on a feedstock input of 500 kg / h (CH4:CO2 = 1:1), shows that feedstock costs account for 55.7% of the total annual cost of the process model, ranking first; followed by capital expenditure (19.7%), electricity consumption (15.1%), and fixed operating expenses (9.6%). Figure 29 The primary financial metric considered here is the cost per ton of syngas produced (UCOP), which reflects the average cost of syngas production over the entire lifecycle of the system. The final calculated UCOP for syngas is €450.76 / ton, significantly lower than other syngas production technologies. Figure 30 This highlights the advantages of IECH technology in reducing costs and minimizing environmental impact.

[0101] In summary, this embodiment prepared HEA-MtH as a direct reaction catalyst driven by magnetic induction confinement instantaneous heating technology. Both theoretical calculations and experimental results show that the direct reduction reaction driven by magnetic induction confinement instantaneous heating technology exhibits ultra-high catalytic activity, which is attributed to the synergistic effect between the electron-enriched Ni–Ru dual active sites and eddy current-induced non-equilibrium hot electrons. Furthermore, the non-equilibrium hot electrons play a crucial role in promoting the activation of reactants adsorbed on the electron-enriched Ni–Ru dual active sites. Therefore, at 600 L g... −1 h −1 Under GHSV conditions, HEA-MtH exhibited high conversion rates of CH4 (~84.6%) and CO2 (~90.6%), with a CH4 reaction rate reaching 3.52 mol / g. cat / h, and in 700 o The C-type IECH driver SDRM maintains stability for 100 hours. It is worth noting that this embodiment is based on 600 L g. -1 h -1 These catalysts were evaluated under GHSV conditions, where the space velocity was several times, even an order of magnitude, higher than in previous studies. This demonstrates that IECH-driven SDRM not only performs exceptionally well in experimental settings but also exhibits superior performance for large-scale production applications. Furthermore, the synergistic effect of HEA-MtH and IECH resulted in a significant methane reduction capacity (2.99 mol CO2 mol CH4). -1This figure is even 1.8 times higher than the thermodynamic equilibrium value, aligning with the goal of maximizing the utilization of carbon dioxide-rich natural gas. This work not only expands the understanding of IECH-driven catalysis but also promotes the practical application of environmentally friendly carbon reduction technologies.

Claims

1. A magnetocaloric heterojunction catalyst capable of achieving confined instantaneous heating, characterized in that, It consists of a conductive porous material with eddy current thermal effect and a nanocatalytic material with superparamagnetic or ferromagnetic properties. The nanocatalytic material is loaded on the outer surface of the conductive porous material and on the surface of the pores inside the conductive porous material. Under the action of an alternating magnetic field, the conductive porous material generates heat instantaneously through the eddy current thermal effect and excites non-equilibrium hot electrons. The non-equilibrium hot electrons are transferred to the nanocatalytic material through the interfacial electron overflow channel between the conductive porous material and the nanocatalytic material. Nanocatalytic materials contain both electron-rich and electron-deficient sites. Driven by the difference in electronegativity of the nanocatalytic materials, non-equilibrium hot electrons are directionally transferred to the electron-rich sites, thereby synergistically enhancing the activation effect of the nanocatalytic materials on reactants and reaction intermediates.

2. The magnetocaloric heterojunction catalyst capable of achieving confined instantaneous heating according to claim 1, characterized in that, The conductive porous material is a carbon felt with a three-dimensional porous network structure formed by conductive carbon fibers; the superparamagnetic or ferromagnetic nanocatalyst material is a high-entropy alloy nanoparticle formed by five metal elements: iron, cobalt, copper, nickel, and ruthenium. The high-entropy alloy nanoparticle is loaded on the surface of the carbon felt and on the surface of the conductive carbon fibers inside the carbon felt. In the high-entropy alloy nanoparticle: the binding energy of nickel and ruthenium shows a negative shift, and the electron density of nickel and ruthenium increases to form electron-rich Ni–Ru dual active sites, while the binding energy of iron, cobalt, and copper shows a positive shift, and the electron density of iron, cobalt, and copper is lacking to form electron-deficient sites.

3. A method for preparing a magnetocaloric heterojunction catalyst capable of confined instantaneous heating, characterized in that, Includes the following steps: Step (1): Add acetylacetone iron, acetylacetone cobalt, acetylacetone nickel, acetylacetone copper, acetylacetone ruthenium and ascorbic acid to oleylamine, mix evenly and sonicate. After sonication, a mixed dispersion is obtained. Step (2): The mixed dispersion is heated to the reaction temperature under magnetic stirring and isothermal reaction is carried out; after the isothermal reaction is completed, the solid product obtained by centrifugation is washed with cyclohexane or anhydrous ethanol, stored in cyclohexane and subjected to ultrasonic treatment to obtain high entropy alloy nanoparticle precursor dispersion. Step (3): Calcine the carbon felt composed of conductive carbon fibers in an argon atmosphere to obtain a pretreated carbon felt; drop a high-entropy alloy nanoparticle precursor dispersion onto the pretreated carbon felt to obtain a high-entropy alloy nanoparticle precursor-carbon felt mixture; dry the high-entropy alloy nanoparticle precursor-carbon felt mixture to obtain a high-entropy alloy nanoparticle-magnetocaloric heterojunction precursor. Step (4): The high-entropy alloy nanoparticle-magnetic-thermal heterojunction precursor is subjected to a two-step calcination treatment to obtain a high-entropy alloy nanoparticle-magnetic-thermal heterojunction intermediate; then the high-entropy alloy nanoparticle-magnetic-thermal heterojunction intermediate is subjected to a reduction treatment under a reducing atmosphere. After the reduction treatment, a magnetic-thermal heterojunction catalyst composed of conductive porous material with eddy current thermal effect and nanocatalyst material with superparamagnetic or ferromagnetic properties is obtained. The high-entropy alloy nanoparticles are loaded as nanocatalyst material on the surface of carbon felt, which is conductive porous material, and on the surface of conductive carbon fiber inside the carbon felt. Under the action of alternating magnetic field: the conductive porous material realizes instantaneous heat generation through eddy current thermal effect and excites non-equilibrium hot electrons. The non-equilibrium hot electrons are transferred to the nanocatalyst material through the interfacial electron overflow channel between the conductive porous material and the nanocatalyst material. Nanocatalytic materials contain both electron-rich and electron-deficient sites. Driven by the difference in electronegativity of the nanocatalytic materials, non-equilibrium hot electrons are directionally transferred to the electron-rich sites, thereby synergistically enhancing the activation effect of the nanocatalytic materials on reactants and reaction intermediates.

4. The method for preparing a magnetocaloric heterojunction catalyst capable of confined instantaneous heating according to claim 3, characterized in that, In step (1), the molar ratio of acetylacetone iron, acetylacetone cobalt, acetylacetone nickel, acetylacetone copper, and acetylacetone ruthenium is (15-20):(20-25):(28-32):(22-28):(5-8); the ratio of the total mass of acetylacetone iron, acetylacetone cobalt, acetylacetone nickel, acetylacetone copper, and acetylacetone ruthenium to the mass of ascorbic acid is 1:(2-4); the total mass volume concentration of acetylacetone iron, acetylacetone cobalt, acetylacetone nickel, acetylacetone copper, and acetylacetone ruthenium in the mixed dispersion is 1-3 mg / mL; the conditions for ultrasonic treatment are: ultrasonic power of 200-600 W and ultrasonic time of 60-120 min.

5. The method for preparing a magnetocaloric heterojunction catalyst capable of confined instantaneous heating according to claim 3, characterized in that, In step (2), the magnetic stirring rate is 3500-4500 rpm, the heating rate is 8-12℃ / min, the constant temperature reaction temperature is 200-250℃, and the constant temperature reaction time is 3-5h; the ultrasonic treatment conditions are: ultrasonic power is 200-600W, ultrasonic time is 30-60min; the mass volume concentration of high entropy alloy nanoparticle precursor in the high entropy alloy nanoparticle precursor dispersion is 1-3mg / mL.

6. The method for preparing a magnetocaloric heterojunction catalyst capable of confined instantaneous heating according to claim 3, characterized in that, In step (3), the diameter of the conductive carbon fiber constituting the carbon felt is 10-15 μm and the length is 2-5 mm; the calcination conditions are: calcination temperature 800-1000℃, calcination time 2-4 h; the mass ratio of high entropy alloy nanoparticle precursor to pretreated carbon felt in the high entropy alloy nanoparticle precursor-carbon felt mixture is 1:(5-15); the drying conditions are: drying temperature 70-90℃, drying time 20-28 h.

7. The method for preparing a magnetocaloric heterojunction catalyst capable of confined instantaneous heating according to claim 3, characterized in that, In step (4), the two-step calcination treatment method is as follows: first, calcining at 200-300℃ for 30-80 min at a heating rate of 8-12℃ / min in an argon atmosphere, and then calcining at 500-700℃ for 30-80 min at a heating rate of 8-12℃ / min; the reduction treatment method is as follows: under a reducing atmosphere of hydrogen and argon mixed gas with a volume ratio of (5-10):1, heating at a heating rate of 8-12℃ / min to a reduction temperature of 500-700℃, reducing for 1-3 h, and then naturally cooling to room temperature.

8. The method for preparing a magnetocaloric heterojunction catalyst capable of confined instantaneous heating according to claim 3, characterized in that, In step (1), the total mass ratio of iron acetylacetone, cobalt acetylacetone, nickel acetylacetone, copper acetylacetone, and ruthenium acetylacetone to ascorbic acid is 1:3; the total mass-volume concentration of iron acetylacetone, cobalt acetylacetone, nickel acetylacetone, copper acetylacetone, and ruthenium acetylacetone in the mixed dispersion is 2 mg / mL; the ultrasonic treatment conditions are: ultrasonic power of 500 W and ultrasonic time of 90 min. In step (2), the magnetic stirring speed is 4000 rpm, the heating rate is 10℃ / min, the constant temperature reaction temperature is 230℃, and the constant temperature reaction time is 3.5h; the ultrasonic treatment conditions are: ultrasonic power is 500W, ultrasonic time is 30min; the mass volume concentration of high entropy alloy nanoparticle precursor in the high entropy alloy nanoparticle precursor dispersion is 2mg / mL. In step (3), the diameter of the conductive carbon fiber is 10-15 μm and the length is 3 mm; the pretreatment calcination conditions are: calcination temperature 900℃, calcination time 3h; the mass ratio of high entropy alloy nanoparticle precursor to pretreated carbon felt in the high entropy alloy nanoparticle precursor-carbon felt mixture is 1:10; the drying conditions are: drying temperature 80℃, drying time 24h. In step (4), the two-step calcination treatment method is as follows: first, calcining at 250℃ for 60 min at a heating rate of 10℃ / min in an argon atmosphere, and then calcining at 600℃ for 60 min at a heating rate of 10℃ / min. After calcination, the temperature is naturally cooled to room temperature. The reduction treatment method is as follows: under a reducing atmosphere of hydrogen and argon mixed gas with a volume ratio of 5:1, the temperature is raised to the reduction temperature of 600℃ at a heating rate of 10℃ / min, and the reduction treatment is carried out for 2 h. Then, the temperature is naturally cooled to room temperature. In the obtained magnetocaloric heterojunction catalyst, the molar ratio of Fe:Co:Cu:Ni:Ru is 18:21:30:25:

6.

9. An application of a magnetocaloric heterojunction catalyst capable of achieving confined instantaneous heating, characterized in that, The magnetocaloric heterojunction catalyst prepared by the method described in claim 1 or 2 or by any of the methods described in claims 3 to 7 is used as the catalyst for the thermochemical reaction. The thermochemical reaction is carried out using a magnetic induction confinement instantaneous heating enhanced thermochemical reaction system. That is, electromagnetic induction is used as the heating method. The magnetocaloric heterojunction catalyst is located in the alternating magnetic field generated by electromagnetic induction. The magnetocaloric heterojunction catalyst is heated to the temperature required for the thermochemical reaction under electromagnetic induction heating. The thermochemical reaction occurs on the material surface outside the magnetocaloric heterojunction catalyst or on the material surface of the internal pores. The thermochemical reaction is a methane conversion reaction, a carbon dioxide conversion reaction, a reforming reaction, a cracking reaction, or a hydrodehydrogenation reaction.

10. The application of the magnetocaloric heterojunction catalyst capable of confined instantaneous heating according to claim 9, characterized in that, A magnetically induction-based confined instantaneous heating enhanced thermochemical reaction system includes a frequency converter, an electromagnetic induction coil, a thermochemical reactor, and a confined instantaneous heating reaction bed. The confined instantaneous heating reaction bed is arranged in the thermochemical reactor, and the electromagnetic induction coil is arranged around the thermochemical reactor. The confined instantaneous heating reaction bed includes a magnetocaloric heterojunction catalyst as described in claim 1 or 2, or a magnetocaloric heterojunction catalyst prepared by the preparation method of any one of claims 3 to 7. The frequency converter controls the electromagnetic induction coil to generate an alternating magnetic field, and the confined instantaneous heating reaction bed is located within the alternating magnetic field region generated by the electromagnetic induction coil. The skin depth is controlled to be less than or equal to 3 mm by adjusting the radius of the thermochemical reactor, the frequency of the alternating magnetic field, the magnetic permeability of the conductive porous material, and the electrical conductivity of the conductive porous material; the formula for calculating the skin depth is: （1）； In equation (1), δ is the skin depth, σ is the conductivity of the conductive porous material, f is the frequency of the alternating magnetic field, and μ is the permeability of the conductive porous material. Along the axial direction of the thermochemical reactor: the ratio of the length of the confined instantaneous reaction bed to the length of the alternating magnetic field region is 1:5 to 10; the thermochemical reactor is a quartz tube reactor; the confined instantaneous reaction bed includes a magnetocaloric heterojunction catalyst, the length of which along the axial direction is 10 mm, and the diameter is 18 mm; the electromagnetic induction coil is made of a copper tube with a diameter of 5 mm, the inner diameter of which is 40 mm, and the number of turns is 5; the alternating magnetic field frequency is 100 to 1000 kHz, and the frequency converter is a power system generated from renewable and / or clean energy sources; the thermochemical reaction is a methane ultra-dry reforming reaction, the catalytic reaction temperature is 650 to 800 °C, and the gas space velocity is 500 to 700 L g⁻¹. h⁻¹, the flow rate of carbon dioxide is 10-20 mL / min, the feed volume ratio of carbon dioxide to methane is (1-3):1; the frequency of the alternating magnetic field is 200-500 kHz, and the alternating current is 100-300 A.

Images