Joule catalysis device and method for preparing low-carbon olefin, alkane and oxygen-containing organic matter

Abstract

The invention discloses a Joule catalytic device and method for preparing low-carbon olefins, alkanes and oxygen-containing organic matters, and the method comprises the following steps: electrifying a catalytic substrate conductive material, enabling the catalytic substrate conductive material to be in contact with a carbon-containing substance and a reducing gas, and carrying out a reaction to obtain a product; the catalytic substrate conductive material comprises a carbon substrate and a metal catalyst arranged on the carbon substrate; the reaction pressure is 0.1 to 5 MPa. According to the Joule catalytic device adopting the integral catalytic matrix conductive material, interaction between the catalyst and the carbon substrate is promoted through the electric heating synergistic effect, the tolerance of the reaction to the temperature and pressure is expanded, the reaction can still be smoothly carried out even under the high-temperature and high-pressure conditions, and by regulating and controlling the reaction conditions or the catalyst, the reaction efficiency is improved. The selective regulation and control of products or product proportions are realized.

Description

Technical Field

[0001] This application relates to the field of electrothermal catalysis technology, and in particular to a Joule catalytic device and method for preparing low-carbon olefins, alkanes and oxygen-containing organic compounds. Background Technology

[0002] The excessive use of fossil fuels leads to massive emissions of greenhouse gases, especially methane (CH4) and carbon dioxide (CO2), which not only severely impact global climate change but also threaten sustainable development. Reducing these greenhouse gas emissions and converting them into valuable chemicals has become an urgent problem for the scientific and industrial communities. In the context of carbon neutrality, the conversion of C1 substances (mainly CO2, CO, and CH4) into high-value-added chemicals (such as ethylene, acetic acid, and other C4 compounds) is a key focus. 2+ The products not only help with carbon sequestration but also create economic value.

[0003] In recent years, electrothermal co-catalysis has gradually gained attention as a novel technology. Currently, the catalytic conversion of carbon dioxide mainly occurs under medium-high temperature (~350℃) and high-pressure conditions (~3MPa), with a higher proportion of hydrogen than theoretically required. During the reaction, the water-gas shift reaction (WGS) is the most significant side reaction, affecting the formation of high-value-added carbon-containing products. Much research currently focuses on the reaction that produces methanol. Joule reactors for methane and carbon dioxide primarily produce CO and H2 through the dry reforming (DRM) reaction of methane. This reaction is carried out at high temperatures above 400℃ (generally 800℃), utilizing Joule heat for rapid heating. However, the C-C coupling reaction is difficult to occur and control. In traditional thermocatalysis, C... 2+ Alkenes and alkanes all require high pressure to be produced, C 2+ Liquid-phase products are also unfavorable at high temperatures (further decomposition to generate gaseous products), and are more favorable at low temperatures. However, Joule-heated fixed-bed equipment is rarely used for the preparation of low-carbon olefins, alkanes, and oxygen-containing organic compounds. Therefore, existing technologies need further improvement. Summary of the Invention

[0004] The main objective of this application is to propose a Joule catalytic device and method for preparing low-carbon olefins, alkanes and oxygen-containing organic compounds, aiming to solve the problem that existing methods for catalytic conversion of methane and carbon dioxide are generally unfavorable for preparing low-carbon olefins, alkanes and oxygen-containing organic compounds under high temperature and high pressure.

[0005] To achieve the above objectives, this application proposes a method for preparing low-carbon olefins, alkanes, and oxygen-containing organic compounds, comprising: The conductive material of the catalytic substrate is brought into contact with carbon-containing substances and reducing gases to react and produce low-carbon olefins, alkanes and oxygen-containing organic compounds. The conductive material of the catalytic substrate includes a carbon substrate and a metal catalyst disposed on the carbon substrate; The reaction pressure is 0.1~5 MPa.

[0006] Preferably, the reaction temperature is 100~2000℃.

[0007] Preferably, the concentration ratio of the carbon-containing substance to the reducing gas is (20:1) to (1:20). The carbon-containing substance includes at least one of carbon monoxide, carbon dioxide, methane, methanol, formaldehyde, ethylene, ethane, ethanol, acetic acid, ethylene glycol, and dimethyl ether; The reducing gas includes at least one of hydrogen and water vapor.

[0008] Preferably, the carbon substrate includes at least one of carbon paper, carbon cloth, carbon felt, and silicon carbide. Preferably, the metal catalyst includes at least one of a monometallic catalyst, a bimetallic catalyst, a multimetallic catalyst, and a nonmetallic modified metal catalyst; Preferably, the metal catalyst comprises at least one of sodium, potassium, copper, nickel, zinc, magnesium, cerium, indium, zirconium, iron, molybdenum, cobalt, titanium, aluminum, platinum, palladium, ruthenium, rhodium, gold, and silver; Preferably, the modifying element in the non-metallic modified metal catalyst includes carbon or nitrogen.

[0009] Preferably, the method for preparing the conductive material of the catalytic substrate includes: forming a metal catalyst on the carbon substrate, wherein the formation includes an in-situ growth method or a coating method; Preferably, the in-situ growth method includes at least one of the following: hydrothermal method, impregnation method, precipitation method, and vapor deposition method; Preferably, the coating method includes spraying or dotting.

[0010] Preferably, the loading of the metal catalyst in the conductive substrate is 0.01wt% to 50wt%.

[0011] This application also proposes a Joule catalytic device, comprising: A catalytic reactor includes a first port, a reaction tube, and a second port connected in sequence. The diameters of the first port and the second port are the same and larger than the diameter of the reaction tube. An air inlet is provided on the first port; An air outlet is provided on the second port; A conductive catalytic substrate is disposed in the reaction tube, the conductive catalytic substrate comprising a carbon substrate and a metal catalyst layer disposed on the carbon substrate; A conductive component includes a first conductive clip and a second conductive clip, wherein the first conductive clip establishes an electrical connection with the conductive material of the catalytic substrate via a first port, and the second conductive clip establishes an electrical connection with the conductive material of the catalytic substrate via a second port.

[0012] Preferably, the reaction tube is a cuboid with a length of 10-150 mm, a width of 0.5-50 mm, and a height of 0.5-10 mm; The diameter of the first port and the second port is 10~30 mm.

[0013] This application also proposes a method for preparing low-carbon olefins, alkanes, and oxygen-containing organic compounds using the Joule catalytic device proposed in this application, comprising: Connect the conductive component to a power source to generate Joule heating in the conductive material of the catalytic substrate; By introducing the carbon-containing substance and reducing gas through the air inlet, low-carbon olefins, alkanes and oxygen-containing organic compounds are produced. Wherein, the carbon-containing substance is a gas, including at least one of carbon monoxide, carbon dioxide, methane, methanol, ethylene, and ethane; The gas being reduced includes at least one of hydrogen and water vapor; The Joule thermal current range of the conductive material of the catalytic substrate is 0~150 A.

[0014] Preferably, the gas flow rate at the air inlet is 5~200 mL / min, and the concentration ratio of the carbon dioxide to the reducing gas is (20:1)~(1:20).

[0015] The electrothermal synergistic Joule thermal coupling catalytic conversion method of this application for the preparation of low-carbon olefins, alkanes, and oxygen-containing organic compounds from carbon dioxide utilizes an integral conductive catalytic matrix material, which promotes current and voltage conduction. During this process, the metal catalyst not only undergoes thermal conduction but also electronic conduction through interaction with the carbon substrate. This allows for the regulation of the electron cloud density on the active metal surface, forming more easily adsorbed and decomposed active valence states and steric hindrance, thus expanding the reaction's tolerance to temperature and pressure. Even outside of high-temperature and high-pressure conditions, the reaction can proceed smoothly, achieving the preparation of low-carbon olefins, alkanes, and oxygen-containing organic compounds. Furthermore, by controlling the reaction conditions or catalyst, the selectivity of products or product ratios can be achieved. In addition, compared to particulate catalysts, the absence of a catalyst bed eliminates bed pressure drop, resulting in a more stable reaction process, which is beneficial for industrial production. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the Joule catalytic device provided in this application; Figure 2 This is a schematic diagram of the structure of the conductive material on the catalytic substrate provided in this application; Figure 3 A schematic diagram of another Joule catalytic device provided in this application; Figure 4 The reaction performance test diagram provided in Example 3 of this application: A is the conversion rate graph; B is the yield graph; C is the ethylene / ethane ratio graph.

[0018] Explanation of icon numbers: 100. Joule catalytic device; 1. Catalytic reactor; 11. First port; 111. Gas inlet; 12. Reaction tube; 13. Second port; 131. Gas outlet; 2. Conductive material of catalytic substrate; 21. Carbon substrate; 22. Metal catalyst layer; 3. Conductive component; 31. First conductive clamp; 32. Second conductive clamp; 4. Stand.

[0019] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0022] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0023] The excessive use of fossil fuels leads to massive emissions of greenhouse gases, especially methane (CH4) and carbon dioxide (CO2), which not only severely impact global climate change but also threaten sustainable development. Reducing these greenhouse gas emissions and converting them into valuable chemicals has become an urgent problem for the scientific and industrial communities. In the context of carbon neutrality, the conversion of C1 substances (mainly CO2, CO, and CH4) into high-value-added chemicals (such as ethylene, acetic acid, and other C4 compounds) is a key focus. 2+ The products not only help with carbon sequestration but also create economic value.

[0024] In recent years, electrothermal co-catalysis has gradually gained attention as a novel technology. Currently, the catalytic conversion of carbon dioxide mainly occurs under medium-high temperature (~350℃) and high-pressure conditions (~3MPa), with a higher proportion of hydrogen than theoretically required. During the reaction, the water-gas shift reaction (WGS) is the most significant side reaction, affecting the formation of high-value-added carbon-containing products. Much research currently focuses on the reaction that produces methanol. Joule reactors for methane and carbon dioxide primarily produce CO and H2 through the dry reforming (DRM) reaction of methane. This reaction is carried out at high temperatures above 400℃ (generally 800℃), utilizing Joule heat for rapid heating. However, the C-C coupling reaction is difficult to occur and control. In traditional thermocatalysis, C... 2+ Alkenes and alkanes all require high pressure to be produced, C 2+Liquid-phase products are also unfavorable at high temperatures (further decomposition to generate gaseous products), and are more favorable at low temperatures. However, Joule-heated fixed-bed reactors are rarely used for the preparation of low-carbon olefins, alkanes, and oxygen-containing organic compounds. Therefore, existing technologies need improvement. Traditional catalytic conversion methods still face significant challenges in achieving high selectivity and long-term catalyst stability for low-carbon olefins, alkanes, and oxygen-containing organic compounds, such as poor product selectivity and rapid catalyst activity decay. In catalyst research, the application of transition metal catalysts (such as Ni, Fe, Cu, etc.) and metal alloy catalysts has made some progress. In addition, the traditional fixed-bed reactor required for the reaction has a significant heat transfer bottleneck. Due to the poor thermal conductivity of the catalyst particles themselves, a significant radial temperature gradient easily forms within the reactor, i.e., the temperature at the center of the bed is lower than that near the wall. To drive the central region to the target reaction temperature, excessive heat must be input into the system, which not only wastes energy but also causes local overheating in the near-wall region, thereby exacerbating side reactions and reducing the selectivity of the target product.

[0025] To address these issues, electrothermal co-catalysis has gained increasing attention as a novel technology in recent years. This technology utilizes Joule heating for energy, enabling rapid temperature increases within a very short time, thus significantly reducing energy consumption. Compared to traditional heating methods, electrothermal co-catalysis can rapidly reach the desired reaction temperature within seconds, saving heating time and increasing the reaction rate. Simultaneously, electronic control through electron transfer to the catalyst can effectively improve the conversion rate and selectivity of the catalytic reaction. However, current Joule heating equipment used for the catalytic conversion of CH4 and CO2 primarily focuses on the dry reforming of methane (DRM) to produce CO and H2. This reaction is carried out at high temperatures above 400 °C (generally around 800 °C), where Joule heating can be used for rapid heating. However, low-carbon olefins, alkanes, and oxygen-containing organic compounds are less favorable at high temperatures (further decomposing into gaseous products) and are more readily produced at lower temperatures. Currently, very few Joule-heated fixed-bed reactors are used for the preparation of low-carbon olefins, alkanes, and oxygen-containing organic compounds. Published conventional fixed-bed or batch reactors operate under high pressure, resulting in low yields. At normal pressure, external energy such as plasma equipment or radiation is required. Based on the current research status, a method for the electrothermal synergistic catalytic conversion of CH4 and CO2 to produce low-carbon olefins, alkanes, and oxygen-containing organic compounds (acetic acid, ethanol, ethylene, etc.) is proposed. This method aims to overcome the bottleneck of traditional catalytic conversion methods and propose a new pathway for greenhouse gas conversion under low temperature and low pressure conditions.

[0026] Based on this, this application proposes a method for electrothermal synergistic generation of Joule thermal coupled catalytic conversion of carbon-containing substances (mainly carbon dioxide) to prepare low-carbon olefins, alkanes, and oxygen-containing organic compounds, comprising: By passing an electric current through a conductive catalytic substrate, the conductive catalytic substrate comes into contact with carbon-containing substances and reducing gases, and a reaction occurs, yielding low-carbon olefins, alkanes, and oxygen-containing organic compounds.

[0027] The conductive material of the catalytic substrate includes a carbon substrate and a metal catalyst disposed on the carbon substrate. The carbon-containing substances mainly refer to C1 gases, including carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), etc. The reaction range can also be expanded to other carbon-containing substances, such as methanol (CH3OH), formaldehyde (HCHO), ethanol (C2H5OH), acetic acid (CH3COOH), ethylene glycol (HOCH2CH2OH), ethylene (C2H4), ethane (C2H6), dimethyl ether (CH3OCH3), etc.; the reducing gas includes at least one of hydrogen (H2) and water vapor (H2O). The reaction pressure is 0.1~5 MPa. For example, the reaction pressure can be 0.1 MPa, 0.5 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, or 5 MPa, etc.

[0028] In some embodiments, the reaction temperature is 100~2000°C. For example, the reaction temperature is 100°C, 500°C, 1000°C, 1500°C, or 2000°C, etc.

[0029] By employing an integral conductive catalytic matrix, current and voltage conduction can be facilitated. During this process, the metal catalyst not only undergoes thermal conduction but also electronic conduction through interaction with the carbon substrate. This modulates the electron cloud density on the active metal surface, creating more readily adsorbable and decomposed active valence states and addressing steric hindrance. This, in turn, promotes smooth C / C coupling at low temperatures and pressures, enabling the preparation of low-carbon olefins, alkanes, and oxygen-containing organic compounds. Furthermore, compared to particulate catalysts, the absence of a catalyst bed eliminates bed pressure drop, resulting in a more stable reaction process, which is beneficial for industrial production.

[0030] In some embodiments, the concentration ratio of carbonaceous material to reducing gas is (20:1) to (1:20). For example, the concentration ratio of carbonaceous material to reducing gas is 20:1, 15:1, 10:1, 5:1, 3:1, 1:1, 1:2, 1:3, 1:5, 1:5, 1:10, 1:15 or 1:20, etc.

[0031] In some embodiments, the carbon substrate includes at least one of carbon paper (CP), carbon cloth (CC), carbon felt (CF), and silicon carbide (SiC). In some embodiments, the carbon substrate may also be a foamed metal (Ni foam, Cu foam, etc.). In some embodiments, the thickness of the carbon substrate is 0.5 to 20 mm, for example, the thickness of the carbon substrate may be 1 mm, 1.2 mm, 2 mm, or 20 mm, etc.

[0032] In some embodiments, the metal catalyst includes at least one of a monometallic catalyst, a bimetallic catalyst, a multimetallic catalyst, and a non-metallic modified metal catalyst. Preferably, the metal catalyst includes at least one of sodium (Na), potassium (K), copper (Cu), nickel (Ni), zinc (Zn), magnesium (Mg), cerium (Ce), indium (In), zirconium (Zr), iron (Fe), molybdenum (Mo), cobalt (Co), titanium (Ti), aluminum (Al), platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), gold (Au), and silver (Ag); the modifying element in the non-metallic modified metal catalyst includes carbon (C) or nitrogen (N).

[0033] In some embodiments, the method for preparing the conductive material of the catalytic substrate includes: forming a metal catalyst on a carbon substrate, the formation of which includes in-situ growth or coating methods. Further, the in-situ growth method includes at least one of hydrothermal method, impregnation method, precipitation method, and vapor deposition method; the coating method includes spraying or dot coating.

[0034] In some embodiments, the loading of the metal catalyst in the conductive catalytic matrix is ​​0.01 wt% to 50 wt%. For example, the loading of the metal catalyst in the conductive catalytic matrix is ​​0.5 wt%, 3 wt%, 10 wt%, 30 wt%, or 50 wt%.

[0035] Please see Figures 1-3This application also proposes a Joule catalytic device 100, which generally includes: a catalytic reactor 1, a conductive catalytic substrate 2, a conductive component 3, and a frame 4. The catalytic reactor 1 is mounted on the frame 4. The catalytic reactor 1 includes a first port 11, a reaction tube 12, and a second port 13 connected in sequence. The diameter of the first port 11 and the diameter of the second port 13 are the same and larger than the diameter of the reaction tube 12. The first port 11 is provided with an inlet 111, and the second port 13 is provided with an outlet 131. The conductive catalytic substrate 2 is disposed in the reaction tube 12 and includes a carbon substrate 21 and a metal catalyst layer 22. The conductive component 3 includes a first conductive clip 31 and a second conductive clip 32. The first conductive clip 31 is electrically connected to the conductive catalytic substrate 2 via the first port 11, and the second conductive clip 32 is electrically connected to the conductive catalytic substrate 2 via the second port 13.

[0036] Specifically, the conductive component 3 is connected to a power source, allowing it to energize the conductive material 2 of the catalytic substrate. This energization generates Joule heat in the conductive material 2. When CO2 and reducing gases are introduced through the inlet 111, CO2 is reduced to activated CO by the reducing gases (H2 and CH4), and both CO and CH4 are also activated. The activated C1 products (*CO, *CH4)... x A coupling reaction occurs on the surface of the conductive material 2 on the catalytic substrate, forming C. 2+ intermediate, C 2+ The intermediate is further hydrogenated, ultimately desorbing to generate low-carbon olefins, alkanes, and oxygen-containing organic compounds. The reaction temperature can be adjusted by the conductive component 3, which controls the voltage and current supplied to the conductive material 2 of the catalyst substrate, to achieve stable or oscillating Joule heating. Stable Joule heating refers to a steady-state reaction under isothermal conditions in the reaction tube 12, while oscillating Joule heating refers to an oscillating reaction within a specific temperature range in the reaction tube 12. For example, oscillating reactions can be carried out at 70~1200℃, 300~1800℃, and 500~2500℃, with a heating rate of up to 1000℃ / min. The isothermal or oscillating reaction modes allow for selective control of the conversion of methane and carbon dioxide catalysts into target liquid or gaseous low-carbon olefins, alkanes, and oxygen-containing organic compounds such as ethanol, acetic acid, and ethylene, improving product selectivity.

[0037] In some embodiments, the catalytic reactor 1 includes at least one of a quartz tube, a corundum tube, and a stainless steel tube. Further, the reaction tube 12 is a flat cuboid with a length of 10-150 mm, a width of 0.5-50 mm, and a height of 0.5-10 mm. For example, the length of the reaction tube 12 can be 10 mm, 50 mm, 100 mm, or 150 mm, the width can be 0.5 mm, 10 mm, 25 mm, or 50 mm, and the height can be 0.5 mm, 5 mm, or 10 mm. Setting the reaction tube 12 as a flat cuboid allows the conductive catalytic substrate 2 to be laid flat within the reaction tube 12, reducing the diffusion of gases, etc., and increasing the contact area and contact frequency between the gas and the conductive catalytic substrate 2, thereby improving the catalytic conversion efficiency. Simultaneously, the design shape of the reaction tube 12 can promote the contact area and collision frequency between the feed gas and the conductive catalytic substrate, promoting the reaction and improving the conversion rate and yield.

[0038] The catalytic substrate conductive material 2 includes a carbon substrate 21 and a metal catalyst layer 22, which are as described above and will not be repeated here. In some embodiments, the catalytic substrate conductive material 2 includes, but is not limited to, Cu-CC, In-CC, RhZn-CC, Ni-CF, Ni foam, CuNiZn-SiC, Pt-CC, Fe-SiC, or NaZnFe-CC.

[0039] In some embodiments, the first conductive clip 31 and the second conductive clip 32 are each independently selected from one of a flat-head clip, an alligator clip, and a screw rotating clip.

[0040] In some embodiments, the detection of electrothermal synergistic generation of Joule thermal coupling catalytic conversion of carbon dioxide to produce low-carbon olefins, alkanes and oxygen-containing organic compounds includes at least one of online gas chromatography, mass spectrometry, nuclear magnetic resonance cumulative time detection, and chromatographic cumulative time detection components.

[0041] Gas chromatography (GC) primarily uses FID and TCD detectors, and the gases tested mainly include H2, CO, CO2, CH4, C2H4, C2H6, C3H6, C3H8, C4H8, and C4H. 10 wait.

[0042] This application also proposes a method for preparing low-carbon olefins, alkanes, and oxygen-containing organic compounds using the Joule catalytic device described above, comprising: Connecting the conductive component to a power source causes Joule heating to occur in the conductive material of the catalytic substrate. Carbonaceous substances and reducing gases are introduced through the air inlet to produce low-carbon olefins, alkanes, and oxygen-containing organic compounds.

[0043] The carbon-containing substances mainly refer to C1 gases, including carbon monoxide (CO), carbon dioxide (CO2), and methane (CH4). The reaction range can also be expanded to include other carbon-containing substances, such as methanol (CH3OH), formaldehyde (HCHO), ethanol (C2H5OH), acetic acid (CH3COOH), ethylene glycol (HOCH2CH2OH), ethylene (C2H4), ethane (C2H6), and dimethyl ether (CH3OCH3). The reducing gas includes at least one of hydrogen (H2) and water vapor (H2O). The Joule thermal current range of the conductive material on the catalytic substrate is 0–150 A. The reaction pressure is 1 mbar–5 bar.

[0044] In some embodiments, the flow rate of the gas introduced through the inlet is 5 to 200 mL / min, for example, the flow rate can be 5 mL / min, 10 mL / min, 30 mL / min, 50 mL / min, 100 mL / min, or 200 mL / min, etc. The concentration ratio of carbon dioxide or carbon monoxide to the reducing gas is (20:1) to (1:20). For example, the concentration ratio of carbon dioxide to the reducing gas is 20:1, 15:1, 10:1, 5:1, 3:1, 1:1, 1:2, 1:3, 1:5, 1:5, 1:10, 1:15, or 1:20, etc.

[0045] In some embodiments, when gas is introduced through the inlet, an inert gas may also be introduced as a purge gas or carrier gas, and the concentration of the raw material gas (such as carbon dioxide and hydrogen) is 5% to 100%. The inert gas includes at least one of nitrogen, argon and helium.

[0046] It should be noted that the Joule catalytic device described above in this application can also be used for catalytic reactions of other carbon-containing substances, which will not be listed here.

[0047] The following specific examples provide further details.

[0048] Example 1 This embodiment provides a method for preparing a carbon cloth-supported zinc oxide catalyst (ZnO-CC), as follows: This example uses a hydrothermal method to directly grow zinc oxide nanomaterials on carbon cloth (CC) to prepare a conductive catalytic matrix. The specific steps are as follows: First, a hydrothermal reaction precursor solution was prepared: 2 mmol of zinc nitrate (Zn(NO3)2), 4 mmol of sodium hydroxide (NaOH), and 2 mmol of hexadecyltrimethylammonium bromide (CTAB) were dissolved in 40 mL of deionized water and sonicated for 1 h to obtain a homogeneous solution. Next, the solution was transferred to a polytetrafluoroethylene-lined hydrothermal reactor, and a pre-treated carbon cloth (CC) was immersed in the solution. After sealing the reactor, it was placed in a 100°C forced-air drying oven and reacted for 10 h. After the hydrothermal reaction was completed, the sample was allowed to cool naturally to room temperature. The carbon cloth sample with deposited zinc oxide (denoted as ZnO-CC) was removed and rinsed several times alternately with ethanol and deionized water to remove residual reactants. Subsequently, the sample was sonicated for 5 min to remove loosely bound particles. Finally, the washed ZnO-CC sample was thoroughly dried in a 90°C oven. To optimize its conductivity and structure, the dried sample was calcined at 350°C in air for 2 h to obtain the final conductive catalytic matrix material.

[0049] The ZnO-CC sample was packed into a Joule heating apparatus and reduced in hydrogen at 350°C for 1 hour before the reaction. After the reaction, the temperature was lowered to 100°C under normal pressure, and the apparatus was set to an oscillating pulse mode with a temperature range of 200–800°C. Carbon dioxide and methane (1:1) were introduced, and the reaction was continued for 1 hour. The exhaust gas was separated by gas-liquid condensation and analyzed by gas chromatography (GC) and nuclear magnetic resonance (NMR).

[0050] Example 2 This embodiment involves loading Rh metal onto ZnO-CC as in Example 1, differing from Example 1 in the loading of Rh. The preparation method is as follows: This embodiment uses a hydrothermal method to grow an integrated zinc oxide (ZnO-CC) nanomaterial catalyst in situ on carbon cloth (CC).

[0051] Rhodium(III) acetylacetonate was selected as the source of Rh. A 0.01 M solution was prepared, and ZnO-CC was immersed in the Rh solution by impregnation. After sonication, the mixture was impregnated for 12 h, dried, and then calcined at 350 °C for 2 h under Ar protection to obtain Rh / ZnO-CC.

[0052] The Rh / ZnO-CC sample was packed into a Joule heating apparatus and reduced in hydrogen at atmospheric pressure at 350°C for 1 hour before the reaction. After the reaction was complete, the temperature was lowered, the pressure was increased to 1.5 MPa, and then the temperature was set to a constant 300°C. Carbon dioxide and hydrogen (3:1) were introduced, and the reaction was continued for 1 hour. The exhaust gas was separated by gas-liquid condensation and analyzed by gas chromatography (GC) and nuclear magnetic resonance (NMR).

[0053] Example 3 This embodiment describes the preparation of a Na-ZnFe2O4 catalyst via precipitation, followed by testing after coating and drying onto carbon cloth. The preparation method is as follows: Zinc nitrate hexahydrate (Zn(NO3)26H2O) and ferric nitrate nonahydrate (Fe(NO3)29H2O) were prepared into 0.01 M solutions and heated and stirred at 70 °C. A 0.01 M sodium carbonate (Na2CO3) solution was prepared and added dropwise to the Zn and Fe-containing solution until the pH reached 10. After stirring for 2 h, the solution was aged for 12 h. After drying, the solution was calcined at 500 °C for 2 h at a heating rate of 2 °C / min to obtain the Na-modified Na-ZnFe2O4 catalyst. The Na-ZnFe2O4 catalyst was dispersed in 1 mL of water, ultrasonically stirred until homogeneous, coated onto carbon cloth (CC), and dried simultaneously to obtain the Na-ZnFe2O4-CC catalyst.

[0054] The Na-ZnFe2O4-CC catalyst was packed into a Joule heating apparatus. In-situ reduction was performed before the reaction. First, nitrogen (N2) was introduced to purge air, followed by the introduction of the same composition as the feed gas (CO / H2 = 1 / 1). Reduction was carried out at 350℃ for 1 h. Subsequently, the temperature was lowered to room temperature, the pressure was increased to 0.3 MPa, and the temperature was raised to 300℃. After stabilization, the voltage was 3V and the current was 13A. Feed gas with a CO / H2 ratio of 1 / 1 to 1 / 3 was then introduced for the reaction. Gas-liquid separation was performed at the reaction outlet. The gas phase was analyzed by online chromatography, and the liquid phase was analyzed by nuclear magnetic resonance.

[0055] Example 4 The catalyst used in this embodiment is the same as that in Example 1. The difference lies in the preparation steps of low-carbon olefins, alkanes, and oxygen-containing organic compounds: The ZnO-CC sample was loaded into a Joule heating apparatus and reduced in hydrogen at 550°C for 1 hour before the reaction. Then, the temperature was lowered to room temperature, the pressure was increased to 0.5 MPa, and the oscillating pulse mode was set. The temperature was maintained at 500~2000°C, and carbon dioxide and methane (20:1) were introduced. The reaction was carried out for 0.5 hours, and the tail gas was separated by gas-liquid condensation to obtain low-carbon olefins, alkanes and oxygen-containing organic compounds.

[0056] Example 5 The catalyst used in this embodiment is the same as that in Example 2. The difference lies in the preparation steps of low-carbon olefins, alkanes, and oxygen-containing organic compounds: Rh / ZnO-CC samples were loaded into a Joule heating apparatus and reduced in hydrogen at 350°C for 1 hour before the reaction. Then, the temperature was lowered to room temperature, the pressure was increased to 5 MPa, and the oscillating pulse mode was set. The temperature was maintained at 500~1000°C, and carbon dioxide and hydrogen (1:20) were introduced. The reaction was carried out for 1 hour, and the tail gas was separated by gas-liquid condensation to obtain low-carbon olefins, alkanes and oxygen-containing organic compounds.

[0057] Example 6 The catalyst used in this embodiment is the same as that in Example 3. The difference lies in the preparation steps of low-carbon olefins, alkanes, and oxygen-containing organic compounds: The Na-ZnFe2O4-CC catalyst sample was loaded into a Joule heating device and reduced in hydrogen at 350°C for 1 hour before the reaction. Then, the temperature was lowered to room temperature, the pressure was increased to 3 MPa, and the oscillating pulse mode was set. The temperature was 400~1200°C, and the feed gas with CO / H2 = 1 / 1~1 / 3 was introduced. The reaction was carried out for 2 hours, and the tail gas was separated by gas-liquid condensation to obtain low-carbon olefins, alkanes and oxygen-containing organic compounds.

[0058] Comparative Example 1 In this comparative example, a blank carbon cloth was prepared using the following method: First, a pretreated commercial carbon cloth (size: 2.5 cm × 9.5 cm) was used as the conductive substrate and catalyst carrier, and longitudinally fixed using flat-head clips and alligator clips, with the clamping points being 0.25 cm on each side edge. The assembled catalyst sample was placed in a quartz reaction tube, and its internal resistance was measured before the reaction began. Subsequently, an inert gas was introduced to purge air from the system. The reactor could be selected for programmed temperature rise or oscillating temperature rise heating modes. Then, the temperature was set (same as in Examples 1, 2, or 3), and a CH4 / CO2 mixture, an H2 / CO2 mixture, or an H2 / CO mixture was introduced, while the reaction pressure was controlled (same as in Examples 1, 2, or 3). The exhaust gas after the reaction was separated by gas-liquid condensation (gas-liquid condenser, gas washing bottle). The gas was connected online to a gas chromatograph for gas phase product analysis, while the liquid was analyzed by chromatography or nuclear magnetic resonance.

[0059] Reaction results ( Figure 4 Taking Example 3 as an example, the Na-ZnFe2O4-CC catalyst can generate C under low temperature and low pressure conditions. 2+ The products are mainly alkenes, and the selectivity of alkenes and alkanes can be controlled by changing the H2 / CO ratio.

[0060] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A method for preparing low-carbon olefins, alkanes, and oxygen-containing organic compounds, characterized in that, include: By passing an electric current through a conductive catalytic substrate, the conductive catalytic substrate comes into contact with carbon-containing substances and reducing gases and reacts to produce low-carbon olefins, alkanes, or oxygen-containing organic compounds. The conductive material of the catalytic substrate includes a carbon substrate and a metal catalyst disposed on the carbon substrate; The reaction pressure is 0.1~5 MPa.

2. The method for preparing low-carbon olefins, alkanes, and oxygen-containing organic compounds as described in claim 1, characterized in that, The reaction temperature is 100~2000℃.

3. The method for preparing low-carbon olefins, alkanes, and oxygen-containing organic compounds as described in claim 1, characterized in that, The concentration ratio of the carbonaceous substance to the reducing gas is (20:1) to (1:20). The carbon-containing substance includes at least one of carbon monoxide, carbon dioxide, methane, methanol, formaldehyde, ethylene, ethane, ethanol, acetic acid, ethylene glycol, and dimethyl ether; The reducing gas includes at least one of hydrogen and water vapor.

4. The method for preparing low-carbon olefins, alkanes, and oxygen-containing organic compounds as described in claim 1, characterized in that, The carbon substrate includes at least one of carbon paper, carbon cloth, carbon felt, and silicon carbide.

5. The method for preparing low-carbon olefins, alkanes, and oxygen-containing organic compounds as described in claim 1, characterized in that, The metal catalyst includes at least one of the following: a single metal catalyst, a bimetallic catalyst, a multimetallic catalyst, and a non-metallic modified metal catalyst. Preferably, the metal catalyst comprises at least one of sodium, potassium, copper, nickel, zinc, magnesium, cerium, indium, zirconium, iron, molybdenum, cobalt, titanium, aluminum, platinum, palladium, ruthenium, rhodium, gold, and silver; Preferably, the modifying element in the non-metallic modified metal catalyst includes carbon or nitrogen.

6. The method for preparing low-carbon olefins, alkanes, and oxygen-containing organic compounds as described in claim 1, characterized in that, The method for preparing the conductive material of the catalytic substrate includes: forming a metal catalyst on the carbon substrate, wherein the formation includes an in-situ growth method or a coating method; Preferably, the in-situ growth method includes at least one of the following: hydrothermal method, impregnation method, precipitation method, and vapor deposition method; Preferably, the coating method includes spraying or dotting.

7. The method for preparing low-carbon olefins, alkanes, and oxygen-containing organic compounds as described in claim 1, characterized in that, The loading of the metal catalyst in the conductive substrate is 0.01wt%~50wt%.

8. A Joule catalytic device, characterized in that, include: A catalytic reactor includes a first port, a reaction tube, and a second port connected in sequence. The diameters of the first port and the second port are the same and larger than the diameter of the reaction tube. An air inlet is provided on the first port; An air outlet is provided on the second port; A conductive catalytic substrate is disposed in the reaction tube, the conductive catalytic substrate comprising a carbon substrate and a metal catalyst layer disposed on the carbon substrate; A conductive component includes a first conductive clip and a second conductive clip, wherein the first conductive clip establishes an electrical connection with the conductive material of the catalytic substrate via a first port, and the second conductive clip establishes an electrical connection with the conductive material of the catalytic substrate via a second port; Preferably, the reaction tube is a cuboid with a length of 10-150 mm, a width of 0.5-50 mm, and a height of 0.5-10 mm; The diameter of the first port and the second port is 10~30 mm.

9. A method for preparing low-carbon olefins, alkanes, and oxygen-containing organic compounds using the Joule catalytic apparatus of claim 8, characterized in that, include: Connect the conductive component to a power source to generate Joule heating in the conductive material of the catalytic substrate; By introducing the carbon-containing substance and reducing gas through the air inlet, low-carbon olefins, alkanes and oxygen-containing organic compounds are produced. Wherein, the carbon-containing substance is a gas, including at least one of carbon monoxide, carbon dioxide, methane, methanol, ethylene, and ethane; The gas being reduced includes at least one of hydrogen and water vapor; The Joule thermal current range of the conductive material of the catalytic substrate is 0~150 A.

10. The method as described in claim 9, characterized in that, The gas flow rate at the inlet is 5~200 mL / min, and the concentration ratio of the carbon dioxide to the reducing gas is (20:1)~(1:20).

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