Metal-supported catalyst, preparation method and application thereof in photo-thermal catalytic methane direct cracking reaction for hydrogen production

Abstract

The application provides a metal-loaded catalyst, a preparation method and application of the metal-loaded catalyst in a photo-thermal catalytic direct cracking of methane to produce hydrogen reaction. (x) / CeO2 catalyst, wherein M metal elements are selected from one of Mn, Fe, Co, Ni and Cu, and x is 0.2-0.8. The application provides a brand-new metal-loaded catalyst, which provides metal-support contact interface active sites by forming a new active phase, and the preparation method is simple and can control different components to solve the problems of difficult utilization of light energy and high demand for heat energy in the direct cracking of methane to produce hydrogen reaction. The metal-loaded catalyst can realize the direct cracking of methane to produce hydrogen at a low temperature, has high H2 yield, and almost no side reaction of oxygen coupling occurs, the yield of byproduct C2H6 is extremely low, and the economic efficiency is good.

Description

Technical Field

[0001] This invention belongs to the field of catalyst preparation technology, and in particular relates to a metal-supported catalyst, its preparation method, and its application in the photothermal catalytic direct cracking of methane to produce hydrogen. Background Technology

[0002] Hydrogen, as a clean and efficient energy carrier, holds significant strategic importance in energy transition and reducing greenhouse gas emissions. Currently, the main industrial method for producing hydrogen is through methane steam reforming, a process that consumes large amounts of energy and generates substantial amounts of carbon dioxide, contradicting current global goals for carbon reduction and sustainable development.

[0003] To address this issue, researchers and engineers have been exploring more environmentally friendly and economical hydrogen production technologies. Among these, direct catalytic conversion of methane has attracted significant attention due to its potential environmental and economic benefits. This technology can directly convert methane into hydrogen and solid carbon without producing carbon dioxide. Solid carbon, as a byproduct, has broad application prospects, including use as an electrode material and catalyst support, thereby increasing the economic value of the entire process.

[0004] However, the high bond energy of the CH bond in the methane molecule makes its activation and breaking difficult, usually requiring high temperatures (above 800°C) to proceed effectively. This not only limits the reaction rate of direct conversion of methane to hydrogen, but also greatly increases energy consumption and equipment requirements, thus restricting the commercial application of direct catalytic conversion technology for methane.

[0005] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a metal-supported catalyst, a preparation method thereof, and its application in the photothermal catalytic direct cracking of methane to produce hydrogen. This catalyst can achieve efficient conversion of methane to hydrogen and solid carbon at a lower temperature, significantly reducing energy consumption and carbon dioxide emissions, while improving economic efficiency.

[0007] To achieve the above and other related objectives, the present invention provides a metal-supported catalyst, wherein the metal-supported catalyst is M. (x) / CeO2 catalyst, wherein the metal element M is selected from one of Mn, Fe, Co, Ni, Cu, and the value of x is 0.2 to 0.8.

[0008] Preferably, the metal-supported catalyst comprises 20% to 80% of the metal element M and 20% to 80% of the CeO2 support, by molar percentage.

[0009] The present invention also provides a method for preparing the above-mentioned metal-supported catalyst, the method comprising the following steps:

[0010] S1. According to the molar ratio between metal M and Ce, dissolve metal M salt and Ce(NO3)3 in deionized water to obtain a mixed metal salt solution.

[0011] S2. Prepare an alkaline solution with a concentration of 5-8 mol / L, wherein the alkaline solution is an aqueous solution of NaOH or KOH;

[0012] S3. The mixed metal salt solution obtained in step S1 is added to the alkaline solution under stirring to cause a precipitation reaction and obtain the mother liquor.

[0013] S4. The mother liquor is subjected to a hydrothermal reaction, and the lower solid precursor is collected;

[0014] S5. The solid precursor is washed, dried, and ground to obtain a powder precursor.

[0015] S6. The powder precursor is calcined in air, reduced in hydrogen, and then passivated to obtain a metal-supported catalyst.

[0016] Preferably, the M metal salt in step S1 is one of the chloride, nitrate, sulfate, and acetate salts of the M metal, and the M metal is selected from one of Mn, Fe, Co, Ni, and Cu.

[0017] Preferably, the molar concentration of total metal ions in the mixed metal salt solution in step S1 is 1.5–2.5 mol / L.

[0018] Preferably, the stirring speed in step S3 is 500-1000 r / min.

[0019] Preferably, the temperature of the hydrothermal reaction in step S4 is 120-150°C, and the time of the hydrothermal reaction is 4-8 hours.

[0020] Preferably, the washing step in step S5 involves washing multiple times with deionized water until the pH of the supernatant is neutral, and then washing again with ethanol.

[0021] Preferably, the drying temperature in step S5 is 75℃~85℃, and the drying time is 6h~10h.

[0022] Preferably, the calcination temperature in step S6 is 400–500°C, and the calcination time is 2–4 hours.

[0023] Preferably, in step S6, the reduction is carried out in hydrogen gas, specifically by introducing hydrogen gas at a flow rate of 100 mL / min, heating to 400℃~500℃ at a heating rate of 2℃ / min, and reducing for 2h~4h.

[0024] Preferably, the passivation gas in step S6 is a mixture of O2 and Ar, with a volume ratio of O2 to Ar of 1:99; the flow rate of the passivation gas is 50-200 mL / min, and the passivation time is 0.5-1.5 h.

[0025] The present invention also provides an application of a metal-supported catalyst in the photothermal catalytic direct cracking of methane to produce hydrogen, wherein the metal-supported catalyst is the metal-supported catalyst described above, or a metal-supported catalyst prepared using the metal-supported catalyst described above.

[0026] Preferably, the light source in the photothermal process is a 200W full-spectrum xenon lamp as the energy input, and the lamp current of the xenon lamp is 15-20A; the heat source in the photothermal process is obtained by combining two convex lenses to focus the light.

[0027] Preferably, the feed gas used is CH4 and N2, the volume ratio of CH4 to N2 is 9:1, and the flow rate of the feed gas is 10 mL / min.

[0028] As described above, the metal-supported catalyst, preparation method, and application of the present invention in the photothermal catalytic direct methane cracking to hydrogen production reaction have the following beneficial effects:

[0029] This invention provides a novel metal-supported catalyst that provides active sites at the metal-support interface by forming a new active phase, thereby improving the absorption efficiency of solar energy and significantly reducing the reaction temperature. This enables efficient utilization of solar and thermal energy from methane, producing hydrogen with high activity and high conversion rate under relatively mild conditions. Furthermore, the preparation method of this metal-supported catalyst is simple, allowing for the control of different components and enabling multi-faceted research to solve the problems of difficult utilization of light energy and high demand for thermal energy in the direct cracking of methane to produce hydrogen.

[0030] The metal-supported catalyst of this invention has excellent comprehensive catalytic performance, enabling efficient catalytic conversion of methane at lower temperatures. In the photothermal catalytic direct cracking of methane to produce hydrogen, the H2 yield can reach up to 447.3 mmol / gcat / h, with almost no side reactions or oxygen coupling, and the yield of the byproduct C2H6 is extremely low, demonstrating good economic efficiency. Attached Figure Description

[0031] Figure 1 The catalyst shown is the metal-supported catalyst (Ni) prepared in Example 1 of this invention. (0.5)XRD diffraction patterns of (CeO2) with pure Ni and pure CeO2.

[0032] Figure 2 The catalyst shown is the metal-supported catalyst (Ni) prepared in Example 1 of this invention. (0.5) Scanning electron microscope image of / CeO2). Detailed Implementation

[0033] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0034] Before further describing specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the respective manufacturers.

[0035] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention, any prior art methods, apparatus, and materials similar to or equivalent to those described, apparatus, and materials in the embodiments of this invention may be used to implement the present invention.

[0036] This invention provides a metal-supported catalyst, wherein the metal-supported catalyst is M. (x) / CeO2 catalyst, wherein the metal element M is selected from one of Mn, Fe, Co, Ni, Cu, and the value of x is 0.2 to 0.8.

[0037] Specifically, X can include values ​​in any range such as 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc. In a specific embodiment of the present invention, a novel metal-supported catalyst is provided, which provides contact interface active sites by forming a new active phase between the metal M and the CeO2 support.

[0038] As an example, the metal-supported catalyst comprises 20% to 80% (e.g., 20%, 40%, 50%, 60%, 80%) of the metal element M and 20% to 80% (e.g., 20%, 40%, 50%, 60%, 80%) of the CeO2 support, by molar percentage.

[0039] This invention also provides a method for preparing a metal-supported catalyst, comprising the following steps:

[0040] S1. According to the molar ratio between metal M and Ce, dissolve metal M salt and Ce(NO3)3 in deionized water to obtain a mixed metal salt solution.

[0041] S2. Prepare an alkaline solution with a concentration of 5-8 mol / L. The alkaline solution is an aqueous solution of NaOH or KOH.

[0042] S3. The mixed metal salt solution obtained in step S1 is added to the alkaline solution under stirring to cause a precipitation reaction and obtain the mother liquor.

[0043] S4. Perform a hydrothermal reaction on the mother liquor and collect the lower solid precursor.

[0044] S5. Wash, dry, and grind the solid precursor to obtain the powder precursor;

[0045] S6. The powdered precursor is calcined in air, reduced in hydrogen, and then passivated to obtain a metal-supported catalyst.

[0046] Specifically, the metal-supported catalyst prepared in step S6 is M. (x) / CeO2 catalyst, where x ranges from 0.2 to 0.8; the metal-supported catalyst comprises 20% to 80% (e.g., 20%, 40%, 50%, 60%, 80%) of metal M and 20% to 80% (e.g., 20%, 40%, 50%, 60%, 80%) of CeO2 support, based on molar percentage. Therefore, the molar ratio between metal M and Ce in step S1 can be any value within the range of 1:4, 1:3, 2:3, 1:1, 3:2, 4:1, etc. As an example, in step S1, the metal M salt is one of the chloride, nitrate, sulfate, or acetate salts of metal M, and metal M is selected from Mn, Fe, Co, Ni, and Cu.

[0047] Specifically, Fe metal salt is Fe +3 Salt.

[0048] As an example, the total molar concentration of metal ions in the mixed metal salt solution in step S1 is 1.5–2.5 mol / L.

[0049] Specifically, the molar concentration of total metal ions in a mixed metal salt solution can be any number within the range of 1.5 mol / L, 1.8 mol / L, 2.0 mol / L, 2.2 mol / L, 2.5 mol / L, etc.; the metal ions in the mixed metal salt solution include M metal ions and Ce metal ions.

[0050] As an example, the stirring speed in step S3 is 500-1000 r / min.

[0051] Specifically, the specific operation steps of step S3 are as follows: the mixed metal salt solution is slowly added dropwise to the continuously stirred alkaline solution to cause a precipitation reaction. After the mixed metal salt solution is completely added, the entire mixed system is stirred for another 30 minutes. The entire process is carried out at room temperature. The stirring speed can be any value within the range of 500 r / min, 600 r / min, 700 r / min, 800 r / min, 900 r / min, 1000 r / min, etc.

[0052] As an example, the temperature of the hydrothermal reaction in step S4 is 120–150°C, and the reaction time is 4–8 hours.

[0053] Specifically, the hydrothermal reaction involves transferring the mother liquor into a stainless steel reactor lined with polytetrafluoroethylene (PTFE), then placing the reactor in a drying oven for heating. After the hydrothermal reaction is complete, the reactor can only be opened after it has completely cooled to room temperature naturally. The temperature of the hydrothermal reaction can be any value within the range of 120℃, 130℃, 140℃, 150℃, etc., and the reaction time can be any value within the range of 4h, 5h, 6h, 7h, 8h, etc.

[0054] As an example, the washing step in step S5 involves washing multiple times with deionized water until the pH of the supernatant is neutral, and then washing again with ethanol.

[0055] Specifically, the washing process should be performed at least twice with deionized water. The exact number of washes is not strictly limited, as long as the pH of the supernatant is neutral. Then, the supernatant should be washed once more with ethanol. The washing process should be carried out by centrifugation. Preferably, the centrifuge speed is 4000-4500 r / min (e.g., 4000 r / min, 4100 r / min, 4200 r / min, 4300 r / min, 4400 r / min, 4500 r / min, etc.), and the centrifugation time is 3-6 min (e.g., 3 min, 4 min, 5 min, 6 min, etc.).

[0056] As an example, the drying temperature in step S5 is 75℃~85℃, and the drying time is 6h~10h.

[0057] Specifically, the drying temperature can be any value within the range of 75℃, 77℃, 78℃, 80℃, 82℃, 84℃, 85℃, etc., and the drying time can be any value within the range of 6h, 7h, 8h, 9h, 10h, etc.

[0058] As an example, the calcination temperature in step S6 is 400-500°C, and the calcination time is 2-4 hours.

[0059] Specifically, the calcination temperature can include any value within the range of 400℃, 420℃, 440℃, 450℃, 460℃, 480℃, 500℃, etc., and the calcination time can include any value within the range of 2h, 2.5h, 3h, 3.5h, 4h, etc.; in a specific embodiment of the present invention, when calcining in air, it is preferable to heat at a heating rate of 3℃ / min.

[0060] As an example, in step S6, the reduction in hydrogen gas is specifically carried out by introducing hydrogen gas at a flow rate of 100 mL / min and heating it to 400℃~500℃ (e.g., 400℃, 420℃, 440℃, 450℃, 460℃, 480℃, 500℃, etc.) at a heating rate of 2℃ / min, and reducing it for 2h~4h (e.g., 2h, 2.5h, 3h, 3.5h, 4h, etc.).

[0061] As an example, the passivation gas in the passivation process is a mixture of O2 and Ar, with a volume ratio of O2 to Ar of 1:99; the flow rate of the passivation gas is 50-200 mL / min, and the passivation time is 0.5 h-1.5 h (e.g., 0.5 h, 0.8 h, 1.0 h, 1.1 h, 1.2 h, 1.5 h, etc.).

[0062] In addition, the present invention also provides an application of a metal-supported catalyst in the photothermal catalytic direct cracking of methane to produce hydrogen, wherein the metal-supported catalyst is prepared by the above-mentioned metal-supported catalyst or by the above-mentioned method for preparing the metal-supported catalyst.

[0063] Specifically, the metal-supported catalyst in the specific embodiments of the present invention improves the absorption efficiency of solar energy through metal-support interaction, significantly reduces the temperature required for the direct cracking of methane to produce hydrogen, and realizes the production of hydrogen from methane with high activity and high conversion rate under relatively mild conditions.

[0064] As an example, the light source in photothermal is a 200W full-spectrum xenon lamp as the energy input, and the lamp current of the xenon lamp is 15-20A; the heat source in photothermal is obtained by combining two convex lenses to focus the light.

[0065] Specifically, the lamp current of a xenon lamp can include any value within the range of 15A, 16A, 17A, 18A, 19A, 20A, etc.

[0066] As an example, the feed gas used is CH4 and N2, with a volume ratio of CH4 to N2 of 9 and a flow rate of 10 mL / min.

[0067] Preferably, the hydrogen production reaction is carried out under normal pressure for 2 hours.

[0068] To better understand the metal-supported catalyst, preparation method, and application in the photothermal catalytic direct methane cracking for hydrogen production of the present invention, specific embodiments are described below. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0069] Example 1

[0070] This embodiment provides a metal-supported catalyst, wherein the metal-supported catalyst is Ni. (0.5) / CeO2, based on the molar percentage of Ni and Ce elements, this metal-supported catalyst comprises 50% Ni metal and 50% CeO2 support.

[0071] This embodiment also provides a metal-supported catalyst (Ni). (0.5) The preparation method of ( / CeO2) adopts a one-pot hydrothermal method, including the following steps:

[0072] S1. Provide nickel nitrate and Ce(NO3)3, weigh them according to the molar ratio of Ni metal element to Ce element of 1:1, dissolve nickel nitrate and Ce(NO3)3 in water to obtain a mixed metal salt solution with a total metal ion molar concentration of 2 mol / L.

[0073] S2. Dissolve NaOH in water to obtain an 8 mol / L alkaline solution;

[0074] S3. The mixed metal salt solution obtained in step S1 is continuously added to the alkaline solution under stirring to cause a precipitation reaction. After the addition is complete, the mixture is stirred at 700 r / min for 30 min to obtain the mother liquor.

[0075] S4. Transfer the mother liquor to a stainless steel reactor lined with polytetrafluoroethylene and hydrothermally react at 150°C for 4 hours, then collect the lower solid precursor.

[0076] S5. After washing the solid precursor with water 7 times, wash it with ethanol once, dry it at 80°C, and then grind it into powder using a mortar and pestle to obtain the powdered precursor.

[0077] S6. The powdered precursor was calcined in a muffle furnace at 450°C in an air atmosphere for 3 hours. Hydrogen gas was then introduced into a tube furnace at a flow rate of 100 mL / min, and the furnace was reduced at 450°C in a hydrogen atmosphere for 3 hours. Finally, it was passivated for 1 hour in a passivation gas with a volume ratio of O2 to Ar2 of 1:99, where the passivation gas flow rate was 100 mL / min, to obtain a metal-supported catalyst (Ni). (0.5) / CeO2).

[0078] See Figure 1 The metal-supported catalyst (Ni) prepared in this embodiment (0.5) XRD diffraction patterns of Ni (CeO2) and pure Ni and pure CeO2. From the figures, it can be seen that Ni... (0.5) / CeO2 simultaneously exhibits characteristic diffraction peaks of both CeO2 (PDF#34-0394) and Ni (PDF#04-0850), confirming that the catalyst (Ni) (0.5) Successful preparation of / CeO2).

[0079] See Figure 2 The metal-supported catalyst (Ni) prepared in this embodiment (0.5) The scanning electron microscope image of Ni ( / CeO2) shows that Ni... (0.5) Ni particles in CeO2 are uniformly distributed on CeO2 nanorods.

[0080] This embodiment also provides a metal-supported catalyst (Ni). (0.5) The application of / CeO2) will enhance the metal-supported catalyst (Ni) in this embodiment. (0.5) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated, specifically:

[0081] Weigh 0.02 g of the metal-supported catalyst (Ni). (0.5) The feed gas was selected as CH4 / N2 = 9 (volume ratio), the flow rate of the feed gas was 10 mL / min, the light source was provided by a 200W full-spectrum xenon lamp with a lamp current of 15A, the heat source was obtained by focusing light with a combination of two convex lenses, the reaction time was 2 h, the reaction pressure was atmospheric pressure, and the performance results are shown in Table 1.

[0082] Example 2

[0083] This embodiment provides a metal-supported catalyst, wherein the metal-supported catalyst is Ni. (0.2) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 20% Ni metal and 80% CeO2 support.

[0084] This embodiment also provides a metal-supported catalyst (Ni).(0.2) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, nickel nitrate and Ce(NO3)3 are weighed according to a molar ratio of Ni metal element to Ce element of 1:4. Other methods and steps are the same as in Example 1, and will not be repeated here.

[0085] This embodiment also provides a metal-supported catalyst (Ni). (0.2) The application of / CeO2) will enhance the metal-supported catalyst (Ni) in this embodiment. (0.2) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 1, and will not be repeated here. The performance results are shown in Table 1.

[0086] Example 3

[0087] This embodiment provides a metal-supported catalyst, wherein the metal-supported catalyst is Ni. (0.4) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 40% Ni metal and 60% CeO2 support.

[0088] This embodiment also provides a metal-supported catalyst (Ni). (0.4) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, nickel nitrate and Ce(NO3)3 are weighed according to a molar ratio of Ni metal element to Ce element of 2:3. Other methods and steps are the same as in Example 1, and will not be repeated here.

[0089] This embodiment also provides a metal-supported catalyst (Ni). (0.4) The application of / CeO2) will enhance the metal-supported catalyst (Ni) in this embodiment. (0.4) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 1, and will not be repeated here. The performance results are shown in Table 1.

[0090] Example 4

[0091] This embodiment provides a metal-supported catalyst, wherein the metal-supported catalyst is Ni. (0.6) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 60% Ni metal and 40% CeO2 support.

[0092] This embodiment also provides a metal-supported catalyst (Ni). (0.6)The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, nickel nitrate and Ce(NO3)3 are weighed according to the molar ratio of Ni metal element to Ce element of 3:2. Other methods and steps are the same as those in Example 1, and will not be repeated here.

[0093] This embodiment also provides a metal-supported catalyst (Ni). (0.6) The application of / CeO2) will enhance the metal-supported catalyst (Ni) in this embodiment. (0.6) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 1, and will not be repeated here. The performance results are shown in Table 1.

[0094] Example 5

[0095] This embodiment provides a metal-supported catalyst, wherein the metal-supported catalyst is Ni. (0.8) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 80% Ni metal and 20% CeO2 support.

[0096] This embodiment also provides a metal-supported catalyst (Ni). (0.8) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, nickel nitrate and Ce(NO3)3 are weighed according to a molar ratio of Ni metal element to Ce element of 4:1. Other methods and steps are the same as in Example 1 and will not be repeated here.

[0097] This embodiment also provides a metal-supported catalyst (Ni). (0.8) The application of / CeO2) will enhance the metal-supported catalyst (Ni) in this embodiment. (0.8) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 1, and will not be repeated here. The performance results are shown in Table 1.

[0098] Table 1. Performance results of the metal-supported catalysts prepared in Examples 1-5 in the photothermal catalytic direct methane cracking reaction for hydrogen production.

[0099] Example 1 199.4 Example 2 94.7 Example 3 148.8 Example 4 168.6 Example 5 148.3

[0100] Example 6

[0101] This embodiment provides a metal-supported catalyst, which is Mn. (0.2) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 20% Mn metal and 80% CeO2 support.

[0102] This embodiment also provides a metal-supported catalyst (Mn). (0.2) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, manganese nitrate and Ce(NO3)3 are provided, and manganese nitrate and Ce(NO3)3 are weighed according to the molar ratio between Mn metal element and Ce element of 1:4, and dissolved in water to obtain a mixed metal salt solution with a total metal ion molar concentration of 2 mol / L; the rest is the same as in Example 1, and will not be repeated here.

[0103] This embodiment also provides a metal-supported catalyst (Mn). (0.2) The application of / CeO2) will enhance the metal-supported catalyst (Mn) in this embodiment. (0.2) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 1, and will not be repeated here. The performance results are shown in Table 2.

[0104] Example 7

[0105] This embodiment provides a metal-supported catalyst, which is Mn. (0.4) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 40% Mn metal and 60% CeO2 support.

[0106] This embodiment also provides a metal-supported catalyst (Mn). (0.4) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, manganese nitrate and Ce(NO3)3 are weighed according to a molar ratio of Mn metal element to Ce element of 2:3; the rest is the same as in Example 6, and will not be repeated here.

[0107] This embodiment also provides a metal-supported catalyst (Mn). (0.4) The application of / CeO2) will enhance the metal-supported catalyst (Mn) in this embodiment. (0.4) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 6, and will not be repeated here. The performance results are shown in Table 2.

[0108] Example 8

[0109] This embodiment provides a metal-supported catalyst, which is Mn. (0.5) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 50% Mn metal and 50% CeO2 support.

[0110] This embodiment also provides a metal-supported catalyst (Mn). (0.5) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, manganese nitrate and Ce(NO3)3 are weighed according to a molar ratio of Mn metal element to Ce element of 1:1; the rest is the same as in Example 6, and will not be repeated here.

[0111] This embodiment also provides a metal-supported catalyst (Mn). (0.5) The application of / CeO2) will enhance the metal-supported catalyst (Mn) in this embodiment. (0.5) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 6, and will not be repeated here. The performance results are shown in Table 2.

[0112] Example 9

[0113] This embodiment provides a metal-supported catalyst, which is Mn. (0.6) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 60% Mn metal and 40% CeO2 support.

[0114] This embodiment also provides a metal-supported catalyst (Mn). (0.6) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, manganese nitrate and Ce(NO3)3 are weighed according to a molar ratio of Mn metal element to Ce element of 3:2; the rest is the same as in Example 6, and will not be repeated here.

[0115] This embodiment also provides a metal-supported catalyst (Mn). (0.6) The application of / CeO2) will enhance the metal-supported catalyst (Mn) in this embodiment. (0.6) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 6, and will not be repeated here. The performance results are shown in Table 2.

[0116] Example 10

[0117] This embodiment provides a metal-supported catalyst, which is Mn. (0.8) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 80% Mn metal and 20% CeO2 support.

[0118] This embodiment also provides a metal-supported catalyst (Mn). (0.8) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, manganese nitrate and Ce(NO3)3 are weighed according to a molar ratio of Mn metal element to Ce element of 4:1; the rest is the same as in Example 6, and will not be repeated here.

[0119] This embodiment also provides a metal-supported catalyst (Mn). (0.8) The application of / CeO2) will enhance the metal-supported catalyst (Mn) in this embodiment. (0.8) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 6, and will not be repeated here. The performance results are shown in Table 2.

[0120] Table 2. Performance results of the metal-supported catalysts prepared in Examples 6-10 in the photothermal catalytic direct methane cracking reaction for hydrogen production.

[0121] Example 6 87.6 Example 7 46.4 Example 8 78.3 Example 9 66.5 Example 10 55.1

[0122] Example 11

[0123] This embodiment provides a metal-supported catalyst, which is Co. (0.2) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 20% Co metal and 80% CeO2 support.

[0124] This embodiment also provides a metal-supported catalyst (Co). (0.2) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, cobalt nitrate and Ce(NO3)3 are provided, and cobalt nitrate and Ce(NO3)3 are weighed according to the molar ratio of Co metal element to Ce element of 1:4, and dissolved in water to obtain a mixed metal salt solution with a total metal ion molar concentration of 2 mol / L; the rest is the same as in Example 1, and will not be repeated here.

[0125] This embodiment also provides a metal-supported catalyst (Co). (0.2) The application of / CeO2) will enhance the metal-supported catalyst (Co) in this embodiment. (0.2) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 1, and will not be repeated here. The performance results are shown in Table 3.

[0126] Example 12

[0127] This embodiment provides a metal-supported catalyst, which is Co. (0.4) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 40% Co metal and 60% CeO2 support.

[0128] This embodiment also provides a metal-supported catalyst (Co). (0.4) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, cobalt nitrate and Ce(NO3)3 are weighed according to a molar ratio of Co metal element to Ce element of 2:3; the rest is the same as in Example 11, and will not be repeated here.

[0129] This embodiment also provides a metal-supported catalyst (Co). (0.2) The application of / CeO2) will enhance the metal-supported catalyst (Co) in this embodiment. (0.2) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 11, and will not be repeated here. The performance results are shown in Table 3.

[0130] Example 13

[0131] This embodiment provides a metal-supported catalyst, which is Co. (0.5) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 50% Co metal and 60% CeO2 support.

[0132] This embodiment also provides a metal-supported catalyst (Co). (0.5) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, cobalt nitrate and Ce(NO3)3 are weighed according to a molar ratio of Co metal element to Ce element of 1:1; the rest is the same as in Example 11, and will not be repeated here.

[0133] This embodiment also provides a metal-supported catalyst (Co). (0.5) The application of / CeO2) will enhance the metal-supported catalyst (Co) in this embodiment. (0.5) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 11, and will not be repeated here. The performance results are shown in Table 3.

[0134] Example 14

[0135] This embodiment provides a metal-supported catalyst, which is Co. (0.6) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 60% Co metal and 40% CeO2 support.

[0136] This embodiment also provides a metal-supported catalyst (Co). (0.6) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, cobalt nitrate and Ce(NO3)3 are weighed according to the molar ratio of Co metal element to Ce element of 3:2; the rest is the same as in Example 11, and will not be repeated here.

[0137] This embodiment also provides a metal-supported catalyst (Co). (0.6) The application of / CeO2) will enhance the metal-supported catalyst (Co) in this embodiment. (0.6) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 11, and will not be repeated here. The performance results are shown in Table 3.

[0138] Example 15

[0139] This embodiment provides a metal-supported catalyst, which is Co. (0.8) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 80% Co metal and 20% CeO2 support.

[0140] This embodiment also provides a metal-supported catalyst (Co). (0.8) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, cobalt nitrate and Ce(NO3)3 are weighed according to a molar ratio of Co metal element to Ce element of 4:1; the rest is the same as in Example 11, and will not be repeated here.

[0141] This embodiment also provides a metal-supported catalyst (Co). (0.8) The application of / CeO2) will enhance the metal-supported catalyst (Co) in this embodiment. (0.8) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 11, and will not be repeated here. The performance results are shown in Table 3.

[0142] Table 3. Performance results of the metal-supported catalysts prepared in Examples 11-15 in the photothermal catalytic direct methane cracking reaction for hydrogen production.

[0143] Example 11 33.6 Example 12 10.2 Example 13 26.3 Example 14 29.5 Example 15 27.3

[0144] Example 16

[0145] This embodiment provides a metal-supported catalyst, wherein the metal-supported catalyst is Fe. (0.2) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 20% Fe metal and 80% CeO2 support.

[0146] This embodiment also provides a metal-supported catalyst (Fe). (0.2) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, ferric nitrate and Ce(NO3)3 are provided, and ferric nitrate and Ce(NO3)3 are weighed according to the molar ratio between Fe metal element and Ce element of 1:4, and dissolved in water to obtain a mixed metal salt solution with a total metal ion molar concentration of 2 mol / L; the rest is the same as in Example 1, and will not be repeated here.

[0147] This embodiment also provides a metal-supported catalyst (Fe). (0.2) The application of / CeO2) will enhance the metal-supported catalyst (Fe) in this embodiment. (0.2) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 1, and will not be repeated here. The performance results are shown in Table 4.

[0148] Example 17

[0149] This embodiment provides a metal-supported catalyst, wherein the metal-supported catalyst is Fe. (0.4) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 40% Fe metal and 60% CeO2 support.

[0150] This embodiment also provides a metal-supported catalyst (Fe). (0.4) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, ferric nitrate and Ce(NO3)3 are weighed according to a molar ratio of Fe metal element to Ce element of 2:3; the rest is the same as in Example 16, and will not be repeated here.

[0151] This embodiment also provides a metal-supported catalyst (Fe). (0.4) The application of / CeO2) will enhance the metal-supported catalyst (Fe) in this embodiment. (0.4) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 16, and will not be repeated here. The performance results are shown in Table 4.

[0152] Example 18

[0153] This embodiment provides a metal-supported catalyst, wherein the metal-supported catalyst is Fe. (0.5) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 50% Fe metal and 50% CeO2 support.

[0154] This embodiment also provides a metal-supported catalyst (Fe). (0.5) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, ferric nitrate and Ce(NO3)3 are weighed according to a molar ratio of Fe metal element to Ce element of 1:1; the rest is the same as in Example 16, and will not be repeated here.

[0155] This embodiment also provides a metal-supported catalyst (Fe). (0.5) The application of / CeO2) will enhance the metal-supported catalyst (Fe) in this embodiment. (0.5) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 16, and will not be repeated here. The performance results are shown in Table 4.

[0156] Example 19

[0157] This embodiment provides a metal-supported catalyst, wherein the metal-supported catalyst is Fe. (0.6) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 60% Fe metal and 40% CeO2 support.

[0158] This embodiment also provides a metal-supported catalyst (Fe). (0.6) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, ferric nitrate and Ce(NO3)3 are weighed according to a molar ratio of Fe metal element to Ce element of 3:2; the rest is the same as in Example 16, and will not be repeated here.

[0159] This embodiment also provides a metal-supported catalyst (Fe). (0.6) The application of / CeO2) will enhance the metal-supported catalyst (Fe) in this embodiment. (0.6) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 16, and will not be repeated here. The performance results are shown in Table 4.

[0160] Example 20

[0161] This embodiment provides a metal-supported catalyst, wherein the metal-supported catalyst is Fe. (0.8) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 80% Fe metal and 20% CeO2 support.

[0162] This embodiment also provides a metal-supported catalyst (Fe). (0.8) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, ferric nitrate and Ce(NO3)3 are weighed according to a molar ratio of Fe metal element to Ce element of 4:1; the rest is the same as in Example 16, and will not be repeated here.

[0163] This embodiment also provides a metal-supported catalyst (Fe). (0.8) The application of / CeO2) will enhance the metal-supported catalyst (Fe) in this embodiment. (0.8) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 16, and will not be repeated here. The performance results are shown in Table 4.

[0164] Table 4. Performance results of the metal-supported catalysts prepared in Examples 16-20 in the photothermal catalytic direct methane cracking reaction for hydrogen production.

[0165] Example 16 57.6 Example 17 21.4 Example 18 46.7 Example 19 50.8 Example 20 48.2

[0166] Example 21

[0167] This embodiment provides a metal-supported catalyst, wherein the metal-supported catalyst is Cu. (0.2) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 20% Cu metal and 80% CeO2 support.

[0168] This embodiment also provides a metal-supported catalyst (Cu). (0.2) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, copper nitrate and Ce(NO3)3 are provided, and copper nitrate and Ce(NO3)3 are weighed according to the molar ratio between Cu metal element and Ce element of 1:4, and dissolved in water to obtain a mixed metal salt solution with a total metal ion molar concentration of 2 mol / L; the rest is the same as in Example 1, and will not be repeated here.

[0169] This embodiment also provides a metal-supported catalyst (Cu). (0.2) The application of / CeO2) will enhance the metal-supported catalyst (Cu) in this embodiment. (0.2) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 1, and will not be repeated here. The performance results are shown in Table 5.

[0170] Example 22

[0171] This embodiment provides a metal-supported catalyst, wherein the metal-supported catalyst is Cu. (0.4) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 40% Cu metal and 60% CeO2 support.

[0172] This embodiment also provides a metal-supported catalyst (Cu). (0.4) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, copper nitrate and Ce(NO3)3 are weighed according to a molar ratio of Cu metal element to Ce element of 2:3; the rest is the same as in Example 21, and will not be repeated here.

[0173] This embodiment also provides a metal-supported catalyst (Cu). (0.4) The application of / CeO2) will enhance the metal-supported catalyst (Cu) in this embodiment. (0.4) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 21, and will not be repeated here. The performance results are shown in Table 5.

[0174] Example 23

[0175] This embodiment provides a metal-supported catalyst, wherein the metal-supported catalyst is Cu. (0.5) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 50% Cu metal and 50% CeO2 support.

[0176] This embodiment also provides a metal-supported catalyst (Cu). (0.5) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, copper nitrate and Ce(NO3)3 are weighed according to a molar ratio of Cu metal element to Ce element of 1:1; the rest is the same as in Example 21, and will not be repeated here.

[0177] This embodiment also provides a metal-supported catalyst (Cu). (0.5) The application of / CeO2) will enhance the metal-supported catalyst (Cu) in this embodiment. (0.5) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 21, and will not be repeated here. The performance results are shown in Table 5.

[0178] Example 24

[0179] This embodiment provides a metal-supported catalyst, wherein the metal-supported catalyst is Cu. (0.6) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 60% Cu metal and 40% CeO2 support.

[0180] This embodiment also provides a metal-supported catalyst (Cu). (0.6) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, copper nitrate and Ce(NO3)3 are weighed according to a molar ratio of Cu metal element to Ce element of 3:2; the rest is the same as in Example 21, and will not be repeated here.

[0181] This embodiment also provides a metal-supported catalyst (Cu). (0.6) The application of / CeO2) will enhance the metal-supported catalyst (Cu) in this embodiment. (0.6) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 21, and will not be repeated here. The performance results are shown in Table 5.

[0182] Example 25

[0183] This embodiment provides a metal-supported catalyst, wherein the metal-supported catalyst is Cu. (0.8) / CeO2, on a molar mass percentage basis, this metal-supported catalyst comprises 80% Cu metal and 20% CeO2 support.

[0184] This embodiment also provides a metal-supported catalyst (Cu). (0.8) The preparation method of / CeO2) differs from that in Example 1 in that: in step S1, copper nitrate and Ce(NO3)3 are weighed according to a molar ratio of Cu metal element to Ce element of 4:1; the rest is the same as in Example 21, and will not be repeated here.

[0185] This embodiment also provides a metal-supported catalyst (Cu). (0.8) The application of / CeO2) will enhance the metal-supported catalyst (Cu) in this embodiment. (0.8) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific method was the same as that in Example 21, and will not be repeated here. The performance results are shown in Table 5.

[0186] Table 5. Performance results of the metal-supported catalysts prepared in Examples 21-25 in the photothermal catalytic direct methane cracking reaction for hydrogen production.

[0187]

[0188]

[0189] Example 26

[0190] This embodiment provides a metal-supported catalyst (Ni). (0.5) The application of / CeO2) will enhance the metal-supported catalyst (Ni) in Example 1. (0.5) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific evaluation method differed from that in Example 1 in that the lamp current was 16A, while all other conditions were the same as in Example 1, and will not be repeated here. The performance results are shown in Table 6.

[0191] Example 27

[0192] This embodiment provides a metal-supported catalyst (Ni). (0.5) The application of / CeO2) will enhance the metal-supported catalyst (Ni) in Example 1. (0.5) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific evaluation method differed from that in Example 1 in that the lamp current was 17A, while all other conditions were the same as in Example 1, and will not be repeated here. The performance results are shown in Table 6.

[0193] Example 28

[0194] This embodiment provides a metal-supported catalyst (Ni). (0.5) The application of / CeO2) will enhance the metal-supported catalyst (Ni) in Example 1. (0.5) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific evaluation method differed from that in Example 1 in that the lamp current was 18A, while all other conditions were the same as in Example 1, and will not be repeated here. The performance results are shown in Table 6.

[0195] Example 29

[0196] This embodiment provides a metal-supported catalyst (Ni). (0.5)The application of / CeO2) will enhance the metal-supported catalyst (Ni) in Example 1. (0.5) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific evaluation method differed from that in Example 1 in that the lamp current was 19A, while all other conditions were the same as in Example 1, and will not be repeated here. The performance results are shown in Table 6.

[0197] Example 30

[0198] This embodiment provides a metal-supported catalyst (Ni). (0.5) The application of / CeO2) will enhance the metal-supported catalyst (Ni) in Example 1. (0.5) / CeO2) was used in the photothermal catalytic direct cracking of methane to produce hydrogen, and the performance of this metal-supported catalyst was evaluated. The specific evaluation method differed from that in Example 1 in that the lamp current was 20A, while all other conditions were the same as in Example 1, and will not be repeated here. The performance results are shown in Table 6.

[0199] Table 6. Performance results of the metal-supported catalyst from Example 1 used in Examples 26-30 for photothermal catalytic direct methane cracking to hydrogen production.

[0200]

[0201]

[0202] Examples 1-5, 6-10, 11-15, 16-20, and 21-25 compared the effects of different molar percentages of different metals Ni, Mn, Co, Fe, and Cu. Regardless of the metal-supported catalyst, the group with the highest hydrogen yield was the group with a molar percentage of metal M of 50%. The catalyst with a molar ratio of metal M to Ce of 1:1 exhibited the best relative reactivity. Examples 1, 8, 13, 18, and 23 compared the effects of different types of metal M support. When Ni was used as the supporting metal, the highest hydrogen yield and best reactivity were observed in the photothermal catalytic direct cracking of methane to produce hydrogen. Examples 26-30 compared the effects of the same catalyst under different lamp currents. As the lamp current increased, both light intensity and heat increased simultaneously, resulting in a gradual increase in hydrogen yield and enhanced reactivity with increasing lamp current.

[0203] In summary, this invention provides a novel metal-supported catalyst that, by forming a new active phase, provides active sites at the metal-support interface, improving solar energy absorption efficiency and significantly reducing the reaction temperature. This enables efficient utilization of solar and thermal energy from methane, producing hydrogen with high activity and high conversion rate under relatively mild conditions. Furthermore, the preparation method of this metal-supported catalyst is simple, allowing for the control of different components and multi-faceted research to address the challenges of difficult utilization of light energy and high thermal energy requirements in the direct methane cracking reaction for hydrogen production. The metal-supported catalyst of this invention exhibits excellent comprehensive catalytic performance, achieving efficient catalytic conversion of methane at relatively low temperatures. In the photothermal catalytic direct methane cracking reaction for hydrogen production, the H2 yield can reach up to 447.3 mmol / gcat / h, with almost no side reactions or oxygen coupling, and an extremely low yield of the byproduct C2H6, demonstrating good economic efficiency. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and has high industrial application value.

[0204] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. The application of a metal-supported catalyst in the photothermal catalytic direct cracking of methane to produce hydrogen, characterized in that, The metal-supported catalyst is prepared using a method for preparing metal-supported catalysts, the preparation method comprising the following steps: S1. According to the molar ratio between metal M and Ce, dissolve metal M salt and Ce(NO3)3 in deionized water to obtain a mixed metal salt solution. S2. Prepare an alkaline solution with a concentration of 5~8 mol / L, wherein the alkaline solution is an aqueous solution of NaOH or KOH; S3. The mixed metal salt solution obtained in step S1 is added to the alkaline solution under stirring to cause a precipitation reaction and obtain the mother liquor. S4. The mother liquor is subjected to a hydrothermal reaction, and the lower solid precursor is collected; the temperature of the hydrothermal reaction in step S4 is 120~150℃, and the time of the hydrothermal reaction is 4~8h. S5. The solid precursor is washed, dried, and ground to obtain a powder precursor. S6. The powder precursor is sequentially calcined in air, reduced in hydrogen, and then passivated to obtain a metal-supported catalyst. The calcination temperature is 400-500℃, and the calcination time is 2-4 hours. The reduction in hydrogen is specifically carried out by introducing hydrogen at a flow rate of 100 mL / min, heating to 400-500℃ at a heating rate of 2℃ / min, and reducing for 2-4 hours. The passivation gas in the passivation treatment is a mixture of O2 and Ar, with a volume ratio of O2 to Ar of 1:

99. The flow rate of the passivation gas is 50-200 mL / min, and the passivation time is 0.5-1.5 hours. The final metal-supported catalyst obtained is M (x) / CeO2 catalyst, wherein the metal element M is selected from one of Mn, Fe, Co, Ni, Cu, and the value of x is 0.2~0.

8.

2. The application of the metal-supported catalyst according to claim 1 in the photothermal catalytic direct cracking of methane to produce hydrogen, characterized in that, The metal-supported catalyst comprises 20% to 80% of metal M and 20% to 80% of CeO2 support, based on molar percentage.

3. The application of the metal-supported catalyst according to claim 1 in the photothermal catalytic direct cracking of methane to produce hydrogen, characterized in that: Step S1 includes one or a combination of the following conditions: The M metal salt is one of the chloride, nitrate, sulfate, and acetate salts of the M metal, and the M metal is selected from one of Mn, Fe, Co, Ni, and Cu. The total molar concentration of metal ions in the mixed metal salt solution is 1.5~2.5 mol / L.

4. The application of the metal-supported catalyst according to claim 1 in the photothermal catalytic direct cracking of methane to produce hydrogen, characterized in that: The stirring speed in step S3 is 500~1000 r / min.

5. The application of the metal-supported catalyst according to claim 1 in the photothermal catalytic direct cracking of methane to produce hydrogen, characterized in that: Step S5 includes one or a combination of the following conditions: The washing process involves washing multiple times with deionized water until the pH of the supernatant is neutral, and then washing again with ethanol. The drying temperature is 75℃~85℃, and the drying time is 6h~10h.

6. The application of the metal-supported catalyst according to claim 1 in the photothermal catalytic direct cracking of methane to produce hydrogen, characterized in that: Includes one or a combination of the following conditions: The light source in the photothermal process is a 200W full-spectrum xenon lamp as the energy input, and the lamp current is 15~20A; the heat source in the photothermal process is obtained by combining two convex lenses to focus the light. The feed gases used were CH4 and N2, with a volume ratio of CH4 to N2 of 9:1 and a flow rate of 10 mL / min.

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