Methane reforming catalyst and method for producing the same

Abstract

The present invention relates to a catalyst for methane reforming and a method for producing a methane reforming catalyst. The methane reforming catalyst according to the above-described embodiment can prevent leaching of the porous metal support component and minimize the influence of the metal support component on the catalyst phase.

Description

Technical Field

[0001] This application relates to a catalyst for methane reforming and a method for manufacturing the same. This application claims the benefit of the filing dates of Korean Patent Application No. 10-2023-0184291, filed with the Korean Intellectual Property Office on December 18, 2023, and Korean Patent Application No. 10-2024-0188464, filed with the Korean Intellectual Property Office on December 17, 2024, and all of its contents are incorporated herein by reference.

Background Art

[0002] As part of activities to reduce greenhouse gas emissions due to global warming, research on carbon dioxide conversion technology has been actively conducted. The carbon dioxide reforming reaction, which is one of the carbon dioxide conversion technologies, is a technology that reacts methane and carbon dioxide to obtain synthesis gas composed of hydrogen and carbon monoxide. Synthesis gas is a substance with high development value as a raw material for various downstream processes.

[0003] As a method for industrially obtaining such synthesis gas (H2 / CO), the reforming reaction of natural gas can be broadly classified into a steam reforming process, a carbon dioxide reforming process, a catalytic partial oxidation process, an autothermal reforming process, a tri-reforming process, etc., as shown in Reaction Formulas 1 to 5 below. [Reaction Formula 1] CH4 + H2O → 3H2 + CO △H = 226 kJ / mol [Reaction Formula 2] CH4 + CO2 → 2H2 + 2CO △H = 261 kJ / mol [Reaction Formula 3] CH4 + 0.5O2 → 2H2 + CO △H = -44 kJ / mol [Reaction Formula 4] Autothermal reforming process: Reaction Formula 1 + Reaction Formula 3 [Reaction Formula 5] Triple reforming process: Reaction equation 1 + Reaction equation 2 + Reaction equation 3

[0004] On the other hand, various catalysts can be used in the reforming process to enhance reforming activity. While using precious metal catalysts in the reforming process offers the advantage of high hydrogen conversion efficiency from natural gas, the high cost of these catalysts reduces economic viability. For this reason, nickel catalysts, which have high hydrogen conversion efficiency and are relatively inexpensive, are mainly used in the reforming process. However, in this case, there is a problem in that the nickel catalyst is deactivated by carbon that is inevitably generated on the surface of the nickel catalyst.

[0005] Therefore, there is a need to develop catalysts that are resistant to carbon deposition and can be effectively applied to the methane reforming process. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Korean Published Patent Publication No. 10-2019-0076367 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The purpose of this application is to provide a catalyst for methane reforming and a method for producing the same. [Means for solving the problem]

[0008] One embodiment of this application provides a catalyst for methane reforming, comprising: a porous metal support; a first coating layer provided on the porous metal support and containing a perovskite compound represented by the following chemical formula 1; and a second coating layer provided on the first coating layer and containing a perovskite compound represented by the following chemical formula 2.

[0009] Furthermore, other embodiments of this application provide a method for producing a methane reforming catalyst, comprising a first coating step of coating a porous metal support with a first coating liquid to form a first coating layer; and a second coating step of coating the first coating layer with a second coating liquid to form a second coating layer, wherein the first coating layer contains a compound represented by the following chemical formula 1, and the second coating layer contains a compound represented by the following chemical formula 2. [Chemical formula 1] Sr 1-a A a TiO3 [Chemical formula 2] Sr 1-x A x Ti 1-y B y O 3-δ In the aforementioned chemical formulas 1 and 2, A is selected from Y, Sc, La, and lanthanide elements. B is Ni, Co, Fe, Mn, Cr, Mo, Ru, or Rh. a is a real number greater than 0 and less than 1. x is a real number between 0 and 1 (exclusive of 1). y is a real number greater than 0 and less than 1. δ is a real number greater than 0 and less than 1. [Effects of the Invention]

[0010] A methane reforming catalyst according to one embodiment of this application can prevent leaching of the porous metal support component and minimize the influence of the metal support component on the catalyst phase. A methane reforming catalyst according to one embodiment of this application can prevent carbon deposition. This can increase the lifespan of the catalyst.

[0011] A method for producing a methane reforming catalyst according to one embodiment of this application can produce a methane reforming catalyst with excellent performance. Specifically, a methane reforming catalyst produced by the method for producing a methane reforming catalyst according to one embodiment of this application can minimize the influence of porous metal supports and prevent carbon deposition. [Brief explanation of the drawing]

[0012] [Figure 1] This is a graph showing the results of an experimental example. [Figure 2] This is a graph showing the results of an experimental example. [Modes for carrying out the invention]

[0013] The following provides a more detailed description of this specification. In this specification, the term "on top of" another member includes not only cases where one member is in contact with another member, but also cases where another member exists between the two members. In this specification, when a part "includes" a component, it means that it may include other components rather than excluding them, unless otherwise stated.

[0014] <Catalyst for methane reforming> A methane reforming catalyst according to one embodiment of this application is characterized by comprising a porous metal support; a first coating layer provided on the porous metal support; and a second coating layer provided on the first coating layer. Furthermore, the first coating layer and the second coating layer are characterized by comprising perovskite compounds represented by chemical formula 1 and chemical formula 2, respectively.

[0015] Due to the aforementioned features, the methane reforming catalyst according to this application can prevent side reactions and carbon deposition phenomena in the porous metal support. This can improve the efficiency and stability of the methane reforming reaction.

[0016] In particular, the first coating layer can prevent the phenomenon in which metals (such as Ni and Cr), which are the main components of the porous metal support, are exposed on the surface in the form of metal oxides (such as NiO and Cr2O3) under high-temperature (750 °C or higher) long-time operation conditions, and serves as a buffer to prevent the component ratio of the main catalyst represented by Chemical Formula 2 from changing due to the migration of metals (such as Ni and Cr) at high temperatures, and can prevent the component ratio change or phase change of the main catalyst substance, so that the durability and performance of the catalyst can be improved.

[0017] In addition, the methane reforming catalyst according to the present application is characterized in that a in Chemical Formula 1 is greater than 0. That is, the methane reforming catalyst according to the present application is characterized by including a perovskite-based compound containing a specific element (A) in the first coating layer. By including the specific element (A), side reactions caused by the porous metal support can be more effectively prevented.

[0018] In one embodiment of the present application, a in Chemical Formula 1 may be a real number greater than 0 and less than 1, preferably a real number greater than 0 and less than or equal to 0.2, and more preferably a real number greater than 0 and less than or equal to 0.1. In one embodiment of the present application, y in Chemical Formula 2 may be a real number greater than 0 and less than 1, preferably a real number greater than 0 and less than 0.9, more preferably a real number greater than 0 and less than 0.7, still more preferably a real number greater than 0 and less than 0.5, and most preferably a real number greater than 0 and less than 0.3.

[0019] In one embodiment of the present application, Chemical Formula 2 may be represented by the following Chemical Formula 3 or 4. [Chemical Formula 3] SrTi 1-y B y O 3-δ [Chemical Formula 4] Sr 1-x Y x Ti 1-y B y O 3-δ In Chemical Formulas 3 and 4, B is Ni or Ru, x is a real number greater than 0 and less than 1. y is a real number greater than 0 and less than 0.3. δ is a real number greater than 0 and less than 1.

[0020] In one embodiment of this application, the porous metal support may be made of a material that can maintain thermal stability at high temperatures of 800°C or higher. In one embodiment of this application, the porous metal support may be NiFeCrAl or a metal foam containing NiCrAl. The porous metal support can have various shapes, have a low heat capacity, excellent heat transfer capabilities, and may be molded into a desired shape. The form, size, etc., of the porous metal support are not particularly limited.

[0021] In one embodiment of this application, the porosity of the porous metal support may be 10% or more and 99% or less. Preferably, the porosity of the porous metal support is 50% or more, 60% or more, 70% or more, or 80% or more, and may be 98% or less, 97% or less, or 96% or less. If the porosity is less than 10%, the specific surface area to which the catalyst is coated becomes small, making it difficult to match the activity of the catalyst. If the porosity exceeds 99%, the strength of the porous metal support is low, making it difficult to use as a process catalyst.

[0022] In one embodiment of this application, the average pore size (cell size) of the porous metal support may be 400 μm or more and 2,000 μm or less. Preferably, the average pore size of the porous metal support is 410 μm or more, 430 μm or more, or 450 μm or more, and may be 1,900 μm or less, 1,700 μm or less, or 1,500 μm.

[0023] If the average pore size of the porous metal support is less than 400 μm, coating with the precursor solution becomes difficult, and if it exceeds 2,000 μm, the surface area on which the catalyst can be coated decreases, which can be disadvantageous in the process and is therefore undesirable. The porous metal support can be appropriately manufactured by a person skilled in the art using methods well known in the art, taking into consideration the material, pore size, porosity, etc. of the porous metal support described above.

[0024] According to one embodiment of this application, porous metal supports having various materials, pore sizes, etc., can be applied, as shown in the examples described later. In one embodiment of this application, the content of the perovskite compound represented by chemical formula 1 may be 1% by weight or more and 10% by weight or less, based on the total weight of the porous metal support. Preferably, the content of the perovskite compound represented by chemical formula 1 is 1.25% by weight or 1.5% by weight or more, and may be 9% by weight or less, or 8% by weight or less, based on the total weight of the porous metal support.

[0025] If the content of the perovskite compound represented by chemical formula 1 exceeds 10% by weight, coating with the perovskite compound represented by chemical formula 2 is not easy, which may result in low catalytic activity relative to the volume of the porous metal support, and is therefore undesirable. Furthermore, if the content of the perovskite compound represented by chemical formula 1 is less than 1% by weight, it may be difficult to obtain the effect of the first coating layer.

[0026] In one embodiment of this application, the content of the perovskite compound represented by chemical formula 2 may be 3% by weight or more and 40% by weight or less, based on the total weight of the methane reforming catalyst. Preferably, the content of the perovskite compound represented by chemical formula 2 is 5% by weight or more, 6% by weight or more, or 7% by weight or more, based on the total weight of the methane reforming catalyst, and may be 38% by weight or less, 35% by weight or less, or 30% by weight or less.

[0027] If the content of the perovskite compound represented by chemical formula 2 is less than 3% by weight, based on the total weight of the methane reforming catalyst, the number of active sites on the catalyst surface will be relatively small, resulting in reduced reactivity, which is undesirable. Furthermore, if the content of the perovskite compound represented by chemical formula 2 exceeds 40% by weight, it will contain a relatively large amount of catalyst component relative to the porous metal support, making it difficult to maintain the porosity structure and hindering the bonding between the catalyst component and the porous metal support, which may reduce the effectiveness of the methane reforming reaction.

[0028] In one embodiment of this application, the weight ratio of the perovskite compound (of chemical formula 1) contained in the first coating layer and the perovskite compound (of chemical formula 2) contained in the second coating layer may be 1:1 to 1:20, or 1:1.1 to 1:15. If the weight ratio deviates from the above, the catalytic activity relative to the volume of the porous metal support may be low, which is undesirable.

[0029] In one embodiment of this application, the first coating layer may be provided over the entire surface of the porous metal support. In one embodiment of this application, at least a portion of the surface of the methane reforming catalyst may include a protruding shape. The protruding shape may be spherical, elliptical, or a combination thereof, but is not limited thereto.

[0030] In one embodiment of this application, the first coating layer can serve to fix the second coating layer onto a porous metal support. The second coating layer may also exist on the first coating layer in the form of protrusions, thereby increasing the reaction surface area of ​​the catalyst and improving the performance of the methane reforming reaction.

[0031] In one embodiment of this application, the methane reforming catalyst may be applied to a steam reforming process, a CO2 reforming process, a catalytic partial oxidation process, an autothermal reforming process, a tri-reforming process, or a mixed reforming process, and the methane reforming process is not particularly limited.

[0032] <Method for producing a catalyst for methane reforming> A method for producing a methane reforming catalyst according to one embodiment of this application is characterized by comprising a first coating step for forming a first coating layer and a second coating step for forming a second coating layer. Furthermore, in the case of the method for producing a methane reforming catalyst according to one embodiment of this application, the first coating layer and the second coating layer are characterized by comprising perovskite compounds represented by chemical formula 1 and chemical formula 2, respectively.

[0033] A method for producing a methane reforming catalyst according to one embodiment of this application can produce the catalyst described in this application. That is, it can produce a methane reforming catalyst having excellent performance.

[0034] Regarding the production of catalysts containing perovskite compounds, several methods are known, including the citric acid method, the Pechini method, high-temperature calcination, polymerization complex method, freeze-drying method, coprecipitation method, and sol-gel method. Generally, the citric acid method or the Pechini method may be the primary method used. Specifically, the known citric acid method involves adding citric acid to produce an amorphous metal complex in a gel state, and then drying and calcining the metal complex to obtain a perovskite catalyst (Appl. Catal. B: Environ., 24(2000)193-205).

[0035] A method for producing a methane reforming catalyst according to one embodiment of this application may further include a step of preparing the first coating solution. The step of preparing the first coating solution may include a solution preparation step of producing a first metal precursor solution containing a strontium (Sr) precursor and a titanium (Ti) precursor; and a pH adjustment step of adjusting the pH of the first metal precursor solution to pH 1 to pH 5, preferably pH 1 to pH 3. If the pH is above 5, precipitates will form, and the desired catalyst form cannot be obtained after calcination. In one embodiment of this application, the pH adjustment step may involve adding urea to the metal precursor solution.

[0036] A method for producing a methane reforming catalyst according to one embodiment of this application may further include a step of preparing the second coating solution. The step of preparing the second coating solution may include a solution preparation step of producing a second metal precursor solution containing a strontium (Sr) precursor and a nickel (Ni) precursor. In one embodiment of this application, the first metal precursor solution and the second metal precursor solution may each further contain a titanium precursor solution.

[0037] The first metal precursor solution and the second metal precursor solution may be applied in the form of a sol or a gel, respectively. Furthermore, if the first metal precursor solution contains the inorganic oxide, the solution containing the inorganic oxide precursor may be provided in the form of a sol or a gel.

[0038] In one embodiment of this application, the metal precursors contained in the first metal precursor solution and the second metal precursor solution are not particularly limited and may be ammonium salts, nitrates, carbonates, chlorides, sulfates, hydroxides, organic acid salts, oxides, or mixtures thereof of the metal element. In one embodiment of this application, the first metal precursor solution and the second metal precursor solution may each independently further contain a solvent, the solvent may be a solvent well known in the art, and is not particularly limited.

[0039] In the method for producing a methane reforming catalyst according to one embodiment of this application, the details regarding the porous metal support, the perovskite compound represented by chemical formula 1, and the perovskite compound represented by chemical formula 2 are as described above.

[0040] A method for producing a methane reforming catalyst according to one embodiment of the present application includes the steps of: coating a porous metal support with the first coating solution and then performing a first heat treatment step to produce a catalyst precursor having a first coating layer; and coating the catalyst precursor having the first coating layer with the second coating solution and then performing a second heat treatment step to produce a catalyst having a second coating layer.

[0041] The coating method for the first and second coating liquids may be any method well known in the art, such as dip-coating or wash-coating, but is not limited to these.

[0042] The first and second heat treatment steps may each independently include drying and firing steps. The drying may be carried out at a temperature of 50°C to 150°C for 1 to 48 hours, or at a temperature of 60°C to 100°C for 5 to 36 hours, but is not limited thereto. The firing may be carried out in an air atmosphere at a temperature of 350°C to 1,200°C for 1 to 10 hours, or at a temperature of 500°C to 1,000°C for 1.5 to 8 hours, but is not limited to these. If the firing step is below 350°C, the perovskite phase may not form smoothly, and if it exceeds 1,200°C, the durability of the porous metal support may decrease, which is undesirable.

[0043] In one embodiment of this application, the process may further include measuring the weight of the catalyst supported on the porous metal support after the second heat treatment step. By measuring the weight of the catalyst supported on the porous metal support, the process of coating with the second coating solution described above and then performing the second heat treatment step can be repeated 1 to 10 times until a desired amount of catalyst is supported on the porous metal support.

[0044] The description of the methane reforming catalyst relating to this application is applicable to a method for producing a methane reforming catalyst according to one embodiment of this application, and vice versa. [Examples]

[0045] The present application will be described in detail below with reference to examples. However, the examples relating to this application can be modified into various other forms, and the scope of this application should not be construed as being limited to the examples described below. The examples relating to this application are provided to give a more complete explanation of this application to a person of average knowledge in the industry.

[0046] Examples <Example 1> 1) Perovskite compounds (Sr 0.92 Y 0.08 Preparation of the first coating solution containing a TiO3 precursor Perovskite compounds (Sr 0.92 Y 0.08 A solution containing a precursor of TiO3 was prepared by a known citric acid method, and then strontium nitrate (Sr(NO3)3H2O) was dissolved in distilled water together with citric acid and ethylene lycolic acid (distilled water-based solution). In addition, titanium isopropoxide (Ti(OCH(CH3)2)4) was dissolved in ethanol (ethanol-based solution). Next, the two solutions were mixed at 70°C, stirred for 3 hours, and then cooled to room temperature before storage. At this time, the pH was 0.3. Next, urea was added to the mixture, and the pH was adjusted to a range of pH 1 to pH 5 to prepare the first coating solution.

[0047] 2) Perovskite compounds (SrTi 0.97 Ni 0.03 O 3-δ Preparation of a second coating solution containing a precursor (0 < δ < 1) Perovskite compounds (SrTi 0.97 Ni 0.03 O 3-δ A solution containing the precursor of ) was prepared by a known citric acid method, and then strontium nitrate (Sr(NO3)3H2O) and nickel nitrate (Ni(NO3)2) were dissolved in distilled water together with citric acid and ethylene lycolic acid (distilled water-based solution). In addition, titanium isopropoxide (Ti(OCH(CH3)2)4) was dissolved in ethanol (ethanol-based solution). Next, the two solutions were mixed at 70°C, stirred for 3 hours, cooled to room temperature, and then stored. At this time, Ni was present in a concentration of 3 mol% relative to Ti.

[0048] 3) Production of catalysts for methane reforming After dipping a porous metal support (NiCrAl, average pore size: 1,200 μm) with the first coating solution (forming the first coating layer), it was dried at 70°C for 24 hours, and then heat-treated at 300°C to 900°C in an air atmosphere for 3 hours. Subsequently, the porous metal support on which the first coating layer was formed was dipped in the second coating solution (formation of the second coating layer), dried at 70°C for 24 hours, and then heat-treated at 300°C to 900°C in an air atmosphere for 3 hours. The dipping, drying, and heat-treatment of the second coating solution was repeated several times until the first coating layer (Sr) was finally formed on the porous metal support. 0.92 Y 0.08 TiO3) and the second coating layer (SrTi 0.97 Ni 0.03 O 3-δ A catalyst was manufactured in which 0 < δ < 1 was provided. The first coating layer (Sr 0.92 Y 0.08The content of TiO3 is 6% by weight based on the total weight of the methane reforming catalyst, and the perovskite compound (SrTi represented by chemical formula 2) is 6% by weight. 0.97 Ni 0.03 O 3-δ The content of (0 < δ < 1) was 7% by weight based on the total weight of the methane reforming catalyst.

[0049] <Examples 2-7 and Comparative Examples 1-6> Except for the perovskite compounds applied to the first and second coating solutions in Example 1 being changed as shown in Table 1 below, the method for producing the methane reforming catalyst is the same as in Example 1.

[0050] [Table 1]

[0051] Although no instrument exists to measure the exact value of δ, Ni is substituted and has a real value contained within the lattice (where δ is greater than 0 but less than 1).

[0052] Experimental example <Experimental Example 1> Evaluation of the dry reforming reaction of methane A stationary bed reaction system was introduced to carry out the dry reforming reaction of methane with the catalysts of Examples 1-7 and Comparative Examples 1-6. A quartz tube reactor (internal diameter = 1 / 2 inch, length = 50 cm) was packed with the catalysts (approximately 2 g) of each example and comparative example. First, a reduction process was carried out at 800°C for 1-2 hours under 10% H2 / N2 conditions, followed by a catalytic reaction for 28 hours.

[0053] Gas composition: CH4:CO2:N2 = 1:1.12:0.1 Flow rate: GHSV (Gas Hour Space Velocity) = 900hr-1 (CH4 standard) Reaction temperature: 850℃ Reaction pressure: 6 bar The composition of the produced gas was analyzed using gas chromatography (GC), and the reaction conversion rate after 100 hours of reaction was calculated and shown in Table 2 below. Conversion rate (Xi, %) = [(Fiin - Fiout) / Fiin] × 100 (Fi = flow rate of i)

[0054] <GC analysis conditions> 1) GC model: Agilent6890 2) Oven temperature: 40°C / 7min - 90°C / 5min - 180°C / 6min 3) Detector: TCD, 250°C 4) Sample loop: 0.25 mL 5) Valve box temperature: 150°C The coke generation rate was also calculated using the following formula 1. The resulting values are shown in Table 2 below. [Formula 1] Coke % = (weight of the catalyst after reaction - weight of the initial catalyst) / (weight of the catalyst after reaction)

[0055]

Table 2

[0056] In Table 2 above, H2 / CO means the molar ratio of H2 and CO in the synthesis gas. According to Table 2, in Examples 1 to 7 and Comparative Examples 1 to 6, the conversion rates were all at excellent levels. However, it can be confirmed that under the same H2 / CO conditions, the coke generation rate (%) after the reaction in Examples 1 to 7 was significantly lower than that in Comparative Examples !to 6.

[0057] <Experimental Example 2> Evaluation of substitution energy During the production of the catalyst, as the substances used in the first coating solution, Sr under the condition of not performing pH change treatment 0.92 Y 0.08 TiO3, Sr 0.99 Y 0.01 TiO3, or Sr 0.9 Y 0.1The density functional theory (DFT) for Ni or Cr substitution in TiO3 (see Examples 1-7) and SrTiO3 (see Comparative Examples 1-6) was calculated to determine the substitution energy. Ni(Cr) substitution energy in SrTiO3 structure = E[SrTi 1-x Ni x O3]-E[SrTiO3]+1-x E[Ti]-x E[Ni(Cr)] Sr 0.92 Y 0.08 Ni(Cr) substitution energy in TiO3 structure = E[Sr 0.92 Y 0.08 Ti 1-x Ni x O3]-E[Sr 0.92 Y 0.08 [TiO3]+1-x E[Ti]-x E[Ni(Cr)] Sr 0.99 Y 0.01 Ni(Cr) substitution energy in TiO3 structure = E[Sr 0.99 Y 0.1 Ti 1-x Ni x O3]-E[Sr 0.99 Y 0.01 [TiO3]+1-x E[Ti]-x E[Ni(Cr)] Sr 0.9 Y 0.1 Ni(Cr) substitution energy in TiO3 structure = E[Sr 0.9 Y 0.01 Ti 1-x Ni x O3]-E[Sr 0.9 Y 0.1 [TiO3]+1-x E[Ti]-x E[Ni(Cr)]

[0058] According to Figure 1, the SrTiO3 structure corresponding to the comparative example (indicated as STO) is different from the SrTiO3 structure corresponding to the example. 0.92 Y 0.08 TiO3, Sr 0.99 Y 0.01 TiO3, or Sr 0.9 Y 0.1We confirmed that the TiO3 structure (represented by SYTO) requires less energy for Ni or Cr to be substituted at the Ti position. From this, we can see that Sr 0.92 Y 0.08 TiO3, Sr 0.99 Y 0.01 TiO3, or Sr 0.9 Y 0.1 In the case of structures satisfying chemical formula 1, such as TiO3, substitution of Ni or Cr is readily available, making them even more suitable for buffer layers where Ni or Cr, due to the porous metal support, can be substituted and retained before affecting the main catalyst layer.

[0059] <Experimental Example 3> Evaluation of Catalytic Reactivity To evaluate catalytic reactivity, TPR (Temperature Programmed Reduction) experiments were performed on the catalysts of Example 2 and Comparative Example 1. The experimental conditions were as follows: Device name: Belcat II (Manufacturer: Microtrac) Reaction gas: 3% H2 / Ar, 800℃ (5℃ / min) To ensure the analysis was conducted under identical surface oxidation conditions, the data obtained from analyzing the initial TPR and the TPR after O2 oxidation treatment are shown in Figure 2 as (2)TPR. According to Figure 2, the dotted line corresponding to "ref." represents a powder sample that was dried and calcined without being coated with the second coating solution containing the perovskite compound corresponding to [Chemical Formula 2] mentioned above.

[0060] For reference, in Example 2 and Comparative Example 1, in order to make the surface condition similar to that of ref., the catalyst was physically removed with a hammer to detach the coating portion, and then the catalyst was sampled in powder form and analyzed. The results are shown in Figure 2, and the evaluation results of hydrogen consumption (i.e., the ICP-OES analysis results of the desorption catalyst) are shown in Table 3 below.

[0061] [Table 3]

[0062] In Figure 2, the area of ​​each peak represents the amount of hydrogen consumed for the reduction of oxides. Compared to the ref. powder catalyst not coated on the porous metal support, hydrogen consumption increased in both Example 2 and Comparative Example 1, but in Example 2, hydrogen consumption decreased by 44% compared to Comparative Example 1. In particular, the peak around 300-500°C in Figure 2 represents the reduction of NiO and Cr6+, indicating that in the case of Comparative Example 1, the influence of Ni or Cr due to the porous metal support was more significant.

[0063] Furthermore, as can be seen from the ICP-OES results in Table 3, the Ti / Ni ratio in the main catalyst solution was 0.95 / 0.03. In Comparative Example 1, the Ni and Cr content increased significantly compared to the added solution, while in Example 2, relatively low levels were detected, and Ni remained at a 3 mol% level. In particular, an increase in the proportion of Ni on the main catalyst makes it difficult to achieve the desired reactivity. Moreover, if the Ni content is excessive, it can sinter at high temperatures, forming large Ni particles and leading to the disadvantage of being vulnerable to coke formation. Similarly, as shown in Figure 1, Cr substituted better than Ni, so it may interfere with Ni substitution or substitute for Ni, forming large Ni particles and potentially making it vulnerable to coke formation.

Claims

1. porous metal support; A first coating layer provided on the porous metal support and comprising a perovskite compound represented by the following chemical formula 1; and A second coating layer is provided on the first coating layer and contains a perovskite compound represented by the following chemical formula 2. Methane reforming catalysts, including: [Chemical formula 1] Mr. １－ａ A ａ Uncle ３ [Chemical formula 2] Sr １－ｘ A ｘ Three １－ｙ B ｙ Oh ３－δ In the aforementioned chemical formulas 1 and 2, A is selected from Y, Sc, La, and lanthanide elements. B is Ni, Co, Fe, Mn, Cr, Mo, Ru, or Rh. a is a real number greater than 0 and less than 1. x is a real number between 0 and 1 (exclusive of 1). y is a real number greater than 0 and less than 1. δ is a real number greater than 0 and less than 1.

2. The catalyst for methane reforming according to claim 1, wherein the porous metal support is NiFeCrAl or a metal foam containing NiCrAl.

3. Steam reforming process, carbon dioxide reforming process (CO ２ reforming), catalytic partial oxidation process, autothermal reforming process, tri-reforming process, or mixed reforming process, the methane reforming catalyst according to claim 1, which is applicable thereto.

4. The catalyst for methane reforming according to claim 1, wherein the porosity of the porous metal support is 10% or more and 99% or less.

5. The methane reforming catalyst according to claim 1, wherein the average pore size (cell size) of the porous metal support is 400 μm to 2,000 μm.

6. The methane reforming catalyst according to claim 1, wherein the content of the perovskite compound represented by chemical formula 1 is 1% by weight or more and 10% by weight or less, based on the total weight of the porous metal support.

7. The methane reforming catalyst according to claim 1, wherein the content of the perovskite compound represented by chemical formula 2 is 3% by weight or more and 40% by weight or less, based on the total weight of the methane reforming catalyst.

8. A first coating step in which a porous metal support is coated with a first coating solution to form a first coating layer; and The second coating step involves coating the first coating layer with a second coating solution to form a second coating layer. Includes, The first coating layer contains a compound represented by the following chemical formula 1, The second coating layer contains a compound represented by the following chemical formula 2, and is used to produce a catalyst for methane reforming: [Chemical formula 1] Mr. １－ａ A ａ Uncle ３ [Chemical formula 2] Sr １－ｘ A ｘ Three １－ｙ B ｙ Oh ３－δ In the aforementioned chemical formulas 1 and 2, A is selected from Y, Sc, La, and lanthanide elements. B is Ni, Co, Fe, Mn, Cr, Mo, Ru, or Rh. a is a real number greater than 0 and less than 1. x is a real number between 0 and 1 (exclusive of 1). y is a real number greater than 0 and less than 1. δ is a real number greater than 0 and less than 1.

9. The step further includes preparing the first coating solution, The step of preparing the first coating solution is: Solution preparation step for producing a first metal precursor solution containing a strontium (Sr) precursor and a titanium (Ti) precursor; and A method for producing a methane reforming catalyst according to claim 8, comprising a pH adjustment step of adjusting the pH of the first metal precursor solution to pH 1 to pH 5.

10. The method for producing a methane reforming catalyst according to claim 9, wherein the pH adjustment step is to add urea to the first metal precursor solution.

11. The method for producing a methane reforming catalyst according to claim 8, wherein the porous metal support is NiFeCrAl or a metal foam containing NiCrAl.

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