Catalyst for methane reforming and method for producing same

Abstract

A methane reforming catalyst according to one embodiment of the present application comprises a porous metal support; and a perovskite-based catalyst component supported on the porous metal support and represented by the above chemical formula 1.

Description

[Technical Field]

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2021-0141052, filed with the Korean Intellectual Property Office on October 21, 2021, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to a catalyst for methane reforming and a method for producing the same. [Background technology]

[0003] As part of efforts to reduce greenhouse gas emissions caused by global warming, much research is underway into carbon dioxide conversion technologies. One of these technologies, the carbon dioxide reforming reaction, is a technique in which methane and carbon dioxide are reacted to produce synthesis gas consisting of hydrogen and carbon monoxide.

[0004] Syngas is a valuable substance for development as a raw material for various downstream processes. Natural gas reforming reactions, which are methods for industrially obtaining syngas (H2 / CO), can be broadly classified into steam reforming, CO2 reforming, catalytic partial oxidation, autothermal reforming, and tri-reforming, as shown in the following reaction equations 1 to 5. [Reaction Scheme 1] CH4+H2O → 3H2+CO △H=226kJ / mol [Reaction Scheme 2] CH4+CO2→ 2H2+2CO △H=261kJ / mol [Reaction Scheme 3] CH4+0.5O2→ 2H2+CO △H=-44kJ / mol [Reaction Scheme 4] Autothermal reforming: Equation 1 + Equation 3 [Reaction Scheme 5] Tri-reforming: Reaction 1 + Reaction 2 + Reaction 3

[0005] Meanwhile, various catalysts can be used in the reforming process for reforming activity. Among them, when a noble metal catalyst is used in the reforming process, it has the advantage of relatively less carbon deposition and higher reaction efficiency compared to a nickel-based catalyst, but the noble metal catalyst is expensive, which reduces economic efficiency.

[0006] For this reason, relatively inexpensive nickel catalysts are mainly used in the reforming process. In particular, a catalyst in which nickel metal is supported on a support such as alumina is widely used as a commercial catalyst. However, in such a case, there is a problem that the nickel catalyst is deactivated by carbon that is inevitably produced on the surface of the nickel catalyst.

[0007] Therefore, there is a need in the art to develop a catalyst that is resistant to carbon deposition and can be effectively applied in methane reforming processes. Summary of the Invention [Problem to be solved by the invention]

[0008] The present application seeks to provide a catalyst for methane reforming and a method for producing the same. [Means for solving the problem]

[0009] One embodiment of the present application is a porous metal support; and A perovskite-based catalyst component supported on the porous metal support and represented by the following chemical formula 1: The present invention provides a catalyst for methane reforming, which comprises: [Chemical formula 1] Sr 1-x A x Ti 1-y B y O 3-δ In the above chemical formula 1, A is Y, La or Ba; B is Ni, Co, Fe, Mn, Cr, Mo, Ru or Rh; x is a real number between 0 and 1, y is a real number greater than 0 and less than 0.5, δ is a real number greater than 0 and less than 1.

[0010] Also, another embodiment of the present application is a porous metal support; and The porous metal support includes a metal oxide catalyst supported on the porous metal support, The present invention provides a catalyst in which the thermal expansion coefficient of the metal oxide catalyst is 84% ​​to 100% of the thermal expansion coefficient of the porous metal support at a temperature of 600°C or higher.

[0011] Also, another embodiment of the present application is preparing a solution containing a precursor of the perovskite-based catalyst component represented by Chemical Formula 1; coating a porous metal support with a solution containing a precursor of the perovskite-based catalyst component; and Drying and baking The present invention provides a method for producing a catalyst for methane reforming, comprising:

[0012] Also, another embodiment of the present application is preparing a metal oxide catalyst precursor solution; coating a porous metal support with a precursor solution of the metal oxide catalyst; and drying and calcining the porous metal support to produce a catalyst in which the metal oxide catalyst is supported on the porous metal support; The present invention provides a method for producing a catalyst, wherein the thermal expansion coefficient of the metal oxide catalyst is 84% ​​to 100% of the thermal expansion coefficient of the porous metal support at a temperature of 600°C or higher. [Effects of the Invention]

[0013] The methane reforming catalyst according to one embodiment of the present application may be formed in the form of perovskite nanoparticles by directly coating the perovskite-based catalyst component represented by Formula 1 on a porous metal support without a separate binder, thereby increasing the active surface area of ​​the methane reforming catalyst.

[0014] In addition, the methane reforming catalyst according to one embodiment of the present application has catalytic components directly supported on a porous metal support having high thermal conductivity, and therefore exhibits good activity even at high space velocities during the methane reforming reaction. It also has the advantage of being able to operate stably for a long period of time without carbon deposition or sintering.

[0015] Furthermore, the catalyst according to one embodiment of the present application has a characteristic that the thermal expansion coefficient of the metal oxide catalyst is 84% ​​to 100% of the thermal expansion coefficient of the porous metal support at temperatures above 600°C, allowing the metal oxide catalyst to be directly supported on the porous metal support without the need for additional additives. Therefore, even in high-temperature hydrocarbon reactions, long-term operation is possible without a decrease in catalyst activity, and stable operation is possible even at high space velocities without coke deposition or sintering of catalyst components. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram showing an electron microscope photograph of the surface of a methane reforming catalyst according to Example 1 of the present application. [Figure 2] FIG. 1 is a diagram showing an electron microscope photograph of a cross section of a methane reforming catalyst according to Example 1 of the present application. [Figure 3] FIG. 1 is a view showing an electron microscope photograph of the surface of a catalyst according to Example 22 of the present application. [Figure 4] FIG. 1 is a view showing an electron microscope photograph of the surface of a catalyst according to Comparative Example 12 of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present specification will be explained in more detail below.

[0018] In this specification, when a member is said to be located "on" another member, this includes not only when the member is in contact with the other member, but also when there is another member between the two members.

[0019] In this specification, when a part is said to "comprise" a certain component, this does not mean that it can further include other components, unless otherwise specified.

[0020] Currently, catalysts widely used in the reformer field are generally powder catalysts and pellet-type support catalysts. Powder catalysts have excellent catalyst dispersion and performance, but are difficult to directly use in industrial applications. For example, when a reformer is operated using a powder catalyst, the catalyst is released along with the materials produced after the reaction. However, the powder catalyst gradually accumulates in the outlet flow tube, eventually clogging the entire tube. Therefore, a drawback is that powder catalysts cannot be used in commercial reformers for industrial use.

[0021] Pellet-type support catalysts are currently widely used in industrial reformers. While their catalytic performance is inferior to that of powder-type catalysts due to mass transfer rate limitations, the use of a support offers the advantage of long-term use. However, γ-Al2O3 pellets, which are commonly used as pellet-type support catalysts, have the disadvantage of being prone to breakage due to weak structural strength, which can lead to differential pressure within the reactor. Furthermore, due to the characteristics of pellet-type support catalysts, their volume is large, making them quite bulky when used in high-capacity reformers. Furthermore, while all reforming reactions are sensitive to reaction temperature, existing pellet-type catalysts have the disadvantage of significantly reduced thermal conductivity, which results in inconsistent heat distribution throughout the reactor.

[0022] Therefore, in this application, we have attempted to improve not only the phenomenon of flow tube clogging, which is a drawback of powder-type catalysts, but also the heat and mass transfer rate, which is a common drawback of both powder and pellet-type catalysts, by coating a catalyst on a porous metal support having a high heat and mass transfer rate.

[0023] Therefore, the present application aims to provide a methane reforming catalyst that can stably maintain high activity for a long period of time.

[0024] A methane reforming catalyst according to one embodiment of the present application comprises a porous metal support; and a perovskite-based catalyst component supported on the porous metal support and represented by the following chemical formula 1: [Chemical formula 1] Sr 1-x A x Ti 1-y B y O 3-δ In the above chemical formula 1, A is Y, La or Ba; B is Ni, Co, Fe, Mn, Cr, Mo, Ru or Rh; x is a real number between 0 and 1, y is a real number greater than 0 and less than 0.5, δ is a real number greater than 0 and less than 1.

[0025] In one embodiment of the present application, the above Chemical Formula 1 can be represented by the following Chemical Formula 2, but is not limited thereto. [Chemical formula 2] SrTi 1-y B y O 3-δ In the above chemical formula 2, B is Ni, Co, Fe, Mn, Cr, Mo, Ru or Rh; y is a real number greater than 0 and less than 0.5, δ is a real number greater than 0 and less than 1.

[0026] In one embodiment of the present application, the above Chemical Formula 1 may be represented by the following Chemical Formula 3 or 4, but is not limited thereto. [Chemical formula 3] SrTi 1-y Ni y O 3-δ [Chemical formula 4] Sr 1-x Y x Ti 1-y Ni y O 3-δ In the above chemical formulas 3 and 4, x is a real number greater than 0 and less than 1, y is a real number greater than 0 and less than 0.5, δ is a real number greater than 0 and less than 1.

[0027] In one embodiment of the present application, the porous metal support may be made of a material that can maintain thermal stability at high temperatures of 800°C or higher.

[0028] In one embodiment of the present application, the porous metal support may be made of one or more selected from NiFeCrAl, NiCrAl, stainless steel, and inconel.

[0029] The porous metal support may have a variety of shapes, has a small heat capacity, and has excellent heat transfer ability, and can be formed into a desired shape for use. The shape and size of the porous metal support are not particularly limited, and the porosity of the porous metal support may be 10% to 99%, preferably 50% to 96%. The average pore size of the porous metal support may be 150 μm to 3,000 μm, 400 μm to 2,000 μm, or 600 μm to 1,700 μm. The porous metal support can be appropriately manufactured by those skilled in the art using methods known in the art, taking into consideration the material, pore size, porosity, and other factors of the porous metal support. According to one embodiment of the present application, porous metal supports having various materials and pore sizes can be used, as described in the examples below.

[0030] In one embodiment of the present application, the content of the perovskite-based catalyst component may be 3 wt% to 40 wt%, 6 wt% to 35 wt%, or 7 wt% to 30 wt% based on the total weight of the methane reforming catalyst. If the content of the perovskite-based catalyst component is less than 3 wt%, the reactivity may be reduced due to the relatively small number of active sites on the catalyst surface, which is undesirable. Furthermore, if the content of the catalyst component exceeds 40 wt%, the catalyst component contains a relatively large amount of catalyst component compared to the porous metal support, making it difficult to maintain the pore structure and to easily bond the catalyst component to the porous metal support, which may reduce the practical benefits of the methane reforming reaction.

[0031] The methane reforming catalyst according to one embodiment of the present application may be formed in the form of perovskite nanoparticles by directly coating the perovskite-based catalyst component represented by Formula 1 on a porous metal support without a separate binder, thereby increasing the active surface area of ​​the methane reforming catalyst.

[0032] In one embodiment of the present application, the methane reforming catalyst may be applied to a steam reforming process, a carbon dioxide 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.

[0033] In addition, in this application, a porous metal support such as a metal foam, which has the mechanical strength of a honeycomb or pellet support, a low apparent density to prevent weight increase, and excellent porosity to reduce pressure loss, is used as a catalyst support to enable application to high-temperature catalytic reactions. Furthermore, to ensure stable introduction of catalyst components into the porous metal support, a metal oxide catalyst having a coefficient of thermal expansion (CTE) similar to that of the porous metal support is supported on the porous metal support.

[0034] A catalyst according to one embodiment of the present application comprises a porous metal support; and a metal oxide catalyst supported on the porous metal support, wherein at a temperature of 600°C or higher, the thermal expansion coefficient of the metal oxide catalyst is 84% ​​to 100% of the thermal expansion coefficient of the porous metal support.

[0035] In the catalyst according to one embodiment of the present application, the porous metal support is as described above.

[0036] In one embodiment of the present application, the thermal expansion coefficient of the metal oxide catalyst at temperatures above 600°C is 84% ​​to 100% of the thermal expansion coefficient of the porous metal support. In particular, the thermal expansion coefficient of the metal oxide catalyst at temperatures between 800°C and 900°C may be 86% to 100% of the thermal expansion coefficient of the porous metal support. If the thermal expansion coefficient of the metal oxide catalyst is less than 84% or more than 100% of the thermal expansion coefficient of the porous metal support, the difference in thermal expansion coefficients between the porous metal support and the metal oxide catalyst may be large, causing the metal oxide catalyst to separate from the porous metal support during cooling / heating. Furthermore, the difference in thermal expansion coefficients between the porous metal support and the metal oxide catalyst may cause cracks to form within the catalyst, which may hinder the catalyst from maintaining a stable structure.

[0037] The thermal expansion coefficient value can be measured using a method known in the art. More specifically, the thermal expansion coefficient value can be measured using a thermal mechanical analyzer (TMA), a dilatometer, etc. A TMA or a dilatometer is an instrument that measures the change in size or volume of a sample as a function of time, temperature, and force.

[0038] As described above, the catalyst according to one embodiment of the present application has a characteristic that the thermal expansion coefficient of the metal oxide catalyst is 84% ​​to 100% of the thermal expansion coefficient of the porous metal support at temperatures of 600°C or higher, allowing the metal oxide catalyst to be directly supported on the porous metal support without the need for additional additives. Therefore, the catalyst may consist of only the porous metal support and the metal oxide catalyst directly supported on the porous metal support, and may not require additional additives.

[0039] In one embodiment of the present application, the metal oxide catalyst can be represented by the following chemical formula 5: [Chemical formula 5] A x B y O 3-δ In the above chemical formula 5, A is one or more selected from Y, La, Ba, and Sr; B is one or more selected from Ni, Co, Fe, Ti, Mn, Cr, Mo, Ru, and Rh; x is a real number greater than 0 and less than or equal to 1, y is a real number greater than 0 and less than or equal to 1, δ is a real number greater than 0 and less than 1.

[0040] In one embodiment of the present application, the above Chemical Formula 5 can be represented by the following Chemical Formula 6, but is not limited thereto. [Chemical formula 6] Sr 1-x’ A' x’ Ti 1-y’ B' y’ O 3-δ In the above chemical formula 6, A' is Y, La or Ba; B' is Ni, Co, Fe, Mn, Cr, Mo, Ru or Rh; x' is a real number between 0 and 1, y' is a real number greater than 0 and less than 0.5, δ is a real number greater than 0 and less than 1.

[0041] In one embodiment of the present application, the above Chemical Formula 5 can be represented by the following Chemical Formula 7, but is not limited thereto. [Chemical formula 7] SrTi 1-y’ B y’ O 3-δ In the above chemical formula 7, B is Ni, Co, Fe, Mn, Cr, Mo, Ru or Rh; y' is a real number greater than 0 and less than 0.5, δ is a real number greater than 0 and less than 1.

[0042] In one embodiment of the present application, the above chemical formula 5 can be represented by the following chemical formula 8 or 9, but is not limited thereto. [Chemical formula 8] SrTi 1-y Ni y O 3-δ [Chemical formula 9] Sr 1-x’ Y x’ Ti 1-y’ Ni y’ O 3-δ In the above chemical formulas 8 and 9, x' is a real number between 0 and 1, y and y' are real numbers greater than 0 and less than 0.5, δ is a real number greater than 0 and less than 1.

[0043] In one embodiment of the present application, the content of the metal oxide catalyst may be 3 wt% to 40 wt%, 6 wt% to 35 wt%, or 7 wt% to 30 wt% based on the total weight of the catalyst. If the content of the metal oxide catalyst is less than 3 wt% based on the total weight of the catalyst, the reactivity may be reduced due to the relatively small number of active sites on the catalyst surface, which is undesirable. Furthermore, if the content of the metal oxide catalyst exceeds 40 wt%, the catalyst contains a relatively large amount of catalytic components compared to the porous metal support, making it difficult to maintain the pore structure and to bond the catalytic components to the porous metal support, which may reduce the practical benefit of hydrocarbon reactions.

[0044] The catalyst according to one embodiment of the present application can be applied to, but is not limited to, hydrocarbon reforming, cracking, oxidation, partial oxidation, or hydrogenation reactions.

[0045] In particular, the catalyst according to one embodiment of the present application may be applied to a methane reforming reaction, and the methane reforming reaction may include steam reforming, carbon dioxide reforming, catalytic partial oxidation, autothermal reforming, tri-reforming, or mixed reforming.

[0046] A method for producing a methane reforming catalyst according to one embodiment of the present application includes the steps of: preparing a solution containing a precursor of a perovskite-based catalyst component represented by Chemical Formula 1 above; coating a porous metal support with the solution containing the precursor of the perovskite-based catalyst component; and drying and calcining the solution.

[0047] In the method for producing a methane reforming catalyst according to one embodiment of the present application, the porous metal support, the perovskite-based catalyst component, etc. are as described above.

[0048] In particular, in the method for preparing a methane reforming catalyst according to one embodiment of the present application, a perovskite-based catalyst component can be directly coated on a porous metal support without a separate binder.

[0049] A method for producing a methane reforming catalyst according to one embodiment of the present application includes the step of preparing a solution containing a precursor of the perovskite-based catalyst component represented by Chemical Formula 1 above.

[0050] The precursor of the perovskite catalyst component is a precursor of a metal constituting the perovskite catalyst component represented by Chemical Formula 1, and its content can be adjusted to control the metal molar ratio of the perovskite catalyst component represented by Chemical Formula 1. In addition, the metal precursor is not particularly limited, and ammonium salts, nitrates, carbonates, chlorides of the metal elements, or a combination thereof can be used.

[0051] A method for preparing a methane reforming catalyst according to one embodiment of the present application includes coating a porous metal support with a solution containing a precursor of the perovskite-based catalyst component. The coating method may be a method known in the art, such as, but not limited to, dip coating or wash coating.

[0052] A method for preparing a methane reforming catalyst according to one embodiment of the present application includes coating a porous metal support with a solution containing a precursor of the perovskite-based catalyst component, followed by drying and calcination. The drying may be performed at a temperature of 50°C to 200°C for 1 hour to 48 hours, or at a temperature of 60°C to 150°C for 5 hours to 36 hours, but is not limited thereto. The calcination may be performed in an air atmosphere at a temperature of 350°C to 1,100°C for 1 hour to 10 hours, or at a temperature of 500°C to 1,000°C for 1.5 hours to 8 hours, but is not limited thereto.

[0053] In one embodiment of the present application, the method may further include a step of measuring the weight of the catalyst supported on the porous metal support after the drying and calcining steps. In addition, by measuring the weight of the catalyst supported on the porous metal support, the steps of coating the porous metal support with a solution containing the precursor of the perovskite catalyst component and drying and calcining may be repeated 1 to 20 times until a desired amount of catalyst is supported on the porous metal support.

[0054] A methane reforming catalyst according to an embodiment of the present application has catalytic components supported on a porous metal support having high thermal conductivity, and therefore exhibits good activity even at high space velocities during a methane reforming reaction. It also has the advantage of being able to operate stably for a long period of time without carbon deposition or sintering.

[0055] Furthermore, a method for producing a catalyst according to one embodiment of the present application includes the steps of preparing a precursor solution of the metal oxide catalyst; coating a porous metal support with the precursor solution of the metal oxide catalyst; and drying and calcining the resulting mixture to produce a catalyst in which the metal oxide catalyst is supported on the porous metal support, wherein the thermal expansion coefficient of the metal oxide catalyst is 84% ​​to 100% of the thermal expansion coefficient of the porous metal support at a temperature of 600°C or higher.

[0056] In the method for producing a catalyst according to one embodiment of the present application, the porous metal support, the metal oxide catalyst, drying, calcination, etc. are the same as those described above.

[0057] In the method for preparing a catalyst according to an embodiment of the present application, the step of coating the porous metal support with the precursor solution of the metal oxide catalyst may be performed by a sol-gel coating process.

[0058] The metal oxide catalyst precursor is a precursor of a metal constituting the metal oxide catalyst, and its content can be adjusted to control the metal molar ratio of the metal oxide catalyst. The metal precursor is not particularly limited, and may be an ammonium salt, nitrate, carbonate, chloride, or a mixture thereof of the metal element. [Example]

[0059] Hereinafter, the present application will be described in detail with reference to examples in order to specifically explain the present application. However, the examples of the present application can be modified in various different forms, and the scope of the present application should not be construed as being limited to the examples detailed below. The examples of the present application are provided to more completely explain the present application to those skilled in the art.

[0060] <Example> Example 1: SrTi 0.97 Ni 0.03 O 3-δ / NiCrAl A solution containing the precursor of the perovskite catalyst component was prepared using the citric acid method. Strontium nitrate (Sr(NO3)3H2O) and nickel nitrate (Ni(NO3)2) were dissolved in distilled water along with citric acid and ethylene glycol. Titanium isopropoxide (Ti(OCH(CH3)2)4) was dissolved in ethanol, and the two solutions were mixed at 70°C. After stirring for 3 hours, the solution was cooled to room temperature and stored. The concentration of the solution was 0.1M, and nickel was contained at 3 mol% relative to titanium.

[0061] The solution containing the precursor of the perovskite catalyst component prepared above was dip-coated onto a porous metal support (NiCrAl, average pore size: 1,200 μm) so that it could be supported, then dried at 150°C for 24 hours, and heat-treated at 900°C in an air atmosphere for 3 hours. This process was repeated several times, and finally, SrTi was coated onto the porous metal support. 0.97 Ni 0.03 O 3-δ A catalyst supporting SrTi (0<δ<1) was prepared. 0.97 Ni 0.03 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0062] An electron microscope photograph of the surface of the methane reforming catalyst according to Example 1 of the present application is shown in Figure 1. Also, an electron microscope photograph of the cross section of the methane reforming catalyst according to Example 1 of the present application is shown in Figure 2.

[0063] The catalyst loading amount can be calculated using the following Equation 1. [Formula 1] Catalyst loading amount (wt%)=(total weight of catalyst−weight of porous metal support) / (total weight of catalyst)×100

[0064] Example 2: SrTi 0.95 Ni 0.05 O 3-δ / NiCrAl The same procedure as in Example 1 was carried out except that the nickel content was increased to 5 mol% relative to the titanium, and SrTi was deposited on the porous metal support. 0.95 Ni 0.05 O 3-δ A catalyst supporting SrTi (0<δ<1) was prepared. 0.95 Ni 0.05 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0065] Example 3: SrTi 0.90 Ni 0.10 O 3-δ / NiCrAl The same procedure as in Example 1 was carried out except that the nickel content was increased to 10 mol% relative to the titanium, and SrTi was deposited on the porous metal support. 0.90 Ni 0.10 O 3-δ A catalyst supporting SrTi (0<δ<1) was prepared. 0.90 Ni 0.10 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0066] Example 4: SrTi 0.85 Ni 0.15 O 3-δ / NiCrAl The same procedure as in Example 1 was carried out except that the nickel content was increased to 15 mol% relative to the titanium, and SrTi was deposited on the porous metal support. 0.85 Ni 0.15 O 3-δ A catalyst supporting SrTi (0<δ<1) was prepared. 0.85 Ni 0.15 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0067] Example 5: SrTi 0.80 Ni 0.20 O 3-δ / NiCrAl The same procedure as in Example 1 was carried out except that the nickel content was increased to 20 mol% relative to the titanium, and SrTi was deposited on the porous metal support. 0.80 Ni 0.20 O 3-δ A catalyst supporting SrTi (0<δ<1) was prepared. 0.80 Ni 0.20 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0068] Example 6: Sr 0.92 Y 0.08 Ti 0.97 Ni 0.03 O 3-δ / NiCrAl The same procedure as in Example 1 was carried out except that 8 mol% of yttrium nitrate (Y(NO3)2) was added to the strontium. 0.92 Y 0.08 Ti 0.97 Ni 0.03 O 3-δ The catalyst was prepared by loading Sr (0<δ<1). 0.92 Y 0.08 Ti 0.97 Ni 0.03 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0069] Example 7: Sr 0.92 Y 0.08 Ti 0.95 Ni 0.05 O 3-δ / NiCrAl The same procedure as in Example 6 was carried out except that the nickel content was increased to 5 mol% relative to the titanium content, and Sr was added to the porous metal support. 0.92 Y 0.08 Ti 0.95 Ni 0.05 O 3-δ The catalyst was prepared by loading Sr (0<δ<1). 0.92 Y 0.08 Ti 0.95 Ni 0.05 O3-δ The amount of (0<δ<1) supported was 10% by weight.

[0070] Example 8: Sr 0.92 Y 0.08 Ti 0.90 Ni 0.10 O 3-δ / NiCrAl The same procedure as in Example 6 was carried out except that the nickel content was increased to 10 mol% relative to the titanium, and Sr was added to the porous metal support. 0.92 Y 0.08 Ti 0.90 Ni 0.10 O 3-δ The catalyst was prepared by loading Sr (0<δ<1) on the total catalyst weight. 0.92 Y 0.08 Ti 0.90 Ni 0.10 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0071] Example 9: Sr 0.92 Y 0.08 Ti 0.85 Ni 0.15 O 3-δ / NiCrAl The same procedure as in Example 6 was carried out except that the nickel content was increased to 15 mol% relative to the titanium, and Sr was added to the porous metal support. 0.92 Y 0.08 Ti 0.85 Ni 0.15 O 3-δ The catalyst was prepared by loading Sr (0<δ<1) on the total catalyst weight. 0.92 Y 0.08 Ti 0.85 Ni 0.15 O 3-δ The amount of (0<δ<1) supported was 10 wt %.

[0072] Example 10: Sr 0.92 Y 0.08 Ti 0.80 Ni 0.20 O 3-δ / NiCrAl The same procedure as in Example 6 was carried out except that the nickel content was increased to 20 mol% relative to the titanium, and Sr was added to the porous metal support. 0.92 Y 0.08 Ti 0.80 Ni 0.20 O 3-δ The catalyst was prepared by loading Sr (0<δ<1). 0.92 Y 0.08 Ti 0.80 Ni 0.20 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0073] Example 11: Sr 0.96 Y 0.04 Ti 0.80 Ni 0.20 O 3-δ / NiCrAl The same procedure as in Example 10 was carried out to deposit Sr on a porous metal support, except that yttrium nitrate (Y(NO3)2) was added at 4 mol% relative to the amount of strontium. 0.96 Y 0.04 Ti 0.80 Ni 0.20 O 3-δ The catalyst was prepared by loading Sr (0<δ<1). 0.96 Y 0.04 Ti 0.80 Ni 0.20 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0074] Example 12: Sr 0.88 Y 0.12 Ti 0.80 Ni 0.20 O 3-δ / NiCrAl The same procedure as in Example 10 was carried out except that the amount of yttrium nitrate (Y(NO3)2) was increased to 12 mol% relative to the amount of strontium, and Sr was deposited on the porous metal support. 0.88 Y 0.12 Ti 0.80 Ni 0.20 O 3-δThe catalyst was prepared by loading Sr (0<δ<1) on the total catalyst weight. 0.88 Y 0.12 Ti 0.80 Ni 0.20 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0075] Example 13: Sr 0.84 Y 0.16 Ti 0.80 Ni 0.20 O 3-δ / NiCrAl The same procedure as in Example 10 was carried out except that the amount of yttrium nitrate (Y(NO3)2) was increased to 16 mol% relative to the amount of strontium, and Sr was deposited on the porous metal support. 0.84 Y 0.16 Ti 0.80 Ni 0.20 O 3-δ The catalyst was prepared by loading Sr (0<δ<1) on the total catalyst weight. 0.84 Y 0.16 Ti 0.80 Ni 0.20 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0076] Example 14: Sr 0.92 Y 0.08 Ti 0.90 Ru 0.10 O 3-δ / NiCrAl The same procedure as in Example 8 was carried out except that ruthenium chloride (RuCl) was used in an amount of 10 mol% relative to titanium instead of nickel nitrate (Ni(NO)). 0.92 Y 0.08 Ti 0.90 Ru 0.10 O 3-δ The catalyst was prepared by loading Sr (0<δ<1) on the total catalyst weight. 0.92 Y 0.08 Ti 0.90 Ru 0.10 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0077] Example 15: Sr 0.92 Y 0.08 Ti 0.85 Ru 0.15 O 3-δ / NiCrAl The same procedure as in Example 14 was carried out to deposit Sr on a porous metal support, except that the amount of ruthenium chloride (RuCl) was increased to 15 mol% relative to titanium. 0.92 Y 0.08 Ti 0.85 Ru 0.15 O 3-δ The catalyst was prepared by loading Sr (0<δ<1) on the total catalyst weight. 0.92 Y 0.08 Ti 0.85 Ru 0.15 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0078] Example 16: Sr 0.92 Y 0.08 Ti 0.80 Ru 0.20 O 3-δ / NiCrAl The same procedure as in Example 14 was carried out to deposit Sr on a porous metal support, except that the amount of ruthenium chloride (RuCl) was increased to 20 mol% relative to titanium. 0.92 Y 0.08 Ti 0.80 Ru 0.20 O 3-δ The catalyst was prepared by loading Sr (0<δ<1) on the total catalyst weight. 0.92 Y 0.08 Ti 0.80 Ru 0.20 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0079] Example 17: Sr 0.92 Y 0.08 Ti 0.80 Ni 0.20 O 3-δ / NiCrAl_800 The same procedure as in Example 10 was carried out except that NiCrAl_800 (average pore size: 800 μm) was used as the porous metal support instead of NiCrAl (average pore size: 1,200 μm). 0.92 Y 0.08 Ti 0.80 Ni 0.20 O 3-δ The catalyst was prepared by loading Sr (0<δ<1) on the total catalyst weight. 0.92 Y 0.08 Ti 0.80 Ni 0.20 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0080] Example 18: Sr 0.92 Y 0.08 Ti 0.80 Ni 0.20 O 3-δ / NiCrAl_1500 The same procedure as in Example 10 was carried out except that NiCrAl_1500 (average pore size: 1,500 μm) was used as the porous metal support instead of NiCrAl (average pore size: 1,200 μm). 0.92 Y 0.08 Ti 0.80 Ni 0.20 O 3-δ The catalyst was prepared by loading Sr (0<δ<1) on the total catalyst weight. 0.92 Y 0.08 Ti 0.80 Ni 0.20 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0081] Example 19: Sr 0.92 Y 0.08 Ti 0.80 Ni 0.20 O 3-δ / NiFeCrAl The same procedure as in Example 10 was carried out except that NiFeCrAl (average pore size: 1,200 μm) was used as the porous metal support instead of NiCrAl (average pore size: 1,200 μm). 0.92 Y 0.08 Ti 0.80 Ni 0.20 O 3-δ The catalyst was prepared by loading Sr (0<δ<1). 0.92 Y 0.08 Ti 0.80 Ni 0.20 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0082] Example 20: Sr 0.92 Y 0.08 Ti 0.80 Ru 0.20 O 3-δ / NiFeCrAl The same procedure as in Example 16 was carried out except that NiFeCrAl (average pore size: 1,200 μm) was used as the porous metal support instead of NiCrAl (average pore size: 1,200 μm). 0.92 Y 0.08 Ti 0.80 Ru 0.20 O 3-δ The catalyst was prepared by loading Sr (0<δ<1). 0.92 Y 0.08 Ti 0.80 Ru 0.20 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0083] <Comparative example 1> SrTi 0.97 Ni 0.03 O 3-δ / Al2O3 The same procedure as in Example 1 was carried out except that Al2O3 was used as the support instead of the porous metal support (NiCrAl). 0.97 Ni 0.03 O 3-δA catalyst supporting SrTi (0<δ<1) was prepared. 0.97 Ni 0.03 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0084] <Comparative example 2> Sr 0.92 Y 0.08 Ti 0.97 Ni 0.03 O 3-δ / Al2O3 The same procedure as in Example 6 was carried out except that Al2O3 was used as the support instead of the porous metal support (NiCrAl). 0.92 Y 0.08 Ti 0.97 Ni 0.03 O 3-δ The catalyst was prepared by loading Sr (0<δ<1). 0.92 Y 0.08 Ti 0.97 Ni 0.03 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0085] <Comparative example 3> SrTi 0.97 Ni 0.03 O 3-δ (powder) Strontium nitrate (Sr(NO3)3H2O) and nickel nitrate (Ni(NO3)2) were dissolved in distilled water with citric acid and ethylene glycol. Titanium isopropoxide (Ti(OCH(CH3)2)4) was dissolved in ethanol, and the two solutions were mixed at 70°C. After stirring for 30 minutes, the temperature was raised to 100°C and stirred for 3 hours. At this time, the concentration of the solution was 0.1M, and the nickel content was 3 mol% relative to the titanium. The temperature was then raised to 150°C and dried for 24 hours. The dried product was heat-treated at 350°C in an air atmosphere for 3 hours, followed by grinding. It was then heat-treated again at 900°C in an air atmosphere for 3 hours. Finally, powder-like SrTi 0.97 Ni 0.03 O 3-δ (0<δ<1) catalyst was prepared.

[0086] <Comparative example 4> Sr 0.92 Y 0.08 Ti 0.97 Ni 0.03 O 3-δ (powder) The same procedure as in Comparative Example 3 was carried out except that yttrium nitrate (Y(NO3)2) was added at 8 mol% relative to strontium, and finally powder-like Sr 0.92 Y 0.08 Ti 0.97 Ni 0.03 O 3-δ (0<δ<1) catalyst was prepared.

[0087] <Comparative Example 5> A porous metal support (NiCrAl, average pore size: 1,200 μm) was used alone as Comparative Example 5.

[0088] <Comparative Example 6> A porous metal support (NiFeCrAl, average pore size: 1,200 μm) was used alone as Comparative Example 6.

[0089] <Comparative Example 7> SrTi 0.97 Ni 0.03 O 3-δ / Al2O3 / NiCrAl A first solution was prepared using an Al2O3 dispersion solution to have 15 wt% Al2O3.

[0090] A solution containing the precursor of the perovskite catalyst component was prepared as in Example 1 and is referred to as the second solution.

[0091] The first solution was applied by dip coating onto a porous metal support (NiCrAl, average pore size: 1,200 μm), followed by drying at 150°C for 24 hours and heat treatment at 900°C for 3 hours in an air atmosphere. The second solution was then applied to the porous metal support carrying the Al2O3 from the first solution by dip coating, followed by drying at 150°C for 24 hours and heat treatment at 900°C for 3 hours in an air atmosphere. This process was repeated several times, finally resulting in the deposition of Al2O3 and SrTi on the porous metal support. 0.97 Ni 0.03 O 3-δ A catalyst supporting SrTi (0<δ<1) was prepared. 0.97 Ni 0.03 O 3-δ The amount of (0<δ<1) supported was 10% by weight.

[0092] <Comparative Example 8> SrTi 0.97 Ni 0.03 O 3-δ / Methyl Cellulose / NiCrAl The same procedure as in Comparative Example 7 was carried out except that methyl cellulose was used instead of Al2O3 when preparing the first solution.

[0093] <Experimental Example 1> Evaluation of methane reforming reaction A fixed-bed reactor was installed to conduct the dry reforming reaction of methane. A quartz tube reactor (internal diameter = 1 / 2 inch, length = 50 cm) was used and packed with each catalyst (approximately 2.5 g) from the Examples and Comparative Examples. First, a reduction process was carried out at 800°C under 10% H2 / N2 conditions for 2 hours, followed by a catalytic reaction for 100 hours.

[0094] Gas composition: CH4:CO2:N2 = 1:1.2:0.96 Flow rate:WHSV(Weight Hour Space Velocity)=30,000h -1 Reaction temperature: 800 °C Reaction pressure: 1 bar The composition of the product gas was analyzed using gas chromatography (GC), and the reaction conversion rate after 100 hours of reaction was calculated and shown in Table 1 below. Conversion rate (Xi, %) = [(Fi in - Fi out ) / Fi in × 100 (Fi = flow rate of i)

[0095] <GC analysis conditions> 1) GC model: Agilent 6890 2) Oven temperature: 40 °C / 7 min - 90 °C / 5 min - 180 °C / 6 min 3) Detector: TCD, 250 °C 4) Sample loop: 0.25 mL 5) Valve box temperature: 150 °C

[0096]

Table 1

[0097] As shown in the above results, when comparing the examples and comparative examples, the catalyst for methane reforming composed of the porous metal support according to the present invention and the perovskite-based catalyst component represented by Chemical Formula 1 has excellent CH4 conversion rate and CO2 conversion rate compared to the conventional catalysts using Al2O3 as a support (Comparative Examples 1-2), the catalysts using the perovskite-based catalyst component alone (Comparative Examples 3-4), and the catalysts using the porous metal support alone (Comparative Examples 5-6). It is considered that the porous metal support is utilized to maximize the active surface, and the perovskite-based catalyst component is supported to minimize carbon deposition.

[0098] In addition, it was confirmed that the CH4 conversion rate and CO2 conversion rate were significantly lower than those of the methane reforming catalyst of the present invention in the case of a catalyst in which a conventional Al2O3 catalyst was additionally supported on a porous metal support (Comparative Example 7) and a catalyst in which a perovskite-based catalyst component was supported on a porous metal support using an organic binder such as methyl cellulose (Comparative Example 8).

[0099] Therefore, the methane reforming catalyst according to one embodiment of the present application may be formed in the form of perovskite nanoparticles by directly coating the perovskite-based catalyst component represented by Chemical Formula 1 on a porous metal support without a separate binder, thereby increasing the active surface area of ​​the methane reforming catalyst.

[0100] In addition, the methane reforming catalyst according to one embodiment of the present application has catalytic components supported on a porous metal support having high thermal conductivity, and therefore exhibits good activity even at high space velocities during the methane reforming reaction. It also has the advantage of being able to operate stably for a long period of time without carbon deposition or sintering.

[0101] Example 21: SrTi 0.97 Ni 0.03 O 3-δ / NiCrAl The precursor solution of the metal oxide catalyst was prepared using the citric acid method (Pechini method). Strontium nitrate (Sr(NO3)3H2O) and nickel nitrate (Ni(NO3)2) were dissolved in distilled water along with citric acid. Titanium isopropoxide (Ti(OCH(CH3)2)4) was dissolved in ethylene glycol, and the two solutions were mixed at 70-90°C. After obtaining a clear solution, it was cooled to room temperature and stored. The concentration of the solution was 0.1M, and the nickel content was 3 mol% relative to the titanium content.

[0102] The metal oxide catalyst precursor solution prepared above was coated onto a porous metal support (NiCrAl, pore size: 1,200 μm) so that it could be supported, and then dried at 70°C for 24 hours and heat-treated at 900°C in an air atmosphere for 3 hours. This process was repeated several times, and finally, SrTi was coated onto the porous metal support. 0.97 Ni 0.03 O 3-δ A catalyst supporting SrTi (0<δ<1) was prepared. 0.97 Ni 0.03 O 3-δ The amount of (0<δ<1) supported was 15 wt %.

[0103] The catalyst loading amount can be calculated using the following Equation 1. [Formula 1] Catalyst loading amount (wt%)=(total weight of catalyst−weight of porous metal support) / (total weight of catalyst)×100

[0104] Example 22: Sr 0.92 Y 0.08 Ti 0.85 Ni 0.15 O 3-δ / NiCrAl The same procedure as in Example 21 was carried out to prepare a porous metal support containing Sr, except that yttrium nitrate (Y(NO3)2) was added at 8 mol% relative to the strontium and the nickel content was increased to 15 mol% relative to the titanium. 0.92 Y 0.08 Ti 0.85 Ni 0.15 O 3-δ The catalyst was prepared by loading Sr (0<δ<1) on the total catalyst weight. 0.92 Y 0.08 Ti 0.85 Ni 0.15 O 3-δ The amount of (0<δ<1) supported was 15 wt %.

[0105] An electron microscope photograph of the surface of the catalyst according to Example 22 is shown in FIG.

[0106] Example 23: Sr0.92 Y 0.08 Ti 0.85 Ru 0.15 O 3-δ / NiCrAl The same procedure as in Example 21 was carried out to prepare a porous metal support containing Sr, except that yttrium nitrate (Y(NO3)2) was added at 8 mol% relative to strontium, and ruthenium chloride (RuCl3) was used at 15 mol% relative to titanium instead of nickel nitrate (Ni(NO3)2). 0.92 Y 0.08 Ti 0.85 Ru 0.15 O 3-δ The catalyst was prepared by loading Sr (0<δ<1). 0.92 Y 0.08 Ti 0.85 Ru 0.15 O 3-δ The amount of (0<δ<1) supported was 15 wt %.

[0107] <Comparative Example 9> SrTi 0.97 Ni 0.03 O 3-δ / Al2O3 The same procedure as in Example 21 was carried out except that Al2O3 was used as the support instead of the porous metal support (NiCrAl, pore size: 1,200 μm). 0.97 Ni 0.03 O 3-δ A catalyst supporting SrTi (0<δ<1) was prepared. 0.97 Ni 0.03 O 3-δ The amount of (0<δ<1) supported was 15 wt %.

[0108] <Comparative Example 10> Sr 0.92 Y 0.08 Ti 0.85 Ni 0.15 O 3-δ / Al2O3 The same procedure as in Example 22 was carried out except that Al2O3 was used as the support instead of the porous metal support (NiCrAl, pore size: 1,200 μm). 0.92 Y0.08 Ti 0.85 Ni 0.15 O 3-δ The catalyst was prepared by loading Sr (0<δ<1). 0.92 Y 0.08 Ti 0.85 Ni 0.15 O 3-δ The amount of (0<δ<1) supported was 15 wt %.

[0109] Comparative Example 11: SrTiO3 / NiCrAl The precursor solution of the metal oxide catalyst was prepared using the citric acid method. Strontium nitrate (Sr(NO3)3H2O) was dissolved in distilled water along with citric acid and ethylene glycol. Titanium isopropoxide (Ti(OCH(CH3)2)4) was dissolved in ethanol, and the two solutions were mixed at 70°C. After stirring for 3 hours, the mixture was cooled to room temperature and stored. The concentration of the solution was 0.1M.

[0110] The precursor solution of the metal oxide catalyst prepared above was coated onto a porous metal support (NiCrAl, pore size: 1,200 μm), dried at 70°C for 24 hours, and then heat-treated at 900°C in air for 3 hours. This process was repeated several times to finally prepare a catalyst in which SrTiO3 was supported on a porous metal support. The amount of SrTiO3 supported was 15 wt% based on the total weight of the catalyst.

[0111] <Comparative Example 12> NiO2 / Al2O3 Nickel nitrate (Ni(NO3)2) was dissolved in distilled water and then NiO2 was supported on the Al2O3 support by the solution drop impregnation method. At this time, the amount of NiO2 supported was 15 wt% based on the total weight of the catalyst.

[0112] An electron microscope photograph of the surface of the catalyst according to Comparative Example 12 is shown in FIG.

[0113] <Comparative Example 13> A porous metal support (NiCrAl, pore size: 1,200 μm) was used alone as Comparative Example 13.

[0114] <Experimental Example 2> Evaluation of thermal expansion coefficient The thermal expansion coefficients of the supports and metal oxide catalysts applied in Examples 21 to 23 and Comparative Examples 9 to 11 were measured and are shown in Table 2 below.

[0115] The thermal expansion coefficient was measured using a TMA device (TA Instrument, Q400) under the conditions of a load of 0.1 N and a N2 flow of 100 ml / min.

[0116] [Table 2]

[0117] <Experimental Example 3> Evaluation of methane reforming reaction A fixed-bed reactor was installed to conduct the dry reforming reaction of methane. A quartz tube reactor (internal diameter = 1 / 2 inch, length = 50 cm) was used and packed with each catalyst (approximately 2.5 g) from the Examples and Comparative Examples. First, a reduction process was carried out at 800°C under 10% H2 / N2 conditions for 2 hours, followed by a catalytic reaction for 100 hours.

[0118] Gas composition: CH4:CO2:N2 = 1:1.12:0.96 Flow rate: GHSV (Gas Hour Space Velocity, CH4 standard) = 1,000hr -1 ~3,150 hours -1 Reaction temperature: 800℃ Reaction pressure: 1 bar The composition of the produced gas was analyzed using gas chromatography (GC), and the reaction conversion rate after 24 hours of reaction was calculated and shown in Table 3 below. Conversion rate (Xi,%) = [(Fi in -Fi out ) / Fi in ] x 100 (Fi=flow rate of i)

[0119] <GC analysis conditions> 1) GC model: Agilent 6890 2) Oven temperature: 40°C / 7 min - 90°C / 5 min - 180°C / 6 min 3) Detector: TCD, 250°C 4) Sample loop: 0.25 mL 5) Valve box temperature: 150°C

[0120]

Table 3

[0121] As described above, it can be confirmed that the catalyst according to an embodiment of the present application has excellent methane conversion rate and CO2 conversion rate during the reforming reaction of methane.

[0122] The catalyst according to an embodiment of the present application has the characteristic that at a temperature of 600°C or higher, the thermal expansion coefficient value of the metal oxide catalyst is 84% - 100% of the thermal expansion coefficient value of the porous metal support, so that the metal oxide catalyst can be directly supported on the porous metal support without a separate additive.

[0123] Therefore, according to an embodiment of the present application, it is possible to operate for a long time without a decrease in the activity of the catalyst even in a high-temperature hydrocarbon reaction, and it is possible to operate stably without coke deposition or sintering of the catalyst components even at a high space velocity.

Claims

1. a porous metal support; and The perovskite-based catalyst component supported on the porous metal support A catalyst for methane reforming comprising: The perovskite-based catalyst component is as shown in Table 1 below: Table 1 (In the table, δ is a real number greater than 0 and less than 1.) and The porous metal support is made of one or more materials selected from the group consisting of NiFeCrAl, NiCrAl, stainless steel, and inconel, and is a catalyst for methane reforming that is applicable to a carbon dioxide reforming process.

2. 2. The methane reforming catalyst according to claim 1, wherein the content of the perovskite-based catalyst component is 3 wt % to 40 wt % based on the total weight of the methane reforming catalyst.

3. A step of preparing a solution containing a precursor of a perovskite-based catalyst component; coating a porous metal support with a solution containing a precursor of the perovskite-based catalyst component; and Drying and baking Including, The perovskite-based catalyst component is as shown in Table 1 below: Table 2 (In the table, δ is a real number greater than 0 and less than 1.) and The porous metal support is made of one or more selected from NiFeCrAl, NiCrAl, stainless steel, and inconel, and is applied to a carbon dioxide reforming process.

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