Catalyst and preparation method therefor

Abstract

The present invention relates to a catalyst and a catalyst preparation method.

Description

Catalyst and method of manufacturing the same

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0123868 dated September 11, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0003] The present invention relates to a catalyst and a method for manufacturing a catalyst.

[0004] Extensive research on carbon dioxide conversion technologies is currently underway as part of efforts to reduce greenhouse gas emissions caused by global warming. One such carbon dioxide conversion technology is the carbon dioxide reforming reaction, which produces synthesis gas composed of hydrogen and carbon monoxide by reacting methane with carbon dioxide.

[0005] Syngas is a material with high development value as a raw material for various downstream processes. As a method to industrially obtain synthesis gas (H2 / CO), natural gas reforming reactions can be broadly classified into steam reforming, CO2 reforming, catalytic partial oxidation, autothermal reforming, and tri-reforming, as shown in reaction equations 1 to 5 below.

[0006] [Reaction Equation 1]

[0007] CH4+ H2O → 3H2+ CO ΔH = 226 kJ / mol

[0008] [Reaction Equation 2]

[0009] CH4+ CO2→ 2H2+ 2CO ΔH = 261 kJ / mol

[0010] [Reaction Equation 3]

[0011] CH4+ 0.5O2→ 2H2+ CO ΔH = -44 kJ / mol

[0012] [Reaction Equation 4]

[0013] autothermal reforming: Equation 1 + Equation 3

[0014] [Reaction Equation 5]

[0015] tri-reforming: Equation 1 + Equation 2 + Equation 3

[0016] Meanwhile, various catalysts can be used in the aforementioned reforming process to enhance reforming activity. Among these, precious metal catalysts offer high reaction efficiency but are very expensive, which limits their use. For this reason, nickel catalysts, which are relatively inexpensive, are primarily used; however, when applied to the methane reforming process, nickel catalysts suffer from reduced activity due to carbon deposition that inevitably occurs on the catalyst surface. Therefore, there is a need in this technical field for the development of catalysts that can be applied to the methane reforming process while possessing high resistance to carbon deposition.

[0017] One objective of the present invention is to provide a perovskite-based catalyst having high resistance to carbon deposition, which can be used as a catalyst in a methane reforming process.

[0018] However, the technical problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below.

[0019] The present invention relates to a catalyst comprising a porous metal support and perovskite-based catalyst particles, wherein

[0020] The above catalyst particles are at 161 cm⁻¹ of the Raman spectrum. -1 to 203 cm -1 Provides a catalyst having an asymmetry parameter (q) of 2.8 or less measured in the band of the region.

[0021] The present invention provides a catalyst having an asymmetry parameter of 1.5 to 2.6.

[0022] The present invention provides a catalyst in which the catalyst is a catalyst for methane reforming.

[0023] In addition, the present invention provides a catalyst for methane reforming that is 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.

[0024] The present invention provides a catalyst in which the porous metal support comprises one or more materials selected from NiFeCrAl, NiCrAl, stainless steel, and Inconel.

[0025] The present invention provides a catalyst in which, based on the total weight of the catalyst, the content of the perovskite-based catalyst particles is 3% to 40% by weight.

[0026] The present invention provides a catalyst in which the perovskite-based catalyst particles are represented by the following chemical formula 2.

[0027] [Chemical Formula 2]

[0028] Sr 1-x Y x Ti 1-y Ni y O 3-δ

[0029] In the above chemical formula 2,

[0030] x is a real number greater than or equal to 0.02 and less than 1, and

[0031] y is a real number greater than or equal to 0.02 and less than 1, and

[0032] δ is a real number greater than 0 and less than 1.

[0033] In addition, the present invention relates to the perovskite-based catalyst particles, wherein Sr 0.9 Y 0.1 Ti 0.97 Ni 0.03 O 3-δ , Sr 0.88 Y 0.12 Ti 0.95 Ni 0.05 O 3-δ , Sr 0.86 Y 0.14 Ti 0.9 Ni 0.1 O 3-δ and Sr 0.96 Y 0.04 Ti 0.97 Ni 0.03 O 3-δ Provides a catalyst that is one or more selected from the group consisting of

[0034] The present invention provides a catalyst in which the amount of coke generated by the following formula 3 is 7 weight% or less:

[0035] [Equation 3]

[0036] Cokes content (wt %) = (Weight of catalyst after reaction / Weight of catalyst before reaction) × 100 (wt %)

[0037] The reaction of Equation 3 above is

[0038] In the presence of the above catalyst, with a gas composition of CH4:CO2:N2 = 1:1.2:0.96 and a Weight Hour Space Velocity (WHSV) of 30,000 h -1 It refers to a methane dry reforming reaction carried out for 100 hours under conditions of flow rate, reaction temperature of 800 ℃ and reaction pressure of 5 bar.

[0039] The catalyst according to the present invention can have excellent activity when applied to a methane reforming reaction, and performance degradation due to carbon deposition or sintering is suppressed, so that the catalyst can maintain an excellent conversion rate even when used for a long time in a high-temperature environment.

[0040] Figures 1 and 2 are figures related to the Raman spectrum and asymmetry parameters of an example.

[0041] Unless otherwise defined in this specification, all technical and scientific terms are used merely to describe exemplary embodiments and are not intended to limit the invention. The singular form includes the plural form unless the context clearly indicates otherwise.

[0042] In this specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Specifically, in this specification, terms such as "comprising," "having," or "having" are intended to specify the existence of the implemented features, numbers, steps, components, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0043] In this specification, 'a to b' means a or more and b or less.

[0044] In this specification, 'a, b, c or d' means a, or b, or c, or d.

[0045] In this specification, element symbols are described based on the periodic table.

[0046] The present invention is described in detail below so that those skilled in the art can easily implement it. However, the present invention may be embodied in various different forms and is not limited to the configurations described herein.

[0047] According to one embodiment of the present invention, a catalyst comprising a porous metal support and perovskite-based catalyst particles, wherein the catalyst particles have a Raman spectrum at 161 cm⁻¹ -1 to 203 cm -1 It is characterized by the fact that the asymmetry parameter (q) measured in the band of the region is 2.8 or less.

[0048] In this specification, the "Asymmetry Parameter (q)" is an indicator representing the asymmetry of Raman peaks and reflects internal stress of the catalyst material, polar regions within the crystal structure, defects or deformation of the crystal structure, so the physical and chemical state of the catalyst can be confirmed through the asymmetry parameter.

[0049] As a result of diligent efforts, the inventors of the present invention have found that the 161 cm⁻¹ Raman spectrum of the perovskite-based catalyst provided in the present invention -1 to 203 cm -1 It was discovered that there is a correlation between the asymmetric parameter in the band of the region and the carbon modification mechanism of the catalyst, and furthermore, it was discovered that in catalysts where the asymmetric parameter is 2.8 or less, coke deposition and sintering phenomena are significantly suppressed, thereby completing the present invention.

[0050] More specifically, coke is generated when CO2 decomposition is not efficient in the carbon reforming mechanism, and polar regions surrounding the perovskite can influence this CO2 decomposition. Meanwhile, the asymmetry parameter is a value that reflects the presence of polar regions around the perovskite structure; the more polar regions there are, the smaller the parameter value becomes. Raman spectrum for the perovskite-based catalyst at 161 cm⁻¹ -1 to 203 cm -1If the asymmetric parameter in the band of the region exceeds 2.8, there is a lack of polar domains within the perovskite structure, so when such a catalyst is applied to a methane reforming reaction, CO2 decomposition is insufficient, and excessive carbon may be deposited on the surface of the catalyst.

[0051] Accordingly, the carbon deposition-reduced perovskite-based catalyst provided by the present invention may have an asymmetry parameter of 2.8 or less, 2.7 or less, or 2.6 or less in the band of the said region. Although the lower limit is not specifically restricted, as the asymmetry parameter approaches 1, there is a greater presence of polar domains, which can increase the degree of CO2 decomposition; therefore, the asymmetry parameter may preferably be 0.9 or more, 1 or more, 1.5 or more, or 2 or more. More specifically, it may be 0.9 to 2.8, 0.9 to 2.7, 0.9 to 2.6, 1 to 2.8, 1 to 2.7, 1 to 2.6, 1.5 to 2.8, 1.5 to 2.7, 1.5 to 2.6, 2 to 2.8, 2 to 2.7, or 2 to 2.6.

[0052] The above asymmetry parameter can be measured according to the following method:

[0053] 1 g of powdered perovskite catalyst was placed into a sampling holder for Raman analysis, and the surface was flattened with a slide glass. Using a Raman spectrometer (Manufacturer: Nanophoton, Model: Raman Touch), a laser with a wavelength of 532 nm was irradiated onto three arbitrary points within a 410 μm × 100 μm measurement area of ​​the sample, and the scattered light was collected to acquire the Raman spectrum. In the obtained Raman spectrum, 161 cm⁻¹ -1to 203 cm -1 Asymmetry parameters (q) can be obtained by performing asymmetry parameter fitting on the region band. In this case, asymmetry parameter fitting can be performed using the OriginPro program, but is not limited to this, and other programs capable of asymmetry parameter fitting can also be used.

[0054] In addition, in the case of a Raman spectrometer, if it is possible to obtain a Raman spectrum by irradiating with a laser of wavelength 532 nm and collecting the scattered light, a Raman spectrometer from another manufacturer may also be used.

[0055] At this time, the above-mentioned asymmetry parameter fitting can be performed through the following Equations 1 and 2.

[0056] [Equation 1]

[0057]

[0058] [Equation 2]

[0059]

[0060] In the above Equations 1 and 2, q is an asymmetry parameter, I(E) is the relative intensity of scattered light measured by a Raman spectrum (unit: au), E is the Raman shift value of scattered light measured by a Raman spectrum, and E F ε is the resonant energy of the perovskite catalyst particle, and Γ represents the spectral width of the Raman spectrum.

[0061] Meanwhile, in the present invention, the Raman analysis is performed after delaminating the perovskite-based catalyst particles coated on a porous metal support and preparing the perovskite-based catalyst in powder form. The perovskite-based catalyst particles used for the Raman analysis can be prepared through the following process:

[0062] Specifically, the method of preparing a perovskite-based catalyst in powder form after delaminating catalyst particles may involve applying vibration to each catalyst to separate the catalyst supported on a porous metal support, and using a sieve to remove foreign matter and separate the delaminated catalyst (component) in powder form.

[0063] The above perovskite-based catalyst particles may include one or more of Sr, Y, Ti, Ni, and Cr, and more specifically, may include Sr, Ti, and Ni, and optionally may further include one or more of Y and Cr. In addition, the above perovskite-based catalyst particles include O.

[0064] That is, the above perovskite-based catalyst particles may include (1) Sr, Ti, Ni, and O, (2) Sr, Ti, Ni, Y, and O, or (3) Sr, Ti, Ni, Y, Cr, and O, but are not limited thereto.

[0065] In the present invention, the perovskite-based catalyst particles can be represented by the following chemical formula 1.

[0066] [Chemical Formula 1]

[0067] Sr 1-x A x Ti 1-y B y O 3-δ

[0068] In the above chemical formula 1,

[0069] A is Y, La, or Ba, and

[0070] B is Ni, Co, Fe, Mn, Cr, Mo, Ru, or Rh, and

[0071] x is a real number greater than or equal to 0 and less than 1, and

[0072] y is a real number greater than 0 and less than 1, and

[0073] δ is a real number greater than 0 and less than 1.

[0074] As an example, the perovskite-based catalyst may be represented by the chemical formula 1 above, and the asymmetry parameter may be 2.8 or less, but is not limited thereto.

[0075] In one embodiment of the present invention, the above chemical formula 1 may be represented by the following chemical formula 2.

[0076] [Chemical Formula 2]

[0077] Sr 1-x Y x Ti 1-y Ni y O 3-δ

[0078] In the above chemical formula 2,

[0079] x is a real number greater than or equal to 0.02 and less than 1, and

[0080] y is a real number greater than or equal to 0.02 and less than 1, and

[0081] δ is a real number greater than 0 and less than 1.

[0082] More preferably, in the above formula 2, x is 0.02 or more and 0.15 or less, y is 0.02 or more and 0.1 or less, and x + y is 0.2 or less.

[0083] In the present invention, the perovskite-based catalyst particles are Sr 0.9 Y 0.1 Ti 0.97 Ni 0.03 O 3-δ , Sr 0.88 Y 0.12 Ti 0.95 Ni 0.05 O 3-δ , Sr 0.86Y 0.14 Ti 0.9 Ni 0.1 O 3-δ and Sr 0.96 Y 0.04 Ti 0.97 Ni 0.03 O 3-δ It can be 1 or more selected from the group consisting of.

[0084] The catalyst of the present invention has a structure in which the perovskite-based catalyst particles are located on the surface and internal pores of a porous metal support, and can have a high active surface area of ​​the catalyst.

[0085] The porous metal support may be in the form of a metal foam containing multiple pores. Since the porous metal support has a low heat capacity and excellent heat transfer ability, it can be manufactured into various desired shapes through molding, and the specific shape and size are not particularly limited.

[0086] The above porous metal support may include one or more selected from NiFeCrAl, NiCrAl, stainless steel, and Inconel, but is not limited thereto.

[0087] The porosity of the porous metal support may be 10% to 99%, and preferably 50% to 96%. In addition, the average pore size of the porous metal support may be 150㎛ to 3,000㎛, 400㎛ to 2,000㎛, or 600㎛ to 1,700㎛, but is not limited thereto. The porous metal support can be appropriately manufactured by a person skilled in the art using methods known in the art, taking into account the material, pore size, porosity, etc. of the porous metal support described above.

[0088] Based on the total weight of the catalyst, the perovskite-based catalyst particles may be included in an amount of 3% to 40% by weight, 6% to 35% by weight, or 7% to 30% by weight. If the content of the perovskite-based catalyst particles is less than 3% by weight, it is undesirable because the reactivity may decrease due to the relatively small number of active sites on the catalyst surface. In addition, if the content of the catalyst particles exceeds 40% by weight, a relatively large amount of catalyst particles is contained relative to the porous metal support, making it difficult to maintain the pore structure and making it difficult for the catalyst particles to bond with the porous metal support, which may result in a reduced benefit from the methane reforming reaction.

[0089] A catalyst according to one embodiment of the present invention can be formed in the form of perovskite nanoparticles by directly coating perovskite-based catalyst particles onto a porous metal support without a separate binder.

[0090] The catalyst according to the present invention may be a catalyst for methane reforming. The methane reforming reaction may be 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, but is not limited thereto.

[0091] The catalyst of the present invention may have a coke generation amount calculated by Formula 3 below of 7% by weight or less, or 6.5% by weight or less.

[0092] [Equation 3]

[0093] Cokes content (wt %) = (Weight of catalyst after reaction / Weight of catalyst before reaction) × 100 (wt %)

[0094] That is, Equation 3 above is a formula for calculating the amount of cokes produced, and the reaction of Equation 3 is carried out in the presence of the catalyst, with a gas composition of CH4:CO2:N2 = 1:1.2:0.96 and a Weight Hour Space Velocity (WHSV) of 30,000 h -1 It refers to a methane dry reforming reaction carried out for 100 hours under conditions of flow rate, reaction temperature of 800 ℃ and reaction pressure of 5 bar.

[0095] That is, as described above, the catalyst according to the present invention is characterized by having a low amount of carbon deposition when used in a methane reforming process.

[0096] The catalyst provided in the present invention can be manufactured by a method comprising the steps of: preparing a solution containing a precursor of perovskite-based catalyst particles; coating a porous metal support with the solution containing the precursor of the perovskite-based catalyst particles; and calcining the porous metal support. Each step is described below. However, the specific manufacturing processes or examples described herein are not intended to limit the catalyst to any specific type or method of manufacturing thereof. This specification may include any catalyst formed by any associated manufacturing method known to a person skilled in the art.

[0097] The perovskite-based catalyst particles of the present invention can be manufactured using the citric acid method, the Pechini method, the high-temperature aging method, the polymerization composite method, the freeze-drying method, etc., and preferably, they can be manufactured through the citric acid method. The citric acid method is a method of obtaining a perovskite catalyst by adding citric acid to create an amorphous metal composite in a gel state, and then drying and calcining it.

[0098] The present invention may include the step of preparing a solution containing a precursor of perovskite-based catalyst particles.

[0099] In addition, there are no special limitations on the precursor of the metal, and a combination of ammonium salts, nitrates, carbonates, chlorides, or mixtures thereof of the metal element may be applied.

[0100] More specifically, strontium nitrate (Sr(NO3)3H2O), nickel nitrate (Ni(NO3)2), yttrium nitrate (Y(NO3)2), titanium isopropoxide (Ti(OCH(CH3)2)4), etc. are precursors of metals constituting perovskite-based catalyst particles, and the metal molar ratio of perovskite-based catalyst particles can be controlled by controlling the content thereof.

[0101] The above solution may include citric acid, ethanol, ethylene glycol, distilled water, etc. Through this, an amorphous metal composite in a gel state can be prepared. Once a solution containing a precursor of perovskite-based catalyst particles is prepared as described above, the method may include the step of coating the solution onto a porous metal support.

[0102] At this time, the coating method is not particularly limited, but, for example, dip-coating, wash-coating, etc. may be used. In the present invention, perovskite-based catalyst particles can be directly coated onto a porous metal support without a separate binder.

[0103] In one embodiment of the present invention, the drying and calcining steps are performed after the step of coating the porous metal support with a solution containing a precursor of the perovskite-based catalyst particles, and the drying may be performed at a temperature of 50°C to 200°C for 1 hour to 48 hours and at a temperature of 60°C to 150°C for 5 hours to 36 hours, but is not limited thereto.

[0104] The precursor solution can be prepared in the form of a sol through the above drying process.

[0105] The above calcination involves heat-treating a solution containing a precursor of perovskite-based catalyst particles. This process may be performed at a temperature of 350°C to 1,100°C for 1 to 10 hours under an air atmosphere, or at a temperature of 500°C to 1,000°C for 1 to 8 hours under an air atmosphere, but is not limited thereto. Perovskite-based catalyst particles can be obtained through the above calcination.

[0106] More specifically, the calcination may be performed at a temperature of 850 ℃ to 1,000 ℃ for 1 to 8 hours, and the heat treatment may be performed one or more times. If the heat treatment is performed two or more times, a process of cooling to room temperature may be included between the heat treatments, and in this specification, the heat treatment time refers to the total time for calcination to be performed in the temperature range, excluding the time for cooling to room temperature. In addition, the calcination may be performed in an air atmosphere, and the air flow rate may be 8 L / min or more, preferably 10 L / min or more. The crystal structure of the perovskite catalyst particles is determined through calcination, and the air flow rate is related to whether the calcination can proceed uniformly.

[0107] The catalyst of the present invention is characterized by having perovskite-based catalyst particles having a symmetrical peak shape structure when the polar region is a homogeneous material without defects or stress, supported on a porous support and a porous metal support.

[0108] That is, if the air flow rate is not satisfied during calcination, the calcination occurs unevenly, and as a result, a catalyst is produced in which the asymmetry parameter (q) of the perovskite-based catalyst particles exceeds 2.8. In this case, when methane reforming is carried out using the said catalyst, a problem arises in which the amount of coke generated increases.

[0109] In addition, for one firing, the amount of catalyst may be 200g to 550g, preferably 250g to 500g. When the above range is satisfied, the likelihood of uniform firing increases.

[0110] Since the above drying and calcination conditions affect the crystal structure and air vacancy degree of the perovskite-based catalyst particles, a catalyst satisfying the asymmetric parameter range of the present invention can be manufactured by calcining to satisfy the above conditions.

[0111] In one embodiment of the present invention, the step of measuring the weight of the catalyst supported on the porous metal support after the drying and calcining step may be further included. Additionally, by measuring the weight of the catalyst supported on the porous metal support, the step of coating a solution containing a precursor of the perovskite-based catalyst particles on the porous metal support described above until a desired amount of catalyst is supported on the porous metal support; and the steps of drying and calcining may be repeated 1 to 20 times.

[0112] The description of the method for manufacturing a catalyst according to the present invention may also be applied to the catalyst according to the present invention. The reverse is also true.

[0113] The present invention will be explained in detail below through the following examples. However, the following examples are merely illustrative of the present invention, and the scope of the present invention is not limited by the following examples.

[0114] [Example 1] Sr 0.9 Y 0.1 Ti 0.97 Ni 0.03 O 3-δ / NiCrAl

[0115] A solution containing precursors of perovskite catalyst particles was prepared using the citric acid method. Strontium nitrate (Sr(NO3)3H2O), nickel nitrate (Ni(NO3)2), and yttrium nitrate (Y(NO3)2) were dissolved in distilled water along with citric acid and ethylene glycol. Subsequently, titanium isopropoxide (Ti(OCH(CH3)2)4) was dissolved in ethanol, and the two solutions were mixed at 70°C to prepare 250 L of precursor solution. Afterward, the solution was stirred for 3 hours, cooled to room temperature, and stored.

[0116] A solution containing the precursor of the perovskite catalyst particles prepared above was deposited on a porous metal support (NiCrAl, average pore size: 1,200 μm) by dip coating, and then dried at 150 °C for 24 hours, and heat treatment was carried out for a total of 3 hours, excluding the cooling time at room temperature, under air conditions of 900 °C to 950 °C (flow rate: 10 L / min, catalyst amount: 500 g).

[0117] Specifically, heat treatment was performed once for 1 hour at 900 ℃ in an air atmosphere (flow rate: 10 L / min, catalyst amount: 500 g), followed by cooling to room temperature and then heat treatment once for 1 hour at 950 ℃ in an air atmosphere (flow rate: 15 L / min, catalyst amount: 500 g), and additionally, after cooling to room temperature, heat treatment was performed once for 1 hour at 900 ℃ in an air atmosphere (flow rate: 10 L / min, catalyst amount: 500 g) (a total of 3 times).

[0118] This process is repeated several times to finally apply Sr to the porous metal support. 0.9 Y 0.1 Ti 0.97 Ni 0.03 O 3-δ A catalyst supported with (0 < δ < 1) was prepared.

[0119] In addition, during the manufacturing process, the concentration of the precursor solution was 0.2 M, and Sr, Y, Ti, and Ni in the precursor solution were Sr 0.9 Y 0.1 Ti0.97 Ni 0.03 satisfied the ratio of.

[0120] [Example 2] Sr 0.88 Y 0.12 Ti 0.95 Ni 0.05 O 3-δ / NiFeCrAl

[0121] In the catalyst preparation method of Example 1, Sr, Y, Ti, and Ni in the precursor solution are Sr 0.9 Y 0.1 Ti 0.97 Ni 0.03 Sr instead of the ratio of 0.88 Y 0.12 Ti 0.95 Ni 0.05 A precursor solution satisfying the ratio was prepared, and a step of performing a heat treatment at a temperature of 500°C in an air atmosphere for 3 hours was added prior to performing a heat treatment at a temperature of 900°C to 950°C in an air atmosphere for 3 hours; 250g of catalyst was added during the heat treatment; and NiFeCrAl (average pore size: 1,200㎛) was used instead of NiCrAl (average pore size: 1,200㎛) as the porous metal support. Except for these factors, a catalyst was prepared in the same manner as in Example 1, and finally, Sr was placed on the porous metal support. 0.88 Y 0.12 Ti 0.95 Ni 0.05 O 3-δ A catalyst supported with (0 < δ < 1) was prepared.

[0122] [Example 3] Sr 0.86 Y 0.14 Ti 0.9 Ni 0.1 O 3-δ / NiCrAl

[0123] In the catalyst preparation method of Example 1, Sr, Y, Ti, and Ni in the precursor solution are Sr 0.9 Y 0.1 Ti 0.97 Ni 0.03 Sr instead of the ratio of 0.86 Y0.14 Ti 0.9 Ni 0.1 A precursor solution satisfying the ratio was prepared, and a catalyst was prepared in the same manner as in Example 1, except that drying was performed at 130°C for 35 hours instead of drying at 150°C for 24 hours, and finally, Sr was placed on a porous metal support. 0.86 Y 0.14 Ti 0.9 Ni 0.1 O 3-δ A catalyst supported with (0 < δ < 1) was prepared.

[0124] [Example 4] Sr 0.96 Y 0.04 Ti 0.97 Ni 0.03 O 3-δ / NiFeCrAl

[0125] In the catalyst preparation method of Example 1, Sr, Y, Ti, and Ni in the precursor solution are Sr 0.9 Y 0.1 Ti 0.97 Ni 0.03 Sr instead of the ratio of 0.96 Y 0.04 Ti 0.97 Ni 0.03 A precursor solution satisfying the ratio was prepared, and a catalyst was prepared in the same manner as in Example 1, except that 250 g of catalyst was added during heat treatment and NiFeCrAl (average pore size: 1,200 µm) was used instead of NiCrAl (average pore size: 1,200 µm) as the porous metal support, so that finally, Sr on the porous metal support 0.96 Y 0.04 Ti 0.97 Ni 0.03 A catalyst supported with (0 < δ < 1) was prepared.

[0126] [Comparative Example 1] Sr 0.94 Y 0.06 Ti 0.85 Ni 0.15 O 3-δ / NiCrAl

[0127] In the catalyst preparation method of Example 1, Sr, Y, Ti, and Ni in the precursor solution are Sr 0.9 Y 0.1 Ti 0.97 Ni 0.03 Sr instead of the ratio of 0.94 Y 0.06 Ti 0.85 Ni 0.15 A precursor solution was prepared in the same manner as in Example 1, except that the precursor solution was prepared to satisfy the ratio of . Afterwards, it was stirred for 3 hours, cooled to room temperature, and stored.

[0128] Dip coating was performed so that a solution containing the precursor of the perovskite catalyst particles prepared above could be supported on a porous metal support (NiCrAl, average pore size: 1,200 μm). Then, it was dried at 150°C for 24 hours, followed by one heat treatment at 900°C in an air atmosphere (flow rate: 5 L / min, catalyst amount: 500 g) for 3 hours, and after cooling to room temperature, one heat treatment at 950°C in an air atmosphere (flow rate: 5 L / min, catalyst amount: 500 g) for 3 hours (total of 2 times).

[0129] This process is repeated several times to finally apply Sr to the porous metal support. 0.94 Y 0.06 Ti 0.85 Ni 0.15 O 3-δ A catalyst supported with (0 < δ < 1) was prepared.

[0130] [Comparative Example 2] Sr 0.96 Y 0.04 Ti 0.8 Ni 0.2 O 3-δ / NiFeCrAl

[0131] In the catalyst preparation method of Example 1, Sr, Y, Ti, and Ni in the precursor solution are Sr 0.9 Y 0.1 Ti 0.97 Ni 0.03 Sr instead of the ratio of 0.96 Y 0.04 Ti 0.8Ni 0.2 A precursor solution was prepared in the same manner as in Example 1, except that the precursor solution was prepared to satisfy the ratio of . Afterwards, it was stirred for 3 hours, cooled to room temperature, and stored.

[0132] Dip coating was performed so that a solution containing the precursor of the perovskite catalyst particles prepared above could be supported on a porous metal support (NiFeCrAl, average pore size: 1,200 μm). Then, it was dried at 150 °C for 24 hours, and heat treatment was performed twice at 900 °C in an air atmosphere (flow rate: 5 L / min, catalyst amount: 500 g) for 3 hours (cooling to room temperature after the first heat treatment, followed by the second heat treatment).

[0133] This process is repeated several times to finally apply Sr to the porous metal support. 0.96 Y 0.04 Ti 0.8 Ni 0.2 O 3-δ A catalyst supported with (0 < δ < 1) was prepared.

[0134] [Comparative Example 3] Sr 0.92 Y 0.08 Ti 0.85 Ni 0.15 O 3-δ / NiCrAl

[0135] In the catalyst preparation method of Example 1, Sr, Y, Ti, and Ni in the precursor solution are Sr 0.9 Y 0.1 Ti 0.97 Ni 0.03 Sr instead of the ratio of 0.92 Y 0.08 Ti 0.85 Ni 0.15 A precursor solution was prepared in the same manner as in Example 1, except that the precursor solution was prepared to satisfy the ratio of . Afterwards, it was stirred for 3 hours, cooled to room temperature, and stored.

[0136] Dip coating was performed so that a solution containing the precursor of the perovskite catalyst particles prepared above could be supported on a porous metal support (NiCrAl, average pore size: 1,200 μm). Then, it was dried at 150 °C for 24 hours, heat treated once at 900 °C in an air atmosphere (flow rate: 5 L / min, catalyst amount: 500 g) for 3 hours, and after cooling to room temperature, heat treated once at 900 °C in an air atmosphere (flow rate: 10 L / min, catalyst amount: 500 g) for 3 hours (total of 2 times).

[0137] This process is repeated several times to finally apply Sr to the porous metal support. 0.92 Y 0.08 Ti 0.85 Ni 0.15 O 3-δ A catalyst supported with (0 < δ < 1) was prepared.

[0138] [Comparative Example 4] Sr 0.88 Y 0.12 Ti 0.9 Ni 0.1 O 3-δ / NiFeCrAl

[0139] In the catalyst preparation method of Example 1, Sr, Y, Ti, and Ni in the precursor solution are Sr 0.9 Y 0.1 Ti 0.97 Ni 0.03 Sr instead of the ratio of 0.88 Y 0.12 Ti 0.9 Ni 0.1 A precursor solution was prepared in the same manner as in Example 1, except that the precursor solution was prepared to satisfy the ratio of . Afterwards, it was stirred for 3 hours, cooled to room temperature, and stored.

[0140] Dip coating was performed so that a solution containing the precursor of the perovskite catalyst particles prepared above could be supported on a porous metal support (NiFeCrAl, average pore size: 1,200 μm). Then, it was dried at 150 °C for 24 hours, followed by one heat treatment at 900 °C in an air atmosphere (flow rate: 5 L / min, catalyst amount: 250 g) for 3 hours, and after cooling to room temperature, one heat treatment at 900 °C in an air atmosphere (flow rate: 10 L / min, catalyst amount: 250 g) for 3 hours (total of 2 times).

[0141] This process is repeated several times to finally apply Sr to the porous metal support. 0.88 Y 0.12 Ti 0.9 Ni 0.1 O 3-δ A catalyst supported with (0 < δ < 1) was prepared.

[0142] [Experimental Example 1] - Measurement of Asymmetry Parameter (q)

[0143] The perovskite-based catalyst particles used in the catalyst of Example 1 were prepared in powder form.

[0144] Specifically, vibration was applied to each of the catalysts of Example 1 to separate the catalyst supported on the porous metal support, and foreign matter was removed using a sieve to separate the catalyst into a detached powder form.

[0145] Next, 1g of the perovskite-based catalyst particles of Example 1 in powder form, as in Method 1 above, was subdivided and placed into a sampling holder for Raman analysis, and a sample was prepared by making the surface uniform with a slide glass. Three points were randomly selected from the sample, and at each point, a laser with a wavelength of 532 nm was irradiated onto randomly selected points within a measurement area of ​​410 μm × 100 μm using a Raman spectrometer (Manufacturer: Nanophoton, Model: Raman Touch). The scattered light was collected to obtain the Raman spectrum of the sample as shown in Fig. 1. Subsequently, as shown in Fig. 2, the Raman spectrum was analyzed at 161 cm⁻¹ -1 to 203 cm -1 Asymmetry parameter fitting was performed using the region band to obtain the asymmetry parameter (q).

[0146] The above asymmetry parameter fitting was performed using the following Equations 1 and 2.

[0147] [Equation 1]

[0148]

[0149] [Equation 2]

[0150]

[0151] In the above Equations 1 and 2, q is an asymmetry parameter, I(E) is the relative intensity of scattered light measured by a Raman spectrum (unit: au), E is the Raman shift value of scattered light measured by a Raman spectrum, and E Fε is the resonant energy of the perovskite catalyst particle, and Γ represents the spectral width of the Raman spectrum.

[0152] The results are listed in Table 1 below.

[0153] For the catalysts of Examples 2 to 4 and Comparative Examples 1 to 4, the perovskite-based catalyst particles used in the catalyst were prepared in powder form using the same method as for the catalyst of Example 1, and then the asymmetry parameter (q) was determined using the same method as for the catalyst of Example 1. The asymmetry parameters of the catalysts of Examples 2 to 4 and Comparative Examples 1 to 4 are also listed in Table 1 below.

[0154] [Experimental Example 2] Evaluation of Methane Reforming Reaction

[0155] A fixed-bed reaction system was introduced to carry out the methane dry reforming reaction. A quartz tube reactor (inner diameter = 1 / 2 inch, length = 50 cm) was used and filled with the catalyst of Example 1 (approx. 2.5 g). First, a reduction process was carried out at 800 °C for 2 hours under 10% H2 / N2 conditions, followed by the methane dry reforming reaction for 100 hours.

[0156] Gas composition: CH4: CO2: N2 = 1 : 1.2 : 0.96

[0157] Flow rate: Weight Hour Space Velocity (WHSV) = 30,000 h -1

[0158] Reaction temperature: 800 ℃

[0159] Reaction pressure: 5 bar

[0160] The composition of the generated gas was analyzed using gas chromatography (GC), and the CH4 conversion rate (XCH4) and CO2 conversion rate (XCO2) were calculated after 100 hours of reaction, respectively, and are shown in Table 1 below.

[0161] Conversion Rate (Xi, %) = [(Fi in - Fi out ) / Fi in ] × 100 (Fi = flow rate of i)

[0162] <GC 분석 조건>

[0163] 1) GC model: Agilent 6890

[0164] 2) Oven temp.: 40℃ / 7min-90℃ / 5min-180℃ / 6min

[0165] 3) Detector: TCD, 250 ℃

[0166] 4) Sample loop: 0.25 mL

[0167] 5) Valve box Temp.: 150 ℃

[0168] In addition, after the dry reforming reaction of methane, the content of coke formed on the catalyst surface was measured through TGA analysis. The results are listed in Table 1 below.

[0169] <TGA 분석 조건>

[0170] Analysis Equipment: Mettler Toledo TGA2

[0171] Temperature range: 50 ~ 1000 ℃

[0172] Heating rate: 10 ℃ / min

[0173] Purge gas: Air 50 ml / min

[0174] <Cokes 함량을 구하는 식>

[0175] Cokes content (wt %) = Weight of catalyst after reaction / Weight of catalyst before reaction × 100 (wt %)

[0176] For the catalysts of Examples 2 to 4 and Comparative Examples 1 to 4, the dry reforming reaction of methane was carried out in the same manner as the catalyst of Example 1, and the CH4 conversion rate (XCH4), CO2 conversion rate (XCO2), and coke content were measured and the results are listed in Table 1 below.

[0177] Catalyst Type Asymmetric Parameter (q) CH4 Conversion Rate (%) CO2 Conversion Rate (%) Cokes (wt%) Example 1 1.76 58 28 54.34 Example 2 1.72 78 28 74.16 Example 3 1.96 18 28 64.93 Example 4 2.40 78 28 64.5 Comparative Example 1 3.02 98 38 67.45 Comparative Example 2 3.09 8 38 77.59 Comparative Example 3 3.18 38 28 68.89 Comparative Example 4 3.31 28 38 67.98

[0178] As can be seen from the results in Table 1 above, the catalysts of Examples 1 to 4, which satisfy an asymmetry parameter (q) of 2.8 or less, showed excellent CH4 conversion rate and CO2 conversion rate, while producing significantly less coke than the catalysts of Comparative Examples 1 to 4, which have an asymmetry parameter greater than 2.8.

[0179] In other words, it was confirmed that the catalysts of Examples 1 to 4 can exhibit good activity during the methane reforming reaction and that carbon deposition occurs in small amounts.

[0180] In other words, it was confirmed that the catalyst according to the present invention exhibits excellent effects, such as good activity even at high space velocities during methane reforming reactions and stable operation for a long time without sintering phenomena due to minimal carbon deposition.

Claims

1. A catalyst comprising a porous metal support and perovskite-based catalyst particles, The above catalyst particles are at 161 cm⁻¹ of the Raman spectrum. -1 to 203 cm -1 For which the asymmetry parameter (q) measured in the band of the region is 2.8 or less, catalyst.

2. In Paragraph 1, The above asymmetric parameter is 1.5 to 2.6, catalyst.

3. In Paragraph 1, The above catalyst is a catalyst for methane reforming, catalyst.

4. In Paragraph 3, The above-mentioned methane reforming catalyst is applicable to steam reforming, CO2 reforming, catalytic partial oxidation, autothermal reforming, tri-reforming, or mixed reforming processes. catalyst.

5. In Paragraph 1, The above porous metal support comprises one or more materials selected from NiFeCrAl, NiCrAl, stainless steel, and Inconel. catalyst.

6. In Paragraph 1, Based on the total weight of the catalyst, the content of the perovskite-based catalyst particles is 3% to 40% by weight. catalyst.

7. In Paragraph 1, The above perovskite-based catalyst particles are represented by the following chemical formula 2, catalyst: [Chemical Formula 2] Mr 1-x AND x You 1-y Neither y EITHER 3-δ In the above chemical formula 2, x is a real number greater than or equal to 0.02 and less than 1, and y is a real number greater than or equal to 0.02 and less than 1, and δ is a real number greater than 0 and less than 1.

8. In Paragraph 7, The above perovskite-based catalyst particles are Sr 0.9 Y 0.1 Ti 0.97 Ni 0.03 O 3-δ , Sr 0.88 Y 0.12 Ti 0.95 Ni 0.05 O 3-δ , Sr 0.86 Y 0.14 Ti 0.9 Ni 0.1 O 3-δ and Sr 0.96 Y 0.04 Ti 0.97 Ni 0.03 O 3-δ One or more selected from the group consisting of, catalyst.

9. In Paragraph 1, The above catalyst is The amount of coke generated by Formula 3 below is 7 weight% or less, catalyst: [Equation 3] Cokes content (wt %) = (Weight of catalyst after reaction / Weight of catalyst before reaction) × 100 (wt %) The reaction of Equation 3 above is carried out in the presence of the catalyst, with a gas composition of CH4:CO2:N2 = 1:1.2:0.96 and a Weight Hour Space Velocity (WHSV) of 30,000 h -1 It refers to a dry methane reforming reaction carried out for 100 hours under conditions of flow rate, reaction temperature of 800℃ and reaction pressure of 5 bar.

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