Catalyst for methane reforming and method for manufacturing the same

Abstract

A catalyst for reforming of methane according to one example embodiment of the present application comprises: a porous metal support; a first coating layer provided on the porous metal support and containing an inorganic oxide; and a second coating layer provided on the first coating layer and containing a perovskite compound represented by Chemical Formula 2.

Description

TECHNICAL FIELD

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2021-0159454, filed on November 18, 2021, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to a catalyst for reforming of methane and a method for manufacturing the same. BACKGROUND

[0003] The carbon dioxide reforming reaction, which is one of carbon dioxide conversion technologies, is a technology of obtaining synthesis gas composed of hydrogen and carbon monoxide by reacting methane with carbon dioxide.

[0004] Synthesis gas is a material having a high development value from a variety of downstream raw materials. As a method of obtaining synthesis gas (H2 / CO) in industry, reforming reactions of natural gas can be mainly classified into a steam reforming process, a carbon dioxide (CO2) reforming process, a catalytic partial oxidation process, an autothermal reforming process, a triple reforming process, etc., as Reaction Scheme 1 to Reaction Scheme 5 below.

[0005] [Reaction Scheme 1]

[0006] CH4+ H2O → 3H2+ CO ΔH = 226 kJ / mol

[0007] [Reaction Scheme 2]

[0008] CH4+ CO2→ 2H2+ 2CO ΔH = 261 kJ / mol

[0009] [Reaction Scheme 3]

[0010] CH4+ 0.5O2→ 2H2+ CO ΔH = -44 kJ / mol

[0011] [Reaction Scheme 4]

[0012] Autothermal reforming: Reaction Scheme 1 + Reaction Scheme 3

[0013] [Reaction Scheme 5]

[0014] Triple reforming: Reaction Scheme 1 + Reaction Scheme 2 + Reaction Scheme 3

[0015] Meanwhile, various catalysts can be used for reforming activity in a reforming process. Among them, when a noble metal catalyst is used in a reforming process, there is an advantage that natural gas is efficiently converted into hydrogen, but there is a problem that economic feasibility is reduced due to the high price of the noble metal catalyst.

[0016] Therefore, a nickel catalyst having a high hydrogen conversion efficiency and being relatively inexpensive is generally used in the reforming process. However, in this case, there is a problem in that the nickel catalyst is deactivated by carbon inevitably generated on the surface of the nickel catalyst.

[0017] Therefore, there is a need in the art to develop a catalyst which is resistant to carbon deposition and can be effectively applied to a methane reforming process. SUMMARY

[0018] TECHNICAL PROBLEM

[0019] The present application is directed to providing a catalyst for methane reforming and a method of preparing the same.

[0020] TECHNICAL SOLUTION

[0021] One exemplary embodiment of the present application provides a catalyst for methane reforming, comprising:

[0022] a porous metal support;

[0023] a first coating layer disposed on the porous metal support and comprising an inorganic oxide; and

[0024] a second coating layer disposed on the first coating layer and comprising a perovskite compound represented by the following Chemical Formula 2.

[0025] [Chemical Formula 2]

[0026] Sr 1-x A x Ti α B y O 3-δ

[0027] In Chemical Formula 2,

[0028] A is selected from Y, Sc, La, and lanthanoids,

[0029] B is Ni, Co, Fe, Mn, Cr, Mo, Ru, or Rh,

[0030] x is a real number of 0 or more and less than 1,

[0031] y is a real number of 0 or more and less than 0.3,

[0032] δ is a real number of 0 or more and less than 1,

[0033] α is a real number of more than 0.7 and 1 or less, and

[0034] (x+y) > 0 is satisfied.

[0035] Further, another exemplary embodiment of the present application provides a method of manufacturing a catalyst for methane reforming, the method comprising:

[0036] each of a first solution including an inorganic oxide or an inorganic oxide precursor; and a second solution including a precursor of a perovskite compound represented by Chemical Formula 2;

[0037] manufacturing a catalyst precursor having a first coating layer by coating a porous metal support with the first solution, and then performing a first heat treatment process; and

[0038] manufacturing a catalyst having a second coating layer by coating the catalyst precursor having the first coating layer with the second solution, and then performing a second heat treatment process.

[0039] Advantages

[0040] The catalyst for methane reforming according to one exemplary embodiment of the present application can not only improve the adhesion between the porous metal support and the second coating layer including the perovskite compound represented by Chemical Formula 2, but also prevent side reactions of the porous metal support by forming an inorganic oxide; or a first coating layer including an inorganic oxide and a perovskite compound represented by the following Chemical Formula 1.

[0041] Further, the catalyst for methane reforming according to one exemplary embodiment of the present application is characterized in that, since the perovskite compound is loaded on the porous metal support having high thermal conductivity, the reaction heat is easily controlled compared to the pellet-type or powder-type catalysts in the related art.

[0042] Further, the catalyst for methane reforming according to one exemplary embodiment of the present application is characterized in that, since there is a synergistic effect between the coated inorganic oxide and the perovskite compound represented by Chemical Formula 2, the activity can be additionally improved.

[0043] Further, the catalyst for methane reforming according to one exemplary embodiment of the present application can exhibit high activity even at a high space velocity during the reforming reaction of methane because the active surface area of the catalyst can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 is a view showing a set of electron microscope photographs of a surface of a catalyst for methane reforming according to Example 1 of the present application.

[0045] Figure 2 is a view showing the results of SEM-EDS scanning analysis of a catalyst for methane reforming according to Example 17 of the present application. DETAILED DESCRIPTION

[0046] Hereinafter, the present specification will be described in more detail.

[0047] In the present specification, when a member is "provided on" another member, this includes not only a case where the one member is in contact with the other member, but also a case where another member is present between the two members.

[0048] In the present specification, when a member "comprises" a constituent element, unless explicitly described otherwise, this does not mean that another constituent element is excluded, but means that another constituent element can be further included.

[0049] Currently, in the case of a catalyst widely used in the field of reformers, roughly speaking, a powder type catalyst and a pellet type carrier catalyst are generally used. Although the powder type catalyst can have excellent performance due to excellent dispersibility of the catalyst, it is difficult to directly use the powder type catalyst in industry. For example, when a powder type catalyst is used to drive a reformer, the catalyst exits together with materials produced after the reaction, in which case, the catalyst in powder form gradually accumulates in a flow pipe at an outlet portion, and eventually, a phenomenon in which the entire pipe is blocked can occur. Therefore, there is a disadvantage in that the powder type catalyst cannot be used in a commercial reformer that cannot be used in industry.

[0050] Further, the pellet type carrier catalyst is currently commonly used in industrial reformers. Due to a limitation in the rate of mass transfer, only in terms of catalyst performance, the performance is deteriorated compared to the powder type catalyst, but an advantage is that the pellet type carrier catalyst can be used for a long time due to the use of a carrier. However, the structural strength of γ-Al2O3 pellets generally used as the pellet type carrier catalyst is weak, and thus can be easily broken, and thus there is a disadvantage in that a pressure difference is generated in a reactor. Further, due to the characteristics of the pellet type carrier catalyst, the volume thereof is large, and when the pellet type carrier catalyst is used in a high-capacity reformer, the volume thereof becomes considerably large. Further, all reforming reactions are sensitive to reaction temperature, but the existing pellet type catalysts all have the following disadvantage: due to a large decrease in thermal conductivity, heat cannot be uniformly distributed in the entire reactor. Further, since the reforming reaction is very fast, in the case of a pellet type carrier or an extruded catalyst, the effective factor of the catalyst is 0.3 or less, so that there is an advantage in that the utility of the catalyst is deteriorated.

[0051] Accordingly, the present application intends to alleviate a phenomenon in which a flow pipe is blocked, which is a disadvantage of a powder type, and to improve the rate of heat and mass transfer, which is a common disadvantage of both powder and pellet types, by a method of coating a porous metal carrier catalyst having high rates of heat and mass transfer with a catalyst. Further, the present application intends to provide a catalyst for methane reforming, which is capable of loading a large amount of catalyst at one time and suppressing a side reaction caused by a binder.

[0052] The catalyst for reforming of methane according to one example embodiment of the present application comprises: a porous metal support; a first coating layer provided on the porous metal support and comprising an inorganic oxide; and a second coating layer provided on the first coating layer and comprising a perovskite compound represented by Chemical Formula 2.

[0053] In one example embodiment of the present application, the first coating layer can further comprise a perovskite compound represented by the following Chemical Formula 1.

[0054] [Chemical Formula 1]

[0055] SrTiO3

[0056] In one example embodiment of the present application, the perovskite compound represented by Chemical Formula 1 is a catalyst component-free compound, the perovskite compound represented by Chemical Formula 2 is a catalyst component-containing compound (A and / or B of Chemical Formula 2), and these are different from each other.

[0057] In one example embodiment of the present application, Chemical Formula 2 can be represented by the following Chemical Formula 3 or Chemical Formula 4.

[0058] [Chemical Formula 3]

[0059] SrTi α B y O 3-δ

[0060] [Chemical Formula 4]

[0061] Sr 1-x Y x Ti α B y O 3-δ

[0062] In Chemical Formula 3 and Chemical Formula 4,

[0063] B is Ni or Ru,

[0064] x is a real number greater than 0 and less than 1,

[0065] y is a real number greater than 0 and less than 0.3,

[0066] δ is a real number greater than 0 and less than 1,

[0067] α is a real number greater than 0.7 and 1 or less.

[0068] In one example embodiment of the present application, the porous metal support can be composed of a material capable of maintaining thermal stability at a high temperature of 800°C or more.

[0069] In one exemplary embodiment of the present application, the porous metal support can be a metal foam comprising NiFeCrAl, NiCrAl, SiC, or a-Al203.

[0070] The porous metal support is a support having various shapes, has a small heat capacity and excellent heat transfer ability, and thus can be shaped into a desired shape for use. The form, size, etc. of the porous metal support are not particularly limited, and the porous metal support can have a porosity of 10% to 99%, 50% to 96%, and 85% to 96%. The porous metal support can have an average pore size (pore chamber size) of 400 μm to 2,000 μm, and 450 μm to 1,500 μm. When the porous metal support has an average pore size of less than 400 μm, it can be difficult to coat the porous metal support with a precursor solution, and when the porous metal support has an average pore size of more than 2,000 μm, the surface area on which a catalyst can be coated is reduced, and thus the average pore size range is not preferred because the range can be disadvantageous in the process. The porous metal support can be suitably manufactured by those skilled in the art using methods known in the art in consideration of the material, pore size, porosity, etc. of the porous metal support. According to one exemplary embodiment of the present application, the porous metal support having various materials, pore sizes, etc. can be applied as in the following examples.

[0071] In one exemplary embodiment of the present application, the inorganic oxide can comprise one or more of Ti02, Si02, Zr02, and Al203. Further, the case where the inorganic oxide comprises Al203 can be disadvantageous in terms of coke generation because more scattered spots can be generated in the temperature range of the following heat treatment process compared to the case where the inorganic oxide comprises other inorganic oxides, and thus it is more preferable that the inorganic oxide comprises one or more of Ti02, Si02, and Zr02.

[0072] In one exemplary embodiment of the present application, the first coating layer can comprise the inorganic oxide alone, and can also comprise both the perovskite compound represented by Chemical Formula 1 and the inorganic oxide.

[0073] In one exemplary embodiment of the present application, the total content of the perovskite compound represented by Chemical Formula 1 and the inorganic oxide can be 1 to 20 wt%, and 1.5 to 18 wt% based on the total weight of the porous metal support. When the total content of the perovskite compound represented by Chemical Formula 1 and the inorganic oxide exceeds 20 wt%, the remaining capacity to coat the perovskite compound represented by Chemical Formula 2 can decrease, and thus the aforementioned total weight range is not preferred because the activity of the catalyst can decrease compared to the volume of the porous metal support. In addition, when the total content of the perovskite compound represented by Chemical Formula 1 and the inorganic oxide is less than 1 wt%, it can be difficult to obtain the effect of the first coating layer due to the small content.

[0074] In one exemplary embodiment of the present application, the weight ratio of the first coating layer to the second coating layer containing the perovskite compound represented by Chemical Formula 2 can be 1:1 to 1:20, and 1:1.1 to 1:15. The weight ratio of the first coating layer to the second coating layer containing the perovskite compound represented by Chemical Formula 2 is not preferred outside the range because the activity of the catalyst can decrease compared to the volume of the porous metal support.

[0075] In one exemplary embodiment of the present application, (α+y) of Chemical Formula 2 can be 1. In addition, in one exemplary embodiment of the present application, (α+y) of Chemical Formula 2 can be a real number greater than 0.90 and less than 1. In Chemical Formula 2, B (e.g., Ni) substitutes for a portion of Ti, and the theoretical stoichiometric ratio of (α+y) is 1, but in the preparation of the perovskite compound represented by Chemical Formula 2, when the Ti content is slightly lower than the theoretical stoichiometric ratio, Ti in Chemical Formula 2 can be more easily substituted by B (e.g., Ni).

[0076] In one exemplary embodiment of the present application, the content of the perovskite compound represented by Chemical Formula 2 can be 3 to 40 wt%, 6 to 35 wt%, and 7 to 30 wt% based on the total weight of the catalyst for methane reforming. When the content of the perovskite compound represented by Chemical Formula 2 is less than 3 wt% based on the total weight of the catalyst for methane reforming, the reactivity can decrease due to the relatively small number of active sites on the surface of the catalyst, and thus the content is not preferred. In addition, when the content of the perovskite compound represented by Chemical Formula 2 exceeds 40 wt%, a relatively large amount of catalyst components are contained compared to the porous metal support, making it difficult to maintain the pore structure, and it can not be easy to adhere the catalyst components to the porous metal support, and thus the actual benefit of the methane reforming reaction can decrease.

[0077] In one exemplary embodiment of the present application, the first coating layer can be provided on the entire surface of the porous metal support.

[0078] In one exemplary embodiment of the present application, at least a portion of the surface of the catalyst for methane reforming can include protrusion shapes. The protrusion shapes can be spherical, elliptical, or a combination thereof, but are not limited thereto.

[0079] In one exemplary embodiment of the present application, the first coating layer including an inorganic oxide can be used to fix the coating layer including the perovskite compound represented by Chemical Formula 2 on the porous metal support. In addition, the coating layer including the perovskite compound represented by Chemical Formula 2 can exist in the form of protrusions on the first coating layer, and thus, by increasing the reaction surface area of the catalyst, the performance of the methane reforming reaction can be improved.

[0080] In addition, according to one exemplary embodiment of the present application, by simultaneously applying the first coating layer including an inorganic oxide and the second coating layer including the perovskite compound represented by Chemical Formula 2, the total content of the catalyst supported on the porous metal support can be increased compared to when the catalyst particles are applied alone. In addition, according to one exemplary embodiment of the present application, the durability and performance of the catalyst can be improved because the phenomenon in which the metal (Ni, Cr, etc.) that is the main component of the porous metal support is exposed to the surface in the form of a metal oxide (NiO, Cr2O3, etc.) under long-term operation conditions at high temperatures (750°C or more) and the proportion of the components or the phase of the catalyst of Chemical Formula 2 is changed can be prevented by applying the first coating layer including an inorganic oxide.

[0081] In one exemplary embodiment of the present application, the catalyst for methane reforming can be applied to a steam reforming process, a carbon dioxide (CO2) reforming process, a catalytic partial oxidation process, an autothermal reforming process, a triple reforming process, or a hybrid reforming process, and the methane reforming process is not particularly limited.

[0082] The method of manufacturing a catalyst for methane reforming according to one exemplary embodiment of the present application includes: preparing each of a first solution including an inorganic oxide or an inorganic oxide precursor, and a second solution including a precursor of a perovskite compound represented by Chemical Formula 2; manufacturing a catalyst precursor having a first coating layer by coating a porous metal support with the first solution and then performing a first heat treatment process; and manufacturing a catalyst having a second coating layer by coating the catalyst precursor having the first coating layer with the second solution and then performing a second heat treatment process.

[0083] In the method of manufacturing a catalyst for methane reforming according to one exemplary embodiment of the present application, the first solution can further include a precursor of a perovskite compound represented by Chemical Formula 1.

[0084] In the method of manufacturing a catalyst for methane reforming according to one exemplary embodiment of the present application, the detailed contents of the porous metal support, the perovskite compound represented by Chemical Formula 1, the inorganic oxide, the perovskite compound represented by Chemical Formula 2, etc. are the same as those described above.

[0085] In particular, the solution containing the precursor of the perovskite compound represented by Chemical Formula 1 and the solution containing the precursor of the perovskite compound represented by Chemical Formula 2 can each be applied in the form of a sol or a gel. In addition, the first solution containing the inorganic oxide can be provided not only in the form of a particle dispersion but also in the form of a sol or a gel of a solution containing a precursor of the inorganic oxide.

[0086] The precursor of the perovskite compound is a precursor of a metal constituting the perovskite compound, and the molar ratio of the metal of the perovskite compound can be adjusted by adjusting the content thereof. In addition, the precursor of the metal is not particularly limited, and an ammonium salt, a nitrate, a carbonate, a chloride, a lactate, a hydroxide, an organic acid salt, an oxide, or a mixture thereof of the metal element can be used in combination.

[0087] The method of manufacturing a catalyst for methane reforming according to one exemplary embodiment of the present application includes each of preparing a first solution containing an inorganic oxide or a precursor of an inorganic oxide; and a second solution containing a precursor of a perovskite compound represented by Chemical Formula 2.

[0088] The first solution and the second solution can each independently further contain a solvent, and as the solvent, a solvent known in the art can be used, and is not particularly limited thereto. In addition, the first solution can further contain an organic dispersant, and as the organic dispersant, an organic dispersant known in the art can be used, and is not particularly limited thereto. In addition, the first solution containing the inorganic oxide can have a pH of 1 to 5, and 1 to 3.

[0089] In addition, the first solution can contain the inorganic oxide, and can further contain a precursor of the inorganic oxide such as a metal salt.

[0090] The method of manufacturing a catalyst for methane reforming according to one exemplary embodiment of the present application includes: manufacturing a catalyst precursor having a first coating layer by coating a porous metal support with the first solution and then performing a first heat treatment process; and manufacturing a catalyst having a second coating layer by coating the catalyst precursor having the first coating layer with the second solution and then performing a second heat treatment process.

[0091] As the coating method of the first solution and the second solution, a method known in the art can be used, and dip coating, wash coating, etc. can be used, but the method is not limited thereto.

[0092] The first heat treatment process and the second heat treatment process can each independently include performing drying and firing. The drying can be performed at a temperature of 50 to 150°C for 1 to 48 hours, and can be performed at a temperature of 60 to 100°C for 5 to 36 hours, but is not limited thereto. Also, the firing can be performed in an air atmosphere at a temperature of 350 to 1,100°C for 1 to 10 hours, and can be performed in an air atmosphere at a temperature of 500 to 1,000°C for 1.5 to 8 hours, but is not limited thereto. When the firing is performed at a temperature less than 350°C, a perovskite phase can not be properly formed. When the firing is performed at a temperature higher than 1,100°C, the durability of the porous metal support can be deteriorated, and thus the temperature is not preferred.

[0093] In one exemplary embodiment according to the present application, the method can further include measuring the weight of the catalyst loaded on the porous metal support after the second heat treatment process. Also, coating the catalyst precursor having the first coating layer with the second solution described above until a desired amount of catalyst is loaded on the porous metal support and then performing the second heat treatment process can be repeated 1 to 10 times until a desired amount of catalyst is loaded on the porous metal support by measuring the weight of the catalyst loaded on the porous metal support.

[0094] The catalyst for the reforming of methane according to one exemplary embodiment of the present application can not only improve the adhesion between the porous metal support and the second coating layer including the perovskite-based compound represented by Chemical Formula 2, but also prevent side reactions of the porous metal support by forming the first coating layer including the inorganic oxide.

[0095] Also, the catalyst for the reforming of methane according to one exemplary embodiment of the present application is characterized in that, since the perovskite-based compound is loaded on the porous metal support having high thermal conductivity, the reaction heat is easily controlled compared to the pellet-type or powder-type catalysts in the related art.

[0096] Also, the catalyst for the reforming of methane according to one exemplary embodiment of the present application is characterized in that, since there is a synergistic effect between the coated inorganic oxide and the perovskite-based compound represented by Chemical Formula 2, the activity can be additionally improved.

[0097] Also, the catalyst for the reforming of methane according to one exemplary embodiment of the present application can exhibit high activity even at a high space velocity during the reforming reaction of methane since the active surface area of the catalyst can be improved.

[0098] Mode for Invention

[0099] In the following, this application will be described in detail with reference to embodiments used to specifically describe this application. However, embodiments of this application can be modified in various ways and should not be construed as limiting the scope of this application to the embodiments described in detail below. Embodiments of this application are provided to provide a more complete explanation of this application to those skilled in the art.

[0100] <Example>

[0101] <Example 1>

[0102] 1) Preparation of the first solution

[0103] A suspension containing 15% by weight of SiO2 was prepared. In this case, the prepared inorganic oxide suspension had a pH of 1 to 3.

[0104] A solution containing a precursor of a perovskite compound (SrTiO3) was prepared by the citrate 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. The mixture was then stirred for 3 hours, cooled to room temperature, and stored. In this case, the solution concentration was 0.1 M.

[0105] A mixed solution containing a perovskite compound (SrTiO3) precursor and an inorganic oxide suspension was prepared.

[0106] 2) Preparation of perovskite compounds (SrTi) represented by chemical formula 2. 0.97 Ni 0.03 O 3-δ The second solution of the precursor (0 < δ < 1)

[0107] Preparation of perovskite compounds (SrTi) via citrate method 0.97 Ni 0.03 O 3-δ The precursor solution was prepared by dissolving strontium nitrate (Sr(NO3)3H2O) and nickel nitrate (Ni(NO3)2) 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. The mixture was then stirred for 3 hours, cooled to room temperature, and stored. In this case, the solution concentration was 0.1 M, and the nickel content relative to titanium was 3 mol%.

[0108] 3) Manufacturing catalysts for methane reforming

[0109] The porous metal carrier (NiCrAl, average pore size: 1,200 μm) was dip-coated with the first solution (forming a first coating), and then dried at 70°C for 24 hours and heat-treated in air at 300°C to 900°C for 3 hours.

[0110] Subsequently, a porous metal carrier in which the first coating is formed (forming the second coating) is dipped into a second solution, and then dried at 70°C for 24 hours, followed by heat treatment in air at 300°C to 900°C for 3 hours. The dip-coating, drying, and heat treatment with the second solution are repeated several times to ultimately produce a structure in which a first coating (SrTiO3+SiO2) and a second coating (SrTiO3+SiO2) are provided on the porous metal carrier. 0.97 Ni 0.03 O 3-δ A catalyst with 0 < δ < 1. Based on the total weight of the catalyst used for methane reforming, the content of the first coating (SrTiO3 + SiO2) is 7% by weight, and the perovskite compound (SrTiO3 + SiO2) represented by chemical formula 2 is used. 0.97 Ni 0.03 O 3-δ The content of (0 < δ < 1) is 20% by weight.

[0111] I am Figure 1 The image shows a set of electron microscope images of the surface of a catalyst for methane reforming according to Example 1 of this application.

[0112] The content of perovskite catalysts represented by chemical formula 1 or chemical formula 2 can be calculated using the following equation 1.

[0113] [Equation 1]

[0114] The content (wt%) of perovskite catalysts represented by chemical formula 1 or chemical formula 2 = (total weight of catalyst - weight of porous metal support) / (total weight of catalyst) × 100

[0115] <Example 2>

[0116] The steps were performed in the same manner as in Example 1, except that nickel nitrate (Ni(NO3)2) was used in the preparation of the second solution based on the metal relative to titanium at an amount of 5 mol%.

[0117] <Example 3>

[0118] The steps were performed in the same manner as in Example 1, except that in the preparation of the second solution, yttrium nitrate (Y(NO3)2) was added in an amount of 12 mol% based on the metal relative to strontium, and nickel nitrate (Ni(NO3)2) was added to make the molar ratio of titanium to nickel 0.80:0.20.

[0119] <Example 4>

[0120] The steps were performed in the same way as in Example 1, except that during the preparation of the second solution yttrium nitrate (Y(N03)2) was added in an amount of 8 mol% based on the metals relative to strontium, and ruthenium chloride (RuCl3) was added instead of nickel nitrate (Ni(N03)2), so that the molar ratio of titanium : ruthenium became 0.80 : 0.15.

[0121] <Example 5>

[0122] The steps were performed in the same way as in Example 1, except that during the preparation of the first solution Zr02was used instead of Si02.

[0123] <Example 6>

[0124] The steps were performed in the same way as in Example 2, except that during the preparation of the first solution Zr02was used instead of Si02.

[0125] <Example 7>

[0126] The steps were performed in the same way as in Example 3, except that during the preparation of the first solution Zr02was used instead of Si02.

[0127] <Example 8>

[0128] The steps were performed in the same way as in Example 4, except that during the preparation of the first solution Zr02was used instead of Si02.

[0129] <Example 9>

[0130] The steps were performed in the same way as in Example 1, except that during the preparation of the first solution Ti02was used instead of Si02.

[0131] <Example 10>

[0132] The steps were performed in the same way as in Example 2, except that during the preparation of the first solution Ti02was used instead of Si02.

[0133] <Example 11>

[0134] The steps were performed in the same way as in Example 3, except that during the preparation of the first solution Ti02was used instead of Si02.

[0135] <Example 12>

[0136] The steps were performed in the same way as in Example 4, except that during the preparation of the first solution Ti02was used instead of Si02.

[0137] <Example 13>

[0138] The steps were performed in the same manner as in Example 3, except that AI2O3 was used instead of SiO2 in the process of preparing the first solution.

[0139] <Example 14>

[0140] The steps were performed in the same manner as in Example 1, except that no perovskite compound (SrTiO3) precursor was included in the process of preparing the first solution and an inorganic oxide suspension was used alone.

[0141] <Example 15>

[0142] The steps were performed in the same manner as in Example 3, except that no perovskite compound (SrTiO3) precursor was included in the process of preparing the first solution and an inorganic oxide suspension was used alone.

[0143] <Example 16>

[0144] The steps were performed in the same manner as in Example 5, except that no perovskite compound (SrTiO3) precursor was included in the process of preparing the first solution and an inorganic oxide suspension was used alone.

[0145] <Example 17>

[0146] The steps were performed in the same manner as in Example 7, except that no perovskite compound (SrTiO3) precursor was included in the process of preparing the first solution and an inorganic oxide suspension was used alone.

[0147] The results of the SEM-EDS scanning analysis of the catalyst for the reforming of methane according to Example 17 are shown below. As shown by the results below, it can be confirmed that the Zr component exists as a coating on the framework surface of the porous metal support and that Sr and Ti, which are the main components of the perovskite compound represented by Chemical Formula 2, exist thereon. Figure 2 Figure 2

[0148] <Example 18>

[0149] The steps were performed in the same manner as in Example 8, except that no perovskite compound (SrTiO3) precursor was included in the process of preparing the first solution and an inorganic oxide suspension was used alone.

[0150] <Example 19>

[0151] The steps were performed in the same manner as in Example 9, except that no perovskite compound (SrTiO3) precursor was included in the process of preparing the first solution and an inorganic oxide suspension was used alone.​​

[0152] <Example 20>

[0153] The steps were performed in the same manner as in Example 11, except that the perovskite compound (SrTiO3) precursor was not included in the process of preparing the first solution and the inorganic oxide suspension was used alone.

[0154] <Example 21>

[0155] The steps were performed in the same manner as in Example 12, except that the perovskite compound (SrTiO3) precursor was not included in the process of preparing the first solution and the inorganic oxide suspension was used alone.

[0156] <Example 22>

[0157] The steps were performed in the same manner as in Example 13, except that the perovskite compound (SrTiO3) precursor was not included in the process of preparing the first solution and the inorganic oxide suspension was used alone.

[0158] <Example 23>

[0159] The steps were performed in the same manner as in Example 15, except that the content of the first coating (SiO2) was adjusted to 1.7% by weight based on the total weight of the catalyst for the reforming of methane.

[0160] <Example 24>

[0161] The steps were performed in the same manner as in Example 15, except that the content of the first coating (SiO2) was adjusted to 13% by weight based on the total weight of the catalyst for the reforming of methane.

[0162] <Example 25>

[0163] The steps were performed in the same manner as in Example 15, except that the content of the first coating (SiO2) was adjusted to 17% by weight based on the total weight of the catalyst for the reforming of methane.

[0164] <Example 26>

[0165] The steps were performed in the same manner as in Example 18, except that ruthenium chloride (RuCl3) was added in the process of preparing the second solution to change the molar ratio of titanium:ruthenium to 0.85:0.15.

[0166] <Example 27>

[0167] The steps were performed in the same manner as in Example 22, except that ruthenium chloride (RuCl3) was added in the process of preparing the second solution to change the molar ratio of titanium:ruthenium to 0.85:0.15.

[0168] <Example 28>

[0169] The steps were carried out in the same manner as in Example 3, except that, as the porous metal carrier, NiFeCrAl (average pore size: 1,200 μm) was used instead of NiCrAl.

[0170] <Example 29>

[0171] The steps were carried out in the same manner as in Example 7, except that, as the porous metal carrier, NiFeCrAl (average pore size: 1,200 μm) was used instead of NiCrAl.

[0172] <Example 30>

[0173] The steps were carried out in the same manner as in Example 11, except that, as the porous metal carrier, NiFeCrAl (average pore size: 1,200 μm) was used instead of NiCrAl.

[0174] <Example 31>

[0175] The steps were carried out in the same manner as in Example 7, except that, as the porous metal carrier, NiCrAl_800 (average pore size: 800 μm) was used instead of NiCrAl.

[0176] <Example 32>

[0177] The steps were carried out in the same manner as in Example 7, except that, as the porous metal carrier, NiCrAl_1500 (average pore size: 1,500 μm) was used instead of NiCrAl.

[0178] <Comparative Example 1>

[0179] A porous metal carrier (NiCrAl, average pore size: 1,200 μm) alone was used as Comparative Example 1.

[0180] <Comparative Example 2>

[0181] The steps were carried out in the same manner as in Example 1, except that coating was carried out with the first solution alone without coating with the second solution.

[0182] <Comparative Example 3>

[0183] The steps were carried out in the same manner as in Example 16, except that the porous metal carrier was coated with the first solution alone without coating the catalyst precursor with the second solution.

[0184] <Comparative Example 4>

[0185] The steps were carried out in the same manner as in Example 16, except that the catalyst precursor was coated with the second solution alone without coating the porous metal support with the first solution.

[0186] <Comparative Example 5>

[0187] The steps were carried out in the same manner as in Example 3, except that the catalyst precursor was coated with the second solution alone without coating the porous metal support with the first solution.

[0188] The configurations of the porous metal support, the first coating layer, and the second coating layer in the examples and comparative examples are shown in Table 1 below.

[0189] [Table 1]

[0190]

[0191]

[0192] <Experimental Example 1> Evaluation of Dry Reforming Reaction of Methane

[0193] A fixed bed reactor system was introduced to perform the dry reforming reaction of methane. A quartz tube reactor (inner diameter = 1 / 2 inch, length = 50 cm) was used, and each of the catalysts of the examples and comparative examples (about 2 g) was packed in the reactor. First, after the catalyst was subjected to a reduction process at 800°C under 10% H2 / N2 conditions for 1 to 2 hours, the catalytic reaction was performed for 100 hours. In order to more clearly compare the difference in activity between the catalysts, the activity characteristics of the catalysts were evaluated at a severe space velocity.

[0194] Gas composition: CH4: CO2: N2 = 1 : 1.2 : 0.96

[0195] Flow rate: gas hourly space velocity (GHSV) = 2,500 h -1 (based on CH4)

[0196] Reaction temperature: 750°C

[0197] Reaction pressure: 1 bar

[0198] The reaction conversion rate after 100 hours of reaction was calculated by analyzing the composition of the gas produced using gas chromatography (GC), and is shown in Table 2 below.

[0199] Conversion rate (Xi, %) = [(Fi 入 - Fi 出 ) / Fi 入 ] x 100 (Fi = flow rate of i)

[0200] <GC analysis conditions>

[0201] 1) GC model: Agilent 6890

[0202] 2) Oven temperature: 40°C / 7min - 90°C / 5min - 180°C / 6min

[0203] 3) Detector: TCD, 250°C

[0204] 4) Sample: 0.25 mL

[0205] 5) Valve box temperature: 150°C

[0206] [Table 2]

[0207]

[0208]

[0209] <Experimental Example 2> Evaluation of dry reforming reaction of methane

[0210] A fixed bed reactor system was introduced to perform the dry reforming reaction of methane. A quartz tube reactor (inner diameter = 1 / 2 inch, length = 50 cm) was used, and each catalyst of the examples and comparative examples (about 2 g) was packed in the reactor. First, after the catalyst was subjected to a reduction process at 800°C for 1 to 2 hours under 10% H2 / N2 conditions, the catalytic reaction was performed for 100 hours.

[0211] Gas composition: CH4: CO2: N2 = 1: 1.2: 0.96

[0212] Flow rate: gas hourly space velocity (GHSV) = 1,500 h -1 (based on CH4)

[0213] Reaction temperature: 800°C

[0214] Reaction pressure: 1 bar

[0215] The reaction conversion rate after 100 hours of reaction was calculated by analyzing the composition of the generated gas using gas chromatography (GC), and is shown in Table 3 below.

[0216] Conversion rate (Xi, %) = [(Fi 入 - Fi 出 ) / Fi 入 ] x 100 (Fi = flow rate of i)

[0217] <GC analysis conditions>

[0218] 1) GC model: Agilent 6890

[0219] 2) Oven temperature: 40°C / 7min - 90°C / 5min - 180°C / 6min

[0220] 3) Detector: TCD, 250°C

[0221] 4) Sample: 0.25 mL

[0222] 5) Valve box temperature: 150°C

[0223] [Table 3]

[0224]

[0225] It can be confirmed from the results of Table 2 and Table 3 that the catalyst for the reforming of methane, which comprises the porous metal support, the first coating layer comprising the inorganic oxide, and the second coating layer comprising the perovskite compound represented by Chemical Formula 2 according to the present application, has excellent CH4conversion rate and CO2conversion rate compared to the comparative example not comprising the configuration.

[0226] Further, it can be confirmed that the ratio of H2 / CO can be improved in the examples of the present application compared to the comparative example. Therefore, it can be confirmed that the side reaction caused by the porous metal support is reduced in the examples of the present application.

[0227] <Experimental Example 3> Evaluation of mixed reforming reaction of methane

[0228] A fixed bed reactor system was introduced to perform the mixed reforming reaction of methane. A quartz tube reactor (inner diameter = 1 / 2 inch, length = 50 cm) was used and packed with the catalyst of Example 17 (about 2 g). First, after the catalyst was subjected to a reduction process at 800°C for 1 to 2 hours under 10% H2 / N2conditions, the catalytic reaction was performed for 100 hours.

[0229] Gas composition: CH4:H2O:CO2= 1:0.8:0.4

[0230] Flow rate: gas hourly space velocity (GHSV) = 1,500 h -1

[0231] Reaction temperature: 800°C

[0232] Reaction pressure: 1 bar

[0233] The reaction conversion rate after 100 hours of reaction was calculated by analyzing the composition of the produced gas using a gas chromatograph (GC), and as a result, the CH4conversion rate was 93%, the CO2conversion rate was 68%, and H2 / CO = 1.9 were obtained.

[0234] Conversion rate (Xi, %) = [(Fi 入 - Fi 出 ) / Fi 入 ] x 100 (Fi = flow rate of i)

[0235] <GC analysis conditions>

[0236] 1) GC model: Agilent 6890

[0237] 2) Furnace temperature: 40°C / 7min - 90°C / 5min ~ 180°C / 6min

[0238] 3) Detector: TCD, 250°C

[0239] 4) Sample: 0.25 mL

[0240] 5) Valve box temperature: 150°C

[0241] As in the foregoing results, the catalyst for methane reforming according to one exemplary embodiment of the present application can not only improve the adhesion between the porous metal support and the second coating layer including the perovskite compound represented by Chemical Formula 2, but also prevent the side reaction of the porous metal support by forming the first coating layer including the inorganic oxide.

[0242] Further, the catalyst for methane reforming according to one exemplary embodiment of the present application is characterized in that, since the perovskite compound is loaded on the porous metal support having high thermal conductivity, the reaction heat is easily controlled compared to the pellet type or powder type catalyst in the prior art.

[0243] Further, the catalyst for methane reforming according to one exemplary embodiment of the present application is characterized in that, since there is a synergistic effect between the coated inorganic oxide and the perovskite compound represented by Chemical Formula 2, the activity can be additionally improved.

[0244] Further, the catalyst for methane reforming according to one exemplary embodiment of the present application can exhibit high activity even at a high space velocity during the reforming reaction of methane since the active surface area of the catalyst can be improved.

Claims

1. A catalyst for methane reforming, comprising: a porous metal support; a first coating layer provided on the porous metal support and containing an inorganic oxide; and a second coating layer provided on the first coating layer and containing a perovskite compound represented by the following Chemical Formula 2, wherein the porous metal support is a metal foam containing NiFeCrAl or NiCrAl, wherein the inorganic oxide contains one or more of TiO2, SiO2, and ZrO2: [Chemical Formula 2] Sr 1-x A x Ti α B y O 3-δ wherein, in Chemical Formula 2, A is selected from Y, Sc, and lanthanoid elements, B is Ni, Co, Fe, Mn, Cr, Mo, Ru, or Rh, x is a real number of 0 or more and less than 1, y is a real number of 0 or more and less than 0.3, δ is a real number of 0 or more and less than 1, α is a real number of more than 0.7 and 1 or less, and x + y > 0 is satisfied.

2. The catalyst for reforming of methane according to claim 1, wherein, the first coating layer further contains a perovskite compound represented by the following Chemical Formula 1: [Chemical Formula 1] SrTiO3.

3. The catalyst for reforming of methane according to claim 1, wherein, Chemical Formula 2 is represented by the following Chemical Formula 3 or Chemical Formula 4: [Chemical Formula 3] SrTi α B y O 3-δ [Chemical Formula 4] Sr 1-x Y x Ti α B y O 3-δ in Chemical Formula 3 and Chemical Formula 4, B is Ni or Ru, x is a real number of more than 0 and less than 1, y is a real number of more than 0 and less than 0.3, δ is a real number of more than 0 and less than 1, α is a real number of more than 0.7 and 1 or less.

4. The catalyst for reforming of methane according to claim 1, wherein, The content of the perovskite compound represented by Chemical Formula 2 is 3 to 40% by weight based on the total weight of the catalyst for methane reforming.

5. The catalyst for reforming of methane according to claim 1, wherein, The catalyst for methane reforming is applied to a steam reforming process, a carbon dioxide reforming process, a catalytic partial oxidation process, an autothermal reforming process, a triple reforming process, or a hybrid reforming process. 6.A method of manufacturing a catalyst for methane reforming, the method comprising: preparing a first solution containing an inorganic oxide or an inorganic oxide precursor, respectively; and a second solution containing a precursor of a perovskite compound represented by the following Chemical Formula 2; manufacturing a catalyst precursor having a first coating layer by coating a porous metal support with the first solution, and then performing a first heat treatment process; and manufacturing a catalyst having a second coating layer by coating the catalyst precursor having the first coating layer with the second solution, and then performing a second heat treatment process, wherein the porous metal support is a metal foam containing NiFeCrAl or NiCrAl, wherein the inorganic oxide contains one or more of TiO2, SiO2, and ZrO2: [Chemical Formula 2] Sr 1-x A x Ti α B y O 3-δ wherein, in Chemical Formula 2, A is selected from Y, Sc, and lanthanoid elements, B is Ni, Co, Fe, Mn, Cr, Mo, Ru, or Rh, x is a real number of 0 or more and less than 1, y is a real number of 0 or more and less than 0.3, δ is a real number of 0 or more and less than 1, α is a real number of more than 0.7 and 1 or less, and x + y > 0 is satisfied.

7. The method of claim 6, wherein, the first solution further contains a precursor of a perovskite compound represented by the following Chemical Formula 1: [Chemical Formula 1] SrTiO3.

8. The method of claim 6, wherein, Chemical Formula 2 is represented by the following Chemical Formula 3 or Chemical Formula 4: [Chemical Formula 3] SrTi α B y O 3-δ [Chemical Formula 4] Sr 1-x Y x Ti α B y O 3-δ In Chemical Formula 3 and Chemical Formula 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, α is a real number greater than 0.7 and 1 or less.

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