Catalyst for methane reforming and method for preparing the same

Abstract

The catalyst for methane reforming according to the exemplary embodiment of the present application includes: a porous metal support; perovskite catalyst particles supported on the porous metal support; and a perovskite binder supported on the porous metal support, the perovskite catalyst particles and the perovskite binder each independently including a compound represented by Chemical Formula 1.

Description

Technical Field

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2021-0158414 filed in the Korean Intellectual Property Office on November 17, 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 preparing the catalyst. Background Art

[0003] As part of efforts to reduce greenhouse gases that contribute to global warming, extensive research has been conducted on carbon dioxide conversion technologies. One such technology is carbon dioxide reforming, which reacts methane with carbon dioxide to produce synthesis gas consisting of hydrogen and carbon monoxide.

[0004] Synthesis gas (syngas) is a material with high development value derived from a variety of downstream feedstocks. As a method for industrially producing syngas (H2 / CO), natural gas reforming reactions can be broadly categorized into steam reforming, carbon dioxide (CO2) reforming, catalytic partial oxidation, autothermal reforming, and tertiary reforming, as shown in reaction schemes 1 through 5 below.

[0005] [Reaction Scheme 1]

[0006] CH4+H2O→3H2+COΔH=226kJ / mol

[0007] [Reaction Scheme 2]

[0008] CH4+CO2→2H2+2COΔH=261kJ / mol

[0009] [Reaction Scheme 3]

[0010] CH4+0.5O2→2H2+COΔH=-44kJ / mol

[0011] [Reaction Scheme 4]

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

[0013] [Reaction Scheme 5]

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

[0015] Meanwhile, a variety of catalysts can be used in the reforming process to adjust the activity. Among them, when noble metal catalysts are used in the reforming process, there is an advantage of high efficiency in converting biogas into hydrogen, but there is a problem of poor economic feasibility due to the high price of noble metal catalysts.

[0016] Therefore, nickel catalysts, which have high hydrogen conversion efficiency and are relatively inexpensive, are often used in reforming processes. However, in this case, there is a problem that the nickel catalyst is deactivated due to carbon inevitably generated on the surface of the nickel catalyst.

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

[0018] Technical issues

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

[0020] Technical Solution

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

[0022] porous metal support;

[0023] Perovskite catalyst particles supported on the porous metal support; and

[0024] a perovskite-based binder loaded on the porous metal support,

[0025] The perovskite-based catalyst particles and the perovskite-based binder each independently include a compound represented by the following Chemical Formula 1.

[0026] [Chemical Formula 1]

[0027] Sr 1-x A x Ti 1-y B y O 3-δ

[0028] In Chemical Formula 1,

[0029] A is Y, La or Ba,

[0030] B is Ni, Co, Fe, Mn, Cr, Mo, Ru or Rh,

[0031] x is a real number greater than 0 and less than 1,

[0032] y is a real number greater than 0 and less than 0.5,

[0033] δ is a real number greater than 0 and less than 1, and

[0034] Satisfies x+y>0.

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

[0036] preparing a slurry by mixing perovskite catalyst particles and a perovskite catalyst sol;

[0037] impregnating a porous metal support with the slurry; and

[0038] drying and firing the porous metal support,

[0039] The perovskite-based catalyst particles and the perovskite-based catalyst sol each independently contain a compound represented by Chemical Formula 1.

[0040] Beneficial effects

[0041] A catalyst for methane reforming according to an exemplary embodiment of the present application can be prepared by preparing a slurry in which catalyst particles of the same or similar series and a catalyst sol are mixed using an inorganic binder, and coating a metal support having high thermal conductivity with the slurry to increase the content of the catalyst loaded once and suppress side reactions caused by the binder.

[0042] In addition, the catalyst for methane reforming according to an exemplary embodiment of the present application is characterized in that, compared with a particle-type or powder-type catalyst in the related art, reaction heat is easily controlled because the catalyst particles and the binder are supported on a porous metal support having high thermal conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a view showing an electron microscope photograph of the surface of a group of catalysts for methane reforming according to Example 1 of the present application. DETAILED DESCRIPTION

[0044] Hereinafter, this specification will be described in more detail.

[0045] In this specification, when one member is disposed “on” another member, this includes not only a case where one member is in contact with another member but also a case where another member exists between the two members.

[0046] In this specification, when a part “comprises” one constituent element, unless otherwise specifically stated, this does not mean that another constituent element is excluded but means that another constituent element may further be included.

[0047] Recently, in the case of catalysts widely used in the field of reformers, generally speaking, powdered or granular supported catalysts are usually used. Although powdered catalysts can have excellent performance due to the excellent dispersion of the catalyst, it is difficult to directly use powdered catalysts in industry. For example, when a powdered catalyst is used to drive a reformer, the catalyst is discharged together with the substances produced after the reaction. In this case, the catalyst in powder form gradually accumulates in the material flow pipe at the outlet, and eventually, the entire pipe may be blocked. Therefore, there is a disadvantage that powdered catalysts cannot be used in commercial reformers used in industry.

[0048] In addition, particle-type supported catalysts are currently commonly used in industrial reformers. Due to the limitation of mass transfer rate, compared with powdered catalysts, their performance deteriorates only in terms of catalyst performance, but there is an advantage that particle-type supported catalysts can be used for a long time due to the use of a carrier. However, the γ-Al2O3 particles commonly used as particle-type supported catalysts have weak structural strength and may therefore be easily broken, thereby having the disadvantage of generating a pressure difference in the reactor. In addition, since the volume is large due to the characteristics of the particle-type supported catalyst, when the particle-type supported catalyst is used in a large-capacity reformer, its volume becomes quite large. In addition, all reforming reactions are sensitive to reaction temperature, but existing particle-type catalysts have the disadvantage that heat cannot be evenly distributed throughout the reactor due to a significant decrease in thermal conductivity.

[0049] Therefore, the present application aims to reduce the disadvantage of the powder type - the phenomenon of blocking the material flow tube, and improve the common disadvantage of the powder type and particle type - the heat and mass transfer rate by coating a porous metal carrier with high heat and mass transfer rate with a catalyst.

[0050] Porous metal support catalysts can be prepared by coating the surface of a porous metal support with a slurry, the slurry being prepared by mixing a catalyst precursor or catalyst powder with a binder, additives, etc. In order to introduce the catalyst particles to the surface of the porous metal support, an organic binder and / or an inorganic binder can be added and used during the preparation of the slurry. The organic binder remains in the slurry until the drying and firing process, and can help reduce surface tension and stabilize the slurry. The inorganic binder remains between the catalyst particles or between the catalyst particles and the porous metal support after the firing process, and is used to fix the catalyst particles on the porous metal support, and can generally be used by adding silica, alumina sol or colloidal form. When a large amount of inorganic binder is used, there is an advantage that the bond between the catalyst particles and the porous metal support becomes harder, but conversely, due to the presence of a large amount of binder on the surface of the catalyst particles, the reaction sites may be reduced, the binder may also affect the catalyst phase, and at the same time, the binder may also participate in the reaction to cause unnecessary side effects. Therefore, in some cases, a binder is not used and a catalyst precursor is used directly for the purpose of directly introducing the catalyst into the porous metal support, but there is a disadvantage that the amount of catalyst loaded at one time is small.

[0051] Therefore, the present application intends to provide a catalyst for methane reforming that is capable of supporting a large amount of catalyst at one time and suppressing the side effects caused by the binder.

[0052] A catalyst for methane reforming according to an exemplary embodiment of the present application includes: a porous metal support; perovskite-based catalyst particles supported on the porous metal support; and a perovskite-based binder supported on the porous metal support.

[0053] In an exemplary embodiment of the present application, the perovskite-based catalyst particles and the perovskite-based binder each independently include a compound represented by the following Chemical Formula 1.

[0054] [Chemical Formula 1]

[0055] Sr 1-x A x Ti 1-y B y O 3-δ

[0056] In Chemical Formula 1,

[0057] A is Y, La or Ba,

[0058] B is Ni, Co, Fe, Mn, Cr, Mo, Ru or Rh,

[0059] x is a real number greater than 0 and less than 1,

[0060] y is a real number greater than 0 and less than 0.5,

[0061] δ is a real number greater than 0 and less than 1, and

[0062] Satisfies x+y>0.

[0063] In an exemplary embodiment of the present application, the perovskite catalyst particles and the perovskite binder may also include the same compound or different compounds. Therefore, in an exemplary embodiment of the present application, the catalyst for methane reforming may include two different perovskite compounds.

[0064] In an exemplary embodiment of the present application, Chemical Formula 1 may be represented by any one of Chemical Formulas 2 to 4 below.

[0065] [Chemical Formula 2]

[0066] SrTi 1-y B y O 3-δ

[0067] [Chemical Formula 3]

[0068] Sr 1-x Y x TiO 3-δ

[0069] [Chemical Formula 4]

[0070] Sr 1-x Y x Ti 1-y B y O 3-δ

[0071] In Chemical Formulas 2 to 4,

[0072] B is Ni or Ru,

[0073] x is a real number greater than 0 and less than 1,

[0074] y is a real number greater than 0 and less than 0.5,

[0075] δ is a real number greater than 0 and less than 1.

[0076] In an exemplary embodiment of the present application, the porous metal support may be composed of a material capable of maintaining thermal stability at a high temperature of 800° C. or higher.

[0077] In an exemplary embodiment of the present application, the porous metal support may be composed of one or more selected from NiFeCrAl, NiCrAl, SiC, Al, stainless steel, and inconel.

[0078] The porous metal carrier is a carrier with a variety of shapes, with a small heat capacity and excellent heat transfer ability, so it can be formed into a desired shape for use. The shape, size, etc. of the porous metal carrier are not particularly limited, and the porosity of the porous metal carrier can be 10% to 99%, preferably 50% to 99%. In addition, the average pore size of the porous metal carrier can be 150μm to 4,000μm, 200μm to 3,500μm, 400μm to 3,000μm. Taking into account the material, pore size, porosity, etc. of the porous metal carrier, the porous metal carrier can be appropriately prepared by those skilled in the art using methods known in the art. According to an exemplary embodiment of the present application, as described in the examples below, a porous metal carrier with a variety of materials, pore sizes, etc. can be applied.

[0079] In an exemplary embodiment of the present application, the total content of the perovskite catalyst particles and the perovskite binder can be 3% to 40% by weight, 6% to 35% by weight, and 7% to 30% by weight, based on the total weight of the catalyst for methane reforming. When the total content of the perovskite catalyst particles and the perovskite binder is less than 3% by weight based on the total amount of the catalyst for methane reforming, the reactivity may be reduced due to the relatively small number of active sites on the catalyst surface, and thus the desired catalyst performance cannot be achieved. In addition, when the total content of the perovskite catalyst particles and the perovskite binder exceeds 40% by weight, compared to the porous metal support, it contains a relatively large amount of catalyst components and blocks the pores, so there is a risk of generating a pressure difference, and therefore, the actual benefit of the methane reforming reaction may decrease.

[0080] In an exemplary embodiment of the present application, at least a portion of the surface of the catalyst particle may include a protrusion. The protrusion shape may be spherical, elliptical, or a combination thereof, but is not limited thereto. Each protrusion may have an average diameter of 20 nm to 1 μm. The protrusion may cover the entire surface of the catalyst particle, or may only cover a portion of the surface of the catalyst particle.

[0081] In an exemplary embodiment of the present application, the perovskite binder is an inorganic binder and can be used to fix the perovskite catalyst particles on a porous metal support. In addition, the perovskite binder can be present in the form of protrusions on the perovskite catalyst particles, thereby improving the performance of the methane reforming reaction by increasing the reactive surface area of ​​the catalyst.

[0082] Furthermore, according to an exemplary embodiment of the present application, by applying a perovskite-based binder in addition to the perovskite-based catalyst particles, the content of the supported catalyst can be increased during a single coating of the porous metal support, compared to when the catalyst particles are applied alone. Furthermore, according to an exemplary embodiment of the present application, by applying a perovskite-based binder, the performance of the methane reforming reaction can be improved by preventing side reactions or catalyst phase changes that may occur when using silica or another colloidal inorganic binder.

[0083] In an 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 ternary reforming process or a hybrid reforming process, and there is no particular limitation on the methane reforming process.

[0084] A method for preparing a catalyst for methane reforming according to an exemplary embodiment of the present application includes: mixing perovskite catalyst particles and perovskite catalyst sol to prepare a slurry; impregnating a porous metal support with the slurry; and drying and firing the porous metal support, wherein the perovskite catalyst particles and the perovskite catalyst sol each independently contain a compound represented by Chemical Formula 1.

[0085] In the method of preparing a catalyst for methane reforming according to an exemplary embodiment of the present application, details regarding the porous metal support, the perovskite-based catalyst particles, etc. are the same as those described above.

[0086] In particular, the perovskite-based binder in the catalyst for methane reforming may be formed from a perovskite-based catalyst sol.

[0087] The perovskite catalyst sol can be formed by a solution comprising a precursor of a perovskite compound and a solvent. The precursor of the perovskite compound is a precursor of the metal constituting the perovskite compound, and the metal molar ratio of the perovskite compound can be adjusted by adjusting its content. In addition, the precursor of the metal is not particularly limited, and ammonium salts, nitrates, carbonates, chlorides, lactates, hydroxides, organic acid salts, oxides of metal elements or mixtures thereof can be used in combination. The solvent is not particularly limited, and any solvent known in the art can be used. For example, water, alcohol solvents, etc. can be used as solvents, but are not limited thereto.

[0088] The method for preparing a catalyst for methane reforming according to an exemplary embodiment of the present application includes preparing a slurry by mixing perovskite catalyst particles and perovskite catalyst sol. In this case, a solvent may be additionally introduced to adjust the concentration of the slurry.

[0089] According to an exemplary embodiment of the present application, a method for preparing a catalyst for methane reforming includes impregnating a porous metal support with a slurry. In this case, the method may further include removing excess slurry from the metal support.

[0090] The method for preparing a catalyst for methane reforming according to an exemplary embodiment of the present application includes drying and firing the porous metal support after impregnating the porous metal support with a slurry. The drying can be carried out at a temperature of 50°C to 100°C for 20 minutes to 2 hours, and can be carried out at a temperature of 60°C to 90°C for 30 minutes to 1.5 hours, but is not limited thereto. In addition, the firing can be carried out in an air atmosphere at a temperature of 350°C to 1100°C for 1 hour to 15 hours, and can be carried out in an air atmosphere at a temperature of 500°C to 1000°C for 3 hours to 10 hours, but is not limited thereto. When firing is carried out for less than 1 hour, the perovskite sol used as a binder is not suitable for forming a crystalline phase, and when firing is carried out for more than 15 hours, it is not preferred in terms of energy consumption.

[0091] In an exemplary embodiment of the present application, the method may further include measuring the weight of the catalyst supported on the porous metal support after drying and firing. In addition, by measuring the weight of the catalyst supported on the porous metal support, impregnating the porous metal support with the slurry and drying and firing the porous metal support may be repeated 1 to 20 times until the desired amount of catalyst is supported on the porous metal support.

[0092] A catalyst for methane reforming according to an exemplary embodiment of the present application can be prepared by preparing a slurry in which catalyst particles of the same or similar series and a catalyst sol are mixed using an inorganic binder, and coating a metal support having high thermal conductivity with the slurry to increase the content of the catalyst loaded once and suppress side reactions caused by the binder.

[0093] Furthermore, the catalyst for methane reforming according to an exemplary embodiment of the present application is characterized in that, compared with a granular or powdered catalyst in the related art, reaction heat is easily controlled since the catalyst particles and the binder are supported on a porous metal support having high thermal conductivity.

[0094] Hereinafter, the present application will be described in detail with reference to the embodiments for specifically describing the present application. However, the embodiments described in the present application can be modified in various forms and should not be interpreted as limiting the scope of the present application to the embodiments described in detail below. The embodiments of the present application are provided to more fully explain the present application to those of ordinary skill in the art.

[0095] <Example>

[0096] <Comparative Example 1>

[0097] 1) Preparation of perovskite catalyst (SrTiO3) sol

[0098] A perovskite catalyst (SrTiO3) sol was prepared using the citrate method. Strontium nitrate (Sr(NO3)3H2O) was dissolved in distilled water along with citric acid and ethylene glycol. Isopropyl titanate (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.

[0099] 2) Perovskite catalyst particles (SrTi 0.995 Ni 0.005 O 3-δ , 0<δ<1)

[0100] The process was performed in the same manner as in 1) above, except that nickel nitrate (Ni(NO 3 ) 2 ) was added and used in an amount of 0.5 mol % relative to titanium.

[0101] The thus prepared solution was put into a crucible, dried at 150° C. for 24 hours, and fired at 900° C. to prepare perovskite catalyst particles.

[0102] 3) Preparation of catalyst for methane reforming

[0103] The slurry was prepared by mixing the prepared perovskite catalyst particles and the perovskite catalyst sol. In this case, the content of the perovskite catalyst particles was 5 wt %, the content of the perovskite catalyst sol was 0.1 M, and water was used as a solvent.

[0104] A porous metal support (NiFeCrAl, average pore size: 800 μm) was impregnated with the slurry for 1 minute, and excess slurry was removed from the porous metal support by a blower. Thereafter, the porous metal support was dried at 70°C for 1 hour and then heat-treated at 900°C for 5 hours in an air atmosphere to prepare a catalyst for methane reforming in which the porous metal support was coated with perovskite catalyst particles and a perovskite binder. This process was repeated multiple times to finally prepare a catalyst for methane reforming.

[0105] <Example 1>

[0106] 1) Perovskite catalyst (Sr 0.95 Y 0.05 Ti 0.97 Ru 0.03 O 3-δ , 0<δ<1) Preparation of sol

[0107] The process was performed in the same manner as 1) of Comparative Example 1, except that ruthenium chloride (RuCl3) was added in an amount of 3 mol% relative to titanium, and yttrium nitrate (Y(NO3)2) was added and used in an amount of 5 mol% relative to strontium.

[0108] 2) Perovskite catalyst particles (Sr 0.85 Y 0.15 Ti 0.95 Ru 0.05 O 3-δ , 0<δ<1)

[0109] The process was performed in the same manner as 1) of Comparative Example 1, except that ruthenium chloride (RuCl3) was added in an amount of 5 mol% relative to titanium and yttrium nitrate (Y(NO3)2) was added and used in an amount of 15 mol% relative to strontium.

[0110] The thus prepared solution was put into a crucible, dried at 150° C. for 24 hours, and fired at 900° C. to prepare perovskite catalyst particles.

[0111] 3) Preparation of catalyst for methane reforming

[0112] The process was performed in the same manner as in 3) of Comparative Example 1, except that a slurry was prepared by mixing the perovskite catalyst particles prepared in Example 1 and the perovskite catalyst sol, and NiFeCrAl (average pore diameter: 400 μm) was used as the porous metal support.

[0113] <Example 2>

[0114] 1) Perovskite catalyst (SrTi 0.97 Ni 0.03 O 3-δ , 0<δ<1) Preparation of sol

[0115] A process was performed in the same manner as in 1) of Comparative Example 1, except that nickel nitrate (Ni(NO 3 ) 2 ) was added and used in an amount of 3 mol % relative to titanium.

[0116] 2) Perovskite catalyst particles (SrTi 0.95 Ni 0.05 O 3-δ , 0<δ<1)

[0117] A process was performed in the same manner as in 1) of Comparative Example 1, except that nickel nitrate (Ni(NO 3 ) 2 ) was added and used in an amount of 5 mol % relative to titanium.

[0118] The thus prepared solution was put into a crucible, dried at 150° C. for 24 hours, and fired at 900° C. to prepare perovskite catalyst particles.

[0119] 3) Preparation of catalyst for methane reforming

[0120] A process was performed in the same manner as in 3) of Comparative Example 1, except that the slurry was prepared by mixing the perovskite catalyst particles prepared in Example 2 and the perovskite catalyst sol.

[0121] <Example 3>

[0122] 1) Perovskite catalyst (Sr 0.95 Y 0.05 Ti 0.97 Ru 0.03 O 3-δ , 0<δ<1) Preparation of sol

[0123] The process was performed in the same manner as 1) of Comparative Example 1, except that ruthenium chloride (RuCl3) was added in an amount of 3 mol% relative to titanium, and yttrium nitrate (Y(NO3)2) was added and used in an amount of 5 mol% relative to strontium.

[0124] 2) Perovskite catalyst particles (Sr 0.95 Y 0.05 Ti 0.90 Ni 0.10 O 3-δ , 0<δ<1)

[0125] The process was performed in the same manner as in 1) of Comparative Example 1, except that nickel nitrate (Ni(NO3)2) was added in an amount of 10 mol% relative to titanium, and yttrium nitrate (Y(NO3)2) was added and used in an amount of 5 mol% relative to strontium.

[0126] The thus prepared solution was put into a crucible, dried at 150° C. for 24 hours, and fired at 900° C. to prepare perovskite catalyst particles.

[0127] 3) Preparation of catalyst for methane reforming

[0128] A process was performed in the same manner as in 3) of Comparative Example 1, except that the slurry was prepared by mixing the perovskite catalyst particles prepared in Example 3 and the perovskite catalyst sol.

[0129] <Example 4>

[0130] 1Perovskite catalyst (SrTi 0.97 Ru 0.03 O 3-δ , 0<δ<1) Preparation of sol

[0131] A process was performed in the same manner as in 1) of Comparative Example 1, except that ruthenium chloride (RuCl 3 ) was added and used in an amount of 3 mol % relative to titanium.

[0132] 2) Perovskite catalyst particles (SrTi 0.93 Ni 0.07 O 3-δ , 0<δ<1)

[0133] A process was performed in the same manner as in 1) of Comparative Example 1, except that nickel nitrate (Ni(NO 3 ) 2 ) was added and used in an amount of 7 mol % relative to titanium.

[0134] The thus prepared solution was put into a crucible, dried at 150° C. for 24 hours, and fired at 900° C. to prepare perovskite catalyst particles.

[0135] 3) Preparation of catalyst for methane reforming

[0136] The process was performed in the same manner as in 3) of Comparative Example 1, except that a slurry was prepared by mixing the perovskite catalyst particles prepared in Example 4 and the perovskite catalyst sol and NiFeCrAl (average pore diameter: 1,200 μm) was used as the porous metal support.

[0137] <Example 5>

[0138] 1) Perovskite catalyst (Sr 0.95 Y 0.05 Ti 0.93 Ni 0.07 O 3-δ , 0<δ<1) Preparation of sol

[0139] The process was performed in the same manner as 1) of Comparative Example 1, except that nickel nitrate (Ni(NO3)2) was added in an amount of 7 mol% relative to titanium and yttrium nitrate (Y(NO3)2) was added and used in an amount of 5 mol% relative to strontium.

[0140] 2) Perovskite catalyst particles (Sr 0.95 Y 0.05 Ti 0.93 Ni 0.07 O 3-δ , 0<δ<1)

[0141] The process was performed in the same manner as 1) of Comparative Example 1, except that nickel nitrate (Ni(NO3)2) was added in an amount of 7 mol% relative to titanium and yttrium nitrate (Y(NO3)2) was added and used in an amount of 5 mol% relative to strontium.

[0142] The thus prepared solution was put into a crucible, dried at 150° C. for 24 hours, and fired at 900° C. to prepare perovskite catalyst particles.

[0143] 3) Preparation of catalyst for methane reforming

[0144] The process was performed in the same manner as in 3) of Comparative Example 1, except that a slurry was prepared by mixing the perovskite catalyst particles prepared in Example 5 and the perovskite catalyst sol and NiFeCrAl (average pore diameter: 1,200 μm) was used as the porous metal support.

[0145] <Example 6>

[0146] 1) Perovskite catalyst (Sr 0.95 Y 0.05 Ti 0.85 Ru 0.15 O 3-δ , 0<δ<1) Preparation of sol

[0147] The process was performed in the same manner as 1) of Comparative Example 1, except that ruthenium chloride (RuCl3) was added in an amount of 15 mol% relative to titanium, and yttrium nitrate (Y(NO3)2) was added and used in an amount of 5 mol% relative to strontium.

[0148] 2) Perovskite catalyst particles (Sr 0.95 Y 0.05 Ti 0.80 Ni 0.20 O 3-δ , 0<δ<1)

[0149] The process was performed in the same manner as 1) of Comparative Example 1, except that nickel nitrate (Ni(NO3)2) was added in an amount of 20 mol% relative to titanium and yttrium nitrate (Y(NO3)2) was added and used in an amount of 5 mol% relative to strontium.

[0150] The thus prepared solution was put into a crucible, dried at 150° C. for 24 hours, and fired at 900° C. to prepare perovskite catalyst particles.

[0151] 3) Preparation of catalyst for methane reforming

[0152] The process was performed in the same manner as in 3) of Comparative Example 1, except that a slurry was prepared by mixing the perovskite catalyst particles prepared in Example 6 and the perovskite catalyst sol and NiFeCrAl (average pore diameter: 3,000 μm) was used as the porous metal support.

[0153] <Example 7>

[0154] 1) Perovskite catalyst (Sr0.95 Y 0.05 Ti 0.90 Ru 0.10 O 3-δ , 0<δ<1) Preparation of sol

[0155] The process was performed in the same manner as 1) of Comparative Example 1, except that ruthenium chloride (RuCl3) was added in an amount of 10 mol% relative to titanium, and yttrium nitrate (Y(NO3)2) was added and used in an amount of 5 mol% relative to strontium.

[0156] 2) Perovskite catalyst particles (Sr 0.95 Y 0.05 Ti 0.80 Ni 0.20 O 3-δ ,,0<δ<1)

[0157] The process was performed in the same manner as 1) of Comparative Example 1, except that nickel nitrate (Ni(NO3)2) was added in an amount of 20 mol% relative to titanium and yttrium nitrate (Y(NO3)2) was added and used in an amount of 5 mol% relative to strontium.

[0158] The thus prepared solution was put into a crucible, dried at 150° C. for 24 hours, and fired at 900° C. to prepare perovskite catalyst particles.

[0159] 3) Preparation of catalyst for methane reforming

[0160] The process was performed in the same manner as in 3) of Comparative Example 1, except that a slurry was prepared by mixing the perovskite catalyst particles prepared in Example 7 and the perovskite catalyst sol and NiFeCrAl (average pore diameter: 3,000 μm) was used as the porous metal support.

[0161] <Example 8>

[0162] 1) Perovskite catalyst (SrTi 0.97 Ni o.03 O 3-δ , 0<δ<1) Preparation of sol

[0163] The process was performed in the same manner as in 1) of Comparative Example 1, except that nickel nitrate (Ni(NO 3 ) 2 ) was added in an amount of 3 mol % relative to titanium.

[0164] 2) Perovskite catalyst particles (SrTi 0.97 Ni 0.03 O 3-δ , 0<δ<1)

[0165] The process was performed in the same manner as in 1) of Comparative Example 1, except that nickel nitrate (Ni(NO 3 ) 2 ) was added in an amount of 3 mol % relative to titanium.

[0166] The thus prepared solution was put into a crucible, dried at 150° C. for 24 hours, and fired at 900° C. to prepare perovskite catalyst particles.

[0167] 3) Preparation of catalyst for methane reforming

[0168] The process was performed in the same manner as in 3) of Comparative Example 1, except that a slurry was prepared by mixing the perovskite catalyst particles prepared in Example 8 and the perovskite catalyst sol and NiCrAl (average pore diameter: 400 μm) was used as the porous metal support.

[0169] <Example 9>

[0170] 1) Perovskite catalyst (Sr 0.95 Y 0.05 Ti 0.97 Ni 0.03 O 3-δ , 0<δ<1) Preparation of sol

[0171] The process was performed in the same manner as 1) of Comparative Example 1, except that nickel nitrate (Ni(NO3)2) was added in an amount of 3 mol% relative to titanium and yttrium nitrate (Y(NO3)2) was added and used in an amount of 5 mol% relative to strontium.

[0172] 2) Perovskite catalyst particles (Sr 0.95 Y 0.05 Ti 0.97 Ni 0.03 O 3-δ , 0<δ<1)

[0173] The process was performed in the same manner as 1) of Comparative Example 1, except that nickel nitrate (Ni(NO3)2) was added in an amount of 3 mol% relative to titanium and yttrium nitrate (Y(NO3)2) was added and used in an amount of 5 mol% relative to strontium.

[0174] The thus prepared solution was put into a crucible, dried at 150° C. for 24 hours, and fired at 900° C. to prepare perovskite catalyst particles.

[0175] 3) Preparation of catalyst for methane reforming

[0176] The process was performed in the same manner as in 3) of Comparative Example 1, except that a slurry was prepared by mixing the perovskite catalyst particles prepared in Example 9 and the perovskite catalyst sol and NiCrAl (average pore diameter: 800 μm) was used as the porous metal support.

[0177] <Example 10>

[0178] 1) Perovskite catalyst (Sr 0.95 Y 0.05 Ti 0.97 Ru 0.03 O 3-δ , 0<δ<1) Preparation of sol

[0179] The process was performed in the same manner as 1) of Comparative Example 1, except that ruthenium chloride (RuCl3) was added in an amount of 3 mol% relative to titanium, and yttrium nitrate (Y(NO3)2) was added and used in an amount of 5 mol% relative to strontium.

[0180] 2) Perovskite catalyst particles (SrTi 0.90 Ni 0.10 O 3-δ , 0<δ<1)

[0181] The process was performed in the same manner as in 1) of Comparative Example 1, except that nickel nitrate (Ni(NO 3 ) 2 ) was added in an amount of 10 mol % relative to titanium.

[0182] The thus prepared solution was put into a crucible, dried at 150° C. for 24 hours, and fired at 900° C. to prepare perovskite catalyst particles.

[0183] 3) Preparation of catalyst for methane reforming

[0184] The process was performed in the same manner as in 3) of Comparative Example 1, except that a slurry was prepared by mixing the perovskite catalyst particles prepared in Example 10 and the perovskite catalyst sol and NiCrAl (average pore diameter: 1,200 μm) was used as the porous metal support.

[0185] <Example 11>

[0186] 1) Perovskite catalyst (Sr 0.95 Y 0.05 Ti 0.90 Ru 0.10 O 3-δ , 0<δ<1) Preparation of sol

[0187] The process was performed in the same manner as 1) of Comparative Example 1, except that ruthenium chloride (RuCl3) was added in an amount of 10 mol% relative to titanium, and yttrium nitrate (Y(NO3)2) was added and used in an amount of 5 mol% relative to strontium.

[0188] 2) Perovskite catalyst particles (Sr 0.95 Y 0.05 Ti0 .80Ni 0.20 O 3-δ , 0<δ<1)

[0189] The process was performed in the same manner as 1) of Comparative Example 1, except that nickel nitrate (Ni(NO3)2) was added in an amount of 20 mol% relative to titanium and yttrium nitrate (Y(NO3)2) was added and used in an amount of 5 mol% relative to strontium.

[0190] The thus prepared solution was put into a crucible, dried at 150° C. for 24 hours, and fired at 900° C. to prepare perovskite catalyst particles.

[0191] 3) Preparation of catalyst for methane reforming

[0192] The process was performed in the same manner as in 3) of Comparative Example 1, except that a slurry was prepared by mixing the perovskite catalyst particles prepared in Example 11 and the perovskite catalyst sol, and NiCrAl (average pore diameter: 1,500 μm) was used as the porous metal support.

[0193] <Example 12>

[0194] 1) Perovskite catalyst (Sr 0.85 Y 0.15 Ti 0.97 Ni 0.03 o 3-δ , 0<δ<1) Preparation of sol

[0195] The process was performed in the same manner as 1) of Comparative Example 1, except that nickel nitrate (Ni(NO3)2) was added in an amount of 3 mol% relative to titanium and yttrium nitrate (Y(NO3)2) was added and used in an amount of 15 mol% relative to strontium.

[0196] 2) Perovskite catalyst particles (Sr 0.85 Y 0.15 Ti 0.97 Ru 0.03 O 3-δ , 0<δ<1)

[0197] The process was performed in the same manner as 1) of Comparative Example 1, except that ruthenium chloride (RuCl3) was added in an amount of 3 mol% relative to titanium, and yttrium nitrate (Y(NO3)2) was added and used in an amount of 15 mol% relative to strontium.

[0198] The thus prepared solution was put into a crucible, dried at 150° C. for 24 hours, and fired at 900° C. to prepare perovskite catalyst particles.

[0199] 3) Preparation of catalyst for methane reforming

[0200] The process was performed in the same manner as in 3) of Comparative Example 1, except that a slurry was prepared by mixing the perovskite catalyst particles prepared in Example 12 and the perovskite catalyst sol, and NiCrAl (average pore diameter: 3,000 μm) was used as the porous metal support.

[0201] <Comparative Example 2>

[0202] A catalyst was prepared by performing the same process as in Example 8, except that an inorganic binder SiO 2 (Ludox) was used instead of the perovskite catalyst sol and NiCrAl (average pore diameter: 1,200 μm) was used as the porous metal support.

[0203] <Comparative Example 3>

[0204] A catalyst was prepared by performing the same process as in Example 2, except that perovskite catalyst particles were not used, only perovskite catalyst sol was used, and NiFeCrAl (average pore diameter: 1,200 μm) was used as the porous metal support.

[0205] <Comparative Example 4>

[0206] A catalyst was prepared by performing the same process as in Example 9, except that the perovskite catalyst sol was not used, only the perovskite catalyst particles were used, and NiFeCrAl (average pore diameter: 3,000 μm) was used as the porous metal support.

[0207] <Comparative Example 5>

[0208] A catalyst was prepared by performing the same process as in Example 8, except that the porous metal support and the perovskite catalyst sol were not used, and only the perovskite catalyst particles were used.

[0209] <Comparative Example 6>

[0210] A catalyst was prepared by performing the same process as in Comparative Example 1, except that only the perovskite catalyst sol was used instead of the perovskite catalyst particles, and NiCrAl (average pore size: 3,000 μm) was used as the porous metal support.

[0211] The compositions of the porous metal support, catalyst particles, and binder in Examples and Comparative Examples are shown in Table 1 below.

[0212] [Table 1]

[0213]

[0214] <Test Example 1> Evaluation of Catalysts for Methane Reforming

[0215] A set of electron microscope photos of the surface of the catalyst for methane reforming according to Example 1 of the present application are as follows: Figure 1 shown.

[0216] When the catalysts for methane reforming in Examples and Comparative Examples were prepared, the content of the perovskite-based catalyst supported on the porous metal support during one coating process was measured, and the results are shown in Table 2 below. In addition, in the catalysts for methane reforming in Examples and Comparative Examples, the presence or absence of protrusions on the surface of the catalyst particles coated on the porous metal support was confirmed, and the results are shown in Table 2 below.

[0217] The catalyst loading amount can be calculated by the following formula 1, and the presence or absence of protrusions can be confirmed by observing the surface image through SEM.

[0218] [Formula 1]

[0219] Catalyst loading (wt%) = (total weight of catalyst - weight of porous metal support) / (total weight of catalyst) × 100

[0220] [Table 2]

[0221]

[0222] As shown in the above results, in Comparative Examples 1 to 3, the amount of catalyst supported in one coating was small, so the number of coatings had to be increased, resulting in a problem of increased process costs. In Comparative Example 4, no catalyst was attached at all. In addition, in Comparative Example 5, since the catalyst particles were used alone, the amount of catalyst particles supported on the porous metal support could not be measured, and in Comparative Example 6, the amount of active metal capable of acting as a catalyst could not be measured.

[0223] <Test Example 2> Evaluation of Methane Reforming Reaction

[0224] A fixed-bed reactor system was introduced to conduct dry reforming of methane. A quartz tube reactor (inner diameter = 1 / 2 inch, length = 50 cm) was used and loaded with each catalyst (approximately 2.5 g) from the Examples and Comparative Examples. The catalysts were first reduced under 10% H2 / N2 at 800°C for 2 hours, followed by a 100-hour catalytic reaction.

[0225] Gas composition: CH4:CO2:N2=1:1.2:0.96

[0226] Flow rate: Weight hourly space velocity (WHSV) = 3,000cc / g·hr to 100,000cc / g·hr

[0227] Reaction temperature: 800℃

[0228] Reaction pressure: 1 bar

[0229] 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.

[0230] Conversion rate (Xi, %) = [(Fi 入 - Fi 出 ) / Fi 入 × 100 (Fi = flow rate of i)

[0231] <GC analysis conditions>

[0232] 1) GC model: Agilent 6890

[0233] 2) Oven temperature: 40°C / 7 min - 90°C / 5 min - 180°C / 6 min

[0234] 3) Detector: TCD, 250°C

[0235] 4) Sample: 0.25 mL

[0236] 5) Valve box temperature: 150°C

[0237] [Table 3]

[0238] WHSV (cc / g·hr) Methane conversion rate (%) <![CDATA[CO2 conversion rate (%)]]> Example 1 6,000 88 88 Example 2 6,000 90 88 Example 3 6,000 95 94 Example 4 6,000 89 88 Example 5 6,000 95 94 Example 6 6,000 96 94 Example 7 6,000 97 94 Example 8 6,000 88 87 Example 9 6,000 94 93 Example 10 6,000 97 94 Example 11 6,000 95 94 Example 12 6,000 96 94 Comparative Example 1 6,000 81 80 Comparative Example 2 6,000 50 53 Comparative Example 3 6,000 86 85 Comparative Example 4 6,000 10 13 Comparative Example 5 6,000 68 65 Comparative Example 6 6,000 10 11

[0239] As shown by the above results, it can be confirmed that the catalyst for methane reforming according to an exemplary embodiment of the present application has excellent methane conversion rate and CO2 conversion rate during the methane reforming reaction.

[0240] The catalyst for methane reforming according to an exemplary embodiment of the present application can be prepared by: preparing a slurry in which catalyst particles and catalyst sol of the same or similar series are mixed using an inorganic binder, and coating a metal carrier with high thermal conductivity with the slurry to increase the content of the catalyst in the primary load and suppress side reactions caused by the binder.

[0241] In addition, the catalyst for methane reforming according to an exemplary embodiment of the present application is characterized in that, compared with the particulate or powder-type catalysts in the related art, it is easy to control the reaction heat because the catalyst examples and the binder are loaded on a porous metal carrier with high thermal conductivity.

Claims

1. A catalyst for methane reforming, comprising: porous metal support; Perovskite catalyst particles supported on the porous metal support; and a perovskite-based binder loaded on the porous metal support, in, The perovskite-based catalyst particles and the perovskite-based binder each independently include a compound represented by the following Chemical Formula 1: [Chemical Formula 1] Sr 1-x A x Ti 1-y B y The 3-δ In 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 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, and Satisfies x+y>0.

2. The catalyst for methane reforming according to claim 1, wherein Chemical Formula 1 is represented by any one of the following Chemical Formulas 2 to 4: [Chemical Formula 2] SrTi 1-y B y The 3-δ [Chemical Formula 3] Sr. 1-x Y x TiO 3-δ [Chemical Formula 4] Mr 1-x AND x You 1-y B y EITHER 3-δ In Chemical Formula 2 to 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 0.5, δ is a real number greater than 0 and less than 1.

3. The catalyst for methane reforming according to claim 1, wherein The perovskite-based catalyst particles and the perovskite-based binder include different compounds.

4. The catalyst for methane reforming according to claim 1, wherein The perovskite-based catalyst particles and the perovskite-based binder include the same compound.

5. The catalyst for methane reforming according to claim 1, wherein The porous metal support is composed of one or more selected from NiFeCrAl, NiCrAl, Al, stainless steel and chromium-nickel-inconel alloy.

6. The catalyst for methane reforming according to claim 1, wherein The total content of the perovskite-based catalyst particles and the perovskite-based binder is 3 wt% to 40 wt% based on the total weight of the catalyst for methane reforming.

7. The catalyst for methane reforming according to claim 1, wherein At least a portion of the surface of the perovskite-based catalyst particle includes a protrusion.

8. The catalyst for methane reforming according to claim 1, wherein The catalyst for methane reforming is applied to a steam reforming process, a carbon dioxide (CO2) reforming process, a catalytic partial oxidation process, an autothermal reforming process, a tertiary reforming process or a mixed reforming process.

9. A method for preparing a catalyst for methane reforming, the method comprising: preparing a slurry by mixing perovskite catalyst particles and a perovskite catalyst sol; impregnating a porous metal support with the slurry; and drying and firing the porous metal support, The perovskite catalyst particles and the perovskite catalyst sol each independently contain a compound represented by the following Chemical Formula 1: [Chemical Formula 1] Sr 1-x A x Ti 1-y B y The 3-δ Wherein, in 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 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, and Satisfies x+y>0.

10. The method according to claim 9, wherein: Chemical Formula 1 is represented by any one of the following Chemical Formulas 2 to 4: [Chemical Formula 2] SrTi 1-y B y The 3-δ [Chemical Formula 3] Sr. 1-x Y x TiO 3-δ [Chemical Formula 4] Mr 1-x AND x You 1-y B y EITHER 3-δ In Chemical Formula 2 to 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 0.5, δ is a real number greater than 0 and less than 1.

11. The method according to claim 9, wherein The porous metal support is composed of one or more selected from NiFeCrAl, NiCrAl, Al, stainless steel and chromium-nickel-inconel alloy.

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