Dehydrogenation catalysts, composite catalysts, and supported catalysts

Abstract

This dehydrogenation reaction catalyst has a perovskite structure that is represented by general formula (A1-xA'x)(Zr1-y-zByB'z)O3 (wherein A represents at least one element that is selected from among alkaline earth metals; A' represents at least one of lanthanum (La) and yttrium (Y); B represents at least one of titanium (Ti) and cerium (Ce); and B' represents at least one element that is selected from among yttrium (Y), scandium (Sc), ytterbium (Yb), aluminum (Al), indium (In) and neodymium (Nd)), with x, y and z satisfying 0 ≤ x ≤ 0.4, 0.3 ≤ (1 – z) ≤ 1, 0 ≤ y and 0 < (1 – y – z).

Description

[Technical Field]

[0001] The present disclosure relates to dehydrogenation catalysts, composite catalysts, and supported catalysts. [Background technology]

[0002] Known methods for producing ethylene include thermal cracking and fractionation of higher hydrocarbons such as naphtha, and thermal cracking of ethane derived from natural gas. Another method proposed is to produce ethylene by converting methane into ethylene through a methane oxidative coupling reaction using a catalyst (see, for example, Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Brittany Lancaster Farrell et al., ACS Catal. 2016,6, 4340-4346 Summary of the Invention [Problem to be solved by the invention]

[0004] Compared with methods for producing ethylene by thermal cracking of hydrocarbons, methods using methane oxidative coupling catalysts are advantageous in that the amount of energy required for ethylene production can be reduced. However, the catalytic activity of conventionally known methane oxidative coupling catalysts is not necessarily sufficient, and a technology for improving the catalytic activity of methane oxidative coupling catalysts has been desired. Furthermore, a technology for improving the activity of catalysts that promote reactions other than the methane oxidative coupling reaction, but which, like the methane oxidative coupling reaction, involve a dehydrogenation process of the reactants, has also been desired. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms. (1) According to one aspect of the present disclosure, a dehydrogenation catalyst is provided. The dehydrogenation catalyst is represented by the general formula (A 1-x A' x )(Zr 1-y-z B y B' z )O3 (wherein A is at least one element selected from alkaline earth metals, A' is at least one element of lanthanum (La) and yttrium (Y), B is at least one element of titanium (Ti) and cerium (Ce), and B' is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), aluminum (Al), indium (In), and neodymium (Nd)), and the x, y, and z are 0≦x≦0.4, 0.3≦(1−z)≦1, 0≦y, 0<(1-yz), Meet the following. According to this form of dehydrogenation catalyst, the activity for promoting the dehydrogenation reaction can be increased. (2) In the dehydrogenation catalyst of the above embodiment, the dehydrogenation catalyst may be an alkane oxidative coupling catalyst that promotes an alkane oxidative coupling reaction that combines reactants containing at least one of an alkane and an alkane derivative. With this configuration, the activity of promoting the alkane oxidative coupling reaction can be increased. (3) In the dehydrogenation catalyst of the above embodiment, the dehydrogenation catalyst may be a methane oxidative coupling catalyst. With this configuration, the activity of promoting the methane oxidative coupling reaction can be increased. (4) In the dehydrogenation catalyst of the above form, the total conductivity is 1.0 × 10 -5 S / cm or more, 1.0×10 -1 With this configuration, the total conductivity of the dehydrogenation catalyst, which is a methane oxidative coupling catalyst, may be 1.0×10 S / cm or less. -5By increasing the total conductivity of the catalyst to 1.0×10 S / cm or more, the activity of promoting the oxidative coupling of methane can be further increased. -1 By setting the proton conductivity to 1.0×10 S / cm or less, the peroxidation of methane, i.e., the complete oxidation reaction of methane to produce carbon dioxide and water, can be suppressed, and as a result, the activity of promoting the oxidative coupling of methane can be increased. (5) In the dehydrogenation catalyst of the above embodiment, the proton conductivity is 1.0×10 -4 S / cm or more. With this configuration, the activity for promoting the dehydrogenation reaction can be further increased. (6) In the dehydrogenation catalyst of the above embodiment, the proton transport number may be 0.01 or more. With such a configuration, the activity for promoting the dehydrogenation reaction can be further increased. (7) In the dehydrogenation catalyst of the above type, The x is 0≦x≦0.2 With such a configuration, the activity for promoting the dehydrogenation reaction can be further increased. (8) In the dehydrogenation catalyst of the above embodiment, the sum of the electron transport number and the hole transport number may be 0.01 or more and 0.95 or less. By adopting such a configuration, the activity for promoting the dehydrogenation reaction, which is a methane oxidative coupling reaction, can be further increased by making the sum of the electron transport number and the hole transport number 0.01 or more. Furthermore, by making the sum of the electron transport number and the hole transport number 0.95 or less, methane peroxidation, i.e., the complete oxidation reaction in which methane produces carbon dioxide and water, can be suppressed, thereby enhancing the activity for promoting the methane oxidative coupling reaction. (9) In the dehydrogenation catalyst of the above embodiment, the proton transport number and the sum of the electron transport number and the hole transport number may each be 0.10 or more. By adopting such a configuration, the activity for promoting the dehydrogenation reaction can be further enhanced. (10) In the above-mentioned dehydrogenation catalyst, the general formula is BaZr 1-z B' zO3 (wherein B' is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), indium (In), and neodymium (Nd)). With this structure, the activity of promoting the dehydrogenation reaction can be further increased. (11) According to another aspect of the present disclosure, there is provided a composite catalyst comprising the methane oxidative coupling catalyst according to (3) or (4) and at least one of a metal catalyst and an oxide catalyst. The composite catalyst of this type can further enhance the function of promoting the oxidative coupling of methane. (12) According to yet another aspect of the present disclosure, there is provided a supported catalyst having a catalytic component supported on a carrier, wherein the catalytic component comprises the methane oxidative coupling catalyst according to (3) or (4). According to this form of supported catalyst, a methane oxidative coupling catalyst having enhanced activity for promoting the methane oxidative coupling reaction can be used in a state supported on a carrier. (13) According to yet another aspect of the present disclosure, there is provided a supported catalyst having a catalyst component supported on a carrier, wherein the catalyst component comprises the composite catalyst according to (11). According to this type of supported catalyst, a composite catalyst having enhanced activity for promoting the oxidative coupling of methane can be used in a state supported on a carrier. The present disclosure may be realized in various forms other than those described above, such as a method for producing a dehydrogenation reaction catalyst, a method for producing a methane oxidative coupling catalyst, or an ethylene production apparatus equipped with a methane oxidative coupling catalyst. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is an explanatory diagram illustrating a schematic overview of a methane oxidative coupling reaction. [Figure 2] FIG. 1 is an explanatory diagram showing in detail an example of a reaction that proceeds on a methane oxidative coupling catalyst. [Figure 3]FIG. 1 is an explanatory diagram showing in detail an example of a reaction that proceeds on a methane oxidative coupling catalyst. [Figure 4] FIG. 1 is an explanatory diagram showing various dehydrogenation reactions that can be promoted by a dehydrogenation catalyst. [Figure 5] FIG. 1 is an explanatory diagram showing a schematic configuration of an ethylene production apparatus. [Figure 6] FIG. 1 is an explanatory diagram showing the results of examining the performance of a methane oxidative coupling catalyst. [Figure 7] FIG. 1 is an explanatory diagram showing the results of examining the performance of a methane oxidative coupling catalyst. DETAILED DESCRIPTION OF THE INVENTION

[0007] A. Dehydrogenation catalyst: The dehydrogenation catalyst of this embodiment is a composite oxide containing a crystalline phase with a perovskite-type oxide crystal structure satisfying the following general formula (1). The dehydrogenation catalyst of this embodiment promotes various reactions involving the dehydrogenation of reactants, etc. An example of a reaction promoted by the dehydrogenation catalyst is the methane oxidative coupling reaction. In this specification, the entire reaction including the dehydrogenation of reactants, such as the methane oxidative coupling reaction, is also referred to as the "dehydrogenation reaction." The dehydrogenation catalyst of this embodiment can be a methane oxidative coupling catalyst. A methane oxidative coupling catalyst is a catalyst that promotes the oxidative coupling of methane (OCM) reaction, which converts methane into C2 hydrocarbons such as ethylene. Furthermore, the dehydrogenation catalyst of this embodiment has proton conductivity and at least one of electron conductivity and hole conductivity in addition to the activity of promoting the dehydrogenation reaction. Dehydrogenation reactions promoted by the dehydrogenation catalyst of this embodiment, such as the methane oxidative coupling reaction, will be described in detail below.

[0008] (A1-xA'x)(Zr1-y-zByB'z)O3 … (1) Here, A is at least one element selected from alkaline earth metals, A' is at least one element selected from lanthanum (La) and yttrium (Y), B is at least one element selected from titanium (Ti) and cerium (Ce), and B' is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), aluminum (Al), indium (In), and neodymium (Nd). y , and z satisfy the following relationship: 0≦x≦0.4 … (2a) 0.3≦(1-z)≦1 … (2b) 0≦y … (2c) 0<(1-yz) … (2d)

[0009] As shown in the formula (1) above, the dehydrogenation catalyst of this embodiment contains at least one element selected from alkaline earth metals in the so-called A site of the perovskite structure. The alkaline earth metal is preferably an element selected from barium (Ba), calcium (Ca), and strontium (Sr). Hereinafter, the alkaline earth metal element contained in the A site will also be referred to as "element A." The dehydrogenation catalyst of this embodiment may further contain at least one element selected from lanthanum (La) and yttrium (Y) in the A site of the perovskite structure. However, lanthanum (La) and yttrium (Y) are not essential. Hereinafter, lanthanum (La) and yttrium (Y) contained in the A site will also be referred to as "element A'." In the dehydrogenation catalyst of this embodiment, the contents of element A and element A' in the formula (1) described above satisfy formula (2a).

[0010] The dehydrogenation catalyst of this embodiment also contains zirconium (Zr) at the so-called B site of the perovskite structure. The dehydrogenation catalyst of this embodiment may further contain at least one element selected from titanium (Ti) and cerium (Ce) at the B site of the perovskite structure. However, titanium (Ti) and cerium (Ce) are not essential. Hereinafter, the titanium (Ti) and cerium (Ce) contained at the B site will also be referred to as "element B." The dehydrogenation catalyst of this embodiment may further contain at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), aluminum (Al), indium (In), and neodymium (Nd) at the B site of the perovskite structure. However, at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), aluminum (Al), indium (In), and neodymium (Nd) is not essential. Hereinafter, at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), aluminum (Al), indium (In), and neodymium (Nd) contained in the B site will also be referred to as "element B'." In the dehydrogenation catalyst of this embodiment, the contents of Zr, element B, and element B' satisfy formulas (2b) to (2d) in formula (1) described above.

[0011] The dehydrogenation catalyst of this embodiment configured as described above can enhance its activity (hereinafter also referred to as "catalytic activity") in promoting a dehydrogenation reaction (e.g., a methane oxidative coupling reaction that converts methane into C2 hydrocarbons such as ethylene). This enhanced activity in promoting a dehydrogenation reaction enhances the activity in promoting the dehydrogenation of the reactant methane, i.e., the reaction that produces methyl radicals from methane, when the dehydrogenation catalyst of this embodiment is used as a methane oxidative coupling catalyst. This enhanced activity enhances the activity in promoting the dehydrogenation of the reactant methane, i.e., the reaction that produces methyl radicals from methane, and as a result, the entire methane oxidative coupling reaction is accelerated. This enhanced catalytic activity makes it possible to enhance the efficiency of ethylene production by using the dehydrogenation catalyst of this embodiment as, for example, a methane oxidative coupling catalyst. Dehydrogenation reactions, such as the reaction that produces methyl radicals from methane, will be described in detail below.

[0012] In the dehydrogenation catalyst of this embodiment, it is desirable that x in the above-mentioned formula (1) satisfies the following formula (2e), which can further enhance the activity for promoting the dehydrogenation reaction.

[0013] 0≦x≦0.2 … (2e)

[0014] Furthermore, the dehydrogenation catalyst of this embodiment preferably has a perovskite structure represented by the following general formula (3), which can further enhance the activity of promoting the dehydrogenation reaction.

[0015] BaZr 1-z B' z O3… (3) Here, B' is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), indium (In), and neodymium (Nd).

[0016] Furthermore, the dehydrogenation catalyst of this embodiment may be used to form a composite catalyst containing this dehydrogenation catalyst and at least one of a metal catalyst and an oxide catalyst. By combining the dehydrogenation catalyst of this embodiment with a metal catalyst or an oxide catalyst, for example by mixing the two, to form a composite catalyst, the effect of promoting the entire desired dehydrogenation reaction can be enhanced. Metal catalysts and oxide catalysts are known to promote not only the dehydrogenation reaction but also the oxidation reaction. Therefore, when an oxidation reaction proceeds using a metal catalyst or an oxide catalyst, carbon dioxide may be produced as a product rather than the desired ethylene. However, when a metal catalyst or an oxide catalyst is combined with a dehydrogenation catalyst as in this embodiment, the dehydrogenation reaction proceeds prior to the oxidation reaction, thereby further promoting the desired reaction, such as ethylene production. The metal catalyst or oxide catalyst to be composited with the dehydrogenation catalyst may be selected appropriately depending on the desired dehydrogenation reaction. Examples of the metal catalyst that can be used include metals selected from palladium (Pd), copper (Cu), iron (Fe), nickel (Ni), platinum (Pt), indium (In), manganese (Mn), ruthenium (Ru), strontium (Sr), zinc (Zn), and lithium (Li). Examples of the oxide catalyst that can be used include oxides selected from Li2ASiO4 (where A is Ca or Sr), Ce2(WO4)3, and CeO2.

[0017] B. Methane oxidative coupling reaction: Hereinafter, the methane oxidative coupling reaction promoted by the dehydrogenation catalyst of this embodiment when used as a methane oxidative coupling catalyst will be described.

[0018] FIG. 1 is an explanatory diagram illustrating a schematic overview of the methane oxidative coupling reaction. The production of C2 hydrocarbons by the methane oxidative coupling reaction is carried out, for example, in the presence of oxygen. As shown in FIG. 1, during the methane oxidative coupling reaction, a reaction to generate methyl radicals from methane (methane dehydrogenation reaction) occurs on a methane oxidative coupling catalyst 10. The generated methyl radicals then generate C2 hydrocarbons, such as ethylene and ethane. The covalent bond between the carbon atom and the hydrogen atom in methane has a bond energy of 104 kcal / mol, making it an extremely stable bond. Therefore, in the methane oxidative coupling reaction, the reaction to generate methyl radicals from methane having a stable covalent bond (the reaction that changes from (b) to (c) in FIG. 1) is generally considered to be the rate-determining step. Therefore, in order to promote the overall methane oxidative coupling reaction, it is important to promote the reaction to generate methyl radicals from methane. The methane oxidative coupling catalyst 10 of the present embodiment has high activity in promoting the above-described reaction of producing methyl radicals from methane. As a result, it is considered that the activity in promoting the methane oxidative coupling reaction is high, and the efficiency of ethylene production can be improved.

[0019] 2 and 3 are explanatory diagrams showing in more detail an example of the methane oxidative coupling reaction that proceeds on the methane oxidative coupling catalyst 10 of this embodiment. In FIGS. 2 and 3, the methane oxidative coupling catalyst 10 is shown formed in a powder or granular form. As shown in FIGS. 2 and 3, when the methane oxidative coupling reaction proceeds, a reaction that produces methyl radicals from methane first proceeds, as shown in formula (4) below.

[0020] CH4 → CH3+H + +e - … (4)

[0021] Furthermore, it is believed that on the methane oxidative coupling catalyst, the reactions of the following formulas (5) and (6) (see Figure 2) and the reactions of the following formulas (7) and (8) (see Figure 3) proceed, thereby producing ethylene and other products.

[0022] 2·CH3+1 / 2O2→ C2H4+H2O … (5) 1 / 2O2+2H + +2e - → H2O … (6)

[0023] 2·CH3 → C2H6 → C2H4+2H + +2e - … (7) O2+4H + +4e - → 2H2O …(8)

[0024] That is, in the methane oxidative coupling catalyst, it is thought that the reaction of the following formula (9) proceeds as a whole through the reactions of formulas (4) to (6) shown in FIG. 2 or the reactions of formulas (4), (7), and (8) shown in FIG. 3.

[0025] 2CH4+O2→ C2H4+2H2O … (9)

[0026] Figures 2 and 3 show the "oxidation site" where reaction (4), which produces methyl radicals from methane, occurs. Figures 2 and 3 also show the process of reaction (5) or (7), which produces ethylene from methyl radicals at this oxidation site. Figures 2 and 3 also show the "reduction site" where reaction (6) or (8), which produces water using the protons and electrons generated along with the methyl radicals in reaction (4), occurs. These reactions can occur anywhere on the methane oxidative coupling catalyst. For reaction (9), which produces C2 hydrocarbons such as ethylene from methane, to proceed satisfactorily, the methane oxidative coupling catalyst must not only have high activity to promote reaction (4), the rate-determining step mentioned above, but also have high proton conductivity and electron conductivity (including hole conductivity) to ensure that subsequent reactions, such as reactions (5) and (6) and reactions (7) and (8), proceed smoothly after reaction (4). Specifically, it is desirable that the proton conductivity and proton transport number, or the electronic conductivity (including the hole conductivity) and the electronic transport number (including the hole transport number) are higher. It is also desirable that the total conductivity of the methane oxidative coupling catalyst as a whole, which is the sum of the proton conductivity and the electronic conductivity (including the hole conductivity), is higher.

[0027] The total conductivity of the methane oxidative coupling catalyst is 1.0 × 10 -5 S / cm or more, 1.0×10 -1 The methane oxidative coupling catalyst of this embodiment satisfies the above-mentioned formula (1) and formulas (2a) to (2d), thereby achieving a total conductivity of 1.0 × 10 -5 S / cm or more, 1.0×10 -1 It is easy to achieve a total conductivity of 1.0×10 S / cm or less. -5 S / cm or more, the catalytic activity can be further increased. -1When the conductivity exceeds 1.0×10 S / cm, the electron conductivity (including the hole conductivity) generally becomes excessively high, which facilitates the peroxidation of methane, i.e., the complete oxidation reaction of methane to produce carbon dioxide and water. Therefore, it is recommended to set the total conductivity of the methane oxidative coupling catalyst to 1.0×10 -1 By setting the catalyst at a concentration of 0.15 S / cm or less, the complete oxidation reaction of methane described above can be suppressed, and as a result, the catalytic activity for producing ethylene from methane can be increased.

[0028] The proton conductivity of the methane oxidative coupling catalyst is 1.0 × 10 -4 The methane oxidative coupling catalyst of this embodiment satisfies the above-mentioned formulas (1) and (2a) to (2d), thereby achieving a proton conductivity of 1.0×10 -4 By setting the proton conductivity of the methane oxidative coupling catalyst to the above value, the catalytic activity can be further increased. There is no particular upper limit to the proton conductivity of the methane oxidative coupling catalyst, but the proton conductivity of the methane oxidative coupling catalyst of this embodiment is usually 1.0 × 10 -1 S / cm or less.

[0029] Furthermore, the proton transport number of the methane oxidative coupling catalyst is desirably 0.01 or greater. The methane oxidative coupling catalyst of this embodiment easily achieves a proton transport number of 0.01 or greater by satisfying the above-described formulas (1) and (2a) to (2d). By setting the proton transport number of the methane oxidative coupling catalyst to the above values, catalytic activity can be further enhanced. While there are no particular limitations on the upper limit of the proton transport number of the methane oxidative coupling catalyst, from the viewpoint of ensuring a sufficient electron transport number (including hole transport number), it is desirably 0.99 or less, and more desirably 0.90 or less.

[0030] Furthermore, the sum of the electron transport number and the Hall transport number of the methane oxidative coupling catalyst is desirably 0.01 or more and 0.95 or less. By satisfying the above-described formulas (1) and (2a) to (2d), the methane oxidative coupling catalyst of this embodiment can easily achieve a sum of the electron transport number and the Hall transport number of 0.01 or more and 0.95 or less. By achieving a sum of the electron transport number and the Hall transport number of the methane oxidative coupling catalyst of 0.01 or more, catalytic activity can be further enhanced. Furthermore, by achieving a sum of the electron transport number and the Hall transport number of the methane oxidative coupling catalyst of 0.95 or less, peroxidation of methane, i.e., the complete oxidation reaction that produces carbon dioxide and water from methane, can be suppressed, thereby enhancing catalytic activity for producing ethylene from methane.

[0031] Furthermore, it is desirable that the proton transport number and the sum of the electron transport number and the hole transport number of the methane oxidative coupling catalyst are each 0.10 or greater. By satisfying the above-described formulas (1) and (2a) to (2d), the methane oxidative coupling catalyst of this embodiment can easily achieve a proton transport number and the sum of the electron transport number and the hole transport number of 0.10 or greater. By achieving a proton transport number and the sum of the electron transport number and the hole transport number of the methane oxidative coupling catalyst of 0.10 or greater, the catalytic activity can be further enhanced.

[0032] C. Other dehydrogenation reactions: FIG. 4 is an explanatory diagram showing examples of various dehydrogenation reactions that can be promoted by the dehydrogenation catalyst of this embodiment. The dehydrogenation catalyst of this embodiment can promote various reactions depending on the raw materials (reactants) used. Formulas (10) to (21) in FIG. 4 show reactions that combine reactants containing at least one of methane and methane derivatives (hereinafter also referred to as "methanes"). Such reactions are also referred to as "oxidative coupling reactions of methanes." The dehydrogenation catalyst of this embodiment, which promotes the oxidative coupling reactions of methanes, is also referred to as "oxidative coupling catalysts of methanes." In formulas (12) to (21) in FIG. 4, A and B contained in the methane derivative represent atoms or atomic groups as substituents that replace hydrogen atoms in the methane molecule, and n is an integer of 2 or greater. The methane derivative shown in FIG. 4 has one or two hydrogen atoms in the methane molecule substituted with the above-mentioned substituents. When one molecule has substituents A and B, A and B may be the same or different substituents. Examples of the substituent represented by A or B include a halogen element, a hydroxy group (-OH), and a phenyl group (-C6H5).

[0033] In Figure 4, formula (10), like formula (9), represents the reaction in which ethylene is produced from methane. Formula (11) represents the reaction in which the polymerization reaction proceeds further to produce polyethylene. Unlike formula (9), formulas (10) to (21) only show the changes in methane and methane derivatives among the molecules involved in the reaction.

[0034] Equations (10) and (11) show reactions in which methane is a reactant. Equations (12) and (13) show reactions in which a methane derivative represented by BACH2 is a reactant. Equations (14) and (15) show reactions in which a methane derivative represented by ACH3 is a reactant. Equations (16) and (17) show reactions in which a methane derivative represented by ACH3 and methane are reactants. Equations (18) and (19) show reactions in which a methane derivative represented by ACH3 and a methane derivative represented by CA2H2 are reactants. Equations (20) and (21) show reactions in which a methane derivative represented by CABH2 and methane are reactants.

[0035] Furthermore, formulas (10), (12), (14), (16), (18), and (20) show reactions for producing hydrocarbons with two carbon atoms (ethylene) or ethylene derivatives (C2 hydrocarbons) using reactants selected from hydrocarbons with one carbon atom (methane) and methane derivatives (C1 hydrocarbons). Formulas (11), (13), (15), (17), (19), and (21) show reactions for producing polymers using reactants selected from C1 hydrocarbons. When producing polymers, C2 hydrocarbons may be produced from C1 hydrocarbons, and then these C2 hydrocarbons may be further polymerized with each other. Alternatively, C1 hydrocarbons may be sequentially polymerized to the ends of molecules to produce polymers. Both of these reactions may occur.

[0036] To explain the reaction shown in Figure 4 more specifically, for example, in formula (13), if the substituents A and B are both fluorine atoms (F), polytetrafluoroethylene (PTFE) is obtained as the product. In formula (17), if the substituent A is a chlorine atom (Cl), polyvinyl chloride (PVC) is obtained as the product. If the substituent A is a hydroxyl group (-OH), polyvinyl alcohol (PVOH) is obtained as the product. If the substituent A is a phenyl group (-CH), polystyrene (PS) is obtained as the product. In formula (21), if the substituents A and B are both fluorine atoms (F), polyvinylidene fluoride (PVDF) is obtained as the product. If the substituents A and B are both chlorine atoms (Cl), polyvinylidene chloride (PVDC) is obtained as the product. Furthermore, in formula (21), if the substituent A is a methyl group (-CH) and the substituent B is a methoxycarbonyl group (-COOCH), polymethyl methacrylate (PMMA) is obtained as the product.

[0037] Although FIG. 4 illustrates the oxidative coupling reaction of methanes, the dehydrogenation catalyst of this embodiment can also be used to promote dehydrogenation reactions other than the oxidative coupling reaction of methanes. Examples of dehydrogenation reactions promoted by the dehydrogenation catalyst of this embodiment include a reaction of combining reactants containing at least one of an alkane and an alkane derivative (hereinafter also referred to as "alkanes"). Such a reaction, together with the oxidative coupling reaction of methanes described above, is also referred to as the "oxidative coupling reaction of alkanes." The dehydrogenation catalyst of this embodiment, which promotes the oxidative coupling reaction of alkanes, is also referred to as the "oxidative coupling catalyst of alkanes." The number of carbon atoms in alkanes, which are the reactants of the oxidative coupling reaction of alkanes promoted by the dehydrogenation catalyst of this embodiment, can be, for example, 1 to 10, preferably 1 to 5, and more preferably 1 or 2. The alkane derivative used in the oxidative coupling reaction of alkanes is one in which hydrogen atoms contained in the alkane molecule have been substituted with the substituents described above, but which has a covalent bond between the carbon atom to be dehydrogenated and the hydrogen atom.

[0038] The dehydrogenation catalyst of this embodiment can also be used to promote dehydrogenation reactions other than the oxidative coupling reaction of alkanes. Examples of other dehydrogenation reactions promoted by the dehydrogenation catalyst of this embodiment include the dehydrogenation reaction of alkanes as exemplified by formula (22) in FIG. 4 and the dehydrogenation reaction of alcohols or alcohol derivatives (hereinafter also referred to as "alcohols") as exemplified by formulas (23) and (24). In formulas (22) to (24), A and B represent hydrogen or, as in formulas (12) to (21), an atom or atomic group as a substituent replacing hydrogen. Formula (22) represents a reaction in which alkenes or alkene derivatives are produced from alkanes. Formula (23) represents a reaction in which aldehydes are produced from alcohols, and formula (24) represents a reaction in which ketones are produced from alcohols. In this way, the dehydrogenation catalyst of this embodiment can be used as a catalyst to promote various dehydrogenation reactions.

[0039] Even when the dehydrogenation catalyst of this embodiment is used for a dehydrogenation reaction other than the methane oxidative coupling reaction shown in FIG. 1 , the dehydrogenation catalyst of this embodiment can promote the dehydrogenation of reactants (such as reactants initially prepared as raw materials or reactants produced during a series of reactions and used in subsequent reactions), such as the reaction transitioning from (b) to (c) in FIG. 1 . The dehydrogenation process of alkanes, which breaks the stable covalent bond between a carbon atom and a hydrogen atom, is generally considered to be the rate-determining process in the progress of alkane oxidative coupling reactions and the like. Therefore, by promoting the dehydrogenation process of alkanes described above using the dehydrogenation catalyst of this embodiment, the entire dehydrogenation reaction, such as the alkane oxidative coupling reaction, can be promoted.

[0040] When carrying out various dehydrogenation reactions, including the dehydrogenation of reactants, such as the alkane oxidative coupling reaction described above, various conditions, such as the reaction pressure, the partial pressures of the reactants and products, the reaction temperature, and the manner of product separation and purification, can be set by methods well known or easily realized by those skilled in the art to construct the entire reaction process so as to obtain the desired compound. For example, as shown in formulas (16) to (21), when multiple types of reactants are used, undesirable reactions may occur. Specifically, when proceeding with reaction (16), for example, reactions (10) and (14) in which reactants of the same type combine may also occur. The conditions for the above reactions may be appropriately set to sufficiently suppress such unintended reactions.

[0041] Even when the dehydrogenation catalyst of the present embodiment is used for a dehydrogenation reaction other than the methane oxidative coupling reaction, for example, the total conductivity of the dehydrogenation catalyst can be set to 1.0 × 10 -5 S / cm or more, 1.0×10 -1 By setting the proton conductivity of the dehydrogenation catalyst to 1.0×10 S / cm or less, the activity of promoting the dehydrogenation reaction can be further increased. -4 S / cm or more, the activity for promoting the dehydrogenation reaction can be further increased. Furthermore, by making the proton transport number of the dehydrogenation catalyst 0.01 or more, the activity for promoting the dehydrogenation reaction can be further increased. Furthermore, by making x in formula (1) representing the dehydrogenation catalyst satisfy the above-mentioned formula (2e), the activity for promoting the dehydrogenation reaction can be further increased. Furthermore, by having the dehydrogenation catalyst of this embodiment have a perovskite structure represented by the above-mentioned general formula (3), the activity for promoting the dehydrogenation reaction can be further increased.

[0042] D. Method for producing dehydrogenation catalyst: The dehydrogenation catalyst of this embodiment can be prepared, for example, by a complex polymerization method. The complex polymerization method is a well-known method capable of preparing a composite oxide in which the component elements are well mixed. Specifically, a powdered raw material such as a metal nitrate is weighed and dissolved in water so that the mixing ratio of the metal elements in the powdered raw material corresponds to the composition of the composite oxide to be prepared. An oxycarboxylic acid such as citric acid is added to form a metal oxycarboxylic acid complex. Glycol or the like is added to the mixture, and the mixture is heated to promote the polymerization reaction, thereby obtaining a polyester polymer gel. This polyester polymer gel is then heat-treated (calcined) to obtain a composite oxide powder.

[0043] The method for producing the dehydrogenation catalyst of this embodiment may be a method other than the complex polymerization method described above. For example, various methods capable of producing a composite oxide, such as a solid-phase reaction method, a coprecipitation method, or a sol-gel method, may be used.

[0044] When the dehydrogenation catalyst of the present embodiment is to be a composite catalyst in which it is combined with at least one of a metal catalyst and an oxide catalyst, as described above, the above-mentioned catalysts can be composited using various known methods, such as an impregnation method.

[0045] E. Supported catalyst comprising a dehydrogenation catalyst: The dehydrogenation catalyst of this embodiment may be configured as a supported catalyst by supporting the dehydrogenation catalyst as a catalytic component on a carrier. In this case, the catalytic component may be a composite catalyst that combines the dehydrogenation catalyst of this embodiment with at least one of a metal catalyst and an oxide catalyst.

[0046] The support can be made of a material selected from, for example, CeO2, γ-Al2O3, zeolite, SiO2, ZrO2, Na2WO4, La2O3, Cs2SO4, Sm2O3, MgO, SrO, YO3, (La,Sr)AlO3, and LaAlO3. The support can have a foam, porous body, porous tube, honeycomb, or porous particle structure. The dehydrogenation catalyst or composite catalyst can be supported on the support by various known methods, such as impregnation.

[0047] F. Apparatus with a methane oxidative coupling catalyst: The methane oxidative coupling catalyst as one embodiment of the dehydrogenation catalyst of this embodiment can be used, for example, in an ethylene production apparatus for producing ethylene from methane. The ethylene production apparatus can be configured in various forms, for example, as a fixed-bed flow reactor equipped with a reactor packed with a powdery or granular methane oxidative coupling catalyst.

[0048] At this time, at least one of a proton conductor and an electron conductor (hereinafter, including a hole conductor) may be mixed with the methane oxidative coupling catalyst, if necessary. Various conventionally known proton conductors can be used as the proton conductor. Specifically, perovskite-type composite oxides such as BaZrO3, BaCeO3, SrZrO3, and SrCeO3 can be used. Furthermore, electron conductors can be selected from oxide electron conductors having a perovskite structure, oxide electron conductors having a spinel crystal structure, and metallic materials such as noble metals. Examples of oxide electron conductors having a perovskite structure include LSM-based oxides in which Sr is added to the La site of a LaMnO3-based compound, and composite oxides such as SrTiO3.

[0049] In the ethylene production apparatus, the methane oxidative coupling catalyst may be supported on a carrier having a granular or honeycomb shape, etc. In this case, the carrier may contain at least one of the above-described proton conductor and electron conductor.

[0050] FIG. 5 is an explanatory diagram showing the schematic configuration of an ethylene production apparatus 100 having a different structure as another example of an ethylene production apparatus. The ethylene production apparatus 100 in FIG. 5 includes a ceramic membrane 20, a first catalyst layer 22 formed on one side of the ceramic membrane 20, and a second catalyst layer 28 formed on the other side of the ceramic membrane 20. The ceramic membrane 20 is a gas-impermeable dense membrane made of ceramic. The ceramic membrane 20 has proton conductivity and electron conductivity and is formed, for example, from a mixture of the proton conductor and electron conductor described above. The ceramic membrane 20 divides the interior of the ethylene production apparatus 100 into two spaces: a first space 24 on the side where the first catalyst layer 22 is formed, and a second space 26 on the side where the second catalyst layer 28 is formed.

[0051] The first catalyst layer 22 contains the methane oxidative coupling catalyst of this embodiment. When methane is supplied to the first space 24 from a methane supply unit (not shown) and oxygen is supplied to the second space 26 from an oxygen supply unit (not shown), the reactions of the above-mentioned formulas (4) and (7) proceed in the first catalyst layer 22, producing ethylene. At the same time, the reaction of the above-mentioned formula (8) proceeds in the second catalyst layer 28. The catalyst included in the second catalyst layer 28 is preferably an oxide having mixed oxide ion-electron conductivity, such as La. 0.6 Sr 0.4 Co 0.2 Fe 0.8 O3 can be used.

[0052] Various modifications are possible to the ethylene production apparatus 100 of Fig. 5. For example, the ceramic membrane 20 may not have electronic conductivity, and an external circuit may be provided that electrically connects the first catalyst layer 22 and the second catalyst layer 28, so that power is generated in the ethylene production apparatus 100 in conjunction with ethylene production. Alternatively, the ceramic membrane 20 may have oxide ion conductivity instead of proton conductivity. Furthermore, in the ethylene production apparatus 100 of Fig. 5, an inert gas or carbon dioxide may be supplied to the second space 26 instead of oxygen.

[0053] Regardless of the configuration of the ethylene production apparatus to which the methane oxidative coupling catalyst of the present embodiment is applied, it is sufficient that the methane oxidative coupling catalyst is disposed at least at a location where the reaction of the above-described formula (4) proceeds. This promotes the reaction of formula (4) and improves the efficiency of ethylene production. [Example]

[0054] 6 and 7 are explanatory diagrams showing the results of evaluating the performance of 34 types of methane oxidative coupling catalysts, Samples 1 to 34. The configuration and manufacturing method of each sample, as well as the results of evaluating their performance, are described below. Of these methane oxidative coupling catalysts, Samples 1 to 29 are composite oxides that satisfy the aforementioned formulas (1) and formulas (2a) to (2d). Samples 30 to 34 are comparative examples.

[0055] <Preparation of each sample> [Sample 1] Catalyst sample 1 (BaZr 0.8 Sc 0.2 O3) was prepared by a complex polymerization method. The raw material powders used were barium nitrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), zirconyl nitrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and scandium nitrate (manufactured by Alfa Aesar). These raw material powders were mixed in a solution containing the metal elements in the composition formula BaZr 0.8 Sc 0.2The raw material powder was weighed to achieve the composition ratio in O3. Then, a citric acid solution and propylene glycol were added to the raw material powder so that the ratio of metal element:citric acid:propylene glycol was 1:3:3 (molar ratio), and the mixture was stirred and mixed at 80°C for 1 hour. This solution was then slowly heated to 300°C to obtain a polymer with each metal element dispersed therein. The resulting polymer was then carbonized by heat treatment at 400°C for 2 hours, and pulverized in an agate mortar to obtain a catalyst powder precursor. The resulting catalyst powder precursor was then heat treated at 1200°C for 6 hours to obtain a powdered methane oxidative coupling catalyst designated as Sample 1.

[0056] It was confirmed by powder XRD analysis that the powdered methane oxidative coupling catalysts obtained in Sample 1 and Samples 2 to 34 described later had the desired composition. Specifically, the results of the powder XRD analysis confirmed that a perovskite structure was obtained and that no peaks were observed from the raw material powder or from simple oxides (oxides containing only one element other than oxygen) or carbonates derived from the raw material powder. Furthermore, the specific surface area of ​​the powdered methane oxidative coupling catalysts obtained in Sample 1 and Samples 2 to 34 described later was measured by gas adsorption, and all were found to be 5 m 2 / g~10m 2 It was confirmed that the value was within the range of / g.

[0057] [Samples 2-34] Except that the types and weighed amounts of the raw material powders of the catalyst were adjusted to the composition ratios of the composition formulas of Samples 2 to 34 shown in FIGS. 6 and 7, and the heat treatment temperature of the catalyst powder precursor was set to the temperature shown in FIGS. 6 and 7, powdered methane oxidative coupling catalysts as Samples 2 to 34 were obtained in the same manner as Sample 1. In order to add each of barium, zirconium, scandium, yttrium, ytterbium, indium, neodymium, cerium, lanthanum, strontium, calcium, iron, and titanium as constituent elements, barium nitrate (manufactured by FUJIFILM Wako Pure Chemical Corporation), zirconyl nitrate (manufactured by FUJIFILM Wako Pure Chemical Corporation), scandium nitrate (manufactured by Alfa Aesar), yttrium nitrate (manufactured by Sigma-Aldrich), ytterbium nitrate (manufactured by Sigma-Aldrich), indium nitrate (manufactured by FUJIFILM Wako Pure Chemical Corporation), neodymium nitrate (manufactured by FUJIFILM Wako Pure Chemical Corporation), cerium nitrate (manufactured by FUJIFILM Wako Pure Chemical Corporation), lanthanum nitrate (manufactured by FUJIFILM Wako Pure Chemical Corporation), strontium nitrate (manufactured by FUJIFILM Wako Pure Chemical Corporation), calcium nitrate (manufactured by FUJIFILM Wako Pure Chemical Corporation), iron nitrate (manufactured by Sigma-Aldrich), and tetra-i-propoxytitanium (manufactured by High-Purity Chemical Research Institute Co., Ltd.) were used for the raw material powders.

[0058] <Measurement of C2 Yield> Each of Samples 1 to 34 was weighed at 0.1 g and placed in a fixed-bed flow-type reactor, and while heated to 750°C, a mixed gas of methane, oxygen, and nitrogen was set to CH4:O2:N2 = 3.8:1:4 in terms of flow rate ratio, and at 1 atm, 45 cm 3 / min was flowed to conduct a catalyst activity test. The composition analysis of the gas introduced into the apparatus and the discharged gas was performed using a micro gas chromatograph (manufactured by Agilent Technologies, 3000A). As a result of the composition analysis, the obtained C2 yields are shown in FIGS. 6 and 7. Note that the C2 hydrocarbons in the gas discharged from the above apparatus include ethane in addition to ethylene, and the ratio of ethylene in the obtained C2 hydrocarbons was about 60 to 70% in any sample (data not shown).

[0059] <Measurement of Total Conductivity> Each of Samples 1 to 34 was press-molded into a rectangular parallelepiped and sintered at 1600°C for 6 hours. Platinum wire was then wrapped around the sample in four places, after which platinum paste (TR-7905, manufactured by Tanaka Kikinzoku Kogyo Co., Ltd.) was applied over the wire and baked at 1000°C for 1 hour to prepare a measurement sample. Each measurement sample was placed in a tubular electric furnace and heated while humidified hydrogen was flowing through it using a bubbler. The total conductivity was measured at 750°C using the AC four-terminal method. The relative density of each sintered body used to measure the total conductivity was measured using the Archimedes method, and it was confirmed that all sintered bodies had a relative density of 96% or higher.

[0060] <Measurement of proton and electron / hole transport numbers> Each of Samples 1 to 34 was press-molded into a disk shape and sintered at 1600°C for 6 hours. Platinum paste was then screen-printed on both sides of the disk and baked at 1000°C for 1 hour to prepare a measurement sample. The transference number measurement device included two alumina tubes, one above the other, aligned axially. The measurement sample was sandwiched between the two alumina tubes, ensuring a gas seal between the alumina tubes and the measurement sample. The area containing the measurement sample was then placed in an electric furnace to measure the transference number. Specifically, the two alumina tubes were heated to 750°C using the electric furnace while humidified hydrogen with different concentrations or humidification levels was circulated through one and the other of the spaces separated by the measurement sample. The electromotive force generated between one and the other of the measurement sample was measured to determine the proton transference number and the electron / hole transference number (the sum of the electron and hole transference numbers).

[0061] <Derivation of proton conductivity> The proton conductivity was calculated by multiplying the total conductivity measured as above by the proton transport number.

[0062] As shown in Figures 6 and 7, Samples 1 to 29 showed higher C2 yields than Samples 30 to 34, and it was confirmed that the catalytic activity of a methane oxidative coupling catalyst can be enhanced by satisfying the above-mentioned formulas (1) and (2a) to (2d). Furthermore, Samples 1 to 29, which satisfied the above-mentioned formulas (1) and (2a) to (2d), all had a total conductivity of 1.0 x 10 -5 S / cm or more, 1.0×10 -1 Among samples 1 to 29, samples 1 to 4, 6 to 12, 15 to 17, 19, 20, 22 to 24, and 26 to 29 had a proton conductivity of 1.0 × 10 -4 S / cm or more. Furthermore, among Samples 1 to 29, Samples 1 to 24 and 26 to 29 had proton transference numbers of 0.01 or more. Furthermore, among Samples 1 to 29, Samples 1 to 20, 22 to 24, and 26 to 29 had a sum of the electron transference number and the hole transference number of 0.01 or more and 0.95 or less. Furthermore, among Samples 1 to 29, Samples 1 to 12, 15 to 17, 19, 20, 23, 24, and 26 to 29 had a proton transference number and a sum of the electron transference number and the hole transference number of 0.10 or more.

[0063] More specifically, for example, when the A' element (at least one of lanthanum (La) and yttrium (Y)) is contained in the A site of the perovskite structure, a comparison between Sample 13 and Sample 32 suggests that x≦0.4 (Equation (2a)) or x≦0.2 (Equation (2e)) is desirable. Furthermore, a comparison between Sample 5 and Samples 13 and 14, and a comparison between Sample 21 and Sample 25, for example, confirmed that catalytic activity tends to be improved, especially when x = 0. Furthermore, a comparison between Sample 5 and Samples 18 and 21, a comparison between Sample 1 and Samples 20 and 23, and a comparison between Sample 6 and Samples 19 and 22, for example, confirmed that catalytic activity tends to be improved by substituting barium (Ba) for the alkaline earth metal A element in Equation (1). In other words, it was confirmed that a methane oxidative coupling catalyst desirably has a perovskite structure represented by the general formula (3) described above.

[0064] Also, for example, from the comparison between Samples 1 to 5 and Sample 30, and the comparison between Samples 5 to 7 and Sample 31, it is considered desirable that "0 ≦ z ≦ 0.7" ((Equation (2b))). And, for example, from the comparison between Samples 1 to 4 and Sample 5, and the comparison between Samples 6 and 7 and Sample 5, it was confirmed that the catalytic activity tends to improve by setting "0 < z", particularly "0.2 ≦ z".

[0065] The present disclosure is not limited to the above-described embodiments and the like, and can be realized in various configurations without departing from the gist thereof. For example, the technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention can be appropriately replaced or combined in order to solve some or all of the above-described problems, or to achieve some or all of the above-described effects. Further, if the technical feature is not described as essential in this specification, it can be appropriately deleted.

[0066] The present disclosure can also be realized in the following forms. [Application Example 1] A dehydrogenation reaction catalyst, having a perovskite structure represented by the general formula (A1-xA'x)(Zr1-y-zByB'z)O3 (where A is at least one element selected from alkaline earth metals, A' is at least one element selected from lanthanum (La) and yttrium (Y), B is at least one element selected from titanium (Ti) and cerium (Ce), and B' is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), aluminum (Al), indium (In), and neodymium (Nd)), and the x, the y , and the z satisfy 0 ≦ x ≦ 0.4, 0.3 ≦ (1 - z) ≦ 1, 0 ≦ y, 0 < (1 - y - z), A dehydrogenation catalyst characterized by satisfying the above. [Application example 2] The dehydrogenation catalyst according to Application Example 1, The dehydrogenation catalyst is an alkane oxidative coupling catalyst that promotes an alkane oxidative coupling reaction that combines reactants containing at least one of an alkane and an alkane derivative. Dehydrogenation catalyst. [Application example 3] The dehydrogenation catalyst according to Application Example 2, The dehydrogenation catalyst is a methane oxidative coupling catalyst. Dehydrogenation catalyst. [Application example 4] The dehydrogenation catalyst according to any one of Application Examples 1 to 3, The total conductivity is 1.0×10 -5 S / cm or more, 1.0×10 -1 S / cm or less Dehydrogenation catalyst. [Application example 5] The dehydrogenation catalyst according to any one of Application Examples 1 to 4, Proton conductivity is 1.0×10 -4 S / cm or more Dehydrogenation catalyst. [Application Example 6] The dehydrogenation catalyst according to any one of Application Examples 1 to 5, characterized by a proton transference number of 0.01 or more Dehydrogenation catalyst. [Application Example 7] The dehydrogenation catalyst according to any one of Application Examples 1 to 6, The x is 0≦x≦0.2 A dehydrogenation catalyst characterized by satisfying the above. [Application Example 8] The dehydrogenation catalyst according to any one of Application Examples 1 to 7, The sum of the electron transport number and the hole transport number is 0.01 or more and 0.95 or less. Dehydrogenation catalyst. [Application Example 9] The dehydrogenation catalyst according to any one of Application Examples 1 to 8, The proton transport number and the sum of the electron transport number and the hole transport number are each 0.10 or more. Dehydrogenation catalyst. [Application Example 10] The dehydrogenation catalyst according to any one of Application Examples 1 to 9, A dehydrogenation catalyst characterized by having a perovskite structure represented by the general formula BaZr1-zB'zO3 (wherein B' is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), indium (In), and neodymium (Nd)). [Application Example 11] A composite catalyst comprising: A dehydrogenation catalyst according to any one of Application Examples 1 to 10, and at least one of a metal catalyst and an oxide catalyst. Composite catalyst. [Application Example 12] A supported catalyst in which a catalyst component is supported on a support, The catalyst component comprises the dehydrogenation catalyst according to any one of Application Examples 1 to 10. Supported catalyst. [Application Example 13] A supported catalyst in which a catalyst component is supported on a support, The catalyst component comprises the composite catalyst according to claim 11. Supported catalyst. [Explanation of symbols]

[0067] 10...Methane oxidative coupling catalyst 20...Ceramics film 22...First catalyst layer 24…1st space 26…Second space 28…Second catalyst layer 100...Ethylene production equipment

Claims

1. A dehydrogenation catalyst comprising: General formula (A 1-x A' x ) (Zr 1-y-z B y B' z ) O 3 (wherein A is at least one element selected from alkaline earth metals calcium (Ca), strontium (Sr), and barium (Ba); A' is at least one element from lanthanum (La) and yttrium (Y); B is at least one element from titanium (Ti) and cerium (Ce); and B' is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), indium (In), and neodymium (Nd)), and the x, y, and z are 0≦x≦0.4, 0.3≦(1-z)<1, 0≦y, 0<(1-y-z), Fulfilling the dehydrogenation catalyst is a methane oxidative coupling catalyst; The total conductivity, which is the sum of the proton conductivity and the electron conductivity (including the hole conductivity), is 1.0 × 10 -5 S / cm or more, 1.0×10 -1 S / cm or less Dehydrogenation catalyst.

2. A dehydrogenation catalyst comprising: General formula (A 1-x A' x ) (Zr 1-y-z B y B' z ) O 3 (wherein A is at least one element selected from alkaline earth metals calcium (Ca), strontium (Sr), and barium (Ba); A' is at least one element from lanthanum (La) and yttrium (Y); B is at least one element from titanium (Ti) and cerium (Ce); and B' is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), indium (In), and neodymium (Nd)), and the x, y, and z are 0≦x≦0.4, 0.3≦(1-z)≦1, 0≦y, 0<(1-y-z), Fulfilling the dehydrogenation catalyst is a methane oxidative coupling catalyst; Proton conductivity is 1.0 × 10 -4 S / cm or more and 1.0×10 −1 S / cm or less Dehydrogenation catalyst.

3. The dehydrogenation catalyst according to claim 1 or 2, characterized in that the proton transport number is 0.01 or more Dehydrogenation catalyst.

4. The dehydrogenation catalyst according to claim 1 or 2, The x is 0≦x≦0.2 A dehydrogenation catalyst characterized by satisfying the above.

5. The dehydrogenation catalyst according to claim 1 or 2, The sum of the electron transport number and the hole transport number is 0.01 or more and 0.95 or less. Dehydrogenation catalyst.

6. The dehydrogenation catalyst according to claim 1 or 2, The proton transport number and the sum of the electron transport number and the hole transport number are each 0.10 or more. Dehydrogenation catalyst.

7. The dehydrogenation catalyst according to claim 1 or 2, A dehydrogenation catalyst characterized by having a perovskite structure represented by the general formula BaZr1-zB'zO3 (wherein B' is at least one element selected from yttrium (Y), scandium (Sc), ytterbium (Yb), indium (In), and neodymium (Nd)).

8. A composite catalyst comprising:

3. A methane oxidative coupling catalyst comprising the catalyst according to claim 1 or 2, and at least one of a metal catalyst using a metal selected from palladium (Pd), copper (Cu), iron (Fe), nickel (Ni), platinum (Pt), indium (In), manganese (Mn), ruthenium (Ru), strontium (Sr), zinc (Zn), and lithium (Li), and an oxide catalyst using an oxide selected from Li2CaSiO4, Li2SrSiO4, Ce2(WO4)3, and CeO2. Composite catalyst.

9. A supported catalyst in which a catalyst component is supported on a support, The catalyst component comprises the methane oxidative coupling catalyst according to claim 1 or 2. Supported catalyst.

10. A supported catalyst in which a catalyst component is supported on a support, The catalyst component comprises the composite catalyst according to claim 8. Supported catalyst.

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