Method for producing hydrocarbon synthesis catalyst, method for synthesizing hydrocarbon, method for synthesizing higher hydrocarbon, and hydrocarbon synthesis catalyst

Abstract

Provided is a method for producing a hydrocarbon synthesis catalyst, the method including: a support step for supporting a second element outside the skeleton of a first element-containing zeolite that contains a first element in the skeleton of the zeolite; and an interface-forming step for precipitating the first element outside the skeleton of the first element-containing zeolite to form an interface having the first element and the second element.

Description

Method for producing a hydrocarbon synthesis catalyst, method for synthesizing hydrocarbons, method for synthesizing higher hydrocarbons, and hydrocarbon synthesis catalyst

[0001] The present invention relates to a method for producing a hydrocarbon synthesis catalyst, a method for synthesizing hydrocarbons, a method for synthesizing higher hydrocarbons, and a hydrocarbon synthesis catalyst.

[0002] In recent years, with the aim of achieving carbon neutrality, carbon dioxide (CO2) ２ Technologies for the efficient recovery and reuse of carbon dioxide are being developed. For example, there is active development of carbon dioxide hydrogenation catalysts that efficiently synthesize useful substances such as methanol, which can be directly used as a raw material for chemicals and fuels, from carbon dioxide.

[0003] As a catalyst for the hydrogenation of carbon dioxide, for example, Non-Patent Document 1 discloses a catalyst in which zinc is supported on a zeolite with copper nanoparticles immobilized inside. In this catalyst, the copper is micronized to the nanometer order, and a copper-zinc (Cu-ZnO) interface that promotes methanol production from carbon dioxide is efficiently formed.

[0004] Ryokuto Kanomata, et al., “Development of Silicalite-1 encapsulated Cu-ZnO catalysts for methanol synthesis by CO2 hydrogenation”, Chemical Engineering Journal, Volume 485, 1 April, 2024, 149896.

[0005] The inventors have discovered a method for producing a hydrocarbon synthesis catalyst that can efficiently synthesize hydrocarbons.

[0006] One aspect of the present invention is a method for producing a hydrocarbon synthesis catalyst, comprising: a supporting step of supporting a second element outside the framework of a first-element-containing zeolite, which contains a first element within the framework of the zeolite; and an interface forming step of precipitating the first element outside the framework of the first-element-containing zeolite to form an interface having the first element and the second element.

[0007] One aspect of the present invention is a hydrocarbon synthesis catalyst comprising a zinc-containing zeolite having a zinc skeleton, and an interface comprising zinc precipitated outside the skeleton of the zinc-containing zeolite and zirconium oxide supported outside the skeleton of the zinc-containing zeolite.

[0008] According to one aspect of the present invention, a method for producing a hydrocarbon synthesis catalyst that can efficiently synthesize hydrocarbons can be provided.

[0009] This graph shows an example of the measurement results of the absorption peak in the example. This graph shows an example of the measurement results of the XPS peak in the example.

[0010] The following describes embodiments for carrying out the present invention. In this specification, unless otherwise specified, the "~" indicating a numerical range means that the numbers before and after it are included as the lower and upper limits. Furthermore, if only the upper limit of a numerical range represented by "~" has a unit specified, it means that the lower limit also has the same unit.

[0011] A method for producing a hydrocarbon synthesis catalyst according to an embodiment of the present invention (hereinafter sometimes simply referred to as "this embodiment") includes a supporting step of supporting a second element outside the framework of a first-element-containing zeolite, which contains a first element within the framework of the zeolite, and an interface forming step of precipitating the first element outside the framework of the first-element-containing zeolite to form an interface having the first element and the second element.

[0012] In conventional carbon dioxide hydrogenation catalysts, the thermal condensation of elements such as copper and zinc reduces the amount of copper-zinc (Cu-ZnO) interfaces, which are active sites for hydrocarbon (e.g., methanol) synthesis, and this can sometimes lead to a decrease in the carbon dioxide conversion efficiency, leaving room for improvement. The method for producing the hydrocarbon synthesis catalyst according to this embodiment was discovered based on the problems with conventional carbon dioxide hydrogenation catalysts. More specifically, the method for producing the hydrocarbon synthesis catalyst according to this embodiment provides a hydrocarbon synthesis catalyst that can synthesize hydrocarbons more efficiently.

[0013] The hydrocarbon synthesis catalyst according to this embodiment has an interface comprising zinc-containing zeolite, which contains zinc within the zeolite skeleton, with zinc precipitated outside the skeleton of the zinc-containing zeolite and zirconium oxide supported outside the skeleton of the zinc-containing zeolite.

[0014] The hydrocarbon synthesis catalyst according to this embodiment can synthesize hydrocarbons more efficiently.

[0015] The method for producing the hydrocarbon synthesis catalyst and the hydrocarbon synthesis catalyst according to this embodiment will be described in detail below.

[0016] (Method for producing a hydrocarbon synthesis catalyst) The method for producing a hydrocarbon synthesis catalyst according to this embodiment includes a supporting step of supporting a second element outside the framework of a first-element-containing zeolite, which contains a first element within the framework of the zeolite, and an interface forming step of precipitating the first element outside the framework of the first-element-containing zeolite to form an interface having the first element and the second element, and may optionally include an element-containing step A, an element-containing step B, and other steps.

[0017] In the method for producing a hydrocarbon synthesis catalyst according to this embodiment, the first element contained in the first element-containing zeolite precipitates outside the framework of the first element-containing zeolite in a monatomic state and dispersed outside the framework of the first element-containing zeolite by hydrogen reduction treatment. The precipitated first element reacts with the second element supported outside the framework of the first element-containing zeolite to form a composite oxide. Since the first element is contained in the composite oxide in a monatomic state, the interface between the first element and the second element (for example, ZnZrO) becomes an active site for hydrocarbon synthesis. ｘ The number of Zn-O-Zr sites in the catalyst increases, improving the carbon dioxide conversion efficiency.

[0018] <Supporting Process> The supporting process involves supporting the second element on the outside of the framework of a zeolite containing the first element within its framework.

[0019] <<Zeolite containing the first element>> Zeolite containing the first element is a zeolite that contains the first element within its framework.

[0020] <<<Zeolite>>> In this specification, "zeolite" refers to a material having a framework in which silicon (Si) and oxygen (O) are bonded in two or three dimensions.

[0021] In this specification, the state in which a zeolite contains the first element within its framework refers to a state in which silicon in the structure of the zeolite, that is, silicon in a crystal structure with silicon and oxygen as its framework, is substituted with the first element.

[0022] As for zeolites, there are no particular restrictions as long as they can contain the first element, and they can be appropriately selected according to the purpose. Examples include zeolites having an MFI structure. Zeolites having an MFI structure are sometimes referred to as ZSM-5 (Zeolite Socony Mobil-5) if they contain Al in their framework, and as silicalite-1 if they do not contain Al in their framework.

[0023] By adjusting the pore size of the zeolite, when using a hydrocarbon synthesis catalyst as a higher hydrocarbon synthesis catalyst, reaction molecules such as hydrocarbons can easily penetrate the pores, and the catalytic active sites can be effectively utilized. The pore size of the zeolite can be appropriately set depending on the number of carbon atoms of the target higher hydrocarbon. For example, when synthesizing higher hydrocarbons with 6 or more carbon atoms, 0.50 to 0.60 nm is preferred, and when synthesizing hydrocarbons with 5 or fewer carbon atoms, 0.30 to 0.50 nm is preferred.

[0024] <<<First Element>>> The first element is contained as part of the zeolite's framework and constitutes a portion of the first element-containing zeolite, and precipitates outside the zeolite framework through subsequent reduction treatment.

[0025] The first element is not particularly limited as long as it can react with the second element, which is supported outside the zeolite framework, to form an interface that serves as an active site for hydrocarbon synthesis. It can be appropriately selected according to the purpose. Examples of the first element include zinc, magnesium, titanium, chromium, gallium, cadmium, indium, gadolinium, samarium, yttrium, niobium, and praseodymium. Among these, zinc is preferred from the viewpoint of achieving good hydrocarbon synthesis efficiency.

[0026] There are no particular restrictions on the content of the first element in the first element-containing zeolite, and it can be appropriately selected according to the purpose. From the viewpoint of being able to stably contain the first element while maintaining the desired zeolite structure in the state of the first element-containing zeolite, it is preferable that the molar ratio of Si to the first element in the first element-containing zeolite is 20 mol / mol or more.

[0027] There are no particular restrictions on the method for measuring the content of element I in element I zeolite, and it can be appropriately selected depending on the purpose. For example, methods such as inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption spectrometry (AAS), and X-ray fluorescence analysis (XRF) can be used to measure the content of element I.

[0028] It is preferable that the zeolite containing the first element contains the first element in a monatomic state. When the first element is contained in the zeolite containing the first element in a monatomic state, it precipitates in a single-atom state, i.e., a highly dispersed state, during the reduction treatment described later. The precipitated first element, together with the oxide of the second element, efficiently forms a first-element-second-element composite interface that serves as an active site for hydrocarbon synthesis, thereby improving the carbon dioxide conversion efficiency.

[0029] There are no particular restrictions on the method for confirming whether the first element is precipitated in a highly dispersed state outside the framework of the first element-containing zeolite; it can be appropriately selected depending on the purpose. For example, ultraviolet-visible absorption spectroscopy (UV-Vis) can be used. For example, if the first element is zinc, and an absorption peak exists around 380 nm in the absorption spectrum of the first element-containing zeolite, it suggests the presence of large-particle zinc oxide (ZnO) on the first element-containing zeolite. That is, it suggests that the zinc present on the first element-containing zeolite is in an aggregated state and is in a low-dispersion state. On the other hand, if there is no absorption peak around 380 nm in the absorption spectrum of the first element-containing zeolite, it suggests that the zinc on the first element-containing zeolite exists in the form of fine particles. That is, it suggests that the zinc present on the first element-containing zeolite is in a highly dispersed state without aggregation.

[0030] As a measurement method for ultraviolet-visible spectroscopy, for example, the diffuse reflectance method, which is commonly used to measure the absorption spectrum of solids, can be used. The diffuse reflectance method can be used, for example, as described in "Masato Mamiya, 'Method for Measuring Absorption Spectra of Solids, Lecture 2: Diffuse Reflectance Method,' Spectroscopic Research, 1976, Vol. 25, No. 2, p. 99."

[0031] <<<Third Element>>> The first element-containing zeolite may contain a third element different from the first and second elements. This third element is an element that can synthesize higher hydrocarbons using hydrocarbons obtained by the hydrocarbon synthesis catalyst as raw materials. In other words, the hydrocarbon synthesis catalyst according to this embodiment can also be used as a higher hydrocarbon synthesis catalyst by the first element-containing zeolite containing the third element.

[0032] In this specification, "higher hydrocarbons" refers to aromatic compounds and aliphatic compounds having four or more carbon atoms.

[0033] The third element is not particularly limited as long as it can be used to synthesize higher hydrocarbons from hydrocarbons obtained by a hydrocarbon synthesis catalyst, and can be appropriately selected according to the purpose. Examples of such third elements include aluminum, iron, gallium, boron, zirconium, tin, and zinc. Among these, aluminum is preferred from the viewpoint of achieving good synthesis efficiency of higher hydrocarbons.

[0034] There are no particular restrictions on the content of the third element in the first element-containing zeolite, and it can be appropriately selected depending on the purpose. From the viewpoint of efficiently converting hydrocarbons to higher hydrocarbons, for example, the molar ratio of Si to the third element in the first element-containing zeolite is preferably 10 to 300, and more preferably 10 to 100.

[0035] There are no particular restrictions on the method for measuring the content of the third element in a first-element-containing zeolite, and it can be appropriately selected depending on the purpose. Examples of methods that can be used to measure the content of the third element include inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption spectrometry (AAS), and X-ray fluorescence analysis (XRF).

[0036] As the zeolite containing the third element and the first element, a suitably synthesized zeolite may be used, or a commercially available product may be used. The method for synthesizing the zeolite containing the third element and the first element will be described later.

[0037] <<Second Element>> The second element can be supported outside the framework of the (first element-containing) zeolite. The second element is not particularly limited and can be appropriately selected depending on the purpose, as long as it can react with the first element precipitated outside the framework of the first element-containing zeolite to form a composite oxide and create a first-element-second element composite interface that serves as an active site for hydrocarbon synthesis. Examples of second elements include zirconium and copper. Among these, zirconium is preferred from the viewpoint of good hydrocarbon synthesis efficiency.

[0038] In this specification, the state in which the second element is supported outside the zeolite framework refers to a state in which the second element is attached outside the zeolite framework. Preferably, the second element is dispersed and attached outside the zeolite framework in the form of an oxide.

[0039] There are no particular restrictions on the amount of the second element supported outside the framework of the first element-containing zeolite, and it can be appropriately selected depending on the purpose. However, from the viewpoint of achieving good hydrocarbon synthesis efficiency, it is preferable that the molar ratio of Si to the first element in the first element-containing zeolite is 20 mol / mol or more.

[0040] There are no particular restrictions on the method for supporting the second element outside the framework of the first element-containing zeolite, and a suitable method can be selected depending on the purpose. However, a preferred method is to impregnate the first element-containing zeolite with an aqueous solution containing second element ions, and then remove the water.

[0041] There are no particular restrictions on the temperature when impregnating a primary element-containing zeolite with an aqueous solution containing secondary element ions. The temperature can be set appropriately depending on the amount of secondary element to be supported outside the framework of the primary element-containing zeolite, for example, between 5°C and 30°C.

[0042] The concentration of secondary element ions in an aqueous solution containing secondary element ions is not particularly limited and can be appropriately set according to the amount of secondary element supported outside the framework of the primary element-containing zeolite, for example, it can be 0.1 to 0.5 mol / L.

[0043] There are no particular restrictions on the method for removing water after impregnating a primary element-containing zeolite with a secondary element ion aqueous solution, and the method can be appropriately selected depending on the purpose. Examples include heating to 30-60°C at room temperature or using a vacuum dryer. Furthermore, to efficiently remove moisture at a low temperature, a vacuum dryer or similar device may be used under reduced pressure. There are no particular restrictions on the time for removing moisture, and the time can be appropriately selected depending on the purpose of moisture removal, but from the viewpoint of work efficiency, 1 to 24 hours is preferred.

[0044] A zeolite containing a primary element may be impregnated with an aqueous solution containing secondary element ions, and after removing the water, the primary element-containing zeolite on which the secondary element is supported may be calcined to produce an oxide of the secondary element. There are no particular restrictions on the calcination method, and it can be appropriately selected according to the purpose, but it can be carried out in a calcination furnace or the like under air conditions at 400 to 600°C for 2 to 20 hours.

[0045] <Interface Formation Process> The interface formation process involves precipitating the first element outside the framework of the first element-containing zeolite to form an interface having the first and second elements.

[0046] In this specification, "interface having a first element and a second element" refers to a composite oxide of a first element and a second element (a state in which the first element is in contact with the second element) that exhibits a reducing effect due to an oxygen vacancy. Here, an oxygen vacancy is a state in which oxygen is deficient due to the difference between the valence of the first element and the valence of the second element. In oxygen vacancies in composite oxides, carbon dioxide (CO2) is present. ２ ) bond by accepting an oxygen atom, and the bonded carbon dioxide is sequentially hydrogenated to formate intermediate (HClO ＊ ) and methoxy intermediate (CH ３ O ＊ It is believed that methanol is produced and eliminated through the following process.

[0047] There are no particular restrictions on the method for precipitating the first element outside the framework of the first element-containing zeolite, and a suitable method can be selected depending on the purpose, but a method of hydrogen reduction of the first element-containing zeolite is preferred. Examples of a hydrogen reduction method for the first element-containing zeolite include flowing an inert gas containing 5 to 100 vol% hydrogen at 300 to 500°C, atmospheric pressure to 3 MPa, and a gas flow rate of 10 to 50 mL / min for 0.5 to 3 hours. Examples of inert gases used here include argon, helium, and nitrogen.

[0048] The interface is preferably composed of precipitated first elements in a monatomic or highly dispersed state. That is, it is preferable that the first element disperses on the surface of the second element by the hydrogen reduction treatment described above to form an interface. In this specification, "dispersed and precipitated" means that the first element precipitates outside the framework of the first element-containing zeolite in a monatomic state without aggregation. The inclusion of the first element in a highly dispersed state at the interface increases the number of interfaces between the first element and the second element that serve as active sites for hydrocarbon synthesis, thereby improving the carbon dioxide conversion efficiency.

[0049] There are no particular restrictions on the method for confirming whether the first element has precipitated and dispersed outside the framework of the first-element-containing zeolite; it can be appropriately selected depending on the purpose. For example, it can be determined by ultraviolet-visible absorption spectroscopy (UV-Vis). For example, if the first element is zinc, when an absorption peak exists around 380 nm in the absorption spectrum of the hydrocarbon synthesis catalyst, it suggests the presence of large-particle zinc oxide (ZnO) outside the framework of the first-element-containing zeolite. That is, it suggests that the zinc outside the framework of the first-element-containing zeolite is aggregated or otherwise in a low-dispersion state. On the other hand, when there is no absorption peak around 380 nm in the absorption spectrum of the hydrocarbon synthesis catalyst, it suggests that the zinc precipitated outside the framework of the first-element-containing zeolite exists in the form of fine particles. That is, it suggests that the zinc outside the framework of the first-element-containing zeolite exists in the form of fine particles without aggregation or other processes, and is in a high-dispersion state.

[0050] There are no particular restrictions on ultraviolet-visible spectroscopy, and the appropriate method can be selected depending on the purpose. Examples include transmission spectroscopy, diffuse reflectance spectroscopy, and specular reflectance spectroscopy. For example, when using diffuse reflectance spectroscopy as the measurement method for ultraviolet-visible spectroscopy, the absorption spectrum can be determined from the diffuse reflectance using the Kuberka-Munk model, etc.

[0051] Since an absorption spectrum is the sum of absorption spectra due to various factors, absorption peaks can sometimes be unclear or difficult to identify. In such cases, a differential absorption spectrum, obtained by differentiating the absorption spectrum with respect to wavelength, can be used. Using a differential absorption spectrum allows for clearer observation of absorption peaks that are obscured by large absorption peaks or baseline drift.

[0052] The crystallite size derived from the second element in the composite oxide is not particularly limited and can be appropriately selected depending on the purpose, but a smaller size is preferable, for example, 80 nm or less is more preferable, and 25 nm or less is even more preferable. When the crystallite size derived from the second element in the composite oxide is within the above range, the number of elements present on the crystal surface increases relative to the elements present inside the crystal, making it easier for hydrocarbon synthesis reactions to occur on the catalyst surface. This increases the reactivity per unit weight of the catalyst, resulting in good hydrocarbon synthesis efficiency.

[0053] There are no particular restrictions on the method for measuring the crystallite size derived from the second element in composite oxides, and it can be appropriately selected depending on the purpose. For example, one method is to calculate it using the Scherrer formula from the width of the diffraction lines measured by the XRD (X-ray Diffraction) method.

[0054] <Element Inclusion Process A> In element inclusion process A, prior to the loading process, the primary element is incorporated into the zeolite using an aqueous solution containing primary element ions. That is, in element inclusion process A, a zeolite containing primary elements is synthesized using an aqueous solution containing at least primary element ions and a silicon source that serves as a raw material for the zeolite.

[0055] Aqueous solutions containing primary element ions can be obtained, for example, by dissolving a salt containing primary element in an aqueous solution. Examples of primary element salts include salts of inorganic acids such as nitrates, carbonates, hydrochlorides, and sulfates, and salts of organic acids such as acetates, formates, lactates, oxalates, and citrates.

[0056] There are no particular restrictions on the amount of salt containing the first element that can be added, and it can be appropriately selected according to the purpose. However, it is preferable to adjust the amount of salt containing the first element so that the molar ratio of Si to the first element in the zeolite containing the first element is 20 mol / mol or more.

[0057] There are no particular restrictions on the silicon source, and it can be appropriately selected depending on the purpose. Examples include colloidal silica, silica gel, silica sol, water glass, fumed silica, silicon dioxide, fly ash, and silicon alkoxides. Examples of silicon alkoxides include tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), and tetrapropyl orthosilicate.

[0058] Organic structure-directing agents (OSDAs) can also be used to determine the lattice structure of the zeolite obtained by element-containing step A. Examples of OSDAs include compounds containing quaternary ammonium ions, pyridinium ions, alkylamines, and phosphonium ions.

[0059] Examples of compounds containing quaternary ammonium ions include tetrapropylammonium hydroxide (TPAOH), tetraammonium salts, and trimethyldamantylammonium salts.

[0060] When synthesizing MFI-type zeolites, it is preferable to use tetrapropylammonium salts such as TPAOH, tetrapropylammonium chloride (TPACl), and tetrapropylammonium bromide (TPABr) as organic structure-controlling agents, with TPAOH being particularly preferred. In this case, it is preferable to add TPAOH such that the Si / TPAOH (molar ratio) is 1 to 5.

[0061] In element-containing step A, alkali sources such as sodium hydroxide and potassium hydroxide may be added as needed. These alkali sources help in the formation of the zeolite crystal structure, and the alkali ions contained in the alkali sources also act as charge compensation for the zeolite crystal structure.

[0062] Water may be added to the raw material solution containing primary element ions, a silicon source, and OSDA. The addition of water hydrolyzes the alkoxide of the silicon source, promoting zeolite synthesis. The amount of water added, when the silicon source and OSDA are aqueous solutions, is calculated by adding the water contained in them to the total amount of H ２ It is preferable to add O / Si so that the molar ratio is between 10 and 100.

[0063] The above raw material liquid may be stirred in order to homogenize it or to allow the hydrolysis of the silicon source alkoxide to proceed slowly. The preferred temperature at this time is 0 to 50°C, and the preferred stirring time is 5 to 300 minutes.

[0064] Zeolite can be formed by heating the stirred raw material liquid in an autoclave and performing hydrothermal synthesis. The temperature of the water in the autoclave may be, for example, 80 to 180°C or 80 to 160°C. The time for hydrothermal synthesis may be, for example, 24 to 120 hours.

[0065] The product (precipitate) obtained by hydrothermal synthesis is separated from water. The method for separating the product from water may be at least one selected from the group consisting of, for example, filtration, centrifugation, and evaporation of water by heating or reduced pressure.

[0066] Salts and other unwanted substances adhering to the product obtained by separation from water may be removed by washing with distilled water or deionized water. As a washing method, the product may be rinsed with pure water, or it may be separated as a precipitate by adding water and using the same method as described in "Method for separating the product from water" above.

[0067] The product after washing may be dried in a reduced pressure atmosphere or a vacuum atmosphere. Alternatively, the product may be dried by heating.

[0068] By firing the dried product, a hydrocarbon synthesis catalyst according to this embodiment can be obtained. When using an OSDA, the template agent is burned out by firing the product. The firing temperature may be, for example, 40 to 600 °C. The firing time may be, for example, 1 to 48 hours. The firing atmosphere may be air or an oxidizing atmosphere. When the firing temperature and the firing time are within the above ranges, the template agent is easily burned out sufficiently, and excessive growth and aggregation of the zeolite are suppressed.

[0069] <Element-containing step B> In element-containing step B, before the loading step, an aqueous solution containing first element ions and third element ions is used to incorporate the first element and the third element into the zeolite. That is, in element-containing step B, a zeolite containing the first element and the third element is synthesized using an aqueous solution containing at least the first element ions, the third element ions, and a silicon source as a raw material for the zeolite.

[0070] The aqueous solution containing the first element ions and the third element ions can be obtained by dissolving a salt containing the third element in the raw material solution prepared in the same manner as in element-containing step A. Examples of the salt containing the third element include salts of inorganic acids such as nitrates, carbonates, hydrochlorides, and sulfates, salts of organic acids such as acetates, formates, lactates, oxalates, and citrates, and oxides such as Al ２ O ３ and the like can be used.

[0071] The content of the third element in the first element-containing zeolite is not particularly limited and can be appropriately selected according to the purpose. From the viewpoint of efficiently converting hydrocarbons into higher hydrocarbons, the Si / third element molar ratio in the first element-containing zeolite is preferably 10 to 100.

[0072] In element-containing step B, in order to maintain the charge balance caused by the third element, a salt that supplies a counter cation may be newly added. As the salt that supplies the counter cation, a salt composed of an alkali metal ion and a halogen ion can be used. Specific examples of the salt that supplies the counter cation include LiCl, NaCl, KCl, LiCl, LiBr, NaBr, and KBr.

[0073] The amount of salt added to supply the countercation is not particularly limited and can be appropriately selected according to the purpose, but it is preferable to add an amount that can maintain the charge balance when the third element is introduced into the first element-containing zeolite. When the third element is aluminum, the amount of salt added to supply the countercation is preferably such that the amount of cation is equal to or greater than the amount of aluminum in molar ratio, with a Si / cation molar ratio of 0.5 to 100.

[0074] The raw material liquid containing primary and tertiary element ions may be subjected to stirring, hydrothermal synthesis, separation, washing, and calcination, as described in the section <Elemental Containment Process A> above. The conditions for each step may also be the same as those described in the section <Elemental Containment Process A> above.

[0075] The zeolite containing the first and third elements obtained in element-containing step B may form acid sites by ion-exchanging countercations with protons to maintain the charge balance of the third element. This can improve the efficiency of converting hydrocarbons to higher hydrocarbons.

[0076] Methods for ion-exchanging the countercations of a first-element-containing zeolite, in which the first and third elements are contained, for example, by treating it with inorganic acids such as hydrochloric acid, nitric acid, and sulfuric acid, or organic acids such as acetic acid and oxalic acid.

[0077] Alternatively, the cations may be exchanged for protons by ion exchange with ammonium ions through treatment with a solution containing ammonium ions, followed by calcination. One example of this method is as follows: 1 g of first-element-containing zeolite containing the first and third elements, and 1 MNH ４ After adding 5 to 20 mL of aqueous Cl solution, let it stand at 40 to 80°C for 10 to 120 minutes, discard the supernatant, and filter by suction. Repeat this procedure 1 to 5 times, then wash with warm water 1 to 5 times, dry at 110°C for 5 to 24 hours, and then calcine at 400 to 600°C for 1 to 48 hours.

[0078] [XPS Evaluation] Hydrocarbon synthesis catalysts obtained by the method for producing hydrocarbon synthesis catalysts can be analyzed on the surface using X-ray photoelectron spectroscopy (XPS) to measure the concentrations of various elements on the surface of the hydrocarbon synthesis catalyst. Furthermore, information about the bonding state of each element can be obtained from the obtained electron binding energy, and the component ratio of each bonding state can be determined by waveform separation.

[0079] (Method for synthesizing hydrocarbons) The method for synthesizing hydrocarbons according to this embodiment includes a hydrocarbon synthesis step of supplying carbon dioxide and hydrogen to a hydrocarbon synthesis catalyst produced by a method for producing hydrocarbon synthesis catalysts to synthesize hydrocarbons, and may include other steps as needed. The method for producing the hydrocarbon synthesis catalyst in this embodiment is the same as the (Method for producing hydrocarbon synthesis catalyst) described above, so redundant explanations are omitted. The hydrocarbon synthesis catalyst produced by the method for producing hydrocarbon synthesis catalysts may or may not contain a third element.

[0080] <Hydrogen Synthesis Process> In the hydrocarbon synthesis process, hydrocarbons are synthesized by supplying carbon dioxide and hydrogen to a hydrocarbon synthesis catalyst produced by a hydrocarbon synthesis catalyst production method.

[0081] When carbon dioxide and hydrogen are supplied to the hydrocarbon synthesis catalyst, the interface in the composite oxide containing the first and second elements becomes an active site, and hydrocarbon synthesis is promoted. A specific example of the hydrocarbon synthesized is methanol (CH4), which is synthesized by the reaction of formula (1) below. ３ Dimethyl ether (CH) produced by the dehydration condensation of OH) and synthesized methanol. ３ OCH ３ Examples include: CO ２ +3H ２ →CH ３ OH + H ２ O ... (1)

[0082] There are no particular limitations on the hydrocarbon synthesis means that can carry out the hydrocarbon synthesis process, and they can be appropriately selected according to the purpose. For example, a catalytic bed system can be used. As for the catalytic bed system, any type can be used, such as a fixed bed, boiling bed, fluidized bed, and moving bed. Among these, it is preferable to use a high-pressure fixed-bed flow reactor.

[0083] [Catalytic Activity Evaluation] There are no particular restrictions on the method for evaluating the activity of hydrocarbon synthesis catalysts in hydrocarbon synthesis processes, and a suitable method can be selected depending on the purpose. For example, one method involves using a high-pressure fixed-bed flow reactor and measuring the concentration and amount of reactants, gaseous products, and liquid products.

[0084] (Higher Hydrocarbon Synthesis Process) The higher hydrocarbon synthesis process according to this embodiment includes a hydrocarbon synthesis process in which carbon dioxide and hydrogen are supplied to a hydrocarbon synthesis catalyst produced by the hydrocarbon synthesis catalyst production method according to this embodiment to synthesize hydrocarbons, and a higher hydrocarbon synthesis process in which higher hydrocarbons are synthesized using hydrocarbons, and may include other processes as needed. Note that the hydrocarbon synthesis process in this embodiment is the same as the (hydrocarbon synthesis method) described above, so redundant explanations will be omitted. Note that the hydrocarbon synthesis catalyst produced by the hydrocarbon synthesis catalyst production method according to this embodiment contains a third element in the first element-containing zeolite.

[0085] <Higher Hydrocarbon Synthesis Process> The higher hydrocarbon synthesis process is a process of synthesizing higher hydrocarbons using the hydrocarbons obtained in the hydrocarbon synthesis process. The hydrocarbon synthesis catalyst produced by the method for producing the hydrocarbon synthesis catalyst according to this embodiment contains a third element in the first element-containing zeolite, so the third element acts as an active site, and higher hydrocarbons are synthesized.

[0086] Conventional methods for synthesizing higher hydrocarbons required multiple plants to perform a multi-step process: synthesizing methanol by a hydrogenation reaction of carbon dioxide, and then synthesizing higher hydrocarbons by a conversion reaction of methanol (meaning methanol denaturation). The hydrocarbon synthesis catalyst produced by the method for producing hydrocarbon synthesis catalysts according to this embodiment can be used as a higher hydrocarbon synthesis catalyst because the first element-containing zeolite contains a third element, allowing the conventional multi-step process to be performed in a single pass. In other words, by using the hydrocarbon synthesis catalyst produced by the method for producing hydrocarbon synthesis catalysts according to this embodiment, higher hydrocarbons can be synthesized with a single catalyst and a single reactor.

[0087] (Hydrogen synthesis catalyst) The hydrocarbon synthesis catalyst according to this embodiment has an interface comprising zinc-containing zeolite containing zinc within the zeolite skeleton, zinc precipitated outside the skeleton of the zinc-containing zeolite, and zirconium oxide supported outside the skeleton of the zinc-containing zeolite. Furthermore, it is preferable that the zinc-containing zeolite contains aluminum within the skeleton of the zinc-containing zeolite.

[0088] Since the hydrocarbon synthesis catalyst according to this embodiment is the same as the hydrocarbon synthesis catalyst described above (method for producing a hydrocarbon synthesis catalyst), redundant explanations will be omitted.

[0089] The embodiment will be described in more detail below with reference to examples, but the embodiment is not limited to the following examples.

[0090] (Preparation of raw materials for hydrocarbon synthesis catalyst) <Preparation of MFI> The following materials were mixed and stirred for 10 minutes, then hydrothermally treated in an autoclave at 150°C for 72 hours, and centrifuged to obtain a precipitate. The precipitate obtained by centrifugation was washed three times with distilled water, dried overnight at 110°C, and then calcined in air at 500°C for 12 hours to obtain zeolite MFI that does not contain zinc (first element) or aluminum (third element). [Materials] ・Aqueous solution of tetrapropylammonium hydroxide (TPAOH) (TPAOH 10%, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.): 68.523 g ・Colloidal silica (Snowtex 50-T, manufactured by Nissan Chemical Corporation (SiO ２ (48%)): 12.604g • Distilled water: 40.937g

[0091] <Preparation of Zn-MFI> The following materials were mixed and stirred for 10 minutes, then hydrothermally treated in an autoclave at 150°C for 72 hours, and centrifuged to obtain a precipitate. The precipitate obtained by centrifugation was washed three times with distilled water, dried overnight at 110°C, and then calcined in air at 500°C for 12 hours to obtain Zn-MFI (elemental first zeolite) in which zinc (elemental first) was contained in MFI (MFI-type zeolite). [Materials] ・TPAOH aqueous solution: 68.523 g ・Colloidal silica: 12.604 g ・Zn(CH ３ COO) ２ ・2H ２ O (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.): 0.222 g • Distilled water: 40.937 g

[0092] <Preparation of Zn-Al-MFI> The following materials were mixed and stirred for 10 minutes, then hydrothermally treated in an autoclave at 150°C for 72 hours, and centrifuged to obtain a precipitate. The precipitate obtained by centrifugation was washed three times with distilled water, dried overnight at 110°C, and then calcined in air at 500°C for 12 hours to obtain Zn-Al-MFI containing zinc (first element) and aluminum (third element) in MFI (MFI-type zeolite). Next, ion exchange was performed on the Zn-Al-MFI from the Na type to the H type. 1 g of Zn-Al-MFI was mixed with 1 M NH ４After adding 10 mL of an aqueous Cl solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), the mixture was allowed to stand at 60°C for 30 minutes. The supernatant was discarded, and 1 M NH4 was added again. ４ After adding 10 mL of Cl aqueous solution, the mixture was allowed to stand at 60°C for 10 minutes. It was filtered by suction, washed three times with warm water, dried overnight at 110°C, and then calcined in air at 500°C for 12 hours. [Materials] ・TPAOH aqueous solution: 68.523 g ・Colloidal silica: 12.604 g ・Zn(CH ３ COO) ２ ・2H ２ O: 0.222g ・Al(NO ３ ) ３ 9H ２ O (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.): 0.190 g NaCl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.): 0.295 g Distilled water: 40.855 g

[0093] (Preparation of hydrocarbon synthesis catalysts) <Examples 1-4: ZrO ２ Preparation of Zn-MFI: Add a predetermined amount of ZrO(NO) to distilled water. ３ ) ２ ・2H ２ After impregnating Zn-MFI with an aqueous solution of dissolved oxygen, it was dried under reduced pressure at 50°C overnight in a vacuum dryer. Subsequently, by air calcination at 500°C for 12 hours, ZrO was laid outside the Zn-MFI framework. ２ ZrO with (second element) supported ２ / Zn-MFI was obtained as a hydrocarbon synthesis catalyst.

[0094] Note that the ZrO in Example 1 ２ In Zn-MFI, the Zn / Zr ratio (mol) is 0.94, so that ZrO(NO) ３ ) ２ ・2H ２ The amount of O added was adjusted. Similarly, in Example 2, the Zn / Zr ratio (mol) was adjusted to 0.31, in Example 3, to 0.14, and in Example 4, to 0.07.

[0095] <Example 3a: ZrO ２ Preparation of Zn-Al-MFI: Add a predetermined amount of ZrO(NO) to distilled water. ３ )２ ・2H ２ After impregnating Zn-Al-MFI with an aqueous solution of dissolved oxygen, it was dried under reduced pressure at 50°C overnight in a vacuum dryer. Subsequently, by air calcination at 500°C for 12 hours, ZrO was laid outside the Zn-Al-MFI framework. ２ ZrO with (second element) supported ２ / Zn-Al-MFI was obtained as a hydrocarbon synthesis catalyst. Note that ZrO ２ In Zn-Al-MFI, the Zn / Zr ratio (mol) is set to 0.14, so that ZrO(NO) ３ ) ２ ・2H ２ The amount of O added was adjusted.

[0096] <Comparative Example 1: ZnZrO Ｘ Preparation of MFI: 0.0363 g of ZnZrO Ｘ 1.0 g of ZnZrO was prepared by grinding and kneading 0.9637 g of MFI in a mortar for 10 minutes. Ｘ / MFI was obtained as a hydrocarbon synthesis catalyst. Note that ZnZrO Ｘ It was synthesized based on “Wang, et al., “A highly selective and stable ZnO-ZrO2 solid solution catalyst for CO2 hydrogenation to methanol”, Science Advanced, 6 October, 2017, Vol 3, Issue 10: e1701290.”

[0097] (Comparative Example 2) In Comparative Example 2, the synthesized Zn-MFI was used as a hydrocarbon synthesis catalyst.

[0098] (Evaluation of various properties of hydrocarbon synthesis catalysts) ZrO in the complex oxides contained in the hydrocarbon synthesis catalysts prepared in each of the above examples and comparative examples ２ Crystallite size, absorption peak of hydrocarbon synthesis catalyst, Zn ２ P ２／３ We evaluated the XPS peaks, the concentrations of various elements on the hydrocarbon synthesis catalyst surface, and the catalytic activity.

[0099] <ZrO in complex oxides ２Measurement of crystallite size > In the hydrocarbon synthesis catalysts of Examples 1 to 4 and Comparative Example 1, ZrO ２ The crystallite size was measured by XRD. The measurement conditions are shown below. The results are shown in Tables 1 to 3. [Crystallite size measurement conditions] ・Measurement device: SmartLab (manufactured by Rigaku Co., Ltd.) ・X-ray source: Cukα1 (λ = 0.154 nm) ・Scan speed: 1° / min ・Scan range: 5° to 80° ・Step size: 0.01°

[0100] [Results] As shown in Table 1, the hydrocarbon synthesis catalysts in Examples 1 to 4 were all ZrO ２ Since the crystallite size was 25 nm or less, it can be said that the particle size is small (i.e., there are many interfaces between the first and second elements). In other words, it was confirmed that the reactivity per unit weight of the catalyst is high and the hydrocarbon synthesis efficiency is good. On the other hand, from Table 3, Comparative Example 1's ZnZrO Ｘ / MFI is ZrO ２ Since the crystallite size exceeded 80 nm, it can be said that the particle size is very large (i.e., there are few interfaces between the first and second elements). In other words, it was confirmed that the reactivity per unit weight of the catalyst is low, and the hydrocarbon synthesis efficiency is poor.

[0101] <Measurement of Absorption Peaks> The absorption peaks of the hydrocarbon synthesis catalysts of Example 3 and Comparative Examples 1 and 2 were measured by ultraviolet-visible spectroscopy (UV-Vis). Based on the differential absorption spectrum obtained by differentiating the obtained absorption spectrum with respect to wavelength, the aggregation state of zinc outside the zeolite framework was evaluated. In the differential absorption spectrum, the line connecting 330 to 430 nm was used as the baseline, and the difference between the peak top value between 350 and 400 nm and the baseline value at the peak top wavelength was defined as ΔPeak. A ΔPeak greater than 0.0010 was considered an indicator of a low-dispersion state. The main measurement conditions are shown below. The measurement results are shown in Tables 2-3 and Figure 1. -Measurement conditions for ultraviolet-visible spectroscopy (UV-Vis)- -Measurement device: V-670 (manufactured by JASCO Corporation) -Bandwidth: 5.0 nm -Scanning speed: 400 nm / min -Scanning range: 180 nm to 700 nm -Data acquisition interval: 1.0 nm

[0102] [Results] From Table 3, the ZrO of Example 3 ２ In the case of Zn / MFI and the Zn-MFI of Comparative Example 2, there was no absorption peak around 380 nm. This confirmed that the zinc outside the zeolite framework existed as fine particles without aggregation, indicating a highly dispersed state. In the case of ZnZrOx / MFI of Comparative Example 1, there was an absorption peak around 380 nm. This confirmed that the zinc outside the zeolite framework had aggregated, indicating a low-dispersion state.

[0103] <Measurement of X-ray photoelectron spectroscopy (XPS) peaks> For Example 3, Example 3a, and Comparative Examples 1 and 2, Zn ２ P ２／３ The XPS peak of Zn was measured based on the following XPS peak measurement conditions. ２ P ２／３ The binding energy was waveform-separated into a peak corresponding to ZnO and a peak corresponding to Zn(0), and the abundance ratio of each chemical state (Zn / ZnO) was determined from the area of ​​the separated peaks. The measurement results are shown in Tables 2-3 and Figure 2. [XPS Peak Measurement Conditions] ・Measurement device: ULVAC-PHI PHI X-tool ・X-ray source: AlKα ・X-ray output: 15kV (50W) ・Number of integrations: 30-50 times ・Pass Energy: 55eV ・Step: 0.1eV (Zn ２ P ３ / ２ 0.05 eV)

[0104] [Results] As shown in Table 3, in Example 3, the Zn / ZnO ratio was large at 1.57, and the proportion of peaks close to the reduced form Zn(0) was large. In contrast, in Comparative Examples 1 and 2, the Zn / ZnO ratios were 0.33 and 0.05, respectively, and the proportion of peaks close to ZnO was large.

[0105] From the above results, it is clear that Zn is in a reduced form than ZnO, therefore CO ２ It can be said that the reduction reaction is more pronounced even with respect to CO. Therefore, Example 3 has a higher reducing ability than Comparative Examples 1 and 2, and ２ It can be said to have excellent hydrocarbon purification capabilities through reduction.

[0106] <Measurement of various elemental concentrations on the surface of hydrocarbon synthesis catalysts> In the hydrocarbon synthesis catalysts of Example 3, Example 3a, and Comparative Examples 1 and 2, the concentrations of various elements on the catalyst surface were measured under the same conditions by X-ray photoelectron spectroscopy (XPS). Zn / Zr is the ratio when each element is calculated as a concentration (atomic %). Zn / ZnO is the ratio at the Zn peak when graphite is used as an internal standard and C1s correction is applied. Furthermore, the value R is obtained by dividing the (Zn / Zr) calculated by the above <Measurement of XPS peaks> by the Zn / Zr ratio (mol / mol), which is the value obtained by converting the composition ratio (molar ratio) of Zn and Zr. Ｚｎ／Ｚｒ The following was calculated. The results are shown in Tables 2 and 3.

[0107] [Result] Value R Ｚｎ／Ｚｒ This indicates the Zn / Zr composition ratio on the catalyst surface; the higher the value, the more ZrO is supported outside the catalyst framework. ｘ This means that there are many zinc particles on the surface. ZrO in Example 3 ２ / Zn-MFI value R Ｚｎ／Ｚｒ 73.40, and ZrO of Example 3a ２ / The value of Zn-Al-MFI R Ｚｎ／Ｚｒ The high value of 68.37 suggests that the ZrO supported outside the catalyst skeleton is ｘ It was confirmed that zinc nanoparticles were present at a high concentration on the surface. The ZnZrOx / MFI of Comparative Example 1 was value R Ｚｎ／Ｚｒ Since the value was 15.00, ZrO supported outside the catalyst skeleton ｘ It was confirmed that the amount of zinc particles present on the surface was at a low concentration.

[0108] <Evaluation of catalyst activity> The hydrocarbon synthesis catalysts of Examples 1-4, Example 3a, and Comparative Examples 1 and 2 were introduced into a high-pressure fixed-bed flow reactor, and the concentrations and amounts of reactants, gaseous products, and liquid products were measured to determine CO ２ The conversion rate and various yields were calculated. The reaction conditions of the high-pressure fixed-bed flow reactor and CO2 were used. ２ The conversion rate, product selectivity, and yield are as follows:

[0109] [Conditions of High-Pressure Fixed-Bed Flow Reactor] - Pretreatment: After raising the catalyst temperature to 400 °C and holding it, hydrogen (H ２ ), and argon (Ar) are supplied to the catalyst for 1 hour of reduction treatment. - Temperature: 350 °C - Pressure: 2 MPa - Raw materials: H ２ :CO ２ :N ２ = 20:6:1 - Raw material flow rate: 30 mL·min －１ - GHSV (Space Velocity, Gaseous Hourly Space Velocity): 3600 mL·h －１ ·g ｃａｔ －１

[0110] [[ID=十七]] [CO ２ Conversion Rate X ＣＯ２ The CO ２ conversion rate X ＣＯ２ was determined by the following formula.

[0111]

[0112] [Selectivity S Ａ of Product] The selectivity S Ａ of the product was determined by the following formula.

[0113]

[0114] [Yield Y Ａ of Product] The yield Y Ａ of the product was calculated by multiplying the conversion rate X ２ of CO by the selectivity S ＣＯ２ of the product and then multiplying by 100. That is, the yield Y Ａ of the product was determined by the following formula. Ａ was obtained by the following formula.

[0115]

[0116] [Results] From Table 1, for ZrO ２ / Zn-MFI of Examples 1 to 4, the CO ２ conversion rate, and the yields of methanol and dimethyl ether were all good. In particular, as the supported amount of the second element increased (i.e., the Zn / Zr ratio (mol) decreased), the yields of methanol and dimethyl ether also increased. From Table 2, for ZrO of Example 3a２ / Zn-Al-MFI is CO ２ The conversion rate was good. Furthermore, higher hydrocarbons of C4 or higher could be synthesized using the synthesized methanol, and since the yields of methanol and dimethyl ether were high, it can be said that the yield of these higher hydrocarbons was also good. These results in each example are thought to be due to the fact that the first element is contained in the composite oxide in a monatomic state, which increases the number of interfaces between the first and second elements that serve as active sites for hydrocarbon synthesis, thereby improving the conversion efficiency of carbon dioxide.

[0117] Table 3 shows that in both cases, when using the catalysts of Comparative Examples 1 and 2, CO ２ The conversion yield was low, resulting in low yields of methanol and dimethyl ether, or making the synthesis of higher hydrocarbons impossible. The results in Comparative Examples 1 and 2 are thought to be due to the aggregation of elements such as zinc in the complex oxide, which reduces the number of interfaces between the first and second elements that serve as active sites for hydrocarbon synthesis in the complex oxide, thereby reducing the carbon dioxide conversion efficiency.

[0118]

[0119]

[0120]

[0121] As described above, embodiments of the present invention have been explained, but these embodiments are presented as examples only, and the present invention is not limited by these embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, or modifications are possible without departing from the spirit of the invention. The above embodiments and their variations are included in the scope or spirit of the invention, as well as in the scope of the invention and its equivalents as described in the claims.

[0122] The embodiments of the present invention disclosed above are further specified, for example, by the following embodiments: [1] A method for producing a hydrocarbon synthesis catalyst, comprising: a supporting step of supporting a second element outside the framework of a first-element-containing zeolite containing a first element within the framework of the zeolite; and an interface forming step of precipitating the first element outside the framework of the first-element-containing zeolite to form an interface having the first element and the second element. [2] The method for producing a hydrocarbon synthesis catalyst according to [1], wherein the first element is zinc. [3] The method for producing a hydrocarbon synthesis catalyst according to [1] or [2], wherein the second element is zirconium. [4] The method for producing a hydrocarbon synthesis catalyst according to any one of [1] to [3], wherein the interface contains the first element in a monatomic state. [5] The method for producing a hydrocarbon synthesis catalyst according to any one of [1] to [4], comprising an element-containing step A before the supporting step, in which the first element is incorporated into the zeolite using an aqueous solution containing first-element ions. [6] The method for producing a hydrocarbon synthesis catalyst according to any one of [1] to [5], wherein the first element-containing zeolite contains a third element different from the first element and the second element. [7] The method for producing a hydrocarbon synthesis catalyst according to [6], wherein the third element is aluminum. [8] The method for producing a hydrocarbon synthesis catalyst according to [6] or [7], further comprising an element-containing step B before the supporting step, in which the first element and the third element are incorporated into the zeolite using an aqueous solution containing the first element ions and the third element ions. [9] The method for producing a hydrocarbon synthesis catalyst according to any one of [1] to [8], wherein the supporting step involves impregnating the first element-containing zeolite with an aqueous solution containing the second element ions, and then removing the water to support the second element outside the framework of the first element-containing zeolite.

[10] The method for producing a hydrocarbon synthesis catalyst according to [9], wherein the water is removed by heating.

[11] The method for producing a hydrocarbon synthesis catalyst according to any one of [1] to

[10] , wherein the interface formation step involves hydrogen reduction of the first element-containing zeolite to precipitate the first element outside the framework of the first element-containing zeolite.

[12] A method for synthesizing hydrocarbons, comprising a hydrocarbon synthesis step of supplying carbon dioxide and hydrogen to the hydrocarbon synthesis catalyst produced by any one of [1] to

[11] to synthesize hydrocarbons.

[13] A method for synthesizing higher hydrocarbons, comprising: a hydrocarbon synthesis step of supplying carbon dioxide and hydrogen to the hydrocarbon synthesis catalyst produced by the method for producing hydrocarbon synthesis catalysts according to [6] or [7] to synthesize hydrocarbons; and a higher hydrocarbon synthesis step of synthesizing higher hydrocarbons using the hydrocarbons.

[14] A hydrocarbon synthesis catalyst having an interface in a zinc-containing zeolite containing zinc in the skeleton of the zeolite, the interface containing zinc deposited outside the skeleton of the zinc-containing zeolite and zirconium oxide supported outside the skeleton of the zinc-containing zeolite.

[15] The hydrocarbon synthesis catalyst according to

[14] , wherein the zinc-containing zeolite contains aluminum in the skeleton of the zinc-containing zeolite.

[0123] This application claims priority based on Japanese Patent Application No. 2025-27272, filed with the Japan Patent Office on 21 February 2025, and incorporates all the contents of the said application.

Claims

1. A method for producing a hydrocarbon synthesis catalyst, comprising: a supporting step of supporting a second element outside the framework of a first-element-containing zeolite, which contains a first element within the framework of the zeolite; and an interface forming step of precipitating the first element outside the framework of the first-element-containing zeolite to form an interface having the first element and the second element.

2. The method for producing a hydrocarbon synthesis catalyst according to claim 1, wherein the first element is zinc.

3. The method for producing a hydrocarbon synthesis catalyst according to claim 1 or 2, wherein the second element is zirconium.

4. The method for producing a hydrocarbon synthesis catalyst according to claim 1 or 2, wherein the interface contains the first element in a monatomic state.

5. A method for producing a hydrocarbon synthesis catalyst according to claim 1 or 2, comprising an element-containing step A, in which an aqueous solution containing primary element ions is used to incorporate the primary element into the zeolite prior to the supporting step.

6. The method for producing a hydrocarbon synthesis catalyst according to claim 1, wherein the zeolite containing the first element contains a third element different from the first element and the second element.

7. The method for producing a hydrocarbon synthesis catalyst according to claim 6, wherein the third element is aluminum.

8. A method for producing a hydrocarbon synthesis catalyst according to claim 6 or 7, comprising an element-containing step B, in which, prior to the supporting step, an aqueous solution containing a first element ion and a third element ion is used to incorporate the first element and the third element into the zeolite.

9. The method for producing a hydrocarbon synthesis catalyst according to claim 1 or 2, wherein the supporting step involves impregnating the first element-containing zeolite with an aqueous solution containing second element ions, and then removing the water to support the second element outside the framework of the first element-containing zeolite.

10. The method for producing a hydrocarbon synthesis catalyst according to claim 9, wherein the water is removed by heating.

11. The method for producing a hydrocarbon synthesis catalyst according to claim 1 or 2, wherein the interface formation step involves hydrogen reduction of the first element-containing zeolite to precipitate the first element outside the framework of the first element-containing zeolite.

12. A method for synthesizing hydrocarbons, comprising a hydrocarbon synthesis step of supplying carbon dioxide and hydrogen to the hydrocarbon synthesis catalyst produced by the method for producing a hydrocarbon synthesis catalyst according to claim 1 or 2 to synthesize hydrocarbons.

13. A method for synthesizing a higher hydrocarbon, comprising: a hydrocarbon synthesis step of supplying carbon dioxide and hydrogen to the hydrocarbon synthesis catalyst produced by the method for producing a hydrocarbon synthesis catalyst according to claim 6 or 7 to synthesize a hydrocarbon; and a higher hydrocarbon synthesis step of synthesizing a higher hydrocarbon using the hydrocarbon.

14. A hydrocarbon synthesis catalyst comprising a zinc-containing zeolite having zinc within its skeleton, and an interface comprising zinc precipitated outside the skeleton of the zinc-containing zeolite and zirconium oxide supported outside the skeleton of the zinc-containing zeolite.

15. The hydrocarbon synthesis catalyst according to claim 14, wherein the zinc-containing zeolite contains aluminum within the skeleton of the zinc-containing zeolite.

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