Method for producing inorganic compound powder and method for producing inorganic compound powder catalyst

Abstract

To provide a method for producing inorganic compound powder and a method for producing inorganic compound powder catalyst, which can be manufactured simply and at low cost using inexpensive and easy-to-handle metal oxides. [Solution] A method for producing an inorganic compound powder containing a metal element and a nonmetal element, comprising the steps of heating and reducing a raw material mixture containing a predetermined metal oxide, one or more reducing agents selected from the group consisting of alkali metals, alkali metal hydrides, alkali metal borides, alkaline earth metals, alkaline earth metal hydrides, and alkaline earth metal borides, and one or more molten salt sources selected from the group consisting of alkali metal salts and alkaline earth metal salts, in the presence of an inert gas to obtain a product, wherein the raw material mixture contains a substance containing the nonmetal element.

Description

[Technical Field]

[0001] This disclosure relates to a method for producing inorganic compound powder and a method for producing inorganic compound powder catalyst. [Background technology]

[0002] Inorganic compounds, such as hydrides, borides, carbides, nitrides, phosphides, and sulfides, are used in a wide range of fields, including hydrogen storage materials, conductive materials, and rigid materials, and there is a need for technological development regarding the manufacturing methods of inorganic compounds. For example, Patent Document 1 discloses a method for producing titanium hydride by reacting a titanium material with hydrogen, characterized in that hydrogen is introduced into a reaction vessel containing the titanium material and heated, and when the decreasing trend of the reaction rate between the hydrogen and the titanium material saturates, the heating is stopped and the vessel is rapidly cooled, and the contact treatment between the hydrogen and the titanium material is continued thereafter. In Patent Document 1, sponge titanium is used as the titanium material. Furthermore, Patent Document 2 discloses a method for producing TiB2 powder, which includes reducing titanium oxide with carbon in the presence of a boron source, and comprises heating a mixture of predetermined raw materials at a temperature of over 1500°C and less than 2000°C in proportions that bring about predetermined reduction, characterized in that the method is performed under predetermined conditions. Furthermore, Patent Document 3 discloses a method for producing tantalum carbide, in which tantalum material, sandwiched between a pair of graphite guide members, is heated at 1500°C or higher for 0.5 hours or more in an atmosphere of carbon source-containing gas. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2013-091588 [Patent Document 2] Special Publication No. 2024-535934 [Patent Document 3] Japanese Patent Publication No. 2020-100530 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, the methods described above required the use of expensive and difficult-to-handle elemental metals as raw materials, as well as heating to temperatures exceeding 1500°C. High-temperature heating also necessitated expensive equipment capable of handling high temperatures. This disclosure provides a method for producing inorganic compound powder and a method for producing inorganic compound powder catalyst, which can be produced simply and at low cost using inexpensive and easy-to-handle metal oxides. [Means for solving the problem]

[0005] This disclosure is, A method for producing an inorganic compound powder containing a metallic element and a non-metallic element, A metal oxide containing one or more elements selected from the group consisting of transition metals of periods 4-6 and groups 3-12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides, One or more reducing agents selected from the group consisting of alkali metals, alkali metal hydrides, alkali metal borides, alkaline earth metals, alkaline earth metal hydrides, and alkaline earth metal borides, One or more molten salt sources selected from the group consisting of alkali metal salts and alkaline earth metal salts, The process includes heating and reducing a raw material mixture containing an inert gas in the presence of an inert gas to obtain a product. The present invention relates to a method for producing an inorganic compound powder, wherein the raw material mixture includes a substance containing the nonmetallic element.

[0006] Furthermore, this disclosure is, A method for producing an inorganic compound powder catalyst containing a metal element and a nonmetal element, A metal oxide containing one or more elements selected from the group consisting of transition metals of the 4th to 6th periods, groups 3 to 12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanoids, One or more reducing agents selected from the group consisting of alkali metals, alkali metal hydrides, alkali metal borohydrides, alkaline earth metals, alkaline earth metal hydrides, and alkaline earth metal borohydrides, One or more molten salt sources selected from the group consisting of alkali metal salts and alkaline earth metal salts, A step of heating and reducing a raw material mixture containing the above in the presence of an inert gas to obtain a product, <0000□73>The present invention relates to a method for producing an inorganic compound powder catalyst, wherein the raw material mixture contains a substance containing the non-metallic element.

Effect of the Invention

[0007] According to the present disclosure, there are provided a method for producing an inorganic compound powder and a method for producing an inorganic compound powder catalyst, which can produce an inorganic compound powder simply and at low cost by using a metal oxide that is inexpensive and easy to handle.

Brief Description of the Drawings

[0008] <000008■> [Figure 1] It is an explanatory diagram showing an X-ray diffraction pattern according to Example 1-1. [Figure 2] It is an explanatory diagram showing an X-ray diffraction pattern according to Example 1-2. [Figure 3] It is an explanatory diagram showing an X-ray diffraction pattern according to Example 1-3. [Figure 4] It is an explanatory diagram showing an X-ray diffraction pattern according to Example 1-4. [Figure 5] It is an explanatory diagram showing an X-ray diffraction pattern according to Example 1-5. [Figure 6] It is an explanatory diagram showing an X-ray diffraction pattern according to Example 1-6. [Figure 7] It is an explanatory diagram showing an X-ray diffraction pattern according to Example 1-7. [Figure 8] This is an explanatory diagram showing the X-ray diffraction patterns related to Examples 1-8. [Figure 9] This is an explanatory diagram showing the X-ray diffraction patterns related to Examples 1-9. [Figure 10] This is an explanatory diagram showing the X-ray diffraction patterns according to Examples 1-10. [Figure 11] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 1-11. [Figure 12] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 2-1. [Figure 13] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 2-2. [Figure 14] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 2-3. [Figure 15] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 2-4. [Figure 16] This is an explanatory diagram showing the X-ray diffraction patterns related to Example 2-5. [Figure 17] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 2-6. [Figure 18] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 3-1. [Figure 19] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 3-2. [Figure 20] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 3-3. [Figure 21] This is an explanatory diagram showing the X-ray diffraction patterns according to Example 3-4. [Figure 22] This is an explanatory diagram showing the X-ray diffraction patterns related to Examples 3-5. [Figure 23] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 3-6. [Figure 24] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 3-7. [Figure 25] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 4-1. [Figure 26] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 4-2. [Figure 27] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 4-3. [Figure 28] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 4-4. [Figure 29] This is an explanatory diagram showing the X-ray diffraction patterns related to Examples 4-5. [Figure 30] This is an explanatory diagram showing the X-ray diffraction patterns related to Example 4-6. [Figure 31] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 4-7. [Figure 32] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 4-8. [Figure 33] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 4-9. [Figure 34] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 4-10. [Figure 35] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 4-11. [Figure 36] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 4-12. [Figure 37] This is an explanatory diagram showing the X-ray diffraction pattern according to Example 4-13. [Figure 38] This is an explanatory diagram showing the SEM measurement results for Example 1-1. [Figure 39] This is an explanatory diagram showing the SEM measurement results for Example 1-2. [Figure 40] This is an explanatory diagram showing the SEM measurement results for Examples 1-3. [Figure 41] This is an explanatory diagram showing the SEM measurement results for Examples 1-4. [Figure 42] This is an explanatory diagram showing the SEM measurement results for Examples 1-5. [Figure 43] This is an explanatory diagram showing the SEM measurement results for Examples 1-6. [Figure 44] This is an explanatory diagram showing the SEM measurement results for Examples 1-7. [Figure 45] This is an explanatory diagram showing the SEM measurement results for Examples 1-8. [Figure 46] This is an explanatory diagram showing the SEM measurement results for Examples 1-9. [Figure 47] This is an explanatory diagram showing the SEM measurement results for Examples 1-10. [Figure 48] This is an explanatory diagram showing the SEM measurement results for Example 1-11. [Figure 49] This is an explanatory diagram showing the SEM measurement results for Example 2-1. [Figure 50] This is an explanatory diagram showing the SEM measurement results related to Example 2-2. [Figure 51] This is an explanatory diagram showing the SEM measurement results for Example 2-3. [Figure 52] This is an explanatory diagram showing the SEM measurement results for Example 2-4. [Figure 53] This is an explanatory diagram showing the SEM measurement results for Example 2-5. [Figure 54] This is an explanatory diagram showing the SEM measurement results for Example 2-6. [Figure 55] This is an explanatory diagram showing the SEM measurement results for Example 3-1. [Figure 56] This is an explanatory diagram showing the SEM measurement results related to Example 3-2. [Figure 57] This is an explanatory diagram showing the SEM measurement results related to Example 3-3. [Figure 58] This is an explanatory diagram showing the SEM measurement results for Example 3-4. [Figure 59] This is an explanatory diagram showing the SEM measurement results for Example 3-5. [Figure 60] This is an explanatory diagram showing the SEM measurement results for Example 3-6. [Figure 61] This is an explanatory diagram showing the SEM measurement results for Example 3-7. [Figure 62] This is an explanatory diagram showing the SEM measurement results for Example 4-1. [Figure 63] This is an explanatory diagram showing the SEM measurement results related to Example 4-2. [Figure 64] This is an explanatory diagram showing the SEM measurement results for Example 4-3. [Figure 65] This is an explanatory diagram showing the SEM measurement results for Example 4-4. [Figure 66] This is an explanatory diagram showing the SEM measurement results for Example 4-5. [Figure 67] This is an explanatory diagram showing the SEM measurement results for Example 4-6. [Figure 68] This is an explanatory diagram showing the SEM measurement results for Example 4-7. [Figure 69] This is an explanatory diagram showing the SEM measurement results for Example 4-8. [Figure 70] This is an explanatory diagram showing the SEM measurement results for Example 4-9. [Figure 71] This is an explanatory diagram showing the SEM measurement results for Example 4-10. [Figure 72] This is an explanatory diagram showing the SEM measurement results for Example 4-11. [Figure 73] This is an explanatory diagram showing the SEM measurement results for Example 4-12. [Figure 74] This is an explanatory diagram showing the SEM measurement results for Example 4-13. [Modes for carrying out the invention]

[0009] The following is a detailed explanation of this disclosure, but is not limited to the following explanation. When a numerical range is expressed as "XX or greater and YY or less" or "XX to YY," unless otherwise specified, it means a numerical range that includes the lower and upper limits. When a numerical range is expressed in steps, the upper and lower limits of each range can be combined in any way.

[0010] In this disclosure, phrases such as "one or more selected from the group consisting of X, Y, and Z" mean any of the following: X, Y, Z, a combination of X and Y, a combination of X and Z, a combination of Y and Z, or a combination of X, Y, and Z. Note that if X is a group, multiple selections may be made from X, and the same applies to Y and Z.

[0011] In this disclosure, any mention of "X such as x1, x2, and x3" is merely an example of X, and does not imply that X is limited to x1, x2, and x3.

[0012] This disclosure is, A method for producing an inorganic compound powder containing a metallic element and a non-metallic element, A metal oxide containing one or more elements selected from the group consisting of transition metals of periods 4-6 and groups 3-12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides, One or more reducing agents selected from the group consisting of alkali metals, alkali metal hydrides, alkali metal borides, alkaline earth metals, alkaline earth metal hydrides, and alkaline earth metal borides, One or more molten salt sources selected from the group consisting of alkali metal salts and alkaline earth metal salts, The process includes heating and reducing a raw material mixture containing an inert gas in the presence of an inert gas to obtain a product. The present invention relates to a method for producing an inorganic compound powder, wherein the raw material mixture includes a substance containing the nonmetallic element.

[0013] According to the manufacturing method of the present disclosure, an inorganic compound powder containing a metal element and a nonmetal element is provided. The following details each component.

[0014] (Process for obtaining the product) A method for producing inorganic compound powder comprises the step of heating and reducing a raw material mixture containing a predetermined metal oxide, a predetermined reducing agent, and a predetermined molten salt source in the presence of an inert gas to obtain a product. The product obtained here can also be used as inorganic compound powder. The heating temperature during reduction varies depending on the type of molten salt source, but it must be above the melting temperature. By heating to a temperature above the melting temperature, the molten salt source becomes a molten salt. The heating temperature is, for example, 200 to 1000°C, preferably 200 to 800°C, and more preferably 200 to 600°C. It may also be 550 to 800°C.

[0015] Alternatively, the molten salt source may be heated first, and the metal oxide and reducing agent may be added while the molten salt source is still molten. Alternatively, the molten salt source may be mixed with the metal oxide or reducing agent, heated, and then the remaining reducing agent or metal oxide may be added. The molten salt acts as a solvent, and within the molten salt, the metal oxide is reduced by a reducing agent (molten salt reduction method). This molten salt reduction method allows for the production of inorganic compound powder under mild, low-temperature conditions. After or simultaneously with reduction by the molten salt reduction method, the metal oxide reacts with a substance containing a desired nonmetallic element to form an inorganic compound powder containing that nonmetallic element. That is, the metal elements contained in the inorganic compound powder correspond to the metal elements contained in the metal oxide. Furthermore, the nonmetallic elements contained in the inorganic compound powder correspond to the nonmetallic elements in the substance containing the nonmetallic element. For example, in inorganic compound powders, metallic elements and nonmetallic elements are chemically bonded to each other. Inorganic compounds, depending on the type of nonmetallic element they contain, can be, for example, hydrides, borides, carbides, nitrides, phosphides, or sulfides. That is, inorganic compound powders are, for example, hydride powders, boride powders, carbide powders, nitride powders, phosphides, or sulfide powders. The nonmetallic element is preferably one or more elements selected from the group consisting of hydrogen, boron, carbon, nitrogen, phosphorus, and sulfur.

[0016] The heating time in the process of obtaining the product depends on the heating temperature, but may be, for example, 0.5 to 24 hours, preferably 1 to 15 hours, and more preferably 1 to 10 hours. When the heating temperature is low, for example, around 200°C, it is preferable to increase the heating time, for example, to around 10 hours. On the other hand, when the heating temperature is high, for example, 700 to 800°C, the heating time can be reduced to 1.5 to 5.0 hours.

[0017] Metal oxides contain one or more elements selected from the group consisting of transition metals of periods 4-6 and groups 3-12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides. Preferably, the metal oxide contains 1 to 8 elements selected from the group consisting of transition metals of the 4th to 6th periods and groups 3 to 12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides; more preferably, the metal oxide contains 1 to 6 elements selected from the group consisting of transition metals of the 4th to 6th periods and groups 3 to 12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides; even more preferably, the metal oxide contains transition metals of the 4th to 6th periods and groups 3 to 12, alkali metals, alkaline earth metals, aluminum, gallium, The metal oxide contains one to five elements selected from the group consisting of indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides. Particularly preferably, the metal oxide contains one to two elements selected from the group consisting of transition metals of the 4th to 6th periods and groups 3 to 12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides. Even more preferably, the metal oxide contains one element selected from the group consisting of transition metals of the 4th to 6th periods and groups 3 to 12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides.

[0018] Examples of transition metal elements include one or more elements selected from the group consisting of scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, molybdenum, technetium, ruthenium, rhodium, palladium, silver, cadmium, lanthanum, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, and mercury. Furthermore, while not particularly limited, lanthanides include one or more elements selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.

[0019] In this disclosure, alkali metals refer to lithium, sodium, potassium, rubidium, cesium, and fraundium. Alkaline earth metals refer to beryllium, magnesium, calcium, strontium, barium, and radium.

[0020] Metal oxides specifically include oxides of single metals such as titanium oxide, zirconium oxide, vanadium pentoxide, niobium pentoxide, tantalum pentoxide, and hafnium oxide, as well as titanic acid. Examples include complex oxides such as calcium, lithium titanate, and nickel molybdate. Furthermore, one type of metal oxide may be used alone, or multiple types of metal oxides may be used in combination.

[0021] The reducing agent is one or more selected from the group consisting of alkali metals, alkali metal hydrides, alkali metal borohydrides, alkaline earth metals, alkaline earth metal hydrides, and alkaline earth metal borohydrides. Examples include elemental alkali metals such as lithium, sodium, potassium, rubidium, and cesium, their hydrides, and their borohydrides, as well as elemental alkaline earth metals such as magnesium, calcium, strontium, and barium, their hydrides, and their borohydrides. Boride hydrides, as used here, include compounds containing BH4, such as sodium borohydride. In particular, CaH2 is preferred because it is a stable powder at room temperature and in the atmosphere, and can be handled relatively safely.

[0022] The content of the reducing agent in the raw material mixture is not particularly limited, but may be 200 to 2500 parts by mass per 100 parts by mass of metal oxide, preferably 200 to 1500 parts by mass, more preferably 200 to 1000 parts by mass, and even more preferably 200 to 500 parts by mass. When alkali metals are used as reducing agents, it is preferable that the number of moles of alkali metals is at least twice the total number of moles of oxygen atoms contained in the metal oxide and molten salt source. When alkaline earth metals are used as reducing agents, it is preferable that the number of moles of alkaline earth metals is at least one times the total number of moles of oxygen atoms contained in the metal oxide and molten salt source. When alkali metal hydrides are used as reducing agents, it is preferable that the number of moles of alkali metal hydrides is at least one time the total number of moles of oxygen atoms contained in the metal oxide and molten salt source. When alkaline earth metal hydrides are used as reducing agents, it is preferable that the number of moles of alkaline earth metal hydrides is at least 0.5 times the total number of moles of oxygen atoms contained in the metal oxide and molten salt source.

[0023] When the inorganic compound powder is a boride powder, the reducing agent preferably contains one or more substances selected from the group consisting of alkali metal borides and alkaline earth metal borides. Borides are substances that contain boron, which is a nonmetallic element. Therefore, the boride can be a boron source, and boron can be a nonmetallic element contained in the inorganic compound powder. When the inorganic compound powder is a hydride powder, the reducing agent preferably contains one or more selected from the group consisting of alkali metal hydrides and alkaline earth metal hydrides. A hydride is a substance that contains hydrogen, which is a nonmetallic element. Therefore, the hydride can act as a hydrogen source, and hydrogen can become a nonmetallic element contained in the inorganic compound powder. When the inorganic compound powder is a powder other than boride powder (for example, hydride powder, carbide powder, nitride powder, phosphide powder, or sulfide powder), it is preferable that the reducing agent does not contain boride hydride. For example, it is preferable that the reducing agent is one or more selected from the group consisting of alkali metals, alkali metal hydrides, alkaline earth metals, and alkaline earth metal hydrides.

[0024] The molten salt source is one or more selected from the group consisting of alkali metal salts and alkaline earth metal salts. Alkali metal salts and alkaline earth metal salts are not particularly limited and include inorganic salts such as nitrates, sulfates, carbonates, phosphates, hydroxides, and halides, as well as organic salts such as alkoxides, acetates, and oxalates. Among these, halides are preferred, and chlorides are more preferred.

[0025] The content of the molten salt source in the raw material mixture is not particularly limited, but may be 100 to 1500 parts by mass per 100 parts by mass of metal oxide, preferably 100 to 1000 parts by mass, and more preferably 100 to 750 parts by mass. The molten salt source melts and acts as a solvent. Therefore, when the content of the molten salt source is within the above range, the metal oxide and the reducing agent come into contact more easily, and the reaction proceeds more readily.

[0026] When the molten salt source is a mixed molten salt source, its melting point is lower than that of a single molten salt, so it can melt even at temperatures below 600°C. Therefore, while the molten salt source may be used alone, it is preferable to use a combination of multiple sources. From this viewpoint, when using a combination of multiple sources, it is particularly preferable to use hydroxides such as lithium hydroxide. When the molten salt source contains hydroxide, the hydroxide content in the molten salt source may be 5 to 30% by mass, and preferably 10 to 20% by mass. Furthermore, the combinations of these compounds, the number of compounds to be combined, and the mixing ratio are not limited and can be appropriately selected according to their stability and ease of handling under atmospheric conditions, or their availability at low cost.

[0027] More specifically, the molten salt source preferably contains one or more selected from the group consisting of lithium chloride, lithium hydroxide, and lithium nitrate. In particular, the molten salt source used in this embodiment is preferably a single molten salt source such as lithium chloride or calcium chloride, or a mixed molten salt source of lithium nitrate and lithium hydroxide. Alternatively, a mixed molten salt source of LiCl and CaCl2, or a mixed molten salt source of LiCl and KCl may be used. Mixed molten salt sources have lower melting points than single molten salt sources, allowing the reaction to occur at lower temperatures. Therefore, when the temperature at which the inorganic compound powder is formed is low, it is preferable to use a mixed molten salt source. For example, the melting point of a mixed molten salt source of LiNO3 and LiOH is as low as 180°C, so the reaction can be carried out even at low temperatures of around 200°C. Also, the melting point of a mixed molten salt source of LiCl and CaCl2 is as low as 470°C, so the reaction can be carried out even at low temperatures of around 550°C. Furthermore, the melting point of a mixed molten salt source of LiCl and KCl is as low as 350°C, so the reaction can be carried out even at low temperatures of around 400°C.

[0028] When the inorganic compound powder is a nitride powder, the molten salt source preferably contains nitrates. Specifically, the molten salt source preferably contains one or more selected from the group consisting of alkali metal nitrates and alkaline earth metal nitrates. Nitrates are substances that contain nitrogen, which is a nonmetallic element. Therefore, the nitrate can serve as a nitrogen source, and nitrogen can become a nonmetallic element contained in the inorganic compound powder. If the molten salt source contains nitrates, the nitrate content in the molten salt source may be 10 to 90% by mass, preferably 30 to 90% by mass, and more preferably 50 to 90% by mass. When the inorganic compound powder is a powder other than nitride powder (for example, hydride powder, boride powder, carbide powder, phosphide powder, or sulfide powder), it is preferable that the molten salt source does not contain nitrates.

[0029] The inert gas is not particularly limited, but for example, nitrogen gas, or noble gases such as helium gas and argon gas can be used. When the inorganic compound powder is a nitride powder, it is preferable that the inert gas contains nitrogen gas. Nitrogen gas is a substance that contains nitrogen, which is a nonmetallic element. Therefore, when the inert gas contains nitrogen gas, nitrogen molecules are included in the raw material mixture, and these nitrogen molecules become a nitrogen source, and nitrogen can become a nonmetallic element contained in the inorganic compound powder. Inorganic compound powders other than nitride powders (for example, hydride powders, boride powders, carbonized powders) In the case of a powder (such as a phosphate powder or sulfide powder), it is preferable that the inert gas does not contain nitrogen gas. For example, the inert gas is preferably a noble gas, and more preferably argon gas.

[0030] The raw material mixture includes a substance containing a nonmetallic element. The substance containing the nonmetallic element may be one or more selected from the group consisting of reducing agents, molten salt sources, inert gases, and additives. The additive is a substance different from the reducing agent, molten salt source, and inert gas. The substance containing the nonmetallic element is preferably a reducing agent, molten salt source, inert gas, or additive.

[0031] The additive is not particularly limited as long as it contains the desired nonmetallic element. For example, if the inorganic compound powder is a carbide powder, the additive is not particularly limited as long as it contains the element carbon, but may be a carbonate, for example, and preferably one or more selected from the group consisting of alkali metal carbonates and alkaline earth metal carbonates. In other words, the raw material mixture preferably contains carbonate. The carbonate content in the raw material mixture is not particularly limited, but may be 60 to 750 parts by mass, and preferably 100 to 600 parts by mass, per 100 parts by mass of metal oxide.

[0032] Furthermore, when the inorganic compound powder is a nitride powder, the additive is not particularly limited as long as it contains the element nitrogen, but is preferably an ammonium salt, and more preferably an ammonium halide. The content of the ammonium salt in the raw material mixture is not particularly limited, but may be 80 to 500 parts by mass, and more preferably 80 to 300 parts by mass, per 100 parts by mass of the metal oxide.

[0033] Furthermore, if the inorganic compound powder is a phosphide powder, the additive is not particularly limited as long as it contains the element phosphorus, but it is preferable, for example, to use elemental phosphorus or a phosphate salt. Furthermore, if the inorganic compound powder is a sulfide powder, the additive is not particularly limited as long as it contains the element sulfur, but it is preferable, for example, elemental sulfur or sulfate.

[0034] A method for producing inorganic compound powder preferably further includes a step of washing the product. Having a washing step allows for the removal of impurities. The washing step allows for the acquisition of inorganic compound powder with higher purity. For example, the washing step is a step of removing from the product the alkali metal of the alkali metal salt used as the molten salt source, or the alkaline earth metal of the alkaline earth metal salt used as the molten salt source. For example, it is a step of removing from the product one or more selected from the group consisting of alkali metals used as reducing agents, alkali metal hydrides, alkali metal borides, alkaline earth metals, alkaline earth metal hydrides, and alkaline earth metal borides. For example, it is a step of removing from the product one or more selected from the group consisting of alkali metal oxides, alkaline earth metal oxides, alkali metal hydroxides, and alkaline earth metal hydroxides that can be produced as by-products by the reaction of the reducing agent and oxygen.

[0035] The cleaning solution used in the cleaning process can be a weakly acidic solution such as NH4Cl solution, phosphoric acid solution, or acetic acid solution, or a strongly acidic solution such as perchloric acid solution, sulfuric acid solution, nitric acid solution, or hydrochloric acid solution. Alternatively, a solution using an organic solvent other than an aqueous solution may be used, or a mixed solution of an aqueous solution and an organic solvent may be used. The acidic solution preferably has a pH in the range of 3 to 6, and more preferably around pH 4 (for example, pH 3.5 to 4.5). Among these, the use of a weakly acidic solution such as NH4Cl solution, phosphoric acid solution, or acetic acid solution is preferred.

[0036] The method for producing inorganic compound powder according to this disclosure allows for the simple and low-cost production of inorganic compound powder. The inorganic compound powder contains a metallic element and a non-metallic element. The metallic element is as described above. Thus, it corresponds to the metallic elements contained in the raw material metal oxide. That is, the metallic elements include one or more elements selected from the group consisting of transition metals of periods 4-6 and groups 3-12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides. The metallic elements preferably comprise 1 to 8 elements selected from the group consisting of transition metals of the 4th to 6th periods and groups 3 to 12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides; more preferably, the metallic elements comprise 1 to 6 elements selected from the group consisting of transition metals of the 4th to 6th periods and groups 3 to 12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides; even more preferably, the metallic elements comprise transition metals of the 4th to 6th periods and groups 3 to 12, alkali metals, alkaline earth metals, aluminum, gallium, The material contains 1 to 5 elements selected from the group consisting of indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides. Particularly preferably, the metallic element contains 1 to 2 elements selected from the group consisting of transition metals of periods 4-6 and groups 3-12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides. More preferably, the metallic element contains 1 element selected from the group consisting of transition metals of periods 4-6 and groups 3-12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides.

[0037] For metallic elements, those listed in the section on metal oxides can be used. As described above, the nonmetallic elements correspond to the nonmetallic elements in the material containing the raw material nonmetallic elements. That is, the nonmetallic elements are not particularly limited, but it is preferable that they be one or more elements selected from the group consisting of hydrogen, boron, carbon, nitrogen, phosphorus, and sulfur. When the metal element contains a plurality of elements, the inorganic compound powder may be, for example, a composite hydride powder, a composite boride powder, a composite carbide powder, a composite nitride powder, a composite phosphide powder, or a composite sulfide powder.

[0038] According to the method for producing an inorganic compound powder of the present disclosure, the heating temperature in the step of obtaining the product can be lowered. As a result, an inorganic compound powder having a large BET specific surface area can be obtained. The BET specific surface area of the inorganic compound powder is, for example, 3.0 m 2 / g or more is preferable, 5.0 m 2 / g or more is more preferable, 10.0 m 2 / g or more is even more preferable, 30.0 m 2 / g or more is even more preferably, 50.0 m 2 / g or more is particularly preferably, 90.0 m 2 / g or more is particularly preferable. When the BET specific surface area is within the above range, the catalytic activity of the inorganic compound powder is more likely to be improved. The upper limit of the BET specific surface area is not particularly limited, but for example, 3.0 to 200.0 m 2 / g, 5.0 to 200.0 m 2 / g, 10.0 to 200.0 m 2 / g, 30.0 to 200.0 m 2 / g, 50.0 to 200.0 m 2 / g, 90.0 to 200.0 m 2 / g can be mentioned. The method for measuring the BET specific surface area will be described later.

[0039] The pore volume of the inorganic compound powder is, for example, 0.01 cm 3 / g or more is preferable, 0.05 cm 3 / g or more is more preferable, 0.10 cm 3 / g or more is even more preferable, 0.20 cm 3 / g or more is particularly preferable. When the pore volume is within the above range, the catalytic activity of the inorganic compound powder is more likely to be improved. The upper limit of the pore volume is not particularly limited, but for example, 0.01 to 1.00 cm 3 / g, 0.05 to 1.00 cm3 / g, 0.10~1.00cm 3 / g, 0.20~1.00cm 3 The value can be expressed as / g. The method for measuring pore volume will be described later.

[0040] The crystallite size of the inorganic compound powder is preferably 2.0 nm or larger, more preferably 4.0 nm or larger, even more preferably 10.0 nm or larger, and particularly preferably 20.0 nm or larger. A crystallite size within the above range indicates that the inorganic compound is well crystallized. The upper limit of the crystallite size is not particularly limited, but examples include 2.0 to 110.0 nm, 4.0 to 100.0 nm, 10.0 to 100.0 nm, and 20.0 to 100.0 nm. The method for measuring the crystallite size will be described later.

[0041] The inorganic compound powder obtained by the method for producing inorganic compound powder according to this disclosure is suitable as a catalyst material. That is, the inorganic compound powder can be used as an inorganic compound powder catalyst. Therefore, the above-described method for producing inorganic compound powder can be used as a method for producing an inorganic compound powder catalyst.

[0042] In other words, the method for producing an inorganic compound powder catalyst according to the present disclosure is a method for producing an inorganic compound powder catalyst containing a metal element and a nonmetal element, A metal oxide containing one or more elements selected from the group consisting of transition metals of periods 4-6 and groups 3-12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides, One or more reducing agents selected from the group consisting of alkali metals, alkali metal hydrides, alkali metal borides, alkaline earth metals, alkaline earth metal hydrides, and alkaline earth metal borides, One or more molten salt sources selected from the group consisting of alkali metal salts and alkaline earth metal salts, The process includes heating and reducing a raw material mixture containing an inert gas in the presence of an inert gas to obtain a product. The present invention relates to a method for producing an inorganic compound powder catalyst, wherein the raw material mixture includes a substance containing the nonmetallic element.

[0043] The following describes a method for measuring the physical properties of inorganic compound powders.

[0044] <Method for measuring the composition and crystallite size of inorganic compound powders> The X-ray diffraction pattern is obtained by XRD measurement of inorganic compound powder using an X-ray diffractometer (manufactured by Rigaku Corporation, SmartLab®) under the following conditions. Conditions: X-ray source CuKα, output 40KV, 40mA Inorganic compound powders are identified from the obtained X-ray diffraction patterns by referring to the PDF (Powder Diffraction File) database provided by ICDD (International Centre for Diffraction Data). The crystallite size is calculated using the Scherrer equation, employing the full width at half maximum of the main peak observed around 2θ = 30-55°.

[0045] <Method for measuring the BET specific surface area and pore volume of inorganic compound powders> Nitrogen adsorption experiments are conducted using a nitrogen adsorption amount measuring device (BELLSORP mini-II, manufactured by Microtrac-Bell Co., Ltd.). Inorganic compound powder is used as a sample, and after drying the sample under vacuum at the following temperature for 60 minutes, the amount of nitrogen adsorbed (BET specific surface area, pore volume) is measured at liquid nitrogen temperature. The BET specific surface area and pore volume are obtained from the relationship between the amount of nitrogen adsorbed and the relative pressure. The drying temperature for the samples should be 120°C for hydrides and 150°C for borides, carbides, nitrides, phosphides, and sulfides.

[0046] <SEM measurement of inorganic compound powders> SEM images are measured using a scanning electron microscope (Hitachi High-Technologies Corporation, S-3700N). Energy-dispersive X-ray spectroscopy (EDS) system (EDAX, Apol Elemental analysis of the SEM image is performed using loX). The sample powder is fixed to the measurement holder using carbon tape. [Examples]

[0047] The following examples will provide a more detailed explanation, but the invention is not limited to these examples unless it exceeds the gist of the invention.

[0048] <Examples of hydride production> (Example 1-1) 0.6 g of TiO2 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a metal oxide, 0.9 g of LiCl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a molten salt source, and 1.8 g of CaH2 (manufactured by Nacalai Tesque Corporation) as a reducing agent were mixed in a glove box under an argon atmosphere using a mortar and pestle. Subsequently, the mixture was reduced to a molten salt by heating in a cylindrical container made of stainless steel at 600°C for 4 hours under an argon atmosphere. The resulting product was cooled to room temperature, the cylindrical container was opened, and impurities were removed by washing the contents with a 0.1 M NH4Cl aqueous solution and distilled water. Next, the obtained washed material was subjected to solid-liquid separation, and the solid component was dried to obtain the inorganic compound powder H1-Ti. The obtained powder was evaluated according to the procedure described above. The evaluation results are shown in Table 2, Figure 1, and Figure 38. In Table 2, 2θ represents the diffraction angle of the main peak observed in the XRD measurement. The same applies to the other tables below.

[0049] (Examples 1-2 to 1-11) Inorganic compound powders for Examples 1-2 to 1-11 were obtained in the same manner as in Example 1-1, except that the types and amounts of raw materials used were changed to the amounts listed in Table 1, and the heating temperature and heating time were changed to the conditions listed in Table 1. The evaluation results are shown in Table 2 and Figures 2 to 11 and 39 to 48. Li2TiO3 is manufactured by Sigma-Aldrich, CaTiO3 by Mitsuwa Chemical Co., Ltd., ZrO2 by Fujifilm Wako Pure Chemical Corporation, V2O5 by Fujifilm Wako Pure Chemical Corporation, Nb2O5 by Fujifilm Wako Pure Chemical Corporation, Ta2O5 by Fujifilm Wako Pure Chemical Corporation, and HfO2 by Fujifilm Wako Pure Chemical Corporation. The same applies to the following examples. [Table 1] [Table 2] In the table, 'na' indicates that the crystallite size could not be calculated using the measurement results. The same applies to the other tables below. Furthermore, the reference data used for identifying H11-Hf was that of deuterium.

[0050] <Examples of boride production> (Examples 2-1 to 2-6) Inorganic compound powders for Examples 2-1 to 2-6 were obtained in the same manner as in Example 1-1, except that CaH2 was replaced with NaBH4 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), the type and amount of raw materials used were changed to the amounts listed in Table 3, and the heating temperature and heating time were changed to the conditions listed in Table 3. The evaluation results are shown in Table 4, Figures 12 to 17, and Figures 49 to 54. [Table 3] [Table 4]

[0051] <Examples of carbonized material production> (Examples 3-1 to 3-7) Except for adding the carbonates listed in Table 5 during the mixing of the raw materials, changing the types and amounts of raw materials used to the amounts listed in Table 5, and changing the heating temperature and heating time to the conditions listed in Table 5, Inorganic compound powders according to Examples 3-1 to 3-7 were obtained in the same manner as in Example 1-1. The evaluation results are shown in Table 6, Figures 18 to 24, and Figures 55 to 61. K2CO3, CaCO3, and Li2CO3 were manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. [Table 5] [Table 6]

[0052] <Examples of Nitride Manufacturing> (Examples 4-1 to 4-12) Inorganic compound powders for Examples 4-1 to 4-12 were obtained in the same manner as in Example 1-1, except that the nitrogen source listed in Table 7 was added during the mixing of the raw materials, the type and amount of raw materials used were changed to the amounts listed in Table 7, and the heating temperature and heating time were changed to the conditions listed in Table 8. The evaluation results are shown in Table 9, Figures 25 to 36, and Figures 62 to 73. CaZrO3 was confirmed as a by-product in Example 4-6, and CaHfO3 was confirmed as a by-product in Example 4-9. LiH is manufactured by Sigma-Aldrich, LiOH by Sigma-Aldrich, LiNO3 by Fujifilm Wako Pure Chemical Industries, Ltd., NH4Cl by Fujifilm Wako Pure Chemical Industries, Ltd., and NiMoO4·nH2O by Mitsuwa Chemical Co., Ltd.

[0053] (Examples 4-13) 0.6 g of NiMoO4·nH2O (manufactured by Mitsuwa Chemical Co., Ltd.) as a metal oxide, 0.9 g of LiCl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a molten salt source, and 1.8 g of CaH2 (manufactured by Nacalai Tesque Co., Ltd.) as a reducing agent were mixed in a glove box under a nitrogen atmosphere using a mortar and pestle. Subsequently, the mixture was reduced to a molten salt by heating in a cylindrical SUS container under a nitrogen atmosphere at 600°C for 2 hours. The obtained product was cooled to room temperature, the cylindrical container was opened, and impurities were removed by washing the contents with a 0.1 M NH4Cl aqueous solution and distilled water. Next, the obtained washed material was subjected to solid-liquid separation, and the solid component was dried to obtain the inorganic compound powder N13-NiMo. The obtained powder was evaluated according to the procedure described above. The evaluation results are shown in Table 9 and Figures 37 and 74. [Table 7] [Table 8] [Table 9]

[0054] Examples of the inventions identified from the above disclosures are as follows: [1] A method for producing an inorganic compound powder containing a metallic element and a non-metallic element, A metal oxide containing one or more elements selected from the group consisting of transition metals of periods 4-6 and groups 3-12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides, One or more reducing agents selected from the group consisting of alkali metals, alkali metal hydrides, alkali metal borides, alkaline earth metals, alkaline earth metal hydrides, and alkaline earth metal borides, One or more molten salt sources selected from the group consisting of alkali metal salts and alkaline earth metal salts, The process includes heating and reducing a raw material mixture containing an inert gas in the presence of an inert gas to obtain a product. A method for producing an inorganic compound powder, wherein the raw material mixture contains a substance containing the nonmetallic element. [2] The method for producing an inorganic compound powder according to [1], wherein the nonmetallic element is one or more elements selected from the group consisting of hydrogen, boron, carbon, nitrogen, phosphorus, and sulfur. [3] A method for producing an inorganic compound powder according to [1] or [2], wherein the inorganic compound powder is a hydride powder, a boride powder, a carbide powder, a nitride powder, a phosphide powder, or a sulfide powder. [4] A method for producing an inorganic compound powder according to any one of [1] to [3], wherein the inert gas is nitrogen gas. [5] A method for producing an inorganic compound powder according to any one of [1] to [4], wherein the substance containing the nonmetallic element is one or more selected from the group consisting of the reducing agent, the molten salt source, the inert gas, and the additive. [6] A method for producing inorganic compound powder according to any one of [1] to [5], wherein the molten salt source comprises one or more selected from the group consisting of lithium chloride, lithium hydroxide, and lithium nitrate. [7] A method for producing an inorganic compound powder according to any one of [1] to [6], wherein the heating temperature in the step of obtaining the product is 200 to 800°C. [8] A method for producing an inorganic compound powder according to any one of [1] to [7], further comprising a step of washing the aforementioned product. [9] A method for producing an inorganic compound powder catalyst containing a metal element and a nonmetal element, A metal oxide containing one or more elements selected from the group consisting of transition metals of periods 4-6 and groups 3-12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides, One or more reducing agents selected from the group consisting of alkali metals, alkali metal hydrides, alkali metal borides, alkaline earth metals, alkaline earth metal hydrides, and alkaline earth metal borides, One or more molten salt sources selected from the group consisting of alkali metal salts and alkaline earth metal salts, The process includes heating and reducing a raw material mixture containing an inert gas in the presence of an inert gas to obtain a product. A method for producing an inorganic compound powder catalyst, wherein the raw material mixture includes a substance containing the nonmetallic element.

[10] The method for producing an inorganic compound powder catalyst according to [9], wherein the nonmetallic element is one or more elements selected from the group consisting of hydrogen, boron, carbon, nitrogen, phosphorus, and sulfur.

[11] A method for producing an inorganic compound powder catalyst according to [9] or

[10] , wherein the inorganic compound powder catalyst is a hydride powder, a boride powder, a carbide powder, a nitride powder, a phosphide powder, or a sulfide powder.

[12] A method for producing an inorganic compound powder catalyst according to any one of [9] to

[11] , wherein the inert gas is nitrogen gas.

[13] The substance containing the nonmetallic element is the reducing agent, the molten salt source, the inert gas, and A method for producing an inorganic compound powder catalyst according to any one of [9] to

[12] , wherein one or more are selected from the group consisting of additives.

[14] A method for producing an inorganic compound powder catalyst according to any one of [9] to

[13] , wherein the molten salt source comprises one or more selected from the group consisting of lithium chloride, lithium hydroxide, and lithium nitrate.

[15] A method for producing an inorganic compound powder catalyst according to any one of [9] to

[14] , wherein the heating temperature in the step of obtaining the product is 200 to 800°C.

[16] A method for producing an inorganic compound powder catalyst according to any one of [9] to

[15] , further comprising a step of washing the aforementioned product.

Claims

1. A method for producing an inorganic compound powder containing a metallic element and a non-metallic element, A metal oxide comprising one or more elements selected from the group consisting of transition metals of the 4th-6th period and groups 3-12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides, One or more reducing agents selected from the group consisting of alkali metals, alkali metal hydrides, alkali metal borides, alkaline earth metals, alkaline earth metal hydrides, and alkaline earth metal borides, One or more molten salt sources selected from the group consisting of alkali metal salts and alkaline earth metal salts, The process includes heating and reducing a raw material mixture containing an inert gas in the presence of an inert gas to obtain a product. A method for producing an inorganic compound powder, wherein the raw material mixture contains a substance containing the nonmetallic element.

2. The method for producing an inorganic compound powder according to claim 1, wherein the nonmetallic element is one or more elements selected from the group consisting of hydrogen, boron, carbon, nitrogen, phosphorus, and sulfur.

3. The method for producing an inorganic compound powder according to claim 1, wherein the inorganic compound powder is a hydride powder, a boride powder, a carbide powder, a nitride powder, a phosphide powder, or a sulfide powder.

4. The method for producing an inorganic compound powder according to claim 1, wherein the inert gas is nitrogen gas.

5. The method for producing an inorganic compound powder according to claim 1, wherein the substance containing the nonmetallic element is one or more selected from the group consisting of the reducing agent, the molten salt source, the inert gas, and the additive.

6. The method for producing an inorganic compound powder according to claim 1, wherein the molten salt source comprises one or more selected from the group consisting of lithium chloride, lithium hydroxide, and lithium nitrate.

7. A method for producing an inorganic compound powder according to claim 1, wherein the heating temperature in the step of obtaining the above product is 200 to 800°C.

8. A method for producing an inorganic compound powder according to any one of claims 1 to 7, further comprising the step of washing the product.

9. A method for producing an inorganic compound powder catalyst containing a metal element and a nonmetal element, A metal oxide comprising one or more elements selected from the group consisting of transition metals of the 4th-6th period and groups 3-12, alkali metals, alkaline earth metals, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony, bismuth, and lanthanides, One or more reducing agents selected from the group consisting of alkali metals, alkali metal hydrides, alkali metal borides, alkaline earth metals, alkaline earth metal hydrides, and alkaline earth metal borides, One or more molten salt sources selected from the group consisting of alkali metal salts and alkaline earth metal salts, The process includes heating and reducing a raw material mixture containing an inert gas in the presence of an inert gas to obtain a product. A method for producing an inorganic compound powder catalyst, wherein the raw material mixture includes a substance containing the nonmetallic element.

10. The aforementioned nonmetallic element is selected from the group consisting of hydrogen, boron, carbon, nitrogen, phosphorus, and sulfur. A method for producing an inorganic compound powder catalyst according to claim 9, wherein the element is one or more elements.

11. The method for producing an inorganic compound powder catalyst according to claim 9, wherein the inorganic compound powder catalyst is a hydride powder, a boride powder, a carbide powder, a nitride powder, a phosphide powder, or a sulfide powder.

12. The method for producing an inorganic compound powder catalyst according to claim 9, wherein the inert gas is nitrogen gas.

13. The method for producing an inorganic compound powder catalyst according to claim 9, wherein the substance containing the nonmetallic element is one or more selected from the group consisting of the reducing agent, the molten salt source, the inert gas, and the additive.

14. The method for producing an inorganic compound powder catalyst according to claim 9, wherein the molten salt source comprises one or more selected from the group consisting of lithium chloride, lithium hydroxide, and lithium nitrate.

15. A method for producing an inorganic compound powder catalyst according to claim 9, wherein the heating temperature in the step of obtaining the above product is 200 to 800°C.

16. A method for producing an inorganic compound powder catalyst according to any one of claims 9 to 15, further comprising the step of washing the product.

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