Perovskite-structured metal oxyhydride compound with hydride ion conductivity, and preparation method therefor

Abstract

One embodiment of the present invention provides a perovskite-structured metal oxyhydride compound with hydride ion conductivity, and a preparation method therefor. According to one embodiment of the present invention, the perovskite-structured metal oxyhydride compound with hydride ion conductivity has intrinsic hydride ion conductivity without an external hydrogen supply, and thus can be utilized in various fields such as hydrogen energy devices and catalyst devices.

Description

Metal oxyhydride compound with a perovskite structure having hydrogen anion conductivity and a method for preparing the same

[0001] The present invention relates to a metal oxyhydride compound having a perovskite structure in which oxygen anions and hydrogen anions coexist, and a method for preparing the same.

[0002] Hydrogen is the most abundant element in the universe with no concerns regarding resource depletion, and because it does not generate pollutants when utilized as an energy source, hydrogen energy storage and conversion material technologies are gaining attention.

[0003] To effectively utilize hydrogen energy, material technology regarding hydrogen solid electrolytes with hydrogen ion conductivity is essential. Conventional hydrogen solid electrolytes operate based on the movement of hydrogen cations within a solid, but they have a technical limitation in that they require an external supply of hydrogen to function because hydrogen is not present within the solid electrolyte.

[0004] To overcome these technical limitations, a novel material technology featuring hydrogen anion conductivity is attracting attention. Hydrogen anion conductors are significantly different from existing technologies in that they exhibit hydrogen ion conductivity without external hydrogen injection because hydrogen is present within the material.

[0005] However, most hydrogen anion conductors developed to date are based on transition metals, and since the types of materials are very limited, the discovery of new materials is required.

[0006] [Prior Art Literature]

[0007] (Patent Document 1) Republic of Korea Registered Patent No. 10-2639462

[0008] The technical problem that the present invention aims to solve is to provide a metal oxyhydride compound with a perovskite structure in which oxygen anions and hydrogen anions coexist, and a method for manufacturing the same, in order to overcome the technical limitations of existing hydrogen cation conductors operating under external hydrogen supply.

[0009] The technical problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned technical problems will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

[0010] To achieve the above technical problem, one embodiment of the present invention provides a metal oxyhydride compound.

[0011] The metal oxyhydride compound according to one embodiment of the present invention is a metal compound containing oxygen anions and hydrogen anions, having a perovskite structure,

[0012] It can be represented by the following chemical formula 1.

[0013] [Chemical Formula 1]

[0014] AeLnO 3-x H y

[0015] Above, Ae is an alkaline earth metal, Ln is a lanthanide element, and 0 <x<3이고, 0<y<3이다.

[0016] In addition, according to one embodiment of the present invention, the metal oxyhydride compound may be in the form of pellets or powder.

[0017] In addition, according to one embodiment of the present invention, the metal oxyhydride compound may have hydrogen anion conductivity.

[0018] In addition, according to one embodiment of the present invention, the metal oxyhydride compound has a hydrogen ion conductivity of 10 at a temperature of 600 °C or lower.-6 S cm -1 It could be more than that.

[0019]

[0020] To achieve the above technical problem, another embodiment of the present invention provides a method for manufacturing a metal oxyhydride compound.

[0021] A method for preparing a metal oxyhydride compound according to one embodiment of the present invention may include the step of preparing a mixed powder by mixing a metal oxide powder having a perovskite structure and a calcium hydride compound powder; and the step of preparing a metal oxyhydride compound by heat treating the mixed powder so that a hydrogen anion is substituted at the oxygen anion position of the metal oxide having a perovskite structure.

[0022] In addition, according to one embodiment of the present invention, between the step of preparing the mixed powder and the step of preparing the metal oxyhydride compound, the step of compression molding the mixed powder into a pellet form may be further included.

[0023] In addition, according to one embodiment of the present invention, after the step of preparing the metal oxyhydride compound, a step of washing to remove impurities from the heat-treated metal oxyhydride compound may be further included.

[0024] In addition, according to one embodiment of the present invention, in the step of preparing the mixed powder, the molar ratio of the metal oxide powder with a perovskite structure and the calcium hydride compound powder may be 0.1:1 to 5:1.

[0025] In addition, according to one embodiment of the present invention, in the step of preparing the metal oxyhydride compound, the heat treatment may be performed in a temperature range of 100°C or higher and 800°C or lower.

[0026] In addition, according to one embodiment of the present invention, in the step of preparing the metal oxyhydride compound, the heat treatment may be performed for a period of 24 hours or more and 240 hours or less.

[0027] A metal oxyhydride compound with a perovskite structure having hydrogen anion conductivity according to one embodiment of the present invention has hydrogen ion conductivity on its own without external hydrogen supply, so it has the effect of being usable in various fields such as hydrogen energy devices and catalyst devices.

[0028] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description of the invention or the claims.

[0029] FIG. 1 is a metal oxyhydride compound having a perovskite structure (AeLnO) according to one embodiment of the present invention. 3-x H y This is a schematic diagram showing the crystal structure of ).

[0030] FIG. 2 is a schematic diagram illustrating a method for preparing a metal oxyhydride compound with a perovskite structure according to one embodiment of the present invention.

[0031] FIG. 3 is a barium cerium oxyhydride (BaCeO₂), a metal oxyhydride compound with a perovskite structure containing both oxygen and hydrogen according to one embodiment of the present invention. 3-x H y, This is a graph comparing the X-ray diffraction patterns of the Example) and barium cerium oxide (BaCeO3, Comparative Example), which is a hydrogen-free perovskite oxide.

[0032] FIG. 4 is a barium cerium oxyhydride (BaCeO₂), a metal oxyhydride compound with a perovskite structure according to one embodiment of the present invention. 3-x H yThis is a graph comparing the cerium 3d core level of barium cerium oxide (BaCeO3, comparative example) and the example.

[0033] FIG. 5 is a barium cerium oxyhydride (BaCeO₂), a metal oxyhydride compound with a perovskite structure according to one embodiment of the present invention. 3-x H y This is a graph comparing the hydrogen (M / z=2) thermal desorption spectrum of the example and barium cerium oxide (BaCeO3, comparative example).

[0034] FIG. 6 is a barium cerium oxyhydride (BaCeO₂), a metal oxyhydride compound with a perovskite structure according to one embodiment of the present invention. 3-x H y This is a graph comparing the neutron powder diffraction patterns of the example and barium cerium oxide (BaCeO3, comparative example).

[0035] FIG. 7 is a barium cerium oxyhydride (BaCeO₂) with a perovskite structure according to one embodiment of the present invention. 3-x H y This is a graph comparing the ion conductivity characteristics according to temperature of the example and barium cerium oxide (BaCeO3, comparative example).

[0036] The present invention will be described below with reference to the attached drawings. However, the present invention may be implemented in various different forms and is therefore not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification have been given similar reference numerals.

[0037] Throughout the specification, when it is stated that a part is "connected (connected, in contact, combined)" with another part, this includes not only cases where they are "directly connected," but also cases where they are "indirectly connected" with other members interposed between them. Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components.

[0038] The terms used herein are merely for describing specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to indicate the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0039]

[0040] Hereinafter, the present invention will be described with reference to the drawings presented in this specification. For reference, the drawings may be partially exaggerated to illustrate the features of the present invention. In such cases, it is preferable to interpret them in light of the entire intent of this specification.

[0041]

[0042] Referring to FIG. 1, a metal oxyhydride compound according to one embodiment of the present invention is described.

[0043] FIG. 1 is a metal oxyhydride compound having a perovskite structure (AeLnO) according to one embodiment of the present invention. 3-x H y This is a schematic diagram showing the crystal structure of ).

[0044] Referring to FIG. 1, a metal oxyhydride compound according to one embodiment of the present invention is a metal compound containing an oxygen anion and a hydrogen anion, has a perovskite structure, and can be represented by the following chemical formula 1.

[0045] [Chemical Formula 1]

[0046] AeLnO 3-x H y

[0047] Above, Ae is an alkaline earth metal, Ln is a lanthanide element, and 0 <x<3이고, 0<y<3이다.

[0048] At this time, the metal oxyhydride compound of Chemical Formula 1 has a hydrogen anion partially substituting for the oxygen anion site. Unlike conventional hydrogen cation conductors, where hydrogen in the form of a hydroxyl group is bonded to the oxygen anion, the hydrogen inside the metal oxyhydride compound is chemically bonded to alkaline earth metal (Ae) and lanthanide (Ln) cations.

[0049] At this time, the metal oxyhydride compound of the perovskite structure may be formed in the form of pellets or powder, but there are no special limitations on the shape or structure, and it may be composed in various forms and may have different forms depending on the purpose of the technical field to which the present invention is applied.

[0050] At this time, the metal oxyhydride compound is characterized by having hydrogen anion conductivity, and the present invention can exhibit hydrogen ion conductivity without external hydrogen injection.

[0051] At this time, the metal oxyhydride compound of the present invention has a hydrogen ion conductivity of 10 at a temperature of 600 ℃ or lower -6 S cm -1 It is characterized by being above.

[0052] Thus, the metal oxyhydride compound of the present invention can be applied to the hydrogen energy and catalyst fields where excellent hydrogen ion conductivity can be utilized, and, for example, can be used in water electrolysis devices.

[0053]

[0054] Referring to FIG. 2, a method for preparing a metal oxyhydride compound according to another embodiment of the present invention will be described.

[0055] Referring to FIG. 2, a method for manufacturing a metal oxyhydride compound according to one embodiment of the present invention may include the step of manufacturing a mixed powder by mixing a metal oxide powder having a perovskite structure and a calcium hydride compound powder (S100); and the step of manufacturing a metal oxyhydride compound by heat treating the mixed powder so that a hydrogen anion is substituted at the oxygen anion position of the metal oxide having a perovskite structure (S200).

[0056] The first step may include a step of preparing a mixed powder. (S100)

[0057] In the first step, the mixed powder is a mixture of a metal oxide powder with a perovskite structure and a calcium hydride compound powder, wherein the molar ratio of the metal oxide powder with a perovskite structure and the calcium hydride (CaH2) compound powder may be 0.1:1 to 5:1.

[0058] At this time, the metal oxide powder with the perovskite structure may be, for example, AeLnO3 (Ae is an alkaline earth metal and Ln is a lanthanide element).

[0059] At this time, the present invention may further include a step (S110) of compression molding the mixed powder into a pellet form before heat treatment according to the final form of the metal oxyhydride compound having a perovskite structure.

[0060]

[0061] In the second step, a step of preparing a metal oxyhydride compound may be included. (S200)

[0062] At this time, heat treatment may be performed to prepare the metal oxyhydride compound, and the heat treatment may be performed in a temperature range of 100 ℃ or higher and 800 ℃ or lower.

[0063] In addition, the above heat treatment is preferably performed for 24 hours or more, and may be performed for a period of 24 hours or more and 240 hours or less.

[0064] In addition, the present invention may further include a step of washing the heat-treated metal oxyhydride compound to remove impurities after the step of preparing the metal oxyhydride compound. (S300)

[0065] At this time, the metal oxyhydride compound produced by the above method for producing a metal oxyhydride compound may be a substance of the following chemical formula 1.

[0066] [Chemical Formula 1]

[0067] AeLnO 3-x H y (Ae: alkaline earth metal, Ln: lanthanide element, 0 <x<3 이고, 0<y<3 이고, 바람직하게는 0<x<1, 0<y<1 일 수 있다.

[0068] At this time, the alkaline earth metal used in the present invention may be, for example, Ca, Sr, or Ba.

[0069]

[0070] The present invention will be explained in more detail below through examples and experimental examples. These examples and experimental examples are solely for the purpose of illustrating the present invention, and the scope of the present invention is not limited by these examples and experimental examples.

[0071] Example: Barium cerium oxyhydride (BaCeO 3-x H y )

[0072] In this embodiment, with reference to FIG. 2, barium cerium oxyhydride (BaCeO₂), a metal oxyhydride compound having a perovskite structure according to one embodiment of the present invention, is used. 3-x H y Explains the manufacturing method.

[0073] First, a mixed powder was prepared by mixing barium cerium oxide (BaCeO3) and calcium hydride compound (CaH2) in a 2:1 molar ratio.

[0074] Next, the prepared mixed powder is pelletized using a glass tube, sealed, and heat-treated at 420°C for 120 hours to produce barium cerium oxyhydride (BaCeO₂). 3-x H y Manufactured ).

[0075]

[0076] Comparative Example: Barium Cerium Oxide (BaCeO3)

[0077] In this comparative example, barium cerium oxide (BaCeO3) was prepared.

[0078]

[0079] Experimental Example 1: Evaluation of Structural Characteristics

[0080] FIG. 1 is a perovskite metal oxyhydride compound (AeLnO) presented in the present invention. 3-x H y This is a diagram showing the crystal structure of ), and it shows that it has a local structure in which hydrogen (H) is partially substituted at the oxygen (O) position in the 6th coordination surrounding the lanthanum (Ln) cation.

[0081] FIG. 3 is a barium cerium oxyhydride (BaCeO2) according to one embodiment of the present invention. 3-x H y This is a diagram comparing the X-ray diffraction patterns of the example and barium cerium oxide (BaCeO3, comparative example).

[0082] Specifically, FIG. 3a above illustrates the barium cerium oxyhydride (BaCeO) of the present invention. 3-x H y Figure 3b shows that the barium cerium oxide (BaCeO3, Comparative Example) has the same perovskite structure as the barium cerium oxide (Example), and the main peaks of barium cerium oxyhydride and barium cerium oxide are compared. The fact that the peak of barium cerium oxyhydride shifts to the left compared to barium cerium oxide indicates that the volume of the unit cell has increased due to hydrogen partial substitution.

[0083] Figure 4 is a diagram comparing the cerium 3d core levels of barium cerium oxyhydride and barium cerium oxide according to one embodiment of the present invention.

[0084] Specifically, Figure 4a is a cerium (Ce) 3d core level spectrum of barium cerium oxyhydride obtained through X-ray photoelectron spectroscopy, and Figure 4b is a diagram showing the cerium 3d core level spectrum of barium cerium oxide.

[0085] In conventional barium cerium oxide, cerium ions are Ce 4+ While it exists as, in barium cerium oxyhydride, the cerium ion is Ce 4+ Wow Ce 3+ It was observed that it exists as such, which means that the oxygen anion sites around cerium were partially replaced by hydrogen anions, and cerium was reduced.

[0086]

[0087] Experimental Example 2: Hydrogen Content and Location Evaluation

[0088] Figure 5 is a diagram comparing the thermal desorption spectra of barium cerium oxyhydride according to an embodiment of the present invention and barium cerium oxide, a comparative example.

[0089] Specifically, the spectra of hydrogen (M / z=2) were compared using thermal desorption spectroscopy. While thermal desorption of hydrogen was not observed in conventional barium cerium oxide, the thermal desorption spectrum of hydrogen was clearly observed in barium cerium oxyhydride in the temperature range from 150 °C to 600 °C, which proves that hydrogen is present inside barium cerium oxyhydride.

[0090] FIG. 6 is a diagram analyzing the neutron powder diffraction pattern of barium cerium oxyhydride and barium cerium oxide according to one embodiment of the present invention.

[0091] This result, along with thermal desorption spectroscopy, proves that hydrogen is present inside barium cerium oxyhydride.

[0092]

[0093] Experimental Example 3: Evaluation of Ionic Conductivity Performance

[0094] Figure 7 is a diagram comparing the ionic conductivity of barium cerium oxyhydride and barium cerium oxide according to an embodiment of the present invention as a function of temperature.

[0095] Specifically, by using electrochemical impedance spectroscopy to compare ion conductivity characteristics in an argon atmosphere without external hydrogen supply in a temperature range between 200°C and 400°C, it was confirmed that while conventional barium cerium oxide has very low ion conductivity characteristics, barium cerium oxyhydride has excellent ion conductivity characteristics across all temperature ranges.

[0096] In other words, the excellent ionic conductivity of barium cerium oxyhydride shown in Experimental Example 3 demonstrates the potential for barium cerium oxyhydride to be utilized as a core material for hydrogen energy devices and catalytic devices.

[0097]

[0098] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0099] The scope of the present invention is defined by the claims set forth below, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention.

Claims

1. A metal compound containing oxygen anions and hydrogen anions, having a perovskite structure, Metal oxyhydride compound characterized by being represented by the following chemical formula 1: [Chemical Formula 1] AeLnO 3-x H y Above, Ae is an alkaline earth metal, Ln is a lanthanide element, and 0 <x<3이고, 0<y<3이다.

2. In Paragraph 1, A metal oxyhydride compound characterized in that the above metal oxyhydride compound is in the form of pellets or powder.

3. In Paragraph 1, The metal oxyhydride compound is characterized by having hydrogen anion conductivity.

4. In Paragraph 1, The above metal oxyhydride compound has a hydrogen ion conductivity of 10 at a temperature of 600 ℃ or lower -6 S cm -1 A metal oxyhydride compound characterized by the above.

5. A step of preparing a mixed powder by mixing a metal oxide powder with a perovskite structure and a calcium hydride compound powder; and A method for preparing a metal oxyhydride compound, characterized by including the step of heat treating the above-mentioned mixed powder so that hydrogen anions are substituted at the oxygen anion positions of the metal oxides having a perovskite structure.

6. In Paragraph 5, Between the step of preparing the above mixed powder and the step of preparing the metal oxyhydride compound, A method for manufacturing a metal oxyhydride compound, characterized by further including the step of compression molding the above-mentioned mixed powder into a pellet form.

7. In Paragraph 5, After the step of preparing the above metal oxyhydride compound, A method for manufacturing a metal oxyhydride compound, characterized by further including a step of washing to remove impurities from the metal oxyhydride compound after the heat treatment is completed.

8. In Paragraph 5, In the step of manufacturing the above mixed powder, A method for preparing a metal oxyhydride compound characterized in that the mixing molar ratio of the metal oxide powder with the perovskite structure and the calcium hydride compound powder is 0.1:1 to 5:

1.

9. In Paragraph 5, In the step of preparing the above metal oxyhydride compound, A method for manufacturing a metal oxyhydride compound, characterized in that the above heat treatment is performed in a temperature range of 100 ℃ or higher and 800 ℃ or lower.

10. In Paragraph 5, In the step of preparing the above metal oxyhydride compound, A method for preparing a metal oxyhydride compound, characterized in that the above heat treatment is performed for a period of 24 hours or more and 240 hours or less.

11. A water electrolysis device characterized by comprising the metal oxyhydride compound of claim 1.

12. A catalytic device characterized by comprising the metal oxyhydride compound of claim 1.

13. A hydrogen energy device characterized by comprising the metal oxyhydride compound of claim 1.

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