KR101662652B1 - solid oxide electrolyzer cell generating carbon monoxide and method of manufacturing the same - Google Patents

Abstract

The present invention provides a solid oxide electrolytic cell operable at a low temperature and producing carbon monoxide with high efficiency. The solid oxide electrolytic cell according to an embodiment of the present invention includes a cathode having a double layer perovskite structure, which generates carbon monoxide, discharges carbon monoxide gas formed by decomposition of carbon dioxide, and has a double layer perovskite structure; An anode disposed facing the cathode and discharging oxygen gas formed by decomposition of the carbon dioxide; And an electrolyte disposed between the anode and the cathode.

Description

TECHNICAL FIELD The present invention relates to a solid oxide electrolytic cell producing carbon monoxide and a method of manufacturing the same,

TECHNICAL FIELD The present invention relates to a solid oxide electrolytic cell for generating carbon monoxide, and more particularly, to a solid oxide electrolytic cell using an oxide having a perovskite-related structure as a cathode and a method for producing the same.

Recently, research on a technique for obtaining energy using hydrogen gas has been attracting attention. Conventional sources of energy such as coal or petroleum contain carbon, whereas hydrogen gas does not contain carbon at all and is mostly converted to water, so there is no generation of unnecessary byproducts after being used as an energy source, . Therefore, hydrogen gas is considered to be the most environmentally friendly and ideal energy source.

In order to use hydrogen as an energy source, it is necessary to obtain hydrogen gas from water, hydrocarbon, or the like. Hydrogen gas can be produced through a steam reforming thermal decomposition gasification process using hydrocarbon-based materials such as natural gas, coal, and petroleum to obtain hydrogen gas. However, such hydrocarbon-based materials generate carbon dioxide and the like, which are undesired by-products, and thus may pollute the environment. In particular, carbon dioxide limits emissions from around the world due to the greenhouse effect.

As a method for reducing such a carbon dioxide emission amount, a technique of converting carbon dioxide into carbon monoxide which can be used as fuel has been attracting attention. As such a technique, there is a technology of converting carbon dioxide into carbon monoxide gas by reduction by electrolysis. The technology for producing carbon monoxide gas by electrolysis of carbon dioxide is in the spotlight as a technology for producing carbon monoxide gas because waste heat can be recycled.

The electrolysis method according to the present technology uses heat at a high temperature of 800 ° C or higher, and thus is limited to the level of waste heat discharged from nuclear power generation. Further, in such a high-temperature environment, nickel, which is an electrode material, is unstable with respect to carbon monoxide-carbon dioxide, and in particular, there is a fear that the nickel is coarsened at high temperature and is deteriorated. In addition, nickel has a high efficiency for generating hydrogen gas, but has a low efficiency for generating carbon monoxide gas.

 Thus, there is a need for an electrolytic technique that is operable at low temperatures and produces carbon monoxide from carbon dioxide at high efficiency.

U.S. Patent No. 8,591,718

The technical problem of the present invention is to provide a solid oxide electrolytic cell that can operate at a low temperature and produces carbon monoxide with high efficiency.

A technical object of the present invention is to provide a method of manufacturing a solid oxide electrolytic cell which is operable at a low temperature and which produces carbon monoxide with high efficiency.

According to an aspect of the present invention, there is provided a solid oxide electrolytic cell comprising: a cathode for discharging carbon monoxide gas formed by decomposition of carbon dioxide; An anode disposed facing the cathode and discharging oxygen gas formed by decomposition of the carbon dioxide; And an electrolyte disposed between the anode and the cathode. The cathode comprises a compound of the following formula (1).

≪ Formula 1 >

RET ₂ O _{5 + 隆}

Wherein R comprises one or more elements selected from rare earth elements or lanthanides, E comprises one or more elements selected from the group of the alkaline earth metals, and T is selected from the group consisting of one selected from transition metals Or more, O is oxygen, and? Is a positive number of 0 or 1 or less, and is a value that makes the compound of formula (1) electrically neutral.

In one embodiment of the present invention, the R is at least one selected from the group consisting of yttrium (Y), neodymium (Nd), praseodymium (Pr), scandium (Sc), samarium (Sm), gadolinium (Gd) ), Terbium (Tb), erbium (Er), or mixtures thereof.

In one embodiment of the present invention, E is at least one element selected from the group consisting of beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba) And mixtures thereof.

In one embodiment of the present invention, T is a metal selected from the group consisting of manganese (Mn), cobalt (Co), iron (Fe), copper (Cu), chromium (Cr), nickel (Ni) Ti), niobium (Nb), or mixtures thereof.

In one embodiment of the present invention, the compound of Formula 1 may have a double-layered perovskite structure.

In one embodiment of the present invention, the cathode may comprise a compound of the following formula (2).

(2)

RBaMn ₂ O _{5 +?}

Wherein R is one or more elements selected from a rare earth group or a lanthanide group, O is oxygen, and? Is a positive number of 0 or 1 or less, the compound of the formula (2) Value.

In one embodiment of the present invention, the compound of Formula 2 may include a compound of YBaMn ₂ O _{5 + delta} , a compound of NdBaMn ₂ O _{5 + delta} , or a compound of PrBaMn ₂ O _{5 + delta} .

In one embodiment of the present invention, the anode comprises La _0.8 Sr _0.2 Fe-YSZ, PrBa _0.5 Sr _0.5 Co _1.5 Fe _0.5 O _{5 + δ} compound, NdBa _0.5 Sr _0.5 Co _1.5 Fe _0.5 O _{5 + 0.5} Sr _0.5 CoFeO _{5 +?} ≪ / RTI > compounds. Is a positive number of 0 or 1 or less and the value of the compound is an electrical neutrality.

In one embodiment of the present invention, the electrolyte is selected from the group consisting of yttria stabilized zirconia (YSZ), scandia stabilized zirconia (ScSZ), samarium doped ceria (SDC), gadolinia doped ceria (GDC) And mixtures thereof.

In one embodiment of the present invention, the operating temperature of the solid oxide electrolytic cell may range from 600 ° C to 800 ° C.

According to an aspect of the present invention, there is provided a solid oxide electrolytic cell comprising: a cathode having a double layer perovskite structure, which discharges carbon monoxide gas formed by decomposition of carbon dioxide; An anode disposed facing the cathode and discharging oxygen gas formed by decomposition of the carbon dioxide; And an electrolyte disposed between the anode and the cathode.

According to an aspect of the present invention, there is provided a method of manufacturing a solid oxide electrolytic cell, comprising: dissolving metal oxide precursors in a solvent to obtain a precursor solution; Evaporating the solvent in the precursor solution to obtain a solid; Firing the solid material in air to obtain a fired product; And polishing the sintered body, wherein the metal oxide precursors comprise a mixture of R, E, and T compounds in stoichiometric proportions capable of producing a compound of Formula 1 below.

≪ Formula 1 >

RET ₂ O _{5 + 隆}

Wherein R comprises one or more elements selected from rare earth elements or lanthanides, E comprises one or more elements selected from the group of the alkaline earth metals, and T is selected from the group consisting of one selected from transition metals Or more, O is oxygen, and? Is a positive number of 0 or 1 or less, and is a value that makes the compound of formula (1) electrically neutral.

In one embodiment of the present invention, the compound of Formula 1 may include a compound of YBaMn ₂ O _{5 + delta} , a compound of NdBaMn ₂ O _{5 + delta} , or a compound of PrBaMn ₂ O _{5 + delta} .

The solid oxide electrolytic cell according to the technical idea of the present invention includes a cathode composed of a compound having a double layer perovskite structure.

Solid oxide electrolyte according to the technical features of the present invention the cell may form a carbon monoxide gas by electrolysis of carbon dioxide of 600 ^o C to 800 ^o C. Since the temperature range is lower than the waste heat temperature of nuclear power generation, various waste heat sources which are relatively low temperature can be used.

In addition, since the solid oxide electrolytic cell according to the technical idea of the present invention has a high electric conductivity in the temperature range, carbon monoxide gas can be efficiently and economically formed.

Further, since the solid oxide electrolytic cell according to the technical idea of the present invention does not use nickel for the cathode but uses a compound having a bilayer perovskite structure, it is possible to fundamentally prevent crystal grain coarsening phenomenon of nickel particles at high temperatures And the cathode has little reactivity with an electrolyte or a carbon monoxide gas, and thus can provide thermal and chemical stability.

The effects of the present invention described above are exemplarily described, and the scope of the present invention is not limited by these effects.

1 is a schematic view showing a solid oxide electrolytic cell according to an embodiment of the present invention.
2 is a schematic view showing a double layer perovskite structure constituting the cathode of the solid oxide electrolytic cell according to the embodiment of the present invention.
3 is a graph showing current-voltage polarization curves of a solid oxide electrolytic cell according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail. In interpreting the terms or words used in the present specification and claims, it is to be understood that the interpretation of terms or words used herein is necessarily conventional, based on the principle that the inventor can properly define the concept of the term to describe its invention in the best way It is to be understood that the invention is not to be interpreted as being limited only by the precautionary sense, but should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention as described in the present specification.

The technical idea of the present invention is to provide a solid oxide electrolytic cell that generates carbon monoxide.

The fuel cell produces electricity by the electrochemical reaction of hydrogen and oxygen and produces water as a byproduct. On the other hand, the water electrolytic reaction is performed by supplying water in the form of water vapor, applying electric energy, Hydrogen gas and oxygen gas are formed. The heat of reaction is the exothermic reaction of the fuel cell, while the hydrothermal reaction is the endothermic reaction. Therefore, contrary to the fuel cell that generates current from the cell, the electrolytic cell decomposes the water as the current is applied to generate hydrogen gas. When carbon dioxide is supplied instead of water and electric energy is applied, carbon monoxide gas and oxygen gas are formed by the decomposition reaction of electrochemical carbon dioxide. This carbon dioxide electrolysis reaction is also an endothermic reaction.

1 is a schematic view showing a solid oxide electrolytic cell 100 according to an embodiment of the present invention.

1, a solid oxide electrolytic cell 100 includes a cathode 110, an anode 120 disposed opposite the cathode 110, and an anode 120 disposed between the cathode 110 and the anode 120, And an electrolyte 130 which is a solid oxide. The cathode 110 may be referred to as a fuel electrode because it is in contact with carbon monoxide gas, and the anode 120 may be referred to as an oxygen electrode in contact with oxygen gas.

The electrochemical reaction of the solid oxide electrolytic cell 100 can be carried out in the same manner as in the electrochemical reaction in which the carbon dioxide (CO ₂ ) of the cathode 110 changes into the carbon monoxide (CO) and the oxygen ion (O ^2- ) (O ₂ ), which is the oxygen ion that has been moved through the oxygen gas (O ₂ ). This reaction is opposite to the reaction principle of a typical fuel cell.

<Reaction Scheme>

Cathode reaction: CO ₂ + 2e ^- -> O ^2- + CO

Anode reaction: O ^2- -> 1/2 O ₂ + 2e ^-

When power is applied to the solid oxide electrolytic cell 100 from the external power supply 140, electrons are supplied from the external power supply 140 to the solid oxide electrolytic cell 100. The electrons react with carbon dioxide provided to the cathode 110 to generate carbon monoxide gas and oxygen ions. The carbon monoxide gas is discharged to the outside, and the oxygen ions are transferred to the anode 120 through the electrolyte 130. The oxygen ions transferred to the anode 120 lose electrons and are converted into oxygen gas and discharged to the outside. The electrons flow to the external power source 140. Through the electron transfer, the solid oxide electrolytic cell 100 can electrolyze the carbon dioxide to form carbon monoxide gas in the cathode 110, and form oxygen gas in the anode 120.

The anode 120 is not particularly limited and may be formed to include various kinds of materials. The anode 120 may include, for example, LaSrFe-YSZ, and may include, for example, La _0.8 Sr _0.2 Fe-YSZ. The anode 120 may comprise, for example, a material having a bilayer perovskite structure. The anode 120 may be formed of, for example, PrBa _a Sr _1-a Co _{2 -b} Fe _b O _{5 + δ} compound (wherein a is a number of 0 or more and 1 or less, b is a number of 0 or more and 2 or less, For example, PrBa _0.5 Sr _0.5 Co _1.5 Fe _0.5 O _{5 +}隆 compound, NdBa _0.5 Sr _0.5 Co _1.5 Fe _0.5 O _{5 +}隆 compound, or GdBa _0.5 Sr _0.5 CoFeO _{5 +?} Compounds and the like.

The electrolyte 130 is not particularly limited as long as it can be generally used in the art. For example, the electrolyte 130 may be a stabilized zirconia based system such as yttria stabilized zirconia (YSZ) and scandia stabilized zirconia (ScSZ); Ceria system to which a rare earth element such as samaria-doped ceria (SDC), gadolinia-doped ceria (GDC) and the like is added; Other LSGM ((La, Sr) (Ga, Mg) O ₃ ) system; And the like. In addition, the electrolyte 130 may include strontium or magnesium-doped lanthanum gallate.

The solid oxide electrolytic cell 100 can be manufactured by using a conventional method known in the art, so a detailed description thereof will be omitted here. In addition, the solid oxide electrolytic cell 100 can be applied to various structures such as a tubular stack, a flat tubular stack, a planar type stack, and the like.

The solid oxide electrolytic cell 100 may be in the form of a stack of unit cells. For example, a membrane electrode assembly (MEA) composed of a cathode 110, an anode 120, and an electrolyte 130 is stacked in series and a separator plate (not shown) electrically connecting the unit cells a stack of unit cells can be obtained.

The technical idea of the present invention relates to a cathode 110 constituting a solid oxide electrolytic cell 100 and having a double layer perovskite structure. Therefore, the materials constituting each of the cathodes 110 will be described in detail.

The cathode 110 may include a compound represented by the following formula (1).

&Lt; Formula 1 >

RET ₂ O _{5 + 隆}

Wherein R comprises one or more elements selected from rare earth elements or lanthanides, E comprises one or more elements selected from the group of the alkaline earth metals, and T is selected from the group consisting of one selected from transition metals Or more, O is oxygen, and? Is a positive number of 0 or 1 or less, and is a value that makes the compound of formula (1) electrically neutral. The above 隆 represents interstitial oxygen in the following double layer perovskite structure and the value of 隆 can be determined according to a specific crystal structure.

The R may be, for example, yttrium (Y), neodymium (Nd), praseodymium (Pr), scandium (Sc), samarium (Sm), gadolinium (Gd), europium (Eu), terbium ), Or mixtures thereof.

The E may include, for example, beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), radium (Ra)

The T may be, for example, Mn, Co, Fe, Cu, Cr, Ni, Ti, Nb, . &Lt; / RTI &gt;

The materials presented for R, E, and T are illustrative, and the technical idea of the present invention is not limited thereto.

The cathode 110 may include a compound of the following formula (2).

(2)

RBaMn ₂ O _{5 +?}

Wherein R is one or more elements selected from a rare earth group or a lanthanide group, O is oxygen, and? Is a positive number of 0 or 1 or less, the compound of the formula (2) Value.

The R may be, for example, yttrium (Y), neodymium (Nd), praseodymium (Pr), scandium (Sc), samarium (Sm), gadolinium (Gd), europium (Eu), terbium ), Or mixtures thereof.

The compound of Formula 2 may include, for example, a compound of YBaMn ₂ O _{5 + delta} , a compound of NdBaMn ₂ O _{5 + delta} , or a compound of PrBaMn ₂ O _{5 + delta} .

The cathode 110 may have a double layer perovskite structure. Hereinafter, the double layer perovskite structure will be described in detail.

A simple perovskite structure may have the formula ABO ₃ . In the single perovskite structure, elements having relatively large ionic radii may be located in the A-site at the corner of the cubic lattice, and the number of coordination numbers (CN , Coordination number). For example, a rare earth element, an alkaline rare earth element, and an alkaline element may be located in the A-site. The B-site, which is the body center of the cubic lattice, may contain elements having relatively small ionic radii, and may have six coordination numbers by oxygen ions. For example, the transition metal may be located in the B-site. Oxygen ions may be located at each face center of the cubic lattice. Such a single perovskite structure can generally result in structural displacements when other materials are substituted on the A-site, and it is often the case that the nearest oxygen ions in the octahedron of BO ₆ consisting of six) it may cause structural variations.

2 is a schematic view showing a double layer perovskite structure constituting the cathode 110 of the solid oxide electrolytic cell 100 according to an embodiment of the present invention.

Referring to FIG. 2, the bilayer perovskite structure is a crystal lattice structure in which two or more elements are regularly arranged on the A-site, and may have a formula of AA'B ₂ O _{5 + delta} . Specifically, a lanthanide compound having a bilayer perovskite structure can be basically repeated with the lamination permutation of [BO ₂ ] - [AO] - [BO ₂ ] - [A'O] along the c axis. For example, B may be manganese (Mn), A may be yttrium (Y) or lanthanide, and A 'may be barium (Ba).

In addition, the barium may be partially substituted, for example, by calcium. The manganese may be partially substituted by a transition metal such as cobalt (Co), iron (Fe), copper (Cu), chromium (Cr), nickel (Ni), titanium (Ti), or niobium have.

Upon reduction in a hydrogen atmosphere, the single perovskite structure material is transformed into a double perovskite material. Such a double perovskite structure can accelerate oxygen ion movement and improve thermal and chemical stability. In addition, a cathode having higher electrical conductivity in a hydrogen atmosphere and thermo-chemical stability than the conventional cathode and exhibiting excellent performance can be realized.

Hereinafter, a method of manufacturing the cathode 110 of the solid oxide electrolytic cell 100 according to the technical idea of the present invention will be described.

The cathode 110 is prepared by mixing each of the metal precursors metered in accordance with the composition of the RET ₂ O _{5 +?} Compound of Formula 1 (for example, wet using a solvent), mixing the (wet) Obtaining a solid product, firing the solid product in air to obtain a fired product, and polishing the fired product.

Examples of the metal precursor include, but are not limited to, nitrides, oxides, and halides of R, E, and T, which are metal components constituting the compound of Formula 1, respectively. For example, the compound of Formula 1 may be PrBaMn ₂ O _{5 + δ} , and the metal precursor may be a nitride, oxide, halide, or the like containing at least one of Pr, Ba, Mn,

In the step of mixing the metal precursor with the solvent, water may be used as a solvent, but the present invention is not limited thereto. The solvent may be any solvent capable of dissolving the metal precursor. Examples of the solvent include lower alcohols having a total carbon number of 5 or less, such as methanol, ethanol, 1-propanol, 2-propanol, and butanol; Acidic solutions such as nitric acid, hydrochloric acid, sulfuric acid, and citric acid; water; Organic solvents such as toluene, benzene, acetone, diethyl ether and ethylene glycol; May be used alone or in combination.

The step of mixing the metal precursor with the solvent may be performed at a temperature in the range of about 100 ° C to about 200 ° C and may be carried out for a predetermined time under agitation so that each component can be thoroughly mixed. The mixing process, removing the solvent, and addition of additives required for this purpose are well known, for example, by the pechini method, and therefore are not described here.

After the mixing process, ultrafine solid material can be obtained by spontaneous combustion. The ultrafine solid can then be heat treated (calcined, sintered) for a time period ranging from about 400 ° C. to about 950 ° C. for a time period ranging from about 1 hour to about 5 hours, for example, at about 600 ° C. for about 4 hours.

If necessary, a second heat treatment (calcination, sintering) may be performed after the firing. This second heat treatment process is a step of calcining in air for about 12 hours at a temperature in the range of about 950 DEG C to about 1500 DEG C, for a period of about 1 hour to about 24 hours, for example, at a temperature in the range of about 950 to about 1500 DEG C To obtain a powdery product.

Then, the fired product may be ground or pulverized to obtain a fine powder having a predetermined size. For example, milling and mixing by ball milling in acetone for about 24 hours. Next, the mixed powder is put in a metal mold and pressed, and then the pressed pellet is sintered in the atmosphere to produce a sintered body. Sintering may be performed at a temperature in the range of about 950 ° C to about 1500 ° C for a period ranging from about 12 hours to about 24 hours, for example, at a temperature in the range of from about 950 to about 1500 ° C for a period of about 24 hours, . The fired product may be ground or pulverized to obtain a fine powder having a predetermined size.

The material for the cathode may then be reduced in an atmosphere of 97% H ₂ (corresponding to 3% H ₂ O) at a temperature of about 800 ° C to form a bilayer perovskite structure.

[Example]

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The above embodiments are not intended to limit the scope of the present invention.

Of the compounds of Formula 1, the PrBaMn ₂ O _{5 + delta} compound was selected as the cathode material.

In order to form the cathode material, the metal precursors were dissolved in a solvent mixed with ethylene glycol, citric acid, and distilled water. After the dissolution, ultrafine solid was obtained through self-combustion process. The ultrafine solid was heat-treated at 600 ° C. for 4 hours, pulverized and mixed in a ball mill for 24 hours in acetone, dried, compressed with pellets at 5 MPa and air-dried at 1500 ° C. for 24 hours Lt; / RTI &gt; Then, a reducing material was formed after reducing in an atmosphere of 100% H ₂ (corresponding to 3% H ₂ O) to form a bilayer perovskite structure. The reducing material was pulverized and mixed with an organic binder (Heraeus V006) to synthesize a cathode slurry.

LSGM powder was compressed with pellets and sintered in air at about 1475 ° C for 5 hours in order to manufacture a full single cell, and polished to obtain a dense electrolyte having a thickness of about 300 mm. Next, after each screen printing an anode slurry comprising for the cathode slurry and _{PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5} O 5 + δ compound in the electrolyte on both sides, and sintered at about 950 ℃ for about 4 hours in air, the cathode , An electrolyte and an anode were prepared.

The thicknesses of the cathode, the anode, and the electrolyte formed as described above were about 20 mu m, about 20 mu m, and about 300 mu m, respectively. For current application, a silver wire was attached to the cathode and the anode using a silver paste. If necessary, 15 wt% of a Co-Fe catalyst may be added to the cathode and the anode.

3 is a graph showing current-voltage polarization curves of a solid oxide electrolytic cell according to an embodiment of the present invention.

The current-voltage (I-V) polarization curve of Figure 3 was measured using a constant potential device from BioLogic. The current-voltage polarization curve of FIG. 3 was measured by providing 100% carbon dioxide, 10% carbon monoxide and 90% carbon dioxide, 50% carbon monoxide and 50% carbon dioxide to the cathode at 800 ° C.

Referring to FIG. 3, when 100% carbon dioxide was used (CO: CO ₂ = 0: 100 in FIG. 3), the current density was negative at a higher voltage than about 0.02 V, The current density was positive at low voltage. In the case of using 10% carbon monoxide and 90% carbon dioxide (CO: CO ₂ = 10:90 in FIG. 3), the current density was negative at a higher voltage than the voltage of about 0.9 V, The current density was positive at low voltage. In the case of using 50% carbon monoxide and 50% carbon dioxide (CO: CO ₂ = 50:50 in FIG. 3), the current density was negative at a higher voltage than the voltage of about 1.0 V, The current density was positive at low voltage.

3, a positive value of the current density means that the solid oxide electrolytic cell can be operated in the fuel cell mode, and the electrons are emitted in the direction shown in FIG. 1, that is, in the direction from the anode 120 to the cathode 110 That is, in the direction from the cathode 110 toward the anode 120. [0064] The negative current density means that the solid oxide electrolytic cell can be operated in the electrolytic mode, and the electrons flow in the same direction as the direction shown in FIG. 1, that is, in the direction from the anode 120 to the cathode 110 &Lt; / RTI &gt; That is, in a range corresponding to the negative current density, electrons move from the energy source to the cathode to decompose carbon dioxide to generate carbon monoxide and oxygen ions, whereby the oxygen ions combined with the electrons generate an electrolyte And can be converted into oxygen gas.

In addition, the absolute value of the current density at 100% carbon dioxide was larger at 90% carbon dioxide or 50% carbon dioxide than at the same voltage.

In-depth analysis of the range in which the current density has a negative value shows that the absolute value of the current density tends to increase as the amount of carbon dioxide supplied increases. For example, when a voltage of 1.3 V is applied at 800 ° C., it is 1.37 Acm ^-2 when 100% carbon dioxide is supplied, 0.54 Acm ^-2 when 90% carbon dioxide is supplied, and 50% And an absolute value of the current density of 0.30 Acm ^-2 . Therefore, when the absolute value of the current density when the carbon dioxide is supplied to the cathode at the same voltage is 100%, the absolute value of the current density is much larger than the absolute value when the carbon dioxide is contained. In the case of 100% carbon dioxide, And carbon monoxide is produced.

The solid oxide electrolytic cell according to the technical idea of the present invention includes a cathode composed of a compound having a double layer perovskite structure.

Solid oxide electrolyte according to the technical features of the present invention the cell may form a carbon monoxide gas by electrolysis of carbon dioxide of 600 ^o C to 800 ^o C. Since the temperature range is lower than the waste heat temperature of nuclear power generation, various waste heat sources which are relatively low temperature can be used.

In addition, since the solid oxide electrolytic cell according to the technical idea of the present invention has a high electric conductivity in the temperature range, carbon monoxide gas can be efficiently and economically formed.

Further, since the solid oxide electrolytic cell according to the technical idea of the present invention does not use nickel for the cathode but uses a compound having a bilayer perovskite structure, it is possible to fundamentally prevent crystal grain coarsening phenomenon of nickel particles at high temperatures And the cathode has little reactivity with an electrolyte or a carbon monoxide gas, and thus can provide thermal and chemical stability.

While the present invention has been particularly shown and described with reference to certain exemplary embodiments thereof, it should be understood that the same is by way of illustration and example only and is not to be taken by way of limitation. It will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. .

Accordingly, all equivalents of the claims and their equivalents, as well as the embodiments described hereinabove and the appended claims, are also within the scope of the inventive concept.

100: solid oxide electrolytic cell, 110: cathode,
120: anode, 130: electrolyte, 140: external power source

Claims (13)

A cathode for discharging carbon monoxide gas formed by decomposition of carbon dioxide;
An anode disposed facing the cathode and discharging oxygen gas formed by decomposition of the carbon dioxide; And
A solid oxide electrolytic cell for generating carbon monoxide, the solid oxide electrolytic cell comprising an electrolyte disposed between the anode and the cathode,
Wherein the cathode comprises a compound of the following formula (1).
&Lt; Formula 1 >
RET ₂ O _{5 + 隆}
Wherein R comprises one or more elements selected from rare earth elements or lanthanides, E comprises one or more elements selected from the group of the alkaline earth metals, and T is selected from the group consisting of one selected from transition metals Or more, O is oxygen, and? Is a positive number of 0 or 1 or less, and is a value that makes the compound of formula (1) electrically neutral. The method according to claim 1,
In the above formula (1), R is at least one selected from the group consisting of Y, neodymium, praseodymium, scandium, samarium, gadolinium, Er), or mixtures thereof. &Lt; / RTI &gt; The method according to claim 1,
Wherein E is at least one element selected from the group consisting of beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), radium Solid oxide electrolytic cell. The method according to claim 1,
In Formula 1, T is at least one element selected from the group consisting of Mn, Co, Fe, Cu, Cr, Ni, Ti, Wherein the solid oxide electrolytic cell produces carbon monoxide. The method according to claim 1,
The compound of formula (1) has a double layer perovskite structure and produces carbon monoxide. The method according to claim 1,
Wherein the cathode comprises a compound of the following formula (2).
(2)
RBaMn ₂ O _{5 +?}
Wherein R is one or more elements selected from a rare earth group or a lanthanide group, O is oxygen, and? Is a positive number of 0 or 1 or less, the compound of the formula (2) Value. The method of claim 6,
Wherein the compound of formula (2) comprises a compound of YBaMn ₂ O _{5 + delta} , a compound of NdBaMn ₂ O _{5 + delta} , or a compound of PrBaMn ₂ O _{5 + delta} . The method according to claim 1,
The anode may be selected from the group consisting of La _0.8 Sr _0.2 Fe-YSZ, PrBa _0.5 Sr _0.5 Co _1.5 Fe _0.5 O _{5 + δ} compound, NdBa _0.5 Sr _0.5 Co _1.5 Fe _0.5 O _{5 + δ} compound or GdBa _0.5 Sr _0.5 CoFeO _{5 +} &Lt; / RTI &gt;
In the _{PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5} O 5 + δ compound, wherein δ is a positive number of less than or equal to 0 or 1, the value of the _{PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5} O 5 + δ compound is electrically neutral,
In the _{NdBa 0.5 Sr 0.5 Co 1.5 Fe 0.5} O 5 + δ compound, wherein δ is a positive number of less than or equal to 0 or 1, the value of the _{NdBa 0.5 Sr 0.5 Co 1.5 Fe 0.5} O 5 + δ compound is electrically neutral,
The GdBa _0.5 Sr _0.5 CoFeO _{5 +} In compounds, wherein δ is a positive number of less than or equal to 0 or 1, the GdBa _0.5 Sr _0.5 CoFeO _{5 + δ} A solid oxide electrolytic cell producing carbon monoxide, the value of which makes the compound electrically neutral. The method according to claim 1,
The electrolyte comprises at least one of yttria stabilized zirconia (YSZ), scandia stabilized zirconia (ScSZ), samarium doped ceria (SDC), gadolinia doped ceria (GDC), lanthanum gallate, Solid oxide electrolytic cell that produces carbon monoxide. The method according to claim 1,
Wherein an operating temperature of said solid oxide electrolytic cell is in a range of 600 캜 to 800 캜. delete Dissolving the metal oxide precursors in a solvent to obtain a precursor solution;
Evaporating the solvent in the precursor solution to obtain a solid;
Firing the solid material in air to obtain a fired product; And
And polishing the sintered body,
Wherein said metal oxide precursors comprise a mixture of stoichiometric ratios of R, E, and T compounds capable of producing a compound of Formula 1: < EMI ID =
&Lt; Formula 1 &gt;
RET ₂ O _{5 + 隆}
Wherein R comprises one or more elements selected from rare earth elements or lanthanides, E comprises one or more elements selected from the group of the alkaline earth metals, and T is selected from the group consisting of one selected from transition metals Or more, O is oxygen, and? Is a positive number of 0 or 1 or less, and is a value that makes the compound of formula (1) electrically neutral. The method of claim 12,
Wherein the compound of formula (1) comprises a compound of YBaMn ₂ O _{5 + delta} , a compound of NdBaMn ₂ O _{5 + delta} , or a compound of PrBaMn ₂ O _{5 + delta} .

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