JP2010215420A - Microcavity structure and hydrogen generating apparatus provided with the same - Google Patents

Abstract

A microcavity structure having a relatively simple flow path structure and suitable for use in processing a large amount of source gas is provided.
A plurality of spherical microcavities that are continuous between a gas inlet and a gas outlet, are controlled in size, and communicate with each other, and a catalytic substance is applied to the surface of a wall of a structure that forms the microcavity. Support. While the microcavity has an inner diameter at which a cavity resonance wavelength that matches the electromagnetic wave absorption band of the source gas is obtained, the source gas is excited and heated by the electromagnetic wave having a specific wavelength close to the absorption band in the microcavity, It forms a thermodynamic nonequilibrium state of gas molecules that suppresses excitation of the product gas generated from the source gas.
[Selection] Figure 3

Description

  The present invention relates to a functional structure having a microcavity and a hydrogen generation apparatus provided with this structure as a reactor, and more specifically, the radiation cavity quantum effect can be used in a chemical process for processing a large amount of source gas. The present invention relates to a hydrogen generating technology such as steam reforming that efficiently utilizes the cavity quantum effect.

  The cavity quantum effect obtained in a micro-order cavity (hereinafter referred to as “micro-cavity”) has already been demonstrated by the present inventors, and the control of chemical reaction using a functional structure having a micro-cavity. Has been filed and published by the present inventors (Patent Document 1 below). The structure according to this related technology forms a large number of square micro cavities on a silicon wafer by MEMS technology (Micro Electro Mechanical Systems), specifically, inductively coupled plasma reactive ion etching, and is adjacent to the front and back. The micro cavities are connected to each other through a micro flow channel having a square cross section, and the gas inlet formed on one side of the structure and the gas discharge port formed on the other side communicate with each other via the micro cavity and the micro flow channel. It has been made. A catalyst layer mainly composed of nickel or the like is formed by sputtering on the inner surface of the wafer forming the microcavity. In the methane steam reforming process using the functional structure thus produced, methane and steam, which are raw material gases, are introduced into the structure from the gas inlet and supplied to the microcavity. And methane and water vapor | steam are heated by the radiation (resonance electromagnetic wave) which arises in a microcavity, and hydrogen produced | generated by the steam reforming reaction of methane is collect | recovered.

Japanese Patent Laying-Open No. 2006-273686 (paragraph numbers 0029 and 0030)

  However, in the technique described in the above-mentioned Patent Document 1, it is necessary to provide a micro flow path for communicating adjacent micro cavities in addition to the micro cavities inside the structure. There is a problem that the structure becomes complicated and it is not suitable for use in processing a large amount of source gas.

  In view of the above problems, the present invention provides a microcavity structure that has a relatively simple internal channel structure and is suitable for use in processing a large amount of source gas. An object of the present invention is to provide a hydrogen generator capable of efficiently utilizing the cavity quantum effect of radiation.

  A microcavity structure according to the present invention is a microcavity structure used in a chemical process using a radioactive gas as a raw material, and is provided between an inlet and an outlet for allowing gas to pass therethrough, and between the inlet and the outlet. The microcavity structure has a plurality of spherical microcavities that are continuous and communicated with each other, and a catalyst substance is supported on the surface of the wall of the structure that forms the microcavity. Here, the spherically formed microcavity has an inner diameter at which a cavity resonance wavelength that matches the electromagnetic wave absorption band of the raw material gas can be obtained. Thus, the raw material is caused by electromagnetic waves having a specific wavelength close to the absorption band in the microcavity. While the gas is excited and heated, a thermodynamic non-equilibrium state of gas molecules is formed in which excitation of the product gas generated from the source gas is suppressed.

  The hydrogen generator according to the present invention includes such a microcavity structure as a reactor.

  According to the present invention, the microcavity formed in the structure is spherical, and the inner diameter of the spherical microcavity is an inner diameter that provides a cavity resonance wavelength that matches the electromagnetic wave absorption band of the source gas. Only the source gas is excited and heated by electromagnetic waves to promote the thermal decomposition thereof, while the excitation of the generated gas can be suppressed. As a result, in the chemical process of the source gas, it is possible to efficiently utilize the radiation cavity quantum effect and to carry out the process at a lower temperature. Here, according to the present invention, since a plurality of spherical micro cavities are formed continuously and in communication with each other, it is not necessary to form a special micro flow path that connects adjacent micro cavities. The flow path structure in the body becomes relatively simple, and application to a use for processing a large amount of source gas becomes easy. According to the present invention, by adopting such a microcavity structure, it is possible to efficiently generate hydrogen by utilizing the radiation cavity quantum effect in the hydrogen generation process.

1 is an overall configuration diagram of a hydrogen generator according to an embodiment of the present invention. Explanatory drawing of the manufacturing process of the micro cavity structure concerning an embodiment same as the above Relationship between resonance spectrum in microcavity and absorption band of source gas

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows the overall configuration of a hydrogen generator according to an embodiment of the present invention.
In the present embodiment, a case will be described in which methane (CH ₄ ), which is a main component of natural gas, and water vapor are used as raw material gas, and hydrogen is generated by a steam reforming reaction of this methane.

The hydrogen generator according to the present embodiment is roughly composed of a raw material gas supply unit A, a reforming reaction unit B, and a product gas recovery unit C.
The raw material gas supply unit A includes a methane gas cylinder 1, a nitrogen cylinder 2, and a storage tank 3. The methane gas cylinder 1 stores methane gas to be reformed, and the nitrogen cylinder 2 stores nitrogen gas filled in the entire system including the storage tank 3 and the microcavity structure 8 prior to the generation of hydrogen by the steam reforming reaction. I store it. The storage tank 3 temporarily stores a mixed gas of methane and water vapor, which is a raw material gas, and stabilizes this mixed gas. The methane gas cylinder 1 and the nitrogen cylinder 2 are connected to the storage tank 3 through branch pipes 4 a and 4 b and a collecting pipe 5. The amount of gas supplied from the methane gas cylinder 1 and the nitrogen cylinder 2 to the storage tank 3 can be controlled by flow control valves 6a and 6b interposed in the branch pipes 4a and 4b. After filling the entire system with nitrogen gas in the nitrogen cylinder 2, methane gas is caused to flow into the storage tank 3 by opening the shut-off valve v1. On the other hand, water vapor is supplied by introducing water into the collecting pipe 5 through the introduction pipe 7 and evaporating the water in the storage tank 3. The inside of the storage tank 3 is adjusted to a temperature around 160 ° C.

  The reforming reaction section B includes a microcavity structure 8 according to the present embodiment and an electric furnace (corresponding to a “heating furnace”) 9. The electric furnace 9 can adjust the temperature condition regarding the steam reforming reaction in the microcavity structure 8. The microcavity in the microcavity structure 8 is connected to the inside of the storage tank 3 through the raw material gas supply pipe 10, and the raw material gas supply pipe 10 is connected to the microcavity by opening the shut-off valve v2. The mixed gas after the stabilization is supplied through.

  The product gas recovery unit C includes a product gas recovery pipe 11 connected to the microcavity structure 9, and recovers hydrogen generated in the microcavity structure 8 through the product gas recovery pipe 11. The recovered hydrogen can be used as a negative electrode gas or the like of the fuel cell. In this embodiment, a flow meter 12 for measuring the flow rate of the generated gas and a part of the generated gas are sampled in the generated gas recovery unit C. A micro syringe 13 is provided. The measured value of the flow meter 12 is monitored by a video camera 14, and the sampled product gas is analyzed by a gas chromatograph analyzer 15.

Here, with reference to FIG. 2, the manufacturing process of the microcavity structure 8 which concerns on this embodiment is demonstrated.
A latex particle P having a uniform micro-order particle size is prepared, and as shown in FIG. 2A, this latex particle P is immersed in a suspension of a substance M that is a raw material for a catalyst such as nickel or ruthenium. Then, the catalyst material M is adsorbed on the surface of the latex particles P. Subsequently, as shown in FIG. 2B, the latex particles P on which the catalyst substance M is adsorbed and the ceramic C solution are sealed in a glass pipe G. Then, as shown in FIG. 2 (c), the glass pipe G is installed in the heating furnace H, aerated by a vacuum pump Pump to remove bubbles, and the ceramic C is dried. After drying, the ceramic C in which the latex particles P are suspended is heated by a heating furnace H and fired in a reducing atmosphere. As the latex particles P decompose and disappear due to heat during firing, a flow path in which a large number of spherical microcavities are continuous is formed inside the sintered ceramic, and the catalyst material adsorbed on the surface of the latex particles P. M adheres to the inner surface of the spherical cavity of the sintered ceramic. In this way, by causing the reduced catalyst material M to be supported and attached to the inner surface of the spherical ceramic, it is possible to suppress the phenomenon that the catalyst material aggregates at a high temperature, which has been a problem in the technique of Patent Document 1 described above. In the present embodiment, the microcavity structure 8 is formed by the sintered ceramic itself.

  In this embodiment, in order to perform steam reforming of methane, the particle size of latex particles is set to about 5 to 6 μm. However, in order to create a microcavity with an appropriate inner diameter and number density, a method for producing an inverse opal structure ( Diguna et al, Material Science and Engineering, p. 1514, 2007).

The specific design of the microcavity is described below.

(Advantages of spherical microcavities)
Planck's cavity radiation theory is based on the assumption that the cavity size (inner diameter) is much larger than the wavelength. On the other hand, in the microcavity, since the size of the cavity is about the same as the wavelength of radiation in the infrared region, it is considered that the wall shape of the cavity has a great influence on the radiation field in the microcavity. There are research reports on the analysis of the radiation field in such a microcavity using the microcavity resonance theory.

  The electromagnetic field in the cavity is represented by Maxell's equation shown below.

  From the above formulas (1) to (4), the electric field E in the cavity is derived as follows.

Here, it is assumed that the microcavity according to the present embodiment is a spherical closed cavity having a radius a, and the wall surface is a complete conductor.
Convert the Maxwell equation to polar coordinates. Since there is no electromagnetic field in the perfect conductor, the boundary conditions are as follows.

When the Maxwell equation is solved under this boundary condition, the resonance wavelength λ _r in the spherical cavity can be obtained as follows.

Here, q ′ _np in the above equation (6) is the root of the spherical Bessel function, and is given as shown in Table 1 according to n and p.

For example, in the case of water vapor, the inner diameter d (= 2a) of the cavity that gives λ _r = 6.3 μm, which is the resonance wavelength matching the natural frequency, is _expressed by the above equation (6) when n = p = 1. To 5.5 μm.

  The Q value of the cavity resonator is given by the following equation (7).

Therefore, when n = p = 1, the Q value of the spherical cavity is Q = 1.01η ₀ / R _s . Here, η ₀ and R _s are the dielectric constant in vacuum and the resistance at the resonance frequency of the conductor, respectively.
On the other hand, since the Q value of the cavity resonator constituted by the square cavity is Q = 0.74η ₀ / R _s , the electromagnetic energy that can be stored in the cavity is larger in the spherical cavity than in the square cavity. I understand that.

(Catalyst selection)
The main reactions in steam reforming of hydrocarbon-based gas fuel are expressed by the following equations (8) to (9).

_{C n H m + nH 2 O} → nCO + (n + m / 2) H 2 (-ΔH 0 298 <0) ··· (8)
CO + H ₂ O → CO ₂ + H ₂ (−ΔH ⁰ ₂₉₈ = 41.2 kJmol ⁻¹ ) (9)
CO + 3H ₂ → CH ₄ + H ₂ O (−ΔH ⁰ ₂₉₈ = 206.2 kJmol ⁻¹ ) (10)
Of the above formulas (8) to (10), the formula (8) is referred to as a steam reforming reaction, the formula (9) is referred to as a shift reaction, and the formula (10) is referred to as a methanation reaction. When the raw material is methane gas, the reverse reaction of the formula (10) is a steam reforming reaction. Here, the overall reaction combining the steam reforming reaction and the shift reaction when methane gas is used as a raw material is expressed as follows.

CH ₄ + 2H ₂ O → CO ₂ + 4H ₂ (ΔH ⁰ ₂₉₈ = 165 kJmol ⁻¹ ) (11)
It can be seen that the steam reforming reaction is an endothermic reaction from the reverse reaction of the above formula (10). Therefore, supply and recovery of reaction heat has been an important issue in conventional industrial production facilities. In a general facility, the temperature conditions relating to the reaction are 450 to 650 ° C. at the temperature of the reaction tube inlet, and 700 to 900 ° C. depending on the purpose at the temperature of the reaction tube outlet. Therefore, the material of the reaction tube is required to be able to withstand use under severe conditions for a long time. Similarly, the catalyst needs to be resistant to harsh conditions, and a catalyst in which nickel is supported on a porous body is widely used.

  Since the composition of the gas finally obtained even if the type of hydrocarbon is changed is the thermodynamic equilibrium composition calculated by the above equations (9) and (10), the composition of the product gas is the reaction temperature and pressure. And it is uniquely determined according to the water vapor ratio to the gas fuel. By analyzing the composition of the product gas obtained when these parameters are changed, a product gas mainly composed of hydrogen and carbon monoxide is obtained under conditions of high temperature and low pressure, and methane is mainly used under conditions of low temperature and high pressure. A product gas as a component is obtained (catalyst society edition, industrial catalytic reaction, pp 264-267 (1985)).

  The catalyst for steam reforming can use nickel and other noble metals (for example, ruthenium and platinum) as a substance having activity against methane. Nickel is widely used as a catalyst material for steam reforming because it has a relatively high activity with respect to methane and is easily available. Any of these noble metals can be used as the catalyst material according to the present embodiment, and when the activity against methane is shown, the following order is obtained.

Rh, Ru>Ni>Ir> Pd, Pt> Co, Fe

(About setting the inside diameter of the microcavity)
In this embodiment, the raw material gases are methane and water vapor, but these gases are generally called radiant gases and are known to interact with electromagnetic waves of a specific wavelength. Here, gas radiation properties will be described.

  A diatomic gas having a polarity composed of heterogeneous atoms such as hydrogen chloride and carbon monoxide and a polyatomic gas such as methane and water vapor exchange energy with electromagnetic waves through movements such as rotation and vibration of constituent atoms ( Maruyama Shigenao, Optical Energy Engineering (14), Mechanical Research, Vol. 53, No. 11, pp 57-64 (2001)).

  The water vapor has a HO—H—H asymmetric top structure, and the position of the absorption line that combines the pure rotation absorption band and the vibration-rotation absorption band exists almost randomly and over a wide range. Table 2 shows main absorption bands in the infrared region of water vapor. Water vapor has the largest absorption band in the vicinity of 6.3 μm.

  In contrast, methane has a symmetric top structure, and its vibration mode has four independent modes. Of these, two modes relate to infrared absorption. Table 3 shows main absorption bands in the infrared region of methane. Methane has a relatively large absorption band around 3.3 μm and 7.6 μm.

The analysis method of the radiation field in the microcavity is used to determine the inner diameter of the microcavity suitable for the steam reforming process of methane.
From Tables 2 and 3, it is the absorption lines of 6.27058 μm and 3.3244 μm that show the greatest absorption intensity for each of water vapor and methane. Therefore, the resonance wavelength (cavity resonance wavelength) of the microcavity is matched with these absorption lines and absorption bands.

  The resonance wavelength of the electromagnetic wave in the cavity can be obtained by the above equation (6). This resonant wavelength has an infinite distribution depending on various modes. The resonance parameter is expressed as the root of the spherical Bessel function in Table 1. Therefore, by determining the inner diameter of the microcavity so that the resonance wavelength of the spherical cavity matches the electromagnetic wave absorption band of the source gas according to this resonance parameter, the source gas can be excited and heated by electromagnetic waves of a specific wavelength. Become.

  The resonance mode that matches the absorption band of the source gas is desired to have high energy, but in this embodiment, the lowest order mode is matched to the absorption lines of methane and water vapor. .

  Of the modes (p, n) in the cavity, the resonance wavelengths in the simplest modes (1, 1) and (1, 2) match the absorption lines of 6.27058 μm and 3.32444 μm, respectively. In the case of making it, the inner diameter d of the microcavity can be calculated by substituting each condition into the above equation (6) with reference to Table 1.

  In the analysis described above, since the inner wall of the cavity is assumed to be a complete conductor, the energy distribution with respect to the wavelength in the cavity is a distribution in which peaks having no width exist discretely. In an actual cavity, the inner wall is coated with a noble metal (in this embodiment, nickel, platinum, etc.) that is a catalyst material, and these catalyst materials have a finite conductivity. Therefore, energy loss occurs in the inner wall, and it is considered that the resonance spectrum in the cavity has a spread. The spread of the resonance spectrum will be described below.

The conductivity depends on the frequency of fluctuation of the electromagnetic field (in this embodiment, the wavelength of radiation). The equation of motion of electrons when the electric field E = | E | ^jωt acts on free electrons in the conductor is expressed by the following equation (12).

  Here, m and e are the mass and charge of electrons, respectively. γ is an electron decay constant, and its reciprocal τ is a relaxation time. r is a position vector, which indicates the movement distance of the electron from the equilibrium point. By analyzing the above equation (12), the conductivity σ is given by the following equation (13).

Here, σ ₀ is the conductivity when there is no change in the electric field. In the estimation of the relaxation time τ, a Drude model in which free electrons are modeled as an oscillator having a spring constant of 0 was used. According to this model, the relationship between the complex refractive index and the relaxation time τ is expressed by the following equation (14).

In the above equation (14), n and k represent the real part and imaginary part of the complex refractive index, and ε ′ and ε ″ represent the real part and imaginary part of the complex dielectric function. Ω _p is the plasma angular oscillation By solving the above equation (14) simultaneously, the following equation can be obtained for the relaxation time τ, and the value can be estimated.

  In order to evaluate the spread of the resonance spectrum, the Q value is obtained. The Q value is defined as follows as a value that gives the half width of the peak in the Lorentz distribution.

  In this embodiment, the vibration energy P in the cavity and the vibration energy loss ΔP per period in the above equation (16) were calculated using the trade name “MAFIA” which is electromagnetic field analysis software.

  FIG. 3 shows the radiation intensity of the resonance spectrum corresponding to the two wavelengths and the absorption intensity for methane and water vapor. In the figure, the water vapor plot is shown on the right, and the methane plot is shown on the left. As can be seen from FIG. 3, the broadening of the resonance spectrum appropriately includes the absorption bands of methane and water vapor.

  In the actual flow within the microcavity structure, there are pores connecting the microcavities, so the boundary conditions are more complicated than those set for the above calculations. This is considered to be a factor for further expanding the spread of the resonance spectrum. Therefore, the resonance wavelength of the microcavity does not need to completely match the electromagnetic wave absorption band of the raw material gas, and can be set with a certain width. For example, the inner diameter of the microcavity can be set within a range of approximately 5 to 6 μm.

  In an actual microcavity, there are a plurality of other vibration modes in the wavelength region where the absorption band exists. Therefore, considering how energy is dispersed in each vibration mode, It is preferable to reflect the energy distribution.

As described above, according to the present embodiment, a continuous spherical microcavity is formed, and a cavity resonance wavelength that matches the inside diameter of the microcavity with the electromagnetic wave absorption bands of methane and water vapor that are source gases can be obtained. By setting the inner diameter a, in the steam reforming process of methane, methane gas and steam are excited and heated by electromagnetic waves of a specific wavelength, and thermal decomposition of methane can be promoted. On the other hand, the absorption band of hydrogen and oxygen generated by reforming is greatly different from the absorption band of the source gas, so that it is not excited by electromagnetic waves, but through pores connecting micro cavities and voids in the ceramic itself. It is discharged from the microcavity structure 8. Therefore, according to the present embodiment, in the steam reforming process of methane, it is possible to efficiently utilize the radiation cavity quantum effect and perform reforming at a lower temperature to efficiently generate hydrogen. .

  According to the present embodiment, in addition to making the microcavity spherical, the microcavity structure 8 is made of ceramics, so that the amount of the catalytic material used is reduced and the catalytic material is placed on the inner surface of the ceramic. Therefore, the catalyst substance can be prevented from agglomerating at a high temperature.

  The present invention is not limited to the methane steam reforming process, but can be applied to other chemical processes such as high-temperature steam electrolysis and steam direct thermal decomposition. In high-temperature steam electrolysis, by matching the resonance wavelength of the microcavity with the electromagnetic wave absorption band of steam, the steam can be efficiently decomposed to generate hydrogen. Direct microlysis of water at high temperatures is possible by using a microcavity made of ceramics and employing a steam pyrolyzable catalyst material. Here, the reaction in a thermodynamic non-equilibrium state is achieved, so that it is possible to cause a reaction at a relatively low temperature that could not be achieved by the conventional high-temperature steam electrolysis and steam direct thermal decomposition. is there.

  In order to produce hydrogen at a hydrogen reformer and a small hydrogen station mounted on a fuel cell vehicle, a hydrogen production apparatus that operates at low temperature and high efficiency is indispensable. Since the present invention makes it possible to efficiently generate hydrogen at a low temperature as described above, it contributes to the practical application of an on-vehicle hydrogen production apparatus.

  DESCRIPTION OF SYMBOLS 1 ... Methane gas cylinder, 2 ... Nitrogen cylinder, 3 ... Storage tank, 8 ... Micro-cavity structure, 9 ... Electric furnace, P ... Latex particle, M ... Catalytic substance, C ... Ceramics.

Claims (16)

A microcavity structure used in a chemical process using a radioactive gas as a raw material,
An inlet and an outlet for allowing gas to permeate, and a plurality of spherical microcavities continuous between the inlet and the outlet and in communication with each other;
A catalyst substance is supported on the surface of the wall of the structure forming the microcavity,
The microcavity has an inner diameter at which a cavity resonance wavelength that matches the electromagnetic wave absorption band of the source gas is obtained, so that the source gas is excited and heated by an electromagnetic wave having a specific wavelength close to the absorption band in the microcavity. On the other hand, a microcavity structure in which a thermodynamic non-equilibrium state of gas molecules is formed, in which excitation of a product gas generated from the source gas is suppressed.   The microcavity structure according to claim 1, wherein the source gas is a hydrocarbon gas or water vapor.   The microcavity structure according to claim 1 or 2, wherein the catalyst material is at least one of nickel, platinum, and ruthenium.   The microcavity structure according to claim 1 or 2, wherein the catalyst material is a steam pyrolyzable catalyst material.   The microcavity structure according to any one of claims 1 to 4, wherein an inner diameter of the microcavity is approximately 5.0 to 6.0 µm.   The catalyst material is adsorbed on the surface of latex particles having a particle diameter substantially equal to the inner diameter, the latex particles adsorbed with the catalyst material are suspended in ceramics, and the latex particles and ceramics are dried and fired, The microcavity structure according to any one of claims 1 to 5, which is produced by thermally decomposing latex particles.   The microcavity structure according to any one of claims 1 to 5, wherein at least the structural body wall portion is made of ceramics.   The microcavity structure according to claim 6 or 7, wherein the ceramic is stabilized zirconia. It is comprised including the micro cavity structure according to any one of claims 1 to 8,
Supplying hydrocarbon gas and water vapor as the raw material gas to the microcavity through the inlet,
A hydrogen generator for recovering hydrogen generated from the hydrocarbon gas in the microcavity through the discharge port. It is comprised including the micro cavity structure according to any one of claims 1 to 8,
Water vapor as the source gas is supplied to the microcavity through the inlet,
A hydrogen generator that recovers hydrogen generated from the water vapor in the microcavity through the outlet.   The hydrogen generator according to claim 9 or 10, further comprising a heating furnace for heating the microcavity structure.   The latex particles are adsorbed on the surface of latex particles having a predetermined microorder particle size, the latex particles adsorbed with the catalyst materials are suspended in ceramics, and the latex particles and ceramics are dried and fired, and the latex particles A micro-cavity structure in which the catalyst material is supported on the inner surface of a sintered ceramic forming a plurality of continuous spherical micro-cavities produced by thermally decomposing the catalyst. A passage forming step for forming a plurality of spherical microcavities in communication with each other and in the reforming portion of the raw material gas; and
A gas reaction step of supplying a raw material gas, a hydrocarbon gas and water vapor, to the microcavity to cause a steam reforming reaction of the hydrocarbon gas in the presence of a catalyst in the microcavity;
A gas recovery step for recovering hydrogen generated in the microcavity;
Have
In the gas reaction step, an electromagnetic wave having a specific wavelength close to an electromagnetic wave absorption band of the raw material gas is generated in the microcavity, and only the raw material gas is generated from the raw material gas and a generated gas generated therefrom. A steam reforming method in which excitation heating is performed by the method. A passage forming step for forming a plurality of spherical microcavities in communication with each other and in the reforming portion of the raw material gas; and
A gas reaction step of supplying raw material water vapor to the microcavity, and causing a thermal decomposition reaction of the water vapor in the presence of a catalyst in the microcavity;
A gas recovery step of recovering hydrogen and oxygen generated in the microcavity;
Have
In the gas reaction step, an electromagnetic wave having a specific wavelength close to an electromagnetic wave absorption band of the raw material gas is generated in the microcavity, and only the raw material gas is generated from the raw material gas and a generated gas generated therefrom. A method for thermally decomposing water vapor excited by heating. A passage forming step for forming a plurality of spherical microcavities in communication with each other and in the reforming portion of the raw material gas; and
An electric field forming step of applying an electric field in the microcavity;
A gas heating step for heating the water vapor, which is a raw material gas, to obtain high-temperature water vapor;
A gas reaction step of supplying the high temperature steam to the microcavity to cause high temperature steam electrolysis in the presence of a catalyst in the microcavity;
A gas recovery step of recovering hydrogen and oxygen generated by the high-temperature steam electrolysis;
Have
In the gas reaction step, an electromagnetic wave having a specific wavelength close to an electromagnetic wave absorption band of the raw material gas is generated in the microcavity, and only the raw material gas is generated from the raw material gas and a generated gas generated therefrom. A high temperature steam electrolysis method in which heating is performed by heating. Adsorbing a catalytic substance on the surface of latex particles having a predetermined micro-order particle size;
Suspending latex particles adsorbed with the catalyst substance in ceramics;
The ceramics in which the latex particles are suspended are dried and fired, and the latex particles are thermally decomposed to obtain sintered ceramics in which the catalytic material is supported on the inner surfaces of a plurality of continuous spherical microcavities;
Having
A method for manufacturing a structure having a microcavity.

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