US20150308002A1

US20150308002A1 - Reactor and method for activating reactor

Info

Publication number: US20150308002A1
Application number: US14/684,447
Authority: US
Inventors: Keiji Onishi; Yasuyuki Naito
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2014-04-28
Filing date: 2015-04-13
Publication date: 2015-10-29
Also published as: JP2015222712A

Abstract

A reactor of the present disclosure includes a solid electrolyte having a first surface and a second surface; a plurality of first electrodes arranged on the first surface; a plurality of second electrodes arranged on the second surface; a first substrate having a plurality of first recesses on one main surface thereof; and a second substrate having a plurality of second recesses on one main surface thereof. The first substrate is arranged on the solid electrolyte in such a manner that each of the first recesses faces one of the first electrodes. The second substrate is arranged on the solid electrolyte in such a manner that each of the second recesses faces one of the second electrodes. A plurality of first chambers and a plurality of second chambers are formed in the reactor. At least one of the plurality of first chambers is arranged so as to overlap two or more of the plurality of second chambers when the reactor is viewed from a direction perpendicular to the one main surface of the first substrate.

Description

BACKGROUND

1. Technical Field
The present application relates to a reactor including a solid electrolyte.
2. Description of the Related Art
In recent years, hydrogen has received attention as a clean energy source. A fuel cell that generates power using hydrogen is known as a device that uses hydrogen. As is well known, the fuel cell includes an anode, a cathode, and an electrolyte held between the anode and the cathode. As the electrolyte, for example, a solid electrolyte capable of conducting protons (hydrogen ions) can be used, and as the solid electrolyte, solid polymer films such as Nafion (registered trademark), and perovskite-type oxides are known.
U.S. Pat. No. 7,993,785 discloses a structure of a fuel cell that uses a MEMS (Micro Electro-Mechanical System) process (see FIG. 1). In the structure disclosed in U.S. Pat. No. 7,993,785, a laminate of an electrode, an electrolyte and an electrode is held between two silicon substrates each provided with a manifold portion. Thus, a channel for bringing a gas into contact with the electrode provided on each of both main surfaces of the solid electrolyte is formed.

SUMMARY

It is required to improve reliability by suppressing damage of a solid electrolyte due to, for example, mechanical impact from outside.
The following is provided as an exemplary embodiment of the present disclosure:
a reactor comprising: a solid electrolyte having a first surface and a second surface, a plurality of first electrodes arranged on the first surface, a plurality of second electrodes arranged on the second surface, a first substrate including a plurality of first chambers each formed of a first recess on one principal plane, a second substrate including a plurality of second chambers each formed of a second recess on one principal plane; and an external power supply. A bottom of each of the first recess is opposite to one of the plurality of the first electrodes. A bottom of each of the second recess is opposite to one of the plurality of the second electrodes. Each first electrode includes a first catalyst. Each second electrode includes a second catalyst. The first substrate is arranged on the first surface in such a manner that each first chamber is interposed between the first substrate and the first surface. The second substrate is arranged on the second surface in such a manner that each second chamber is interposed between the second substrate and the second surface. At least one of the plurality of the first chambers overlaps two or more second chambers, when viewed from a direction perpendicular to the one principal surface of the first substrate. The external power supply is electrically interposed between the plurality of the first electrodes and the plurality of the second electrodes in such a manner that a voltage difference is generated between the plurality of the first electrodes and the plurality of the second electrodes.
According to the present disclosure, there is provided a reactor with improved reliability, which ensures that damage to a solid electrolyte can be suppressed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a schematic partial sectional view of reactor 100 in a first exemplary embodiment of the present disclosure;

FIG. 1B is a drawing schematically showing an arrangement of first chamber 104 a and second chamber 104 b;

FIG. 2 is an enlarged schematic sectional view of a main part of the reactor in the first exemplary embodiment of the present disclosure;

FIG. 3 is a schematic sectional view for explaining one example of a method for manufacturing reactor 100;

FIG. 4 is a schematic top view for explaining one example of a method for manufacturing reactor 100;

FIG. 5 is a schematic sectional view for explaining one example of a method for manufacturing reactor 100;

FIG. 6 is a schematic sectional view for explaining one example of a method for manufacturing reactor 100;

FIG. 7 is a schematic sectional view for explaining one example of a method for manufacturing reactor 100;

FIG. 8 is a schematic sectional view for explaining one example of a method for manufacturing reactor 100;

FIG. 9 is a schematic sectional view for explaining one example of a method for manufacturing reactor 100;

FIG. 10 is a schematic sectional view for explaining one example of a method for manufacturing reactor 100;

FIG. 11 is a schematic sectional view of reactor 100A including joining layer 107;

FIG. 12A is a schematic top view showing an example of a shape and an arrangement of first chamber 104 a and second chamber 104 b;

FIG. 12B is a schematic top view showing another example of a shape and an arrangement of first chamber 104 a and second chamber 104 b;

FIG. 13 is a schematic partial sectional view showing a configuration of reactor 100B in a second exemplary embodiment of the present disclosure;

FIG. 14 is a schematic partial sectional view showing a configuration of reactor 100C in the second exemplary embodiment of the present disclosure;

FIG. 15 is a schematic partial sectional view showing a configuration of reactor 100D in the second exemplary embodiment of the present disclosure; and

FIG. 16 is a schematic partial sectional view showing a configuration of reactor 100E in the second exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

First, an outline of one aspect of the present disclosure will be described.
A reactor as one aspect of the present disclosure comprises a solid electrolyte having a first surface and a second surface, a plurality of first electrodes arranged on the first surface, a plurality of second electrodes arranged on the second surface, a first substrate including a plurality of first chambers each formed of a first recess on one principal plane, a second substrate including a plurality of second chambers each formed of a second recess on one principal plane; and an external power supply. A bottom of each of the first recess is opposite to one of the plurality of the first electrodes. A bottom of each of the second recess is opposite to one of the plurality of the second electrodes. Each first electrode includes a first catalyst. Each second electrode includes a second catalyst. The first substrate is arranged on the first surface in such a manner that each first chamber is interposed between the first substrate and the first surface. The second substrate is arranged on the second surface in such a manner that each second chamber is interposed between the second substrate and the second surface. At least one of the plurality of the first chambers overlaps two or more second chambers, when viewed from a direction perpendicular to the one principal surface of the first substrate. The external power supply is electrically interposed between the plurality of the first electrodes and the plurality of the second electrodes in such a manner that a voltage difference is generated between the plurality of the first electrodes and the plurality of the second electrodes.
In a certain aspect, the reactor further comprises a joining layer arranged between the solid electrolyte and the first substrate.
In a certain aspect, the second substrate is electrically conductive. The second substrate is electrically connected to the external power supply in such a manner that the a voltage having the same polarity as that of the second electrode is applied to the second substrate.
In a certain aspect, the second substrate is electrically conductive. The second substrate is electrically connected to the external power supply in such a manner that a voltage having the same polarity as that of the first electrode is applied to the second substrate.
In a certain aspect, a distance between an outer edge of the second electrode and the second substrate on the second surface is larger than a thickness of the solid electrolyte.
In a certain aspect, the first substrate is electrically conductive. The first substrate is electrically connected to the external power supply in such a manner that a voltage having the same polarity as that of the second electrode is applied to the first substrate.
In a certain aspect, the plurality of first chambers each have a circular or polygonal shape when viewed from a direction perpendicular to the one main surface of the first substrate. The plurality of first chambers are arranged so as to form a lattice pattern.
In a certain aspect, a carrier in the solid electrolyte is a hydrogen ion or an oxygen ion.
A method for activating the reactor as one aspect of the present disclosure comprises
(a) preparing a reactor comprising:
a solid electrolyte having a first surface and a second surface;
a plurality of first electrodes arranged on the first surface;
a plurality of second electrodes arranged on the second surface;
a first substrate including a plurality of first chambers each formed of a first recess on one principal plane;
a second substrate including a plurality of second chambers each formed of a second recess on one principal plane; and
an external power supply,
wherein
a bottom of each of the first recess is opposite to one of the plurality of the first electrodes;
a bottom of each of the second recess is opposite to one of the plurality of the second electrodes;
each first electrode includes a first catalyst;
each second electrode includes a second catalyst;
the first substrate is arranged on the first surface in such a manner that each first chamber is interposed between the first substrate and the first surface;
the second substrate is arranged on the second surface in such a manner that each second chamber is interposed between the second substrate and the second surface;
at least one of the plurality of the first chambers overlaps two or more second chambers of the plurality of the second chambers, when viewed from a direction perpendicular to the one principal surface of the first substrate;
the external power supply is electrically interposed between the plurality of the first electrodes and the plurality of the second electrodes;
the second substrate is electrically conductive; and
the second substrate is electrically connected to the external power supply in such a manner that a voltage having the same polarity as that of the second electrode is applied to the second substrate;
(b) applying voltages, which have mutually different polarities, to the first electrode and the second electrode; and
(c) applying to the second substrate a voltage having the same polarity as that of the voltage applied to the second electrode.
A method for activating the reactor as one aspect of the present disclosure comprises
(a) preparing a reactor comprising:
a solid electrolyte having a first surface and a second surface;
a plurality of first electrodes arranged on the first surface;
a plurality of second electrodes arranged on the second surface;
a first substrate including a plurality of first chambers each formed of a first recess on one principal plane;
a second substrate including a plurality of second chambers each formed of a second recess on one principal plane; and
an external power supply,
wherein
a bottom of each of the first recess is opposite to one of the plurality of the first electrodes;
a bottom of each of the second recess is opposite to one of the plurality of the second electrodes;
each first electrode includes a first catalyst;
each second electrode includes a second catalyst;
the first substrate is arranged on the first surface in such a manner that each first chamber is interposed between the first substrate and the first surface;
the second substrate is arranged on the second surface in such a manner that each second chamber is interposed between the second substrate and the second surface;
at least one of the plurality of the first chambers overlaps two or more second chambers of the plurality of the second chambers, when viewed from a direction perpendicular to the one principal surface of the first substrate;
the external power supply is electrically interposed between the plurality of the first electrodes and the plurality of the second electrodes;
the second substrate is electrically conductive; and
the second substrate is electrically connected to the external power supply in such a manner that a voltage having the same polarity as that of the first electrode is applied to the second substrate.
(b) applying voltages, which have mutually different polarities, to the first electrode and the second electrode; and
(c) applying to the second substrate a voltage having the same polarity as that of the voltage applied to the first electrode.
A method for activating the reactor as one aspect of the present disclosure comprises
(a) preparing a reactor comprising:
a solid electrolyte having a first surface and a second surface;
a plurality of first electrodes arranged on the first surface;
a plurality of second electrodes arranged on the second surface;
a first substrate including a plurality of first chambers each formed of a first recess on one principal plane;
a second substrate including a plurality of second chambers each formed of a second recess on one principal plane; and
an external power supply,
wherein
a bottom of each of the first recess is opposite to one of the plurality of the first electrodes;
a bottom of each of the second recess is opposite to one of the plurality of the second electrodes;
each first electrode includes a first catalyst;
each second electrode includes a second catalyst;
the first substrate is arranged on the first surface in such a manner that each first chamber is interposed between the first substrate and the first surface;
the second substrate is arranged on the second surface in such a manner that each second chamber is interposed between the second substrate and the second surface;
at least one of the plurality of the first chambers overlaps two or more second chambers of the plurality of the second chambers, when viewed from a direction perpendicular to the one principal surface of the first substrate;
the external power supply is electrically interposed between the plurality of the first electrodes and the plurality of the second electrodes;
the first substrate is electrically conductive; and
the first substrate is electrically connected to the external power supply in such a manner that a voltage having the same polarity as that of the second electrode is applied to the first substrate;
(b) applying voltages, which have mutually different polarities, to the first electrode and the second electrode; and
(c) applying to the second substrate a voltage having the same polarity as that of the voltage applied to the first electrode.
Exemplary embodiments of the present disclosure will be described below with reference to the drawings.

First Exemplary Embodiment

FIG. 1A and FIG. 1B are a schematic partial sectional view and a top view, respectively, of a reactor in the first exemplary embodiment. FIG. 1A is a sectional view taken along line 1A-1A in FIG. 1B. For reference, mutually orthogonal X, Y and Z axes are shown in FIG. 1A and FIG. 1B. X, Y and Z axes may be shown in other drawings.
Reactor 100 shown in FIG. 1A includes solid electrolyte 101, a plurality of first electrodes 103 a and a plurality of second electrodes 103 b. As shown in FIG. 1A, first electrodes 103 a are provided on main surface S1 of solid electrolyte 101 on one side, and second electrodes 103 b are provided on main surface S2 of solid electrolyte 101 on the other side. Reactor 100 can function as, for example, a fuel cell. When reactor 100 functions as, for example, a fuel cell, first electrode 103 a and second electrode 103 b function as, for example, a cathode and an anode, respectively. Hereinafter, first electrode 103 a and second electrode 103 b are referred to as cathode 103 a and anode 103 b, respectively.
Upper substrate 102 a is arranged on main surface S1 of solid electrolyte 101. As illustrated, upper substrate 102 a has a plurality of recesses 107 a formed so as to correspond, respectively, to a plurality of cathodes 103 a. Upper substrate 102 a is arranged on solid electrolyte 101 in such a manner that recesses 107 a face main surface S1. Thus, a plurality of first chambers 104 a each having one of a plurality of cathodes 103 a are formed. Similarly, lower substrate 102 b is arranged on main surface S2 of solid electrolyte 101. Lower substrate 102 b has a plurality of recesses 107 b formed so as to correspond, respectively, to a plurality of anodes 103 b. Recesses 107 b are arranged on solid electrolyte 101 so as to face main surface S2. Thus, a plurality of second chambers 104 b each having one of a plurality of anodes 103 b are formed.
FIG. 1B schematically shows an arrangement of first chamber 104 a and second chamber 104 b when reactor 100 is viewed from a direction perpendicular to upper substrate 102 a. Here, the arrangement of first chamber 104 a and second chamber 104 b is shown when reactor 100 is viewed from a direction perpendicular to surface Sa of upper substrate 102 a on the solid electrolyte 101 side (see FIG. 1A). In FIG. 1B, cathode 103 a and anode 103 b are not illustrated.
In FIG. 1B, a joint to surface Sa of upper substrate 102 a in main surface S1 of solid electrolyte 101 (see FIG. 1A) is shown by a shaded area, and the shape of first chamber 104 a is schematically shown by a solid line. Here, in this specification, the “shape” of the first chamber or the second chamber means the shape of the contour of individual areas excluding a joint between the solid electrolyte and the substrate (upper substrate or lower substrate) on the main surface of the solid electrolyte. The same applies to the “shape” of the recess in this specification.
In the illustrated example, first chamber 104 a has a circular shape when viewed from a direction perpendicular to upper substrate 102 a. In FIG. 1B, the shape of second chamber 104 b is schematically shown by a dashed line. In the illustrated example, second chamber 104 b also has a circular shape. In the illustrated example, the diameter of the circle shown by the solid line is almost equal to the diameter of the circle shown by the dashed line.
In the example shown in FIG. 1B, first chambers 104 a are two-dimensionally arranged at equal intervals in an X-Y plane in the drawing. In the plurality of circles shown by solid lines in FIG. 1B, distances (pitches) between centers of adjacent circles are the same. In FIG. 1B, the distance between centers of adjacent circles is shown by arrow p. In the example shown in FIG. 1B, second chambers 104 b are two-dimensionally arranged at equal intervals similarly to first chambers 104 a. It is to be noted that the arrangement of second chambers 104 b are shifted by a half-pitch along the X direction with respect to the arrangement of first chambers 104 a.
As illustrated in FIG. 1B, in the present disclosure, at least one of a plurality of first chambers 104 a is arranged so as to overlap two or more of a plurality of second chambers 104 b when reactor 100 is viewed from a direction perpendicular to one main surface (surface Sa here) of upper substrate 102 a. In other words, a plurality of first chambers 104 a formed on the one main surface S1 side of solid electrolyte 101 include at least one first chamber formed over two or more of a plurality of second chambers 104 b formed on the other main surface S2 side. For example, in FIG. 1B, one first chamber 104 r is arranged so as to overlap two second chambers 104 s and 104 t. In the present disclosure, typically, the center of each first chamber 104 a is not coincident with the center of each second chamber 104 b when the reactor is viewed from a direction perpendicular to upper substrate 102 a.
A structure in which more portions of a solid electrolyte are supported by a substrate can be provided as compared to a conventional configuration in which a space over one main surface of a solid electrolyte overlaps a space over the other main surface. According to the present disclosure, more portions of solid electrolyte 101 can be supported by surface Sa of upper substrate 102 and/or surface Sb of lower substrate 102 b on the solid electrolyte 101 side as schematically shown in FIG. 1A. That is, the area of portions of solid electrolyte 101, which are not supported either by surface Sa of upper substrate 102 a or by surface Sb of lower substrate 102 b, can be reduced. Therefore, even if mechanical impact is applied to the reactor, damage to the solid electrolyte is suppressed, so that mechanical reliability of the reactor can be improved.
According to the present disclosure, the solid electrolyte is relatively easily made thin because more portions of the solid electrolyte can be supported by the substrate. By making the solid electrolyte thin, the ion conductivity of the solid electrolyte can be improved. Therefore, the operation temperature of the reactor can be lowered. Since the area of portions of the solid electrolyte, where both main surfaces are exposed to the space (e.g. space in the first chamber and space in the second chamber), can be reduced, damage to the solid electrolyte can be suppressed even when the solid electrolyte is made thin. Damage to the solid electrolyte due to, for example, a difference in pressure between a reactant (liquid or gas) supplied to the space over one main surface of the solid electrolyte and a reactant (liquid or gas) supplied to the space over the other main surface, and thermal impact at the time of starting or stopping operation of the reactor can be suppressed. Therefore, a reactor having improved reliability can be provided. Such a reactor is prepared by a user. In other words, the user procures the reactor.
Configurations of components and operation of the reactor in the present disclosure will be described more in detail below.
<Solid Electrolyte>
Solid electrolyte 101 is, for example, a proton conductive organic film or solid oxide. For example, a perovskite-type oxide (generally represented by the chemical formula: ABO₃) as a proton conductor can be used as the solid electrolyte. When at least one alkali earth metal selected from the group consisting of Ba, Sr and Ca is placed at site A situated at a top of a cubic crystal, at least one element selected from the group consisting of Zr, Hf, Y, La, Ce, Gd, In, Ga, Al and Ru is placed at site B situated at the body center of the cubic crystal, and O (oxygen) is placed at a site situated at the face center of the cubic crystal, a good proton conductor can be obtained.
For example, solid electrolyte 101 has a thickness of from 0.5 μm to 2 μm (inclusive). By making the solid electrolyte thin, proton conductivity can be improved, so that power generation efficiency can be improved, for example, when reactor 100 is used as a fuel cell. In a conventional structure as shown in FIG. 1 in U.S. Pat. No. 7,993,785, it is difficult to make a solid electrolyte thin while sufficient mechanical strength is secured. According to the present disclosure, first chambers 104 a and second chambers 104 b are arranged such that each first chamber 104 a and each second chamber 104 b do not completely overlap each other. Therefore, even if mechanical impact is applied, damage to solid electrolyte 101 can be suppressed. Therefore, a solid electrolyte having a thickness in the above-mentioned range is relatively easily used.
<First Electrode and Second Electrode>
Cathode 103 a and anode 103 b each have a catalyst. For example, when reactor 100 is made to operate as a fuel cell, cathode 103 a has a catalyst that reduces oxygen, and anode 103 b has a catalyst that oxidizes hydrogen. Cathode 103 a is formed of, for example, a material having proton permeability (conductivity), electron conductivity and a catalytic function. Examples of the material include metals such as platinum (Pt) and solid oxides such as SrRuO₃. Cathode 103 a may have a laminated structure of a metal and a solid oxide. Cathode 103 a is not required to be formed of a single material having all of proton permeability, electron conductivity and a catalytic function, and may be formed of, for example, a laminated structure of an electrode having electron conductivity and a catalyst. Anode 103 b can be formed using a material similar to that of cathode 103 a. Materials of cathode 103 a and anode 103 b can be appropriately changed according to the intended use of reactor 100. Therefore, anode 103 b is not required to have a structure identical to that of cathode 103 a.
As shown in FIG. 1A, each of cathodes 103 a is exposed in an inside of first chamber 104 a, and each of anodes 103 b is exposed in an inside of second chamber 104 b. That is, each of first chambers 104 a and each of second chambers 104 b can function as a space for reaction of reactants to be introduced. Cathodes are typically connected to each other by a wiring (not illustrated), and similarly anodes are typically connected to each other by a wiring (not illustrated).
<Upper Substrate and Lower Substrate>
As has been described with reference to FIG. 1A, upper substrate 102 a has a plurality of recesses 107 a facing main surface S1 of solid electrolyte 101. Recess 107 a defines at least a part of a side surface and an upper surface of first chamber 104 a. Similarly, lower substrate 102 b has a plurality of recesses 107 b facing main surface S2 of solid electrolyte 101, and recess 107 b defines at least a part of a side surface and an upper surface of second chamber 104 b. In the configuration illustrated in FIG. 1A, the side surface of first chamber 104 a extends in a direction almost perpendicular to main surface S1 of solid electrolyte 101, and the side surface of second chamber 104 b extends in a direction almost perpendicular to main surface S2 of solid electrolyte 101.
Upper substrate 102 a includes a plurality of first fluid inlets 105 a and a plurality of first fluid outlets 106 a provided so as to correspond, respectively, to a plurality of first chambers 104 a. As illustrated, fluid inlet 105 a and fluid outlet 106 a communicate with first chamber 104 a. Lower substrate 102 b includes a plurality of second fluid inlets 105 b and a plurality of second fluid outlets 106 b provided so as to correspond, respectively, to a plurality of second chambers 104 b. As illustrated, fluid inlet 105 b and fluid outlet 106 b communicate with second chamber 104 b. That is, reactor 100 has a plurality of channels capable of supplying a gas or a liquid independently to cathode 103 a in each first chamber 104 a, and a plurality of channels capable of supplying a gas or a liquid independently to anode 103 b in each second chamber 104 b. These channels provided in reactor 100 are each kept air-tight and water-tight, and configured to ensure that fluids introduced into the channels are not mixed together. Therefore, in first chambers 104 a and second chambers 104 b, reactions of substances introduced into the chambers independently proceed.
Examples of a material of upper substrate 102 a include silicon, glass and quartz. Upper substrate 102 a may be a layer formed on a main surface of solid electrolyte 101 by PVD (Physical Vapor Deposition), CVD (Chemical Vapor Deposition), electroforming or the like and formed of an oxide, a nitride or a metal (e.g. nickel (Ni)). A material similar to that of upper substrate 102 a can be used for lower substrate 102 b. For example, when a silicon substrate is used for upper substrate 102 a or lower substrate 102 b, recesses, fluid inlets and fluid outlets can be easily formed by dry etching, wet etching or the like. The shape of each of upper substrate 102 a and lower substrate 102 b is not limited to a plate shape as illustrated in FIG. 1A, and may be a shape having steps and curvatures.
Depending on the intended use of the reactor, the channel for introducing a reactant and the channel for discharging a reactant may be identical. That is, one of the fluid inlet and the fluid outlet may be omitted. For example, when a proton conductor is used as solid electrolyte 101, reactor 100 can be used as a hydrogen gas sensor. When reactor 100 is used as a hydrogen gas sensor, a gas to be measured and a gas as a reference (e.g. air) are introduced into first chamber 104 a and second chamber 104 b, respectively. When these gases are introduced, protons corresponding to the partial pressure of hydrogen in the gas to be measured move through the solid electrolyte. At this time, first electrode 103 a and second electrode 103 b function as a sensing electrode and a counter electrode, respectively. Specifically, a current having a magnitude corresponding to the concentration of hydrogen in the gas to be measured passes between first electrode 103 a and second electrode 103 b. A substance in first chamber 104 a and a substance in second chamber 104 b are not changed before and after measurement. Therefore, the channel for introducing a gas to be measured and the channel for discharging a gas to be measured may be identical. Similarly, the channel for introducing a gas as a reference and the channel for discharging a gas as a reference may be identical.
<Operation of Reactor>
One example of operation of rector 100 will now be described.
When a proton conductor is used as solid electrolyte 101, for example, a reactant (e.g. hydrogen) is introduced from fluid inlet 105 b into second chamber 104 b. As described above, second chambers 104 b are mutually independent, and fluid inlets 105 b and fluid outlets 106 b are formed individually in second chambers 104 b. Fluid inlets 105 b communicating with second chambers 104 b are connected to, for example, a first reactant storage vessel (not illustrated).
The reactant introduced from fluid inlet 105 b comes into contact with anode 103 b in second chamber 104 b. By an action of anode 103 b, protons are pulled out from the reactant, and introduced into solid electrolyte 101. The protons in solid electrolyte 101 arrive at cathode 103 a by means of at least one of a concentration gradient of the protons, a difference in partial pressure (of hydrogen) between second chamber 104 b and first chamber 104 a facing second chamber 104 b, and a difference in voltage applied between anode 103 b and cathode 103 a. First chambers 104 a each having cathode 103 a therein are mutually independent similarly to second chambers 104 b, and fluid inlets 105 a and fluid outlets 106 a are formed individually in first chambers 104 a. Fluid inlets 105 a communicating with first chambers 104 a are connected to, for example, a second reactant storage vessel (not illustrated). A product in each first chamber 104 a is collected through fluid outlet 106 a.
Reactor 100 can be used for various intended uses according to the combination of anode 103 b and cathode 103 a to be used. Reactor 100 can be used for hydrogenation devices, dehydrogenation devices, hydrogen sensors and so on as well as fuel cells. Here, an example of using reactor 100 to perform electrolysis of water vapor and hydrogenation of a substance to be hydrogenated will be described. Hereinafter, a device to be used for electrolysis of water vapor and hydrogenation of a substance to be hydrogenated may be referred to as a “water vapor electrolysis and hydrogenation device.”
When reactor 100 is used as a water vapor electrolysis and hydrogenation device, an anode containing a catalyst that oxidizes hydrogen in a gas containing water is used, and a cathode containing a hydrogenation catalyst is used. Examples of the catalyst that oxidizes hydrogen in a gas containing water, and the hydrogenation catalyst include metals and alloys containing Pt.
Turn to FIG. 2. Depending on the intended use of reactor 100, external power source 108 is connected to cathode 103 a and anode 103 b as shown in FIG. 2. Thus, solid electrolyte 101 can efficiently conduct carriers such as protons.
During operation of the water vapor electrolysis and hydrogenation device, the whole water vapor electrolysis and hydrogenation device is kept at about 300° C., and, for example, water vapor is introduced into second chamber 104 b through fluid inlet 105 b. For example, toluene (C₆H₅CH₃) is introduced into first chamber 104 a through fluid inlet 105 a. Further, external power source 108 is connected to cathode 103 a and anode 103 b, and a potential difference (e.g. 1.5 V) is applied between the anode and the cathode. In second chamber 104 b, water vapor is brought into contact with anode 103 b, whereby protons are pulled out from water vapor (water). Protons generated in anode 103 b move through solid electrolyte 101 to arrive at cathode 103 a. Toluene is brought into contact with cathode 103 a to be hydrogenated. Thus, methylcyclohexane (C₆H₁₁CH₃) can be obtained in first chamber 104 a.
Usually, in a reactor using a solid oxide as a solid electrolyte, the above-mentioned reaction is achieved at a temperature ranging from 400° C. to 800° C. On the other hand, according to the present disclosure, a so-called organic hydride such as methylcyclohexane can also be obtained by activating the reactor at a temperature of, for example, about 300° C. According to the present disclosure, damage to solid electrolyte 101 by mechanical impact can be suppressed, and therefore a solid electrolyte having a thickness of, for example, about several micrometers can also be used. By using a solid electrolyte having a thickness of about several micrometers, a higher ion conductivity can be achieved. Therefore, the operation temperature of the reactor can be set to be lower than before.
<Method for Manufacturing Reactor>
One example of a method for manufacturing a reactor according to the present disclosure will be described with reference to FIGS. 3 to 10.
First, Pt film 13 b, solid electrolyte 101 and Pt film 13 a are sequentially formed on silicon (Si) substrate 10 as shown in FIG. 3. For example, a single crystal substrate is used as Si substrate 10 so that a three-layer film of Pt film 13 b, solid electrolyte 101 and Pt film 13 a is formed by epitaxial growth. Growth of a three-layer epitaxial film may be promoted by forming a buffer layer on Si substrate 10 beforehand. As the buffer layer, for example, an oxide film of MgO, SrRuO₃or the like can be selected, and a good epitaxial film can be obtained by forming beforehand on Si substrate 10 a buffer layer having a thickness ranging from several nanometers to several tens of nanometers.
For formation of Pt film 13 b, solid electrolyte 101 and Pt film 13 a, for example, a sputtering method can be used. Thicknesses of Pt film 13 b, solid electrolyte 101 and Pt film 13 a are, for example, 20 nm, 1 μm and 20 nm, respectively. As solid electrolyte 101, a perovskite-type oxide having BaZrO₃as a backbone with site B partially substituted with Y (yttrium) can be used. The method for forming the layers is not limited to a sputtering method, and a PLD (Pulsed Laser Deposition) method, a vacuum deposition method, an ion plating method, a CVD method, MBE (Molecular Beam Epitaxy) or the like may be used.
Next, Pt film 13 a as an uppermost layer is patterned by photolithography. Thus, cathode 103 a can be formed. Here, as shown in FIG. 4, a plurality of cathodes 103 a each having a circular shape with a diameter of about 150 μm are formed by patterning. In the example shown in FIG. 4, the circular cathodes are arranged two-dimensionally in the X direction and the Y direction in the drawing such that distances between centers (centers of gravity) of the circles are equal to one another. In FIG. 4, a wiring between the cathodes is not illustrated. The wiring connecting the cathodes can be formed by, for example, patterning.
Next, two single crystal Si substrates 12 a and 12 b each provided with a thermal oxide film having a thickness of 1 μm are provided. Thicknesses of these substrates are, for example, about 500 μm.
Next, as shown in FIG. 5, a plurality of recesses 107 a are formed on one main surface of Si substrate 12 a by deep dry etching (Deep-RIE (Reactive Ion Etching)). Here, recesses each having a circular contour when viewed from a direction perpendicular to surface Sa of Si substrate 12 a are formed. Diameter d and depth e of each recess 107 a are, for example, about 200 μm and about 50 μm, respectively. Here, a plurality of recesses 107 a are formed two-dimensionally in the X direction and the Y direction in the drawing such that distances between centers of openings are equal to one another. Distance p between the centers of the openings is, for example, 250 μm. In the example shown in FIG. 5, since recess 107 a is formed by dry etching, the cross section thereof is rectangular. For formation of recesses 107 a, wet etching may be used, and therefore the cross section of each recess 107 a may be tapered.
Next, as shown in FIG. 6, through-holes each extending to each recess 107 a from a main surface on a side opposite to the surface provided with a plurality of recesses 107 a are formed. Thus, first substrate 102 a including fluid inlets 105 a and fluid outlets 106 a is obtained. Here, diameter f of each of fluid inlet 105 a and fluid outlet 106 a is about 10 μm.
Next, as shown in FIG. 7, a plurality of recesses 107 b are formed on one main surface of Si substrate 12 b in the same manner as in the case of Si substrate 12 a. Here, a plurality of recesses 107 b each including an opening having a circular contour when viewed from a direction perpendicular to surface Sb of Si substrate 12 b are formed two-dimensionally in the X direction and the Y direction in the drawing. At this time, a plurality of recesses 107 b can be formed on Si substrate 12 b so as to form a pattern similar to that of a plurality of recesses 107 a on Si substrate 12 a. For example, a plurality of recesses 107 b can be arranged such that a distance between centers of adjacent openings is about 250 μm.
It is to be noted that a plurality of recesses 107 b are formed such that when Si substrate 12 a is superimposed on Si substrate 12 b in such a manner that surface Sa of Si substrate 12 a faces surface Sb of Si substrate 12 b, the contours of the openings on one substrate do not coincide with the contours of the openings on the other substrate. More specifically, at least one of perpendicular projections of the openings on Si substrate 12 a to a surface parallel to surface Sa (or surface Sb) overlaps two or more of perpendicular projections of the openings on Si substrate 12 b to a surface parallel to surface Sa (or surface Sb) (see FIG. 1B). The contour of the opening formed on Si substrate 12 b is not required to have a shape identical to that of the contour of the opening formed on Si substrate 12 a.
Next, as shown in FIG. 8, through-holes each extending to each recess 107 b from a main surface on a side opposite to the surface provided with a plurality of recesses 107 b are formed in the same manner as in the case of Si substrate 12 a. Thus, lower substrate 102 b including fluid inlets 105 b and fluid outlets 106 b is obtained. The size of each of the recess, the fluid inlet and the fluid outlet on each of upper substrate 102 a and lower substrate 102 b can be appropriately set according to the intended use of the reactor.
Next, as shown in FIG. 9, solid electrolyte 101 having, on main surface S1, cathodes 103 a formed by patterning, is joined to upper substrate 102 a provided with a plurality of recesses 107 a. More specifically, upper substrate 102 a is arranged on main surface S1 of solid electrolyte 101 in such a manner that each one of a plurality of recesses 107 a faces each one of a plurality of cathodes 103 a, and these components are pressurized while being subjected to heating and application of a voltage (anode joining). This can be diffusion joining between the solid electrolyte as an oxide and a thermal oxide film (not illustrated) formed on a surface of the Si substrate beforehand. When a joining surface has good cleanliness and flatness, such direct joining can be performed.
Next, Si substrate 10 is removed by wet etching from a side opposite to the surface to which upper substrate 102 a is joined. Dry etching may be used instead of wet etching. In formation of an epitaxial multilayer film on Si substrate 10, a sacrificial layer may be formed on Si substrate 10 beforehand, followed by removing Si substrate 10 by an epitaxial lift-off method, sacrificial layer etching, or the like.
Next, as shown in FIG. 10, anodes 103 b are formed by patterning Pt film 13 b in the same manner as in the case of Pt film 13 a. For example, a plurality of anodes 103 b each having a circular shape with a diameter of about 150 μm are formed on main surface S2 of solid electrolyte 101. At this time, anodes 103 b are arranged so as to form a pattern similar to that of recesses 107 b on lower substrate 102 b. In other words, patterning is performed so as to expose one of a plurality of anodes 103 b in each of a plurality of recesses 107 b when main surface Sb of lower substrate 102 b and main surface S2 of solid electrolyte 101 are made to face each other. A wiring that connects the anodes can also be formed by patterning.
Thereafter, in the same manner as in the case of upper substrate 102 a, solid electrolyte 101 having anodes 103 b on main surface S2 and lower substrate 102 b provided with a plurality of recesses 107 b are pressurized while being subjected to heating and application of a voltage, whereby these components are anode-joined. At this time, lower substrate 102 b is arranged on main surface S2 of solid electrolyte 101 in such a manner that each one of a plurality of recesses 107 b faces each one of a plurality of anodes 103 b. Reactor 100 shown in FIG. 1A can be obtained in the manner described above.
In the example described above, an electrode is formed with solid electrolyte 101 supported by a substrate (Si substrate 10 or upper substrate 102 a). Therefore, unlike a method of joining an electrode/solid electrolyte/electrode laminate to a substrate, occurrence of defects such as pinholes in a solid electrolyte can be suppressed even when a relatively thin solid electrolyte is used. Further, occurrence of damage to a solid electrolyte due to mechanical impact in a manufacturing process can be suppressed. Therefore, a reactor having improved reliability can be obtained.
For example, between adjacent cathodes, a wiring (not illustrated) that connects the cathodes to each other is provided as described above. In the example described above, the wiring between the cathodes is electrically isolated from upper substrate 102 a by a thermal oxide film of upper substrate 102 a. Similarly, for example, the wiring between adjacent anodes is electrically isolated from lower substrate 102 b by a thermal oxide film of lower substrate 102 b.
As shown in FIG. 11, a joining layer may be arranged between solid electrolyte 101 and upper substrate 102 a and/or lower substrate 102 b. Reactor 100A shown in FIG. 11 has joining layer 107 each of between solid electrolyte 101 and upper substrate 102 a and between solid electrolyte 101 and lower substrate 102 b. Joining layer 107 is, for example, an organic film, an oxide film, a metal layer, a glass layer or the like. For example, by providing an epoxy resin, a glass powder (glass frit) or the like on upper substrate 102 a (or lower substrate 102 b) or solid electrolyte 101 before joining, the substrate and the solid electrolyte can be joined together with a joining layer interposed therebetween. By providing joining layer 107, stronger joining can be performed. By providing an epoxy resin or the like on solid electrolyte 101 before joining, a region to be joined to upper substrate 102 a (or lower substrate 102 b) can be made flat.
By joining solid electrolyte 101 and upper substrate 102 a (or lower substrate 102 b) to each other with the joining layer interposed therebetween, leakage of a reactant between adjacent first chambers (or adjacent second chambers) can be suppressed. A similar effect is obtained when upper substrate 102 a (or lower substrate 102 b) is formed by the foregoing various film formation methods. For example, by coating a surface of the wiring using an insulating material, joining layer 107 can be formed from a metallized ceramic layer. When an insulating material is used as a material of joining layer 107, the degree of freedom of design of the wiring between cathodes and/or anodes is improved, and therefore the degree of freedom of design of the shape, arrangement and so on of first chambers 104 a and/or second chambers 104 b is also improved.
FIG. 12A shows an example of the shape and arrangement of first chambers 104 a and second chambers 104 b. In the example shown in FIG. 12A, first chambers 104 a each have a circular shape when viewed from a direction perpendicular to upper substrate 102 a, and first chambers 104 a are two-dimensionally arranged such that centers of circles shown by a solid line in FIG. 12A form a triangular lattice pattern (which may also be referred to as a hexagonal lattice pattern). Similarly, second chambers 104 b each have a circular shape when viewed from a direction perpendicular to upper substrate 102 a, and are two-dimensionally arranged such that centers of circles shown by a dashed line in FIG. 12A form a triangular lattice pattern. The arrangement of the second chambers are shifted by a half-pitch along the Y direction in the drawing with respect to the arrangement of the first chambers as shown in FIG. 12A.
FIG. 12B shows another example of the shape and arrangement of first chambers 104 a and second chambers 104 b. In the example shown in FIG. 12B, an arrangement of first chambers 104 a and second chambers 104 b is similar to the arrangement shown in FIG. 12A. It is to be noted that the shape of each first chamber 104 a and the shape of each second chamber 104 b are hexagonal. The shape of each first chamber 104 a and/or each second chamber 104 b when the chambers are viewed from a direction perpendicular to upper substrate 102 a as described above is not necessarily circular, and may be rectangular or polygonal. When the shape of each first chamber 104 a and/or each second chamber 104 b is circular, local stress concentration on solid electrolyte 101 can be suppressed.
As illustrated in FIG. 12A and FIG. 12B, first chambers 104 a and/or second chambers 104 b can be arranged so as to form a lattice pattern. The lattice pattern is, for example, a triangular lattice pattern, a square lattice pattern, a rectangular lattice pattern or a rhombic lattice pattern. When first chambers and second chambers each having a circular shape or a polygonal shape are arranged so as to form a triangular lattice pattern as illustrated in FIG. 12A and FIG. 12B, the first chambers and the second chambers can be densely arranged with respect to the area of the solid electrolyte. According to the above-mentioned form, area efficiency of reaction can be improved. Further, damage to solid electrolyte 101 can be suppressed because there is almost no deviation in portions of solid electrolyte 101, which are supported by one of surface Sa of upper substrate 102 a and surface Sb of lower substrate 102 b. Therefore, a reactor having excellent mechanical reliability can be obtained. When first chambers 104 a and/or second chambers 104 b have an indefinite shape, they should be arranged such that centers of gravity of first chambers 104 a and/or second chambers 104 b form a lattice pattern.

Second Exemplary Embodiment

An electrically conductive substrate may be used as an upper substrate or a lower substrate.
FIG. 13 shows an example of a configuration of a reactor including an electrically conductive upper substrate. In reactor 100B shown in FIG. 13, upper substrate 102 a is an electrically conductive substrate formed of Si, Ni or the like. In the example shown in FIG. 13, a high potential section and a low potential section of external power source 108 are connected to anode 103 b and cathode 103 a, respectively, and further, upper substrate 102 a is connected to the high potential section of external power source 108. That is, reactor 100B is configured to ensure that a voltage having the same polarity as that of a voltage applied to anode 103 b is applied to upper substrate 102 a.
As is apparent from FIG. 13, voltages having mutually different polarities are applied to anode 103 b and cathode 103 a during operation of reactor 100B. A voltage having the same polarity as that of a voltage applied to anode 103 b is applied to upper substrate 102 a. Thus, not only an electric field along a direction in which an anode and a cathode facing each other are connected, but also an electric field along an in-plane direction of solid electrolyte 101 can be generated. Therefore, protons can be caused to move from anode 103 b to cathode 103 a more efficiently, leading to improvement of reaction efficiency. During operation of reactor 100B, anode 103 b and upper substrate 102 a are not required to have equal potentials, and anode 103 b and upper substrate 102 a may be kept at mutually different potentials as long as they have the same polarity. For example, upper substrate 102 a may be connected to a power source different from external power source 108.
FIG. 14 shows an example of a configuration of a reactor including an electrically conductive upper substrate and an electrically conductive lower substrate. In reactor 100C shown in FIG. 14, lower substrate 102 b is an electrically conductive substrate formed of Si, Ni or the like similarly to upper substrate 102 a. In the example shown in FIG. 14, lower substrate 102 b is also connected to the high potential section of external power source 108. That is, reactor 100C is configured to ensure that a voltage having the same polarity as that of a voltage applied to anode 103 b is applied to lower substrate 102 b.
As is apparent from FIG. 14, voltages having mutually different polarities are applied to anode 103 b and cathode 103 a during operation of reactor 100C. A voltage having the same polarity as that of a voltage applied to anode 103 b is applied to lower substrate 102 b. Thus, an electric field along a direction perpendicular to a main surface of solid electrolyte 101 can be further generated, so that protons can be caused to move from anode 103 b toward cathode 103 a more efficiently. During operation of reactor 100C, anode 103 b and upper substrate 102 a and lower substrate 102 b are not required to have equal potentials, and anode 103 b and upper substrate 102 a and lower substrate 102 b may be kept at mutually different potentials as long as they have the same polarity. For example, each of upper substrate 102 a and lower substrate 102 b may be connected to a power source different from external power source 108. Only lower substrate 102 b may be connected to the high potential section of external power source 108 rather than connecting both upper substrate 102 a and lower substrate 102 b to the high potential section of external power source 108 as shown in FIG. 14.
FIG. 15 shows another example of a configuration of a reactor including an electrically conductive lower substrate. In the example shown in FIG. 15, a high potential section and a low potential section of external power source 108 are connected to anode 103 b and cathode 103 a, respectively, and the low potential section of external power source 108 is connected to electrically conductive lower substrate 102 b. That is, reactor 100D shown in FIG. 15 is configured to ensure that a voltage having the same polarity as that of a voltage applied to cathode 103 a is applied to lower substrate 102 b.
As is apparent from FIG. 15, voltages having mutually different polarities are applied to anode 103 b and cathode 103 a during operation of reactor 100D. A voltage having the same polarity as that of a voltage applied to cathode 103 a is applied to lower substrate 102 b. With this configuration, not only an electric field along a direction in which an anode and a cathode facing each other are connected, but also an electric field along an in-plane direction of solid electrolyte 101 can be generated. During operation of reactor 100D, cathode 103 a and lower substrate 102 b are not required to have equal potentials. For example, lower substrate 102 b may be connected to a power source different from external power source 108.
Further, electrically conductive upper substrate 102 a may be connected to the high potential section of external power source 108 as shown in FIG. 16. That is, reactor 100E shown in FIG. 16 is configured to ensure that a voltage having the same polarity as that of a voltage applied to anode 103 b is applied to upper substrate 102 a, and a voltage having the same polarity as that of a voltage applied to cathode 103 a is applied to lower substrate 102 b.
As is apparent from FIG. 16, for example, voltages having mutually different polarities are applied to anode 103 b and cathode 103 a, and a voltage having the same polarity as that of a voltage applied to anode 103 b is applied to upper substrate 102 a during operation of reactor 100E. Thus, an electric field along an in-plane direction of solid electrolyte 101 can be generated. Further, a voltage having the same polarity as that of a voltage applied to cathode 103 a may be applied to lower substrate 102 b. Thus, an additional electric field along the in-plane direction of solid electrolyte 101 can be generated. During operation of reactor 100E, anode 103 b and upper substrate 102 a are not required to have equal potentials, and cathode 103 a and lower substrate 102 b are not required to have equal potentials. For example, each of upper substrate 102 a and lower substrate 102 b may be connected to a power source different from external power source 108.
In a configuration ensuring that a voltage having the same polarity as that of a voltage applied to cathode 103 a can be applied to lower substrate 102 b as illustrated in FIG. 15 and FIG. 16, the distance between an outer edge of anode 103 b and lower substrate 102 b is preferably larger than the thickness of solid electrolyte 101 (thickness shown by “h” in FIG. 15 and FIG. 16). Here, the distance between the outer edge of the anode and the lower substrate means a distance between an end of the anode and a joint between the lower substrate and the solid electrolyte (distance shown by “w” in FIG. 15 and FIG. 16) in a plane parallel to a main surface of the solid electrolyte. According to the above-mentioned form, protons moving through the solid electrolyte are considered to be easily attracted to upper substrate 102 a facing anode 103 b because the magnitude of an electric filed along a direction perpendicular to a main surface of the solid electrolyte can be made greater than the magnitude of an electric field in a direction along the main surface of the solid electrolyte.
In the examples shown in FIGS. 13 to 16, the polarity of external power source 108 may be converse to the polarity in the illustrated configuration. For example, a configuration may be employed in which voltages having mutually different polarities are applied to anode 103 b and cathode 103 a, and a voltage having the same polarity as that of a voltage applied to the cathode is applied to upper substrate 102 a and/or lower substrate 102 b.
As described above, according to the present disclosure, there can be provided a reactor with improved reliability, which ensures that damage to a solid electrolyte due to mechanical impact and thermal impact at the time of starting or stopping operation can be suppressed. According to the present disclosure, damage to the solid electrolyte is suppressed, and therefore the solid electrolyte is relatively easily made thin. Therefore, a higher ion conductivity can be achieved, so that the reactor can be activated at an operation temperature of, for example, about 300° C.
As the solid electrolyte, not only a proton conductor but also an oxygen ion conductor formed of a solid oxide may be used, and therefore carriers in the solid electrolyte may be oxygen ions.
The reactor according to the present disclosure can be used for fuel cells, hydrogenation devices, dehydrogenation devices, water vapor electrolysis devices, water vapor electrolysis and hydrogenation devices and so on. The reactor according to the present disclosure can also be used as a gas sensor such as a hydrogen sensor or an oxygen sensor by measuring an electromotive force generated between a first electrode and a second electrode.

REFERENCE SINGS LIST

- 100 reactor
- 101 solid electrolyte
- 102 a upper substrate (first substrate)
- 102 b lower substrate (second substrate)
- 103 a cathode (first electrode)
- 103 b anode (second electrode)
- 104 a first chamber
- 104 b second chamber
- 105 a, 105 b fluid inlet
- 106 a, 106 b fluid outlet
- 107 joining layer
- 108 external power source

Claims

What is claimed is:

1. A reactor comprising:

a solid electrolyte having a first surface and a second surface;

a plurality of first electrodes arranged on the first surface;

a plurality of second electrodes arranged on the second surface;

a first substrate including a plurality of first chambers each formed of a first recess on one principal plane;

a second substrate including a plurality of second chambers each formed of a second recess on one principal plane; and

an external power supply,

wherein

a bottom of each of the first recess is opposite to one of the plurality of the first electrodes;

a bottom of each of the second recess is opposite to one of the plurality of the second electrodes;

each first electrode includes a first catalyst;

each second electrode includes a second catalyst;

the first substrate is arranged on the first surface in such a manner that each first chamber is interposed between the first substrate and the first surface;

the second substrate is arranged on the second surface in such a manner that each second chamber is interposed between the second substrate and the second surface;

at least one of the plurality of the first chambers overlaps two or more second chambers, when viewed from a direction perpendicular to the one principal surface of the first substrate; and

the external power supply is electrically interposed between the plurality of the first electrodes and the plurality of the second electrodes in such a manner that a voltage difference is generated between the plurality of the first electrodes and the plurality of the second electrodes.

2. The reactor according to claim 1, further comprising:

a joining layer arranged between the solid electrolyte and the first substrate.

3. The reactor according to claim 1, wherein

the second substrate is electrically conductive; and

the second substrate is electrically connected to the external power supply in such a manner that the a voltage having the same polarity as that of the second electrode is applied to the second substrate.

4. The reactor according to claim 1, wherein

the second substrate is electrically conductive; and

the second substrate is electrically connected to the external power supply in such a manner that the a voltage having the same polarity as that of the first electrode is applied to the second substrate.

5. The reactor according to claim 4, wherein

a distance between an outer edge of the second electrode and the second substrate on the second surface is larger than a thickness of the solid electrolyte.

6. The reactor according to claim 1, wherein

the first substrate is electrically conductive; and

the first substrate is electrically connected to the external power supply in such a manner that the a voltage having the same polarity as that of the second electrode is applied to the first substrate.

7. The reactor according to claim 1, wherein

the plurality of first chambers each have a circular or polygonal shape when viewed from a direction perpendicular to the one main surface of the first substrate; and

the plurality of first chambers are arranged so as to form a lattice pattern.

8. The reactor according to claim 1, wherein

a carrier in the solid electrolyte is a hydrogen ion or an oxygen ion.

9. A method for activating the reactor, the method comprising:

(a) preparing a reactor comprising:

a solid electrolyte having a first surface and a second surface;

a plurality of first electrodes arranged on the first surface;

a plurality of second electrodes arranged on the second surface;

an external power supply,

wherein

each first electrode includes a first catalyst;

each second electrode includes a second catalyst;

at least one of the plurality of the first chambers overlaps two or more second chambers of the plurality of the second chambers, when viewed from a direction perpendicular to the one principal surface of the first substrate;

the external power supply is electrically interposed between the plurality of the first electrodes and the plurality of the second electrodes;

the second substrate is electrically conductive; and

the second substrate is electrically connected to the external power supply in such a manner that the a voltage having the same polarity as that of the second electrode is applied to the second substrate;

(b) applying voltages, which have mutually different polarities, to the first electrode and the second electrode; and

(c) applying to the second substrate a voltage having the same polarity as that of the voltage applied to the second electrode.

10. A method for activating the reactor, the method comprising:

(a) preparing a reactor comprising:

a solid electrolyte having a first surface and a second surface;

a plurality of first electrodes arranged on the first surface;

a plurality of second electrodes arranged on the second surface;

an external power supply,

wherein

each first electrode includes a first catalyst;

each second electrode includes a second catalyst;

the second substrate is electrically conductive; and

(c) applying to the second substrate a voltage having the same polarity as that of the voltage applied to the first electrode.

11. A method for activating the reactor, the method comprising:

(a) preparing a reactor comprising:

a solid electrolyte having a first surface and a second surface;

a plurality of first electrodes arranged on the first surface;

a plurality of second electrodes arranged on the second surface;

an external power supply,

wherein

each first electrode includes a first catalyst;

each second electrode includes a second catalyst;

the first substrate is electrically conductive; and

the first substrate is electrically connected to the external power supply in such a manner that the a voltage having the same polarity as that of the second electrode is applied to the first substrate;