JP2008108647A - Reformer integrated fuel cell - Google Patents

Abstract

A conventional steam reformer, a hydrogen purifier, and a fuel cell are integrated into a single unit, so that the configuration of the apparatus can be remarkably reduced, the cost can be reduced, the utility is high, and the power generation efficiency and durability can be improved. A reformer integrated fuel cell is obtained.
A barrier layer, a hydrogen separation / anode layer, an electrolyte layer, and a cathode layer are sequentially disposed on a porous reforming catalyst layer, and Ni, Rh, ru, Ir, Pd, Pt, Re, Co, one or more of metals and _{Ln 1-x a x MO 3} ( where the Fe, Ln is a rare earth element, a is Ba, Sr, one of Ca one A reformer-integrated fuel comprising a surface layer including M, wherein M is at least one of Cr and Ti, and the range of X is 0 ≦ X ≦ 1 battery. The reformer integrated fuel cell is configured as a reformer integrated fuel cell having various shapes such as a flat plate shape, a circular cross section, a rectangular cross section, and a polygonal cross section.
[Selection] Figure 1

Description

  The present invention relates to a reformer integrated fuel cell in which a fuel reformer and a fuel cell are integrated.

  Fuel cells include solid polymer fuel cells (PEFCs), phosphoric acid fuel cells (PAFCs), molten carbonate fuel cells (MCFCs), solid oxides, depending on the material used for the ionic conductor, or electrolyte. There are various types such as a physical fuel cell (SOFC), but these are the same in principle. As the electrolyte, solid polymer is used in PEFC, molten carbonate is used in MCFC, phosphoric acid is used in PAFC, and solid oxide is used in SOFC.

  Among these fuel cells, the fuel of PEFC, PAFC, and MCFC is hydrogen, but in MCFC, carbon monoxide generates hydrogen by a shift reaction at the anode, so that carbon monoxide is also fuel. The fuel of SOFC is hydrogen and carbon monoxide, but methane is reformed to hydrogen and carbon monoxide by the metal (Ni etc.) of the anode of SOFC to become fuel. These fuels are usually obtained by a steam reforming method or a partial combustion method of hydrocarbon fuel. However, in order to extract only hydrogen or only hydrogen and carbon monoxide from the reformed gas, a separate hydrogen purifier is required. Moreover, when using for PEFC, the heat exchanger which cools high temperature reformed gas to 100 degrees C or less is also needed.

Hereinafter, the SOFC will be mainly described as an example, but the same applies to other fuel cells. The SOFC has an operating temperature in the range of 800 to 1000 ° C., usually as high as 1000 ° C., but it is 650 like a supported membrane type, that is, a SOFC that supports a solid oxide electrolyte such as zirconia or LaGaO ₃ with a thick anode. Those having an operating temperature of about ˜800 ° C., for example, about 750 ° C. are being developed. The SOFC is composed of a three-layer unit of an anode and a cathode with a solid oxide electrolyte in between.

Taking the case where the oxidant gas is air as an example, oxygen in the air introduced into the cathode becomes oxide ions (O ²⁻ ) at the cathode, and reaches the anode through the solid oxide electrolyte. Here, it reacts with the fuel introduced into the anode and emits electrons to produce a reaction product such as electricity and water. Used air at the cathode is discharged as cathode offgas, and spent fuel at the anode is discharged as anode offgas. The anode offgas contains unreacted fuel at the anode, reaction products such as water vapor and carbon dioxide. include.

  By the way, Japanese Patent Application Laid-Open No. 2004-146337 discloses a fuel cell having a hydrogen purification function of reformed gas that is supplied fuel gas. FIG. 10 is a cross-sectional view shown in the publication. The electrolyte membrane 40 is sandwiched between the oxygen electrode 10 and the hydrogen electrode 30, and the electrolyte membrane 40 has a five-layer structure centered on a dense substrate 43 made of vanadium. Thin films of electrolyte layers 42 and 44 made of solid oxide are formed on both surfaces of the substrate 43, and palladium (Pd) coatings 41 and 45 are provided on the outer surfaces of the electrolyte layers 42 and 44.

  Although the Pd coatings 41 and 45 correspond to hydrogen permeable materials, since hydrogen-rich fuel gas is supplied to the hydrogen electrode 30, there is no explicit description in the publication, but hydrocarbons are separately used as fuel. It is understood that fuel reformed by a reformer or the like is used. The base material 43 also serves as a support for the electrolyte layers 42 and 44 together with the Pd coating. Since the base material 43 is dense, the electrolyte layers 42 and 44 are considerably thinned (about 1 μm or less). Is possible.

  Japanese Patent Application Laid-Open No. 2005-19041 discloses that a solid electrolyte layer is sandwiched between an anode and a cathode, the anode is formed by a hydrogen permeable electrode in which a hydrogen permeable metal film is bonded to a porous substrate, and a solid A fuel cell is described in which the electrolyte layer comprises a proton conductive oxide thin film. However, also in this fuel cell, a fuel obtained by reforming a hydrocarbon-based fuel with a separate fuel reformer is used as the fuel supplied from the porous substrate side.

JP 2004-146337 A JP-A-2005-19041

  In the present invention, the fuel reformer and the fuel cell are not separately disposed as in the conventional case, and the fuel reformer is not disposed separately from the fuel reformer, the hydrogen purifier, and the fuel cell. It is an object of the present invention to provide a reformer-integrated fuel cell that is extremely compact and has excellent durability by integrally configuring a mass device, a hydrogen purifier, and a fuel cell.

The present invention (1) is a fuel cell in which a fuel reformer and a fuel cell are integrated, and a barrier layer, a hydrogen separation / anode layer, an electrolyte layer, and a cathode layer are sequentially disposed on a porous reforming catalyst layer. And at least one of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe on the barrier layer side of the porous reforming catalyst layer and Ln _1-x A _x MO ₃ (In the formula, Ln is a rare earth element, A is one or more of Ba, Sr, and Ca, M is one or more of Cr and Ti, and the range of X is 0 ≦ X ≦ 1. Is a reformer integrated fuel cell, characterized in that a surface layer is provided.

The present invention (2) is a fuel cell in which a fuel reformer and a fuel cell are integrated, and a barrier layer, a hydrogen separation and anode are sequentially formed on the outer peripheral surface of a porous reforming catalyst layer having a fuel flow path therein. A layer, an electrolyte layer, and a cathode layer, and one or more metals of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe on the barrier layer side of the porous reforming catalyst layer And Ln _1-x A _x MO ₃ (wherein Ln is a rare earth element, A is at least one of Ba, Sr, and Ca, M is at least one of Cr and Ti, The reformer-integrated fuel cell is provided with a surface layer including a range of 0 ≦ X ≦ 1.

The present invention (3) is a fuel cell in which a fuel reformer and a fuel cell are integrated. The fuel cell has an oxidant gas flow path therein, and sequentially forms a barrier layer on the inner peripheral surface of the porous reforming catalyst layer. , A hydrogen separation / anode layer, an electrolyte layer, and a cathode layer, and any one of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe on the barrier layer side of the porous reforming catalyst layer One or more metals and Ln _1-x A _x MO ₃ (wherein Ln is a rare earth element, A is one or more of Ba, Sr and Ca, and M is one or more of Cr and Ti) And the range of X is 0 ≦ X ≦ 1). The reformer-integrated fuel cell is provided with a reformer-integrated fuel cell.

The present invention (4) is a fuel cell in which a fuel reformer and a fuel cell are integrated, and a porous reforming catalyst layer is sequentially formed on an electrically insulating porous substrate tube having a fuel flow path therein. A plurality of power generation element portions having a layer structure in which a barrier layer, a hydrogen separation / anode layer, an electrolyte and a cathode layer are stacked adjacent to each other, and Ni, Rh, ru, Ir, Pd, Pt, Re, Co, one or more of metals and _{Ln 1-x a x MO 3} ( where the Fe, Ln is a rare earth element, a is Ba, Sr, one of Ca one And M is one or more of Cr and Ti, and the range of X is 0 ≦ X ≦ 1, and at least two adjacent power generations are provided. The element part is electrically connected in series by an interconnector Reformer to an integral type fuel cell.

In the following, the chemical formula “Ln _1-x A _x MO ₃ , wherein Ln is a rare earth element, A is one or more of Ba, Sr, and Ca, and M is one or more of Cr and Ti. And the range of X is 0 ≦ X ≦ 1) ”is abbreviated as“ Ln _1−x A _x MO ₃ ”as appropriate.

  In the reformer-integrated fuel cell of the present invention, the fuel reformer and the fuel cell are integrated, and the apparatus configuration can be remarkably reduced in size. As a result, the startup time can be shortened, and it can be used as a power generator for mobile objects such as automobiles and ships, a power generator installed in a home or factory, or a power generator that is easy to carry. It is very useful in practice, such as enabling cost reduction. Further, the reformer-integrated fuel cell of the present invention reforms and purifies a hydrocarbon fuel by itself and uses the purified hydrogen as a fuel, so that the power generation efficiency as a fuel cell can be improved.

In particular, according to the present invention, Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, Fe on the surface of the porous reforming catalyst layer, that is, the surface of the porous reforming catalyst layer 1 on the barrier layer 2 side. By providing a surface layer containing at least one of these metals and Ln _1-x A _x MO ₃ , the adhesion between the porous reforming catalyst layer and the barrier layer is improved, and the reforming is excellent in durability. The unit-integrated fuel cell can be obtained, and the production yield can be improved.

  FIG. 1 is a diagram for explaining the basic configuration of the present invention. In FIG. 1, reference numeral 1 denotes a porous reforming catalyst layer, which is a first layer constituting a reformer-integrated fuel cell. Reference numeral 2 denotes a barrier layer, which is a second layer constituting the reformer-integrated fuel cell. Reference numeral 3 denotes a hydrogen separation / anode layer, which is a third layer constituting the reformer-integrated fuel cell. Reference numeral 4 denotes an electrolyte layer, which is a fourth layer constituting the reformer-integrated fuel cell. Reference numeral 5 denotes a cathode layer, which is a fifth layer constituting the reformer-integrated fuel cell.

As shown in FIG. 1, in the reformer-integrated fuel cell of the present invention, the surface of the porous reforming catalyst layer 1, that is, the surface of the porous reforming catalyst layer 1 on the barrier layer 2 side has Ni, Rh, A surface layer 1 ′ including at least one of Ru, Ir, Pd, Pt, Re, Co, and Fe and Ln _1-x A _x MO ₃ is provided. As a result, the adhesion between the porous reforming catalyst layer 1 and the barrier layer 2 can be improved, a reformer-integrated fuel cell having excellent durability can be obtained, and the yield at the time of production can be improved. Can do.

  Since the surface layer 1 ′ contains one or more of the reforming catalyst metals Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe, it also has a function as a reforming catalyst. This can be interpreted as a part of the porous reforming catalyst layer 1.

  In the following, each layer constituting the reformer-integrated fuel cell will be described first, and then aspects of the reformer-integrated fuel cell of the present invention (1) to (4) will be described.

<Porous reforming catalyst layer as first layer>
The porous reforming catalyst layer, which is the first layer, is a layer that serves as a support for the fuel cell in addition to the role as a reforming catalyst. In FIG. 1, this is a layer corresponding to the porous reforming catalyst layer 1.

The porous reforming catalyst layer preferably has a porosity of 10 to 85% and an average pore diameter of 0.05 to 10 μm. The thickness depends on the strength required for the support, but is preferably 100 μm or more. In the porous reforming catalyst layer, reformed gas is generated by steam reforming of the hydrocarbon fuel. The reformed gas contains H ₂ , CO, and CO ₂ , but only H ₂ flows to the electrolyte layer through the hydrogen separation / anode layer described later. The porous reforming catalyst layer only needs to have a reforming catalyst function when the reformer-integrated fuel cell is used, that is, when the reformer integrated fuel cell is operated. There is no need to have a function.

  As a constituent material of the porous reforming catalyst layer, a material having both a role as a reforming catalyst and a role as a support for a fuel cell is used. Examples thereof include, but are not limited to, a sintered body (Ni-YSZ cermet or the like) mainly composed of a mixture of nickel and yttria-stabilized zirconia, porous ceramics, porous cermet and the like.

<Surface layer provided on porous reforming catalyst layer>
Ni, Rh, Ru, Ir, Pd, Pt, Ni, Rh, Ru, Ir, Pt, in order to improve the adhesion with the barrier layer as the second layer on the second layer side surface of the porous reforming catalyst layer as the first layer A surface layer containing one or more metals of Re, Co, and Fe and Ln _1-x A _x MO ₃ used for the barrier layer is provided. In FIG. 1, this is a layer corresponding to the surface layer 1 ′.

  The surface layer is an important structure in the present invention (1) to (4). Thereby, the adhesiveness and durability of a porous reforming catalyst layer and a barrier layer can be improved, and the yield at the time of the production can be improved.

The constituent material other than one or more metals of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe and Ln _1-x A _x MO _{3 in the} surface layer is a porous reforming catalyst layer Yttria-stabilized zirconia, which is a part of the constituent material, and can be a part of the constituent material of the barrier layer (described later <barrier layer as the second layer>). In addition to yttria-stabilized zirconia, a mixture of one or more materials selected from stabilized zirconia, partially stabilized zirconia, zirconia, alumina, and magnesia may be included.

  Thus, since the surface layer contains one or more metals of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe which are the reforming catalyst metals, the surface layer also has a reforming function. In this sense, the surface layer can be said to be a part of the porous reforming catalyst layer that is the first layer, and can also be said to be an intermediate layer because it is interposed between the porous reforming catalyst layer and the barrier layer.

  In the following description in the section of <Surface layer provided on porous reforming catalyst layer>, the surface layer is the above yttria-stabilized zirconia, or “stabilized zirconia, partially stabilized zirconia, zirconia, alumina, The term “yttria-stabilized zirconia” is used as appropriate, including the case of including a mixture of one or more materials selected from magnesia.

The content of Ln _1-x A _x MO ₃ in the surface layer is 10 to 90% (mol%, the same applies hereinafter), preferably 20 to 80%, more preferably, in the molar ratio determined from elemental analysis by EDX or the like. 30-70%. As the content of Ln _1-x A _x MO ₃ increases, the adhesion to the barrier layer improves, but a gap is likely to occur at the boundary between the surface layer and the porous reforming catalyst layer.

The content of one or more metals of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe in the surface layer is 5 to 50% (mol%, the same applies hereinafter), preferably 20 to 40 %. The content of yttria-stabilized zirconia in the surface layer is 5 to 50%, preferably 20 to 40%. By using at least one of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe and / or yttria-stabilized zirconia, the Ln _1-x A _x MO ₃ containing part and the non-containing part Adhesion can be obtained.

The thickness of the surface layer is not limited and can be set arbitrarily. Further, the Ln _1-x A _x MO ₃ component may be contained in the entire porous reforming catalyst layer from the submicron order. Ln _1-x A _x MO ₃ is more expensive than nickel or yttria-stabilized zirconia, so it is preferable that Ln _1-x A _x MO ₃ is contained only on the surface, not the entire porous reforming catalyst layer. Further, the structure may be inclined so that the Ln _1-x A _x MO ₃ content ratio decreases from the surface portion to the inside of the porous reforming catalyst layer.

The porous reforming catalyst layer can be constituted, for example, by mixing Ni particles, NiO particles and yttria-stabilized zirconia particles, molding the mixture by extrusion molding, pressure molding, or the like, and sintering the mixture. In addition, when the metal is Ni, the surface layer is a slurry coating method, spray spraying method, printing, or the like, mixed powder of NiO, Ln _1-x A _x MO ₃ and yttria-stabilized zirconia on the porous reforming catalyst layer. It can be formed by the method.

<Barrier layer as the second layer>
The barrier layer as the second layer is a layer for preventing mutual diffusion of Ni of the porous reforming catalyst layer and Pd of the hydrogen separation membrane component in the hydrogen separation / anode layer. In FIG. 1, this is a layer corresponding to the barrier layer 2.

  The constituent material is required not to be decomposed into a metal by reduction in a hydrogen atmosphere at 400 to 700 ° C. which is a use temperature. When metal is generated by decomposition by reduction, it reacts with the third layer, the hydrogen separation / anode layer constituted by the Pd film or Pd alloy film, and (a) a hole is opened in the hydrogen separation / anode layer. b) Defects and problems such as a decrease in hydrogen separation occur, which is not preferable. It is also necessary not to decompose in a carbon dioxide atmosphere at the use temperature.

For this reason, as the constituent material of the barrier layer, (a) electrically conductive Ln _1-x A _x MO ₃ (wherein Ln is a rare earth element, A is any one of Ba, Sr, and Ca) , M is at least one of Cr and Ti, and the range of X is 0 ≦ X ≦ 1), (b) any one of stabilized zirconia, partially stabilized zirconia, zirconia, alumina, and magnesia A mixture or a compound of the above and Ln _1-x A _x MO ₃ is used. These materials have durability even in a reducing atmosphere and a CO ₂ atmosphere.

Further, the barrier layer needs to be porous in order for gas to pass through. The porosity is preferably 5 to 85%, and the average pore diameter is preferably 0.05 to 10 μm. The thickness is preferably 5 to 100 μm. In the barrier layer, the material having electrical conductivity is Ln _1-x A _x MO ₃ , and the current generated in the third layer, the hydrogen separation / anode layer, passes through the first layer through Ln _1-x A _x MO ₃ . It is led out to the porous reforming catalyst layer side which is a layer. Therefore, the content of Ln _1-x A _x MO ₃ barrier layer is higher, thereby improving the battery performance. The content ratio is 20 to 100% (mol%, the same applies hereinafter), preferably 40 to 100%, more preferably 60 to 100%. In the surface layer, a part of electrical conductivity is carried by one or more metals of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe. In the barrier layer, Ln _1-x Since only A _x MO ₃ bears electrical conductivity, the content ratio of Ln _1-x A _x MO ₃ is preferably greater than or equal to that in the surface layer.

  The barrier layer needs to be porous, but may be porous when formed, or may be porous when used as a fuel cell. Further, when the barrier layer is formed in such a manner, the anchoring effect of causing the components of the hydrogen separation / anode layer, which is the third layer, to penetrate into the barrier layer is used for the porous reforming catalyst layer, which is the first layer. The hydrogen separation / anode layer can be held more firmly. In addition, the barrier layer has the effect of expanding the solid solution site of hydrogen from the fuel gas phase to the anode phase (hydrogen separation and anode layer) three-dimensionally. Can be reduced.

  The barrier layer can be formed by a dip coating method, a spray spraying method, a printing method, or a catalyst metal dissolution and removal method on the surface layer on the porous reforming catalyst layer. Among these, the printing method is particularly useful when the porous reforming catalyst layer is flat. Moreover, you may perform simultaneous baking with a surface layer at the time of the preparation.

For example, Ln _1-x Ca _x CrO ₃ powder is dispersed in water or an organic solvent to form a slurry, which is applied to the surface layer formed on the porous reforming catalyst layer by spraying, printing, etc., and heat-treated. Can be formed. Since Ln _1-x Ca _x CrO ₃ has electrical conductivity, electricity generated in the hydrogen separation / anode layer flows to the porous reforming catalyst layer through the barrier layer and the surface layer.

<Third layer, hydrogen separation and anode layer>
The third hydrogen separation / anode layer is formed on the surface of the barrier layer formed on the porous reforming catalyst layer. The hydrogen separation / anode layer has a function and a role as an anode in addition to a function and a role as a hydrogen separation membrane. In FIG. 1, this layer corresponds to the hydrogen separation / anode layer 3.

  As a constituent material of the hydrogen separation / anode layer, any material can be used as long as it has a function of selectively permeating hydrogen from the reformed gas and a function as an anode of the fuel cell. Preferred examples thereof include a Pd film, a Pd alloy film, a Group 5 metal (V, Nb or Ta) film, a Group 5 metal alloy film, a Group 5 metal film or a Group 5 metal alloy film and a Pd film or a Pd alloy film. The multilayer film is mentioned. Examples of the metal alloyed with Pd include Au, Ag, Cu, Pt, Rh, Ru, Ir, Ce, Sm, Tb, Dy, Ho, Er, Yb, Y, and Gd. Two or more of these metals may be combined.

  These constituent materials for the hydrogen separation / anode layer are supported on the barrier layer by forming the surface of the barrier layer on the surface of the barrier layer by plating, vapor deposition, or other appropriate methods. The hydrogen separation membrane / anode layer needs to be a dense membrane without holes (holes), but since the barrier separation layer is interposed, the hydrogen separation membrane / anode layer itself can be thinned. The thickness is preferably 30 μm or less. Pd and Pd alloys are expensive, but the cost can be reduced by reducing the film thickness, and the hydrogen permeation rate can be improved.

<The electrolyte layer which is the 4th layer>
The electrolyte layer, which is the fourth layer, plays a role of conducting and passing hydrogen ions (protons) ionized at the anode by hydrogen as the fuel. In FIG. 1, this is a layer corresponding to the electrolyte layer 4.

As the constituent material of the electrolyte layer, any material that can conduct protons is used. Examples thereof include the formula: ABO ₃ (wherein A is one or more of Ba, Sr and Ca, B is one or more of Ce and Zr. Ce and Zr of B site are And a perovskite compound that can be partially substituted with rare earth elements). Of these compounds, especially compounds containing Ce at the B site are known to have poor chemical stability against CO ₂ in the fuel gas, but the third layer, the hydrogen separation and anode layer, is dense. If it is formed, the direct contact between the electrolyte material and the fuel gas layer is interrupted, so that such a problem can be avoided.

The electrolyte layer is obtained, for example, by adding BaCe _0.8 Y _0.2 O ₃ ± δ or the like together with a binder and a dispersant to water or an organic solvent and mixing it to form a slurry, which is applied to the surface of the hydrogen separation and anode layer by screen printing or the like. It can be formed by heat treatment. Alternatively, it may be formed by a so-called sol-gel method, physical vapor deposition, or chemical vapor deposition using an alkoxide solution containing metal ions of BaCe _0.8 Y _0.2 O ₃ ± δ.

  The electrolyte layer only needs to be composed of such a material capable of conducting protons as a main component, and may be a mixture with other materials within a range having proton conductivity. The thickness of the electrolyte layer is preferably 10 μm or less.

<Cathode layer as the fifth layer>
The cathode layer which is the fifth layer is a layer corresponding to the cathode layer 5 in FIG. The constituent materials of the cathode layer include Ln _1-x A _x CoO ₃ ± δ, Ln _1-x A _x FeO ₃ ± δ, Ln _1-x A _x MnO ₃ ± δ (in these formulas, Ln is a rare earth element) , A is Ba, Sr, or Ca) or a metal such as Ag, Pt, or Ph. Among them the chemical formula and illustrated with the case of _{Ln 1-x A x CoO 3} ± δ La 0. 6 Sr 0. 4 CoO 3 ± δ, Sm 0. 5 Sr 0. 5 CoO 3 ± δ, Pr 0. 5 Ba _0. such as ₅ CoO ₃ ± _δ and the like.

  The cathode layer is formed by applying a heat treatment after applying the slurry or paste of the material to the surface of the electrolyte layer by screen printing or the like. The thickness of the cathode layer is preferably 30 μm or less.

<< Mode of Reformer-Integrated Fuel Cell of the Present Invention (1) >>
In the present invention (1), a barrier layer, a hydrogen separation / anode layer, an electrolyte layer, and a cathode layer are sequentially disposed on the porous reforming catalyst layer, and the porous reforming catalyst layer is on the barrier layer side. A reformer-integrated fuel cell comprising a surface layer containing at least one of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe and Ln _1-x A _x MO ₃ It is.

When the structure in this embodiment is viewed as a layer structure, it becomes “porous reforming catalyst layer—surface layer—barrier layer—hydrogen separation / anode layer—electrolyte layer—cathode layer”, and the surface layer is Ni, Rh, Ru, It is made of a material containing at least one of Ir, Pd, Pt, Re, Co, and Fe and Ln _1-x A _x MO ₃ .

Thus, in the reformer-integrated fuel cell of the present invention (1), it is essential to have the layer structure, and Ni, Rh, Ru, Ir are provided between the porous reforming catalyst layer and the barrier layer. , Pd, Pt, Re, Co, Fe, and a surface layer containing one or more metals and Ln _1-x A _x MO ₃ . Thereby, the adhesiveness of a porous reforming catalyst layer and a barrier layer can be improved, and it can be set as the reformer integrated fuel cell excellent in durability. This also applies to the reformer-integrated fuel cell of the present invention (2) to (4) described later.

  The shape of the porous reforming catalyst layer may be a flat plate shape, a circular cross section, an elliptical cross section, a rectangular cross section, or a polygonal cross section. Since each layer is arranged in layers on the porous reforming catalyst layer, the reformer-integrated fuel cell of the present invention (1) is configured in a shape corresponding to the shape of the porous reforming catalyst layer. In any of these shapes, the porous reforming catalyst layer has a fuel flow path on the side opposite to the side where the surface layer, barrier layer, hydrogen separation / anode layer, electrolyte layer, and cathode layer are disposed, and the cathode layer The side becomes an oxidant gas flow path.

  In addition, when the shape of the porous reforming catalyst layer is a circular cross-section, an elliptical cross-section, a rectangular cross-section, or a polygonal cross-section, an inner space that communicates with the inner longitudinal direction can be provided. If the inner space is used as a fuel flow path, a reformer integrated fuel cell corresponding to the present invention (2) is obtained.

<Aspect Example 1: Example of Flat Reformer-Integrated Fuel Cell>
FIG. 2 is a diagram illustrating an example of a planar reformer-integrated fuel cell as an example of the reformer-integrated fuel cell of the present invention (1). 2A is a plan view, and FIG. 2B is a cross-sectional view taken along line AA in FIG. 2A. Each of the layers 1 to 5 in FIG. 2 corresponds to each of the layers 1 to 5 in FIG. The same applies to the reformer-integrated fuel cell described below.

  As shown in FIG. 2B, a closed circuit is formed between the porous reforming catalyst layer 1 and the cathode layer 5, and electric power is taken out by applying a load. At that time, electricity can be taken out by arranging the current collector in contact with the porous reforming catalyst layer 1. Thus, the point which arrange | positions a collector is the same also about the aspect described below.

<Aspect Example 2: Stacking Aspect of Flat Reformer-Integrated Fuel Cell>
The flat reformer-integrated fuel cell can be stacked by stacking with a separator. FIG. 3 is a diagram showing this aspect. As shown in FIG. 3, a plurality of planar reformer-integrated fuel cells are arranged between adjacent porous reforming catalyst layers 1 and cathode layers 5 positioned above and below with each cathode layer 5 oriented in the same direction. Are stacked with the separator SE interposed therebetween.

  Thus, it is possible to reduce the size by stacking a plurality of planar reformer integrated fuel cells. As shown in FIG. 3, fuel and water vapor are introduced into the anode side and oxidant gas is introduced into the cathode side from the lateral direction of the stacked stack. Then, a closed circuit is formed between the outermost porous reforming catalyst layer 1a and the outermost cathode layer 5a, and electric power is taken out by applying a load. At that time, since the porous reforming catalyst layer is porous, that is, has a large number of communication holes, the porous reforming catalyst layer itself serves as a fuel flow path and reforms the hydrocarbon fuel.

<< Aspect of Reformer-Integrated Fuel Cell of the Present Invention (2) >>
In the present invention (2), a barrier layer, a hydrogen separation / anode layer, an electrolyte layer, and a cathode layer are sequentially arranged on the outer peripheral surface of a porous reforming catalyst layer having a fuel flow path therein. A surface layer containing at least one of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe and Ln _1-x A _x MO ₃ is provided on the barrier layer side of the porous catalyst layer. This is a reformer integrated fuel cell.

When the configuration in this embodiment is viewed as a layer structure, it becomes “a porous reforming catalyst layer having a fuel flow passage inside—a surface layer—a barrier layer—a hydrogen separation / anode layer—an electrolyte layer—a cathode layer”, and the surface layer is It is made of a material containing at least one of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe and Ln _1-x A _x MO ₃ . In relation to the above-described <aspect of the reformer-integrated fuel cell of the present invention (1)>, the present invention (2) has a structure in which the porous reforming catalyst layer in the present invention (1) has “a fuel flow path inside. It differs in that it is a “porous reforming catalyst layer”.

  In the present invention (2), the shape of the “porous reforming catalyst layer having a fuel flow path therein” may be a circular cross section, an elliptical cross section, a rectangular cross section, or a polygonal cross section. Since each layer is arranged in layers on a porous reforming catalyst layer having a fuel flow path therein, the reformer-integrated fuel cell of the present invention (2) corresponds to the shape of the porous reforming catalyst layer. Configured in shape.

<Example 1: Cylindrical tubular reformer integrated fuel cell>
FIG. 4 is a diagram for explaining a reformer integrated fuel cell having a circular cross section as an example of the reformer integrated fuel cell of the present invention (2). 4A is a longitudinal sectional view, and FIG. 4B is a sectional view taken along line AA in FIG. 4A. The porous reforming catalyst layer 1 is formed in a cylindrical tubular shape (circular cross section) having an inner space S communicating from one end to the other end. The inner space S is a flow path of fuel and water vapor, that is, a fuel flow path.

<Example 2: Cylindrical tubular reformer integrated fuel cell>
FIG. 5 is a diagram for explaining a modified embodiment of the above <embodiment example 1>, and is shown as a perspective view in FIG. As shown in FIG. 5A, the interconnector IN is formed in the longitudinal direction. As a constituent material of the interconnector IN, a metal such as Ag or an Ag alloy, or Ln _1-x A _x MO ₃ (wherein Ln is a rare earth element, A is any one of Ba, Sr, and Ca) , M is one or more of Cr and Ti, and the range of X is 0 ≦ X ≦ 1), etc., a mixture of conductive ceramics and zirconia, alumina, etc., InO ₂ , SnO ₂ A mixture of a conductive material such as glass and glass is used. The interconnector IN is joined and connected to the porous reforming catalyst layer 1. In this aspect, a closed circuit is formed between the interconnector IN and the cathode layer 5, and electric power is extracted by applying a load.

  FIG. 5B shows an example of a stack in which a plurality of such cylindrical tubular reformer integrated fuel cells are juxtaposed. Each cylindrical tubular reformer-integrated fuel cell unit is electrically connected in parallel or in series by an interconnector IN to form a closed circuit, and electric power is taken out by applying a load. A high current is obtained when electrically connected in parallel, and a high voltage is obtained when electrically connected in series.

<Example 3: Reformer-integrated fuel cell having a rectangular cross section>
FIG. 6 is a diagram for explaining a reformer-integrated fuel cell having a rectangular cross section as another embodiment of the reformer-integrated fuel cell of the present invention (2). 6A is a longitudinal sectional view, and FIG. 6B is a sectional view taken along line AA in FIG. 6A. The porous reforming catalyst layer 1 is formed in a rectangular cross section having an inner space S communicating from one end to the other end. The inner space S is a flow path of fuel and water vapor, that is, a fuel flow path.

<< Aspect of Reformer-Integrated Fuel Cell of the Present Invention (3) >>
The present invention (3) has an oxidant gas flow path inside, and a barrier layer, a hydrogen separation / anode layer, an electrolyte layer, and a cathode layer are sequentially arranged on the inner peripheral surface of the porous reforming catalyst layer. The surface containing one or more metals of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe and Ln _1-x A _x MO ₃ on the barrier layer side of the porous reforming catalyst layer A reformer-integrated fuel cell provided with a layer. The present invention (2) differs from the present invention (2) in that an oxidant gas flow path is provided inside.

When the structure in this embodiment is viewed in a layer structure, it becomes “porous reforming catalyst layer-surface layer-barrier layer-hydrogen separation / anode layer-electrolyte layer-cathode layer” from the outside to the inside, and the surface layer Is made of a material containing at least one of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe and Ln _1-x A _x MO ₃ . The shape of the porous reforming catalyst layer may be a circular cross section, an elliptical cross section, a rectangular cross section, or a polygonal cross section. Since the layers are sequentially arranged inside the porous reforming catalyst layer, the reformer-integrated fuel cell is configured in a shape corresponding to the shape of the porous reforming catalyst layer.

  FIG. 7 is a diagram for explaining a reformer-integrated fuel cell of the present invention (3), that is, a reformer-integrated fuel cell having a circular cross section having an oxidant gas passage SA therein. As shown in FIG. 7, a surface layer 1 ′, a barrier layer 2, a hydrogen separation / anode layer 3, an electrolyte layer 4, and a cathode layer 5 are sequentially arranged on the inner peripheral surface of the porous reforming catalyst layer 1 having a circular cross section. An oxidant gas flow path SA is provided inside the cathode layer 5. The inner membrane cross section elliptical fuel cell other than the inner membrane cross section fuel cell, the inner membrane cross section rectangular fuel cell, and the inner membrane cross section polygonal fuel cell are similarly configured. In any of these shapes, the porous reforming catalyst layer has a fuel flow path on the side opposite to the side where the surface layer, barrier layer, hydrogen separation / anode layer, electrolyte layer, and cathode layer are disposed, and the cathode layer The side becomes an oxidant gas flow path. That is, the oxidant gas channel on the cathode layer side is an oxidant gas channel referred to as “having an oxidant gas channel inside” in the reformer-integrated fuel cell of the present invention (3). The other points are the same as those in <Aspect Example 1: Cylindrical reformer-integrated fuel cell> in <Aspect of reformer-integrated fuel cell of the present invention (2)>.

<< Mode of Reformer-Integrated Fuel Cell of the Present Invention (4) >>
In the present invention (4), a porous reforming catalyst layer, a barrier layer, a hydrogen separation / anode layer, an electrolyte, and a cathode layer are sequentially laminated on an electrically insulating porous substrate tube having a fuel flow path therein. A plurality of power generating element portions having a layer structure are formed adjacent to each other, and any one of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe is formed on the barrier layer side of the porous reforming catalyst layer. A reformer provided with a surface layer containing one or more metals and Ln _1-x A _x MO _{3 and} having at least two adjacent power generating element portions electrically connected in series by an interconnector This is an integrated fuel cell.

The structure of each power generating element part in this embodiment is viewed as a layer structure: “Electrically insulating porous substrate tube having a fuel flow path therein—porous reforming catalyst layer—surface layer—barrier layer—hydrogen separation and anode layer A material containing at least one of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co and Fe and Ln _1-x A _x MO _3. It is formed with. The constituent materials of the electrically insulating porous substrate tube are (a) MgO, MgAl ₂ O ₄ , (b) stabilized zirconia, zirconia, (c) alumina, or (a), (b) and (c). A mixture of any two of them, a mixture of (a), (b) and (c), etc. are used.

  The shape of the electrically insulating porous substrate tube provided with the fuel flow path inside may be a hollow cross-section circular shape, a hollow cross-section elliptical shape, a hollow cross-section rectangular shape, or a hollow cross-section polygonal shape. . In the case of a hollow circular cross section, it can be said to be a hollow cylindrical shape, and in the case of a hollow cross sectional rectangular shape, it can be said to be a hollow plate shape. Since each layer is arranged in layers on an electrically insulating porous substrate tube having a fuel flow path therein, the reformer-integrated fuel cell of the present invention (4) has “with a fuel flow path inside. It is configured in a shape corresponding to the shape of “electrically insulating porous substrate tube”.

  This reformer-integrated fuel cell can be said to be a horizontal-striped fuel cell because the power generation element portions are arranged in a horizontal-striped manner. Further, in relation to the above-mentioned << embodiment of the reformer-integrated fuel cell of the present invention (1) >>, on the inner side of the porous reforming catalyst layer in the present invention (1), that is, on the opposite side to the position of the barrier layer. The difference is that an “electrically insulating porous substrate tube having a fuel flow path” is disposed therein.

  FIG. 8 is a diagram illustrating the reformer-integrated fuel cell. 8A is a plan view, FIGS. 8B to 8C are cross-sectional views taken along line AA in FIG. 8A, and FIG. 8D is a part of FIG. 8B taken out. FIG. Although FIG. 8 shows the case of a rectangular cross section, the same configuration is applied to a circular cross section, an elliptical cross section, and a polygonal cross section.

  As shown in FIG. 8, the porous reforming catalyst layer 1, the surface layer 1 ′, the barrier layer 2, the hydrogen separation / anode layer 3, the electrolyte layer 4, and the cathode layer 5 are sequentially disposed on the electrically insulating porous substrate tube SU. . Adjacent cells, that is, the porous catalyst layer 1 and the cathode layer 5 of the power generation element (power generation element portion) are electrically connected in series by the interconnector IN. The constituent material of the interconnector IN is the same as described above. In FIG. 8, the interconnector IN is disposed at the center in the width direction as illustrated in FIG. 8A, but may be disposed on one side of the width in the width direction or on the entire width in the width direction.

At the time of use as a fuel cell, as shown in FIG. 8D, fuel and water vapor are circulated on the electrically insulating porous substrate tube SU side, and oxidant gas is circulated on the cathode layer 5 side. The fuel and steam reach the porous reforming catalyst layer 1 through the holes of the electrically insulating porous substrate pipe SU, where the fuel is steam reformed, and only H ₂ in the reformed gas is separated into the hydrogen separation and anode layer 3. It flows through the electrolyte layer 4 and contributes to power generation. In addition, in FIG.8 (d), the flow of the electric current at the time of electric power generation is shown.

  The reformer-integrated fuel cells of the present invention (1) to (4) can be operated at a temperature of 550 to 650 ° C. This temperature is equivalent to the steam reforming temperature of the hydrocarbon fuel in the porous reforming catalyst layer. The reformer-integrated fuel cells of the present invention (1) to (4) are appropriately used in a heat insulating container or the like. At that time, the supply mechanism of fuel and water vapor to the porous reforming catalyst layer side (the electrically insulating porous substrate tube side in the present invention (4)), the derivation mechanism of the anode off gas, the oxidant gas to the cathode layer side A supply mechanism and a cathode off-gas lead-out mechanism are arranged.

  The fuel to be supplied to the porous reforming catalyst layer side (the electrically insulating porous substrate tube side in the present invention (4)) is city gas, natural gas, petroleum gas, gasoline, kerosene, and other various hydrocarbon fuels. Can be used. In the case of a fuel containing a sulfur compound such as city gas, it is desulfurized and supplied to the reforming catalyst layer side. An oxidant gas is supplied to the cathode layer side. As the oxidant gas, oxygen-enriched air, oxygen, and the like are used in addition to air.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail based on an Example, of course, this invention is not limited to these Examples. FIG. 9 is a diagram showing a manufacturing process of the flat reformer integrated fuel cell in Examples 1 to 5 among Examples 1 to 6.

<Example 1>
Nickel oxide powder and yttria-stabilized zirconia powder were mixed at a weight ratio of 6: 4, an organic binder was additionally mixed, and then formed into a sheet by sheet casting. Six sheets were laminated, passed through a degreasing step, and sintered at 1400 ° C. to obtain a porous reforming catalyst layer 1 of □ 22 mm × 1.2 mm thick. This is shown in FIG. The porous reforming catalyst layer 1 also serves as a support in the reformer-integrated fuel cell.

A mixed powder paste (molar ratio 5: 2: 3) of La _0.8 Ca _0.2 CrO ₃ , nickel oxide and yttria-stabilized zirconia is formed on the porous reforming catalyst layer 1 by heating, and heated to 1400 ° C. A surface layer 1 ′ was formed. This is shown in FIG. Since the surface layer 1 ′ contains nickel oxide, it also serves as a reforming catalyst. Nickel oxide is reduced to nickel during the operation of the reformer-integrated fuel cell and functions as a reforming catalyst.

La _0.8 Ca _0.2 CrO ₃ and yttria-stabilized zirconia mixed paste (molar ratio 8: 2) is formed on the porous reforming catalyst layer 1 as a barrier layer 2 by printing, and then heated to 1400 ° C. for baking. It was. This is shown in FIG. The barrier layer 2 is formed on the porous reforming catalyst layer 1 via the surface layer 1 ′. In the sample after baking, peeling of the barrier layer 2 was not observed. When this sample was evaluated for the adhesion of the barrier layer by a scratch test, it was peeled off at a load of 37N.

A 14 μm Pd film was formed on the barrier layer 2 as a hydrogen separation / anode layer 3 by plating. This is shown in FIG. A BaCe _0.8 Y _0.2 alkoxide solution was applied as an electrolyte layer 4 on the hydrogen separation / anode layer 3 by dip coating, dried, and calcined. The coating with an alkoxide solution and drying were repeated 10 times in total, and then fired at 1000 ° C. to form a BaCe _0.8 Y _0.2 O ₃ ± δ electrolyte membrane having a thickness of 1 μm. This is shown in FIG. As a cathode, a paste of La _0.6 Sr _0.4 CoO ₃ ± δ was formed by a printing method and baked at 900 ° C. Thus, a planar reformer integrated fuel cell was obtained. The fuel cell can be operated at 600 ° C. and temperatures around it.

  In Example 1, the adhesion between the porous reforming catalyst layer and the barrier layer was good, and the reformer integrated fuel cell could be produced without peeling off the barrier layer during production.

<Example 2>
In the same manner as in Example 1, a porous reforming catalyst layer of nickel oxide and yttria-stabilized zirconia having a square size of 22 mm and a thickness of 1.2 mm was obtained. A mixed powder paste (molar ratio 5: 2: 3) of La _0.8 Ca _0.2 CrO ₃ , nickel oxide and yttria-stabilized zirconia is formed on the porous reforming catalyst layer by heating, and heated to 1400 ° C. A layer was formed. Further, a La _0.8 Ca _0.2 CrO ₃ paste was formed as a barrier layer on the porous reforming catalyst layer by a printing method, and then baked by heating to 1400 ° C. In the sample after baking, peeling of the barrier layer was not observed. When this sample was evaluated for the adhesion of the barrier layer by a scratch test, it was peeled off at a load of 35N.

A 14 μm Pd film was formed on the barrier layer by a plating method as a hydrogen separation and anode layer. Next, a BaCe _0.8 Y _0.2 alkoxide solution was applied as an electrolyte layer on the hydrogen separation / anode layer, applied by dip coating, dried, and calcined. The coating film drying with the alkoxide solution was repeated a total of 10 times, followed by firing at 1000 ° C. to obtain a BaCe _0.8 Y _0.2 O ₃ ± δ electrolyte membrane having a thickness of 1 μm. Further, a paste of La _0.6 Sr _0.4 CoO ₃ ± δ was formed as a cathode by a printing method and baked at 900 ° C. to obtain a planar reformer integrated fuel cell.

  In Example 2, the adhesion between the porous reforming catalyst layer and the barrier layer was good, and the reformer integrated fuel cell could be produced without peeling off the barrier layer during production. The fuel cell can be operated at 600 ° C. and temperatures around it.

<Example 3>
In the same manner as in Example 1, a porous reforming catalyst layer / support of □ 22 mm × 1.2 mm thickness of nickel oxide and yttria stabilized zirconia was obtained. A mixed powder paste (molar ratio 6: 2: 2) of La _0.8 Ca _0.2 CrO ₃ , nickel oxide and yttria-stabilized zirconia is formed on the porous reforming catalyst layer by heating, and heated to 1400 ° C. A quality reforming catalyst layer surface layer was formed. Further, a La _0.8 Ca _0.2 CrO ₃ paste was formed as a barrier layer on the porous reforming catalyst layer by a printing method, and then baked by heating to 1400 ° C. In the sample after baking, peeling of the barrier layer was not observed. When this sample was evaluated for the adhesion of the barrier layer by a scratch test, it was not peeled up to a load of 32N.

A 14 μm Pd film was formed on the barrier layer by a plating method as a hydrogen separation and anode layer. Next, a BaCe _0.8 Y _0.2 alkoxide solution was applied as an electrolyte layer on the hydrogen separation / anode layer by dip coating, dried, and calcined. The coating film drying with the alkoxide solution was repeated a total of 10 times, followed by firing at 1000 ° C. to obtain a BaCe _0.8 Y _0.2 O ₃ ± δ electrolyte membrane having a thickness of 1 μm. Further, a paste of La _0.6 Sr _0.4 CoO ₃ ± δ was formed as a cathode by a printing method and baked at 900 ° C. to obtain a planar reformer integrated fuel cell.

  In Example 3, the adhesion between the porous reforming catalyst layer and the barrier layer was good, and the reformer integrated fuel cell could be produced without peeling off the barrier layer during production. The fuel cell can be operated at 600 ° C. and temperatures around it.

<Example 4>
In the same manner as in Example 1, a porous reforming catalyst layer of nickel oxide and yttria-stabilized zirconia having a square size of 22 mm and a thickness of 1.2 mm was obtained. A mixed powder paste of La _0.8 Ca _0.2 CrO ₃ , nickel oxide and yttria-stabilized zirconia (molar ratio 7: 1: 2) is formed on the porous reforming catalyst layer by a printing method, heated to 1400 ° C. and porous A quality reforming catalyst layer surface layer was formed. Furthermore, La _0.8 Ca _0.2 CrO ₃ and yttria-stabilized zirconia mixed paste (molar ratio 8: 2) were formed on the porous reforming catalyst layer by a printing method as a barrier layer, and then baked by heating to 1400 ° C. . In the sample after baking, peeling of the barrier layer was not observed. When this sample was evaluated for the adhesion of the barrier layer by a scratch test, it was not peeled up to a load of 30 N.

A 14 μm Pd film was formed on the barrier layer by a plating method as a hydrogen separation and anode layer. Next, a BaCe _0.8 Y _0.2 alkoxide solution was applied as an electrolyte layer on the hydrogen separation / anode layer by dip coating, dried, and calcined. The coating film drying with the alkoxide solution was repeated a total of 10 times, followed by firing at 1000 ° C. to obtain a BaCe _0.8 Y _0.2 O ₃ ± δ electrolyte membrane having a thickness of 1 μm. Further, a paste of La _0.6 Sr _0.4 CoO ₃ ± δ was formed as a cathode by a printing method and baked at 900 ° C. to obtain a planar reformer integrated fuel cell.

  In Example 4, the adhesion between the porous reforming catalyst layer and the barrier layer was good, and the reformer integrated fuel cell could be produced without peeling off the barrier layer during production. The fuel cell can be operated at 600 ° C. and temperatures around it.

<Example 5>
In the same manner as in Example 1, a porous reforming catalyst layer / support of □ 22 mm × 1.2 mm thickness of nickel oxide and yttria stabilized zirconia was obtained. A mixed powder paste (molar ratio 3: 4: 3) of La _0.8 Ca _0.2 CrO ₃ , nickel oxide and yttria-stabilized zirconia is formed on the porous reforming catalyst layer by heating, and heated to 1400 ° C. to be porous. A quality reforming catalyst layer surface layer was formed. Further, a mixed paste of La _0.8 Ca _0.2 CrO ₃ and yttria-stabilized zirconia (molar ratio 6: 4) was formed as a barrier layer on the porous reforming catalyst layer by printing, and then heated to 1400 ° C. and baked. It was. In the sample after baking, peeling of the barrier layer was not observed. When this sample was evaluated for the adhesion of the barrier layer by a scratch test, it was not peeled up to a load of 50N.

A 14 μm Pd film was formed on the barrier layer by a plating method as a hydrogen separation and anode layer. Next, a BaCe _0.8 Y _0.2 alkoxide solution was applied as an electrolyte layer on the hydrogen separation / anode layer by dip coating, dried, and calcined. The coating film drying with the alkoxide solution was repeated a total of 10 times, followed by baking at 1000 ° C. to form a BaCe _0.8 Y _0.2 O ₃ ± δ electrolyte membrane having a thickness of 1 μm. Further, a paste of La _0.6 Sr _0.4 CoO ₃ ± δ was formed as a cathode by a printing method and baked at 900 ° C. to obtain a planar reformer integrated fuel cell.

  In Example 5, the adhesion between the porous reforming catalyst layer and the barrier layer was good, and the reformer integrated fuel cell could be produced without peeling off the barrier layer during production. The fuel cell can be operated at 600 ° C. and temperatures around it.

<Example 6>
In the cylindrical tubular reformer integrated fuel cell of the present invention (2), a reformer integrated fuel cell having a cylindrical tube shape as shown in FIG. 4 was produced by the following method. Each powder of nickel oxide and yttria-stabilized zirconia and an organic binder were mixed, and then formed into a cylindrical tube shape by an extrusion method. This molded body was subjected to a degreasing step and then sintered at 1400 ° C. to obtain a porous reforming catalyst layer having an outer diameter of 10 mm, an inner diameter of 8 mm, and a length of 100 mm. The porous reforming catalyst layer also serves as a support in the reformer-integrated fuel cell.

On the porous reforming catalyst layer, a mixed powder slurry (molar ratio 5: 2: 3) of La _0.8 Ca _0.2 CrO ₃ , nickel oxide and yttria-stabilized zirconia is formed by dip coating, and heated to 1400 ° C. A surface layer was formed. Further, a mixed slurry of La _0.8 Ca _0.2 CrO ₃ and yttria-stabilized zirconia (molar ratio 8: 2) was formed as a barrier layer on the surface layer by dip coating, and then heated to 1400 ° C. to heat the surface layer and the barrier layer. Were baked at the same time. In the sample after baking, peeling of the barrier layer was not observed.

After the barrier layer was produced, a Pd film of 14 μm was formed on the barrier layer by plating as a hydrogen separation and anode. A BaCe _0.8 Y _0.2 alkoxide solution was used as an electrolyte layer on the hydrogen separation / anode layer, applied by dip coating, dried, and calcined. The coating film drying with the alkoxide solution was repeated a total of 10 times, followed by firing at 1000 ° C. to obtain a BaCe _0.8 Y _0.2 O ₃ ± δ electrolyte membrane having a thickness of 1 μm. Further, a slurry of La _0.6 Sr _0.4 CoO ₃ ± δ was formed as a cathode by a dip coating method and baked at 900 ° C. to obtain a reformer integrated fuel cell having a cylindrical tube shape.

  In Example 6, the adhesion between the porous reforming catalyst layer and the barrier layer was good, and the reformer integrated fuel cell could be produced without peeling off the barrier layer during production. The fuel cell can be operated at 600 ° C. and temperatures around it.

<Comparative example 1>
In the same manner as in Example 1, a porous reforming catalyst layer of nickel oxide and yttria-stabilized zirconia having a square size of 22 mm and a thickness of 1.2 mm was obtained. On the porous reforming catalyst layer, La _0.8 Ca _0.2 CrO ₃ and yttria-stabilized zirconia mixed paste (molar ratio 8: 2) are formed by a printing method as a barrier layer, and then heated to 1400 ° C. for baking. It was. In the sample after baking, there was a sample in which the barrier layer was peeled off. When this sample was subjected to a scratch test to evaluate the adhesion of the barrier layer, it was peeled off with a load of 22N.

<Comparative example 2>
In the same manner as in Example 1, a porous reforming catalyst layer of nickel oxide and yttria-stabilized zirconia having a square size of 22 mm and a thickness of 1.2 mm was obtained. On the porous reforming catalyst layer, a La _0.8 Ca _0.2 CrO ₃ paste was formed as a barrier layer by a printing method, and then heated to 1400 ° C. and simultaneously baked. In the samples after baking, the barrier layer was peeled off in most samples. When a scratch test was performed on this sample and the adhesion of the barrier layer was evaluated, the sample peeled off with a load of 10N.

  Table 1 summarizes the scratch test results of Examples 1 to 5 and Comparative Examples 1 and 2 described above. As shown in Table 1, it can be seen that in Examples 1 to 5, the load leading to peeling is much larger than in Comparative Examples 1 and 2, and the adhesion is improved.

The figure explaining the basic composition of the present invention The figure explaining the example of the aspect of the reformer integrated fuel cell of this invention (1) A diagram showing an aspect of stacking and stacking flat reformer integrated fuel cells The figure explaining the reformer integrated fuel cell of the present invention (2) The figure explaining the deformation | transformation aspect of <cylindrical reformer integrated fuel cell> among the reformer integrated fuel cells of this invention (2). The figure explaining the reformer integrated fuel cell of rectangular cross section among the reformer integrated fuel cells of the present invention (2) The figure explaining the reformer integrated fuel cell of the cross-section circular shape which has oxidant gas flow path SA inside which is a reformer integrated fuel cell of this invention (3). The figure explaining the reformer integrated fuel cell of the present invention (4) The figure which showed the preparation process of the flat reformer integrated fuel cell in Examples 1-5 Fuel cell equipped with hydrogen purification function for reformed gas, which is the supplied fuel gas (prior art)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Porous reforming catalyst layer which is 1st layer 1 'Surface layer 2 Barrier layer which is 2nd layer 3 Hydrogen separation and anode layer which is 3rd layer 4 Electrolyte layer which is 4th layer 5 5th The cathode layer that is the outermost layer (outermost layer) S The inner air channel (fuel channel) of the porous reforming catalyst layer 1
SA cathode layer 5 inner air channel (oxidant gas channel)
SE separator IN interconnector SU electrically insulating porous substrate 10 oxygen electrode 30 hydrogen electrode 40 electrolyte membrane 43 dense substrate 42, 44 electrolyte layer 45 made of solid oxide 45 Pd coating

Claims (12)

A fuel cell in which a fuel reformer and a fuel cell are integrated, wherein a barrier layer, a hydrogen separation / anode layer, an electrolyte layer, and a cathode layer are sequentially disposed on a porous reforming catalyst layer, One or more metals of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, Fe and Ln _1-x A _x MO ₃ (wherein Ln is a rare earth) on the barrier layer side of the reforming catalyst layer A surface layer including an element, A is at least one of Ba, Sr, and Ca, M is at least one of Cr and Ti, and the range of X is 0 ≦ X ≦ 1) A reformer-integrated fuel cell.   The reformer-integrated fuel cell according to claim 1, wherein the porous reforming catalyst layer has a flat plate shape. A fuel cell in which a fuel reformer and a fuel cell are integrated, and a barrier layer, a hydrogen separation / anode layer, an electrolyte layer, and a cathode layer are sequentially formed on the outer peripheral surface of a porous reforming catalyst layer having a fuel flow path therein. At least one of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, and Fe and Ln _1-x A _x on the barrier layer side of the porous reforming catalyst layer. MO ₃ (wherein Ln is a rare earth element, A is at least one of Ba, Sr, and Ca, M is at least one of Cr and Ti, and the range of X is 0 ≦ X ≦ 1. A reformer-integrated fuel cell, characterized in that a surface layer is provided.   4. The reformer-integrated fuel cell according to claim 3, wherein the porous reforming catalyst layer having a fuel flow path therein is any one of a cross-sectional circular shape, a cross-sectional elliptical shape, a cross-sectional rectangular shape, or a cross-sectional polygonal shape. A reformer-integrated fuel cell having a shape. A fuel cell in which a fuel reformer and a fuel cell are integrated, and has an oxidant gas flow path therein, and sequentially forms a barrier layer, a hydrogen separation / anode layer on the inner peripheral surface of the porous reforming catalyst layer, An electrolyte layer and a cathode layer are disposed, and one or more metals of Ni, Rh, Ru, Ir, Pd, Pt, Re, Co, Fe and Ln are formed on the barrier layer side of the porous reforming catalyst layer. _1-x A _x MO ₃ (wherein Ln is a rare earth element, A is at least one of Ba, Sr, and Ca, M is at least one of Cr and Ti, and the range of X is A reformer-integrated fuel cell, comprising a surface layer including 0 ≦ X ≦ 1.   6. The reformer-integrated fuel cell according to claim 5, wherein the porous reforming catalyst layer having an oxidant gas flow channel therein has any one of a circular cross-section, an elliptical cross-section, a rectangular cross-section, or a polygonal cross-section. A reformer-integrated fuel cell characterized by the above. A fuel cell in which a fuel reformer and a fuel cell are integrated, and a porous reforming catalyst layer, a barrier layer, and a hydrogen separator are sequentially formed on an electrically insulating porous substrate tube having a fuel flow path therein. A plurality of power generating element portions having a layer structure in which an anode layer, an electrolyte, and a cathode layer are laminated are formed adjacent to each other, and Ni, Rh, Ru, Ir, Pd, Pt are formed on the barrier layer side of the porous reforming catalyst layer. , Re, Co, Fe and one or more metals and Ln _1-x A _x MO ₃ (wherein Ln is a rare earth element, A is one or more of Ba, Sr, Ca, M is A surface layer including at least one of Cr and Ti, and the range of X is 0 ≦ X ≦ 1, and at least two adjacent power generation element portions are electrically connected by an interconnector. Integrated reformer characterized by being connected in series Fuel cell.   The reformer-integrated fuel cell according to claim 7, wherein the electrically insulating porous substrate tube has a hollow plate shape or a hollow cylindrical shape.   The reformer-integrated fuel cell according to any one of claims 1 to 8, wherein a constituent material of the porous reforming catalyst layer is a sintered body mainly composed of a mixture of nickel and stabilized zirconia, porous A reformer-integrated fuel cell, characterized by being a porous ceramic or a porous cermet. The reformer-integrated fuel cell according to any one of claims 1 to 8, wherein the constituent material of the barrier layer is any one or more of stabilized zirconia, partially stabilized zirconia, zirconia, alumina, and magnesia. And Ln _1-x A _x MO ₃ (wherein Ln is a rare earth element, A is at least one of Ba, Sr, and Ca, M is at least one of Cr and Ti, A reformer-integrated fuel cell, wherein the range is 0 ≦ X ≦ 1) or a compound.   The reformer-integrated fuel cell according to any one of claims 1 to 8, wherein the constituent material of the hydrogen separation / anode layer is a Pd film, a Pd alloy film, a group 5 metal (V, Nb, Ta). A reformer-integrated fuel cell comprising: a film, a group 5 metal alloy film, or a multilayer film of a group 5 metal film or a group 5 metal alloy film and a Pd film or a Pd alloy film. The reformer-integrated fuel cell according to any one of claims 1 to 8, wherein the constituent material of the electrolyte layer is a formula: ABO ₃ (where A is any one of Ba, Sr, and Ca). And B is at least one of Ce and Zr, and Ce and Zr at the B site may be partially substituted with rare earth elements). A reformer-integrated fuel cell.

Images