JP5117769B2 - REACTOR AND METHOD FOR PRODUCING REACTOR - Google Patents

Description

The present invention relates to a reactor and a method for producing the reactor.

In recent years, as a clean power source with high energy conversion efficiency, fuel cells that generate electric energy by electrochemical reaction of hydrogen have begun to be applied to automobiles and portable electronic devices. Since hydrogen used as fuel is a gas at normal temperature and normal pressure, if it is stored as it is, the amount of storage per unit volume is not sufficient and there is a problem in the storage method. This is stored as a compound containing hydrogen atoms in the composition of alcohol, hydrocarbons, etc., and by reacting the stored alcohol, hydrocarbons, etc. in the presence of a catalyst, a gas containing hydrogen as a main component is generated. It is preferable to supply the gas as a component to the fuel cell.
As a small chemical reaction device for supplying hydrogen to such a fuel cell, a fine reaction channel is formed by a substrate typified by silicon or glass, and a small-scale chemical reaction device is formed on the basis of an aqueous methanol solution or the like in the channel. There are devices called reformers that cause chemical reactions. Including such a small reformer, a reactor capable of controlling the concentration and temperature more precisely than before by performing the reaction in a minute space having a large surface area per volume is called a microreactor. In order to obtain a large amount of reaction products, the microreactor does not scale up the reaction vessel like a conventional chemical plant. It is considered.

As an example of a power generation system, for example, power generation fuel such as methanol in a fuel container is vaporized by a vaporizer, and the vaporized power generation fuel is reformed by hydrogen gas, carbon dioxide, and carbon monoxide by a reformer. The carbon monoxide in the reformed reformed gas is removed (reduced in concentration) by the carbon monoxide remover, and the hydrogen gas after carbon monoxide removal is used as a fuel cell (power generation cell). To supply. In a fuel cell, hydrogen and oxygen are converted into electrical energy. However, if all hydrogen is allowed to stay in the hydrogen electrode where hydrogen is introduced until it causes an electrochemical reaction, the hydrogen concentration will continue to be extremely low for a long time. Therefore, about 70% of the hydrogen in the reformed gas is converted into electric energy, and the remaining hydrogen is burned by reaction with oxygen in the air in a catalytic combustor to convert it into heat energy. The reformer and the carbon monoxide remover are heated and used for reaction heat for reforming so that a predetermined chemical reaction proceeds.
Here, a catalyst, which is an important functional substance for advancing a chemical reaction, is formed in the fine reaction channel described above, and the above-described chemical reaction is efficiently advanced. For example, Cu / ZnO, Pd / ZnO, etc. are used as a catalyst used for the steam reforming reaction (refer to the following chemical reaction formula (1)) to obtain hydrogen and carbon dioxide by reacting methanol fuel with water. Can be mentioned.
CH ₃ OH + H ₂ O → 3H ₂ + CO ₂ (1)

  By the way, in order to produce hydrogen from methanol fuel using the catalyst described above, a high temperature of about 300 ° C. is necessary. For this purpose, a reformer, a carbon monoxide remover, and a catalyst combustor are installed in a vacuum heat insulating container. The housing reduces heat loss, and the reaction heat for reforming is supplemented by heat generated by catalytic combustion as described above. At this time, the heat transfer from the catalytic combustor to the reformer is an important factor for efficiently producing hydrogen, and in addition, the pressure loss generated when the reactants pass through the fine reaction channel is reduced. Therefore, a plate type that is directly fixed to the channel wall surface is more suitable as a catalyst form on the reaction flow path than a general granular packing type. Such a plate-type catalyst needs to have a surface area of a catalyst with higher reaction efficiency as large as possible and be firmly fixed in a limited space.

Therefore, as an example of a plate-type catalyst, there is a monolith catalyst in which a catalytic active species is supported on a cylindrical catalyst support having a honeycomb-like hole used for purifying exhaust gas of automobiles. As an example of examining the improvement in adhesion to such a plate-type catalyst, the slurry powder is coated on the surface of a porous metal substrate having a three-dimensional network structure, and then the catalyst powder is fixed by applying a sintering treatment. A supporting method is known (for example, see Patent Document 1).
In addition, there is a method in which an oxide precursor prepared using a sol-gel method is mixed with the above slurry liquid in order to increase the catalyst adhesion strength of the plate-type catalyst. The oxide formed by the sintering process after coating functions to increase the adhesion strength between the catalyst powder and the catalyst support. A typical example of the sol-gel method is a method of forming alumina from a solution containing a colloid generated by hydrolysis of aluminum alkoxide.
JP-A-2005-007298

However, the conventional plate-type catalyst and the manufacturing method thereof have the following problems. First, in order to ensure the adhesion strength between the catalyst layer and the catalyst support, a catalyst support that has been subjected to a special treatment such as a three-dimensional network structure is required, and the man-hours and costs for such treatment are reduced. There is a problem that it takes. Alternatively, it is necessary to improve the adhesion strength by providing a layer of a metal oxide thin film having a high affinity with the catalyst material in advance on the catalyst support. Specifically, there are methods such as the formation of ceramics such as cordierite and mullite on the plate support, and the formation of oxide sol films by hydrolysis of alkoxides. Man-hours and costs are required.
The present invention has been made in view of the above circumstances, and its object is to provide a manufacturing method of the reactor and the reactor can be facilitated improved adhesion strength to the support.

In order to solve the above-mentioned problems, a reactor according to the invention of claim 1 is a reactor that causes a reforming reaction of alcohol, and is formed of a support, and formed on the support , contains ZnO, and is a porous catalyst . a certain matrix film, and the catalyst particles are arranged dispersed in the matrix layer containing a contributing Pd / ZnO in the reforming reaction, and the composite catalyst layer containing, characterized in that Ru comprising a.
Before SL composite catalyst layer is preferably polycrystalline.
It is preferable that the crystal lattice diameter of the catalyst particles of the composite catalyst layer is substantially equal to the pore diameter of the base film that is the porous catalyst .
The reactor may further include an intermediate layer formed between the support and the composite catalyst layer, and the intermediate layer may be made of the same material as the base film.
As a manufacturing method of the reactor for manufacturing these reactors,
The composite catalyst layer may be formed by applying a catalyst solution in which the catalyst material is dispersed in a solution of the material to be the base film on the support, and then performing a calcination treatment.
Alternatively, an intermediate layer is formed by applying a solution having a material to be an intermediate layer on the support, the catalyst solution is applied to the intermediate layer, and then subjected to a firing treatment, and the composite catalyst layer is applied to the intermediate layer. It may be formed on the layer.

  According to the present invention, the adhesion strength to the support can be improved without impairing the characteristics of the particulate catalyst.

The best mode for carrying out the present invention will be described below with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.
FIG. 1 is a schematic cross-sectional side view of a support 101 such as Fe—Cr—Al stainless steel on which a composite catalyst layer 102 is formed.
<Composite catalyst layer>
The composite catalyst layer 102 is formed on the support 101, is a substantially particulate dispersoid, and includes a catalyst 103 that contributes to the reaction, and a base film 104 that is a dispersion medium. The catalyst 103 preferably contains Pd, such as a Pd / ZnO catalyst. The base film 104 preferably contains zinc, for example, a ZnO catalyst.
The film-like zinc oxide base film 104 is used as a binder for the catalyst 103. By subjecting the Fe-Cr-Al stainless steel to heat treatment at a temperature of about 1000 ° C., irregularities of alumina are formed on the surface, but when the catalyst layer 102 is formed, the liquid base film 104 is used as a dispersion medium. An anchor effect on the irregularities of alumina formed on Fe-Cr-Al stainless steel can be expected. Therefore, it is possible to prevent peeling or cracking that occurs as compared with the case where the Pd / ZnO catalyst is directly formed on the support 101.
The composite catalyst layer 102 composed of the catalyst 103 and the base film 104 is polycrystalline, and has a crystallite diameter of about 17 nm and pores of about 17 to 20 nm. Since the composite catalyst layer 102 is a porous body, when viewed microscopically, fine irregularities are formed on the surface, so that the surface area is large. The film thickness of the composite catalyst layer 102 is preferably 10 μm to 150 μm. This is because when the thickness is smaller than 10 μm, the catalytic function is low, and when the thickness is larger than 150 μm, the composite catalyst layer 102 is easily peeled off from the support 101.
Examples of the support 101 include stainless steel, glass, or plastic other than those described above.

FIG. 2 is a flowchart showing a method for adjusting a zinc acetate solution, FIGS. 3 and 4 are flowcharts showing a method for adjusting a Pd / ZnO catalyst as the catalyst 103, and FIG. 5 shows a method for adjusting a catalyst solution. It is a flowchart.
Next, a method for producing the composite catalyst layer 102 will be described.
(1) Zinc acetate solution As shown in FIG. 2, a zinc acetate solution is prepared. In this embodiment, a sol-gel method in which zinc hydroxide, which is a precursor of zinc oxide, is formed by hydrolysis of zinc acetate is used for forming the zinc oxide film. Zinc acetate hydrolysis starts by adding a substance that extracts protons in water, but when water is used as a solvent, gelation starts immediately after addition of a substance having proton-extracting action (for example, ammonia). In this example, the solvent is alcohol, specifically 2-methoxyethanol, and monoethanolamine is used as a proton extracting material (reaction initiator).

(2) Pd / ZnO catalyst Next, a Pd / ZnO catalyst is prepared using a coprecipitation method. As a starting material, a mixed solution of palladium and zinc can be used. For example, a mixed solution of palladium nitrate and zinc nitrate can be used. Note that the content (supported amount) of paradium in the catalyst can be adjusted by the starting material. If palladium in the catalyst is present in an amount of about 3% by weight, a steam reforming reaction that sufficiently generates hydrogen can occur, but if it is contained in an amount of about 8-22% by weight, hydrogen can be generated more effectively. .
As the precipitant, an aqueous sodium carbonate solution can be used, and in addition, a basic aqueous solution such as sodium hydrogen carbonate, sodium hydroxide, sodium citrate, ammonia or the like can be used.
And by mixing a precipitant with a starting material, palladium precipitates with the zinc hydroxide which is a coprecipitation support | carrier. As this method, as shown in FIG. 3, a simultaneous dropping method in which the starting material and the precipitating agent are simultaneously dropped into a solvent such as distilled water, and as shown in FIG. 4, the precipitating agent is directly dropped into the starting material. There are two methods of dropping the precipitant.
(A) Simultaneous dripping method A solution of a starting material and a solution of a precipitant are simultaneously dropped into distilled water. Since the starting material solution is acidic and the precipitant solution is basic, the pH of the mixed solution varies as the two solutions are added dropwise. At this time, it is preferable to form a precipitate while maintaining the pH of the mixed solution at 6.5 to 8.5.
(B) Precipitating agent dropping method The precipitation agent solution is gradually added dropwise to the starting material solution. Heat of neutralization is generated by mixing the starting material solution and the precipitant solution. At this time, the temperature of the mixed solution is preferably maintained at 20 to 60 ° C, and more preferably maintained at 30 to 50 ° C.
The precipitate formed by either the simultaneous dropping method or the precipitating agent dropping method is filtered to obtain a precipitate. Distilled water is added to the precipitate and stirred, and the washing process of filtering again is repeated several times to dry the precipitate after the last filtration.
A calcination treatment is performed on the dried precipitate. By firing, the zinc hydroxide becomes zinc oxide. Calcination can be performed, for example, by placing the precipitate in an inert gas atmosphere such as nitrogen at 500 ° C. or more for 1 hour.
As described above, a Pd / ZnO catalyst is obtained.

(3) Catalyst Solution Next, as shown in FIG. 5, after mixing a Pd / ZnO catalyst and hydroxyethyl cellulose (HEC) as a thickener to obtain a mixed powder, this mixed powder is used as a mother liquor zinc acetate. Disperse in the solution, and drop the zinc acetate solution appropriately for viscosity adjustment. Further, a catalyst solution is prepared by mixing polyethylene glycol (PEG) as a dispersant.

  Thereafter, the support is immersed in the catalyst solution, and then the immersed support is pulled up, dried at room temperature, and then fired in an air stream. The firing temperature is preferably about 500 ° C. In this way, a composite catalyst layer is formed on the support. Moreover, formation of a composite catalyst layer can also be performed by application | coating or inflow of the catalyst solution on a support body so that it may mention later.

《Reactor》
Next, the reactor 1 using the support 101 and the composite catalyst layer 102 will be described. 6 is a perspective view showing the front, side, and plane of the reactor 1, and FIG. 7 is a cross-sectional view taken along the cutting line VII-VII in FIG.
The reactor 1 includes a flow path substrate 10 and a lid substrate 20 provided on the upper portion of the flow path substrate 10.

8 is a top view of the flow path substrate 10, FIG. 9 is a cross-sectional view taken along the cutting line VIIII-VIIII in FIG. 8, and FIG. 10 is a bottom view of the flow path substrate 10. As the flow path substrate 10, for example, a stainless steel substrate, a glass substrate, a silicon substrate, a ceramic substrate, or the like can be used. A meandering groove 11 is formed on the upper surface of the flow path substrate 10. On the inner wall surface of the groove 11, a composite catalyst layer 102 having a substantially particulate reaction catalyst 103 made of Pd / ZnO of the present invention and a base film 104 made of a film-like zinc oxide covering the reaction catalyst 103 inside. Is coated. At this time, since the base film 104 is porous, a part of the surface of the reaction catalyst 103 is exposed to the outside. The groove 11 becomes a reaction flow path by being covered with the lid substrate 20. Note that a groove may be formed in the lid substrate 20 as well as the flow path substrate 10.
Further, a thin film heater 13 made of a twisted electric resistor is formed on the lower surface of the flow path substrate 10. The thin film heater 13 serves as a heat source during a reforming reaction that is an endothermic reaction when a voltage is applied, and is also used during firing of the composite catalyst layer 102 and a support layer described later.

11 is a top view of the lid substrate 20, and FIG. 12 is a cross-sectional view taken along the line XII-XII in FIG. The lid substrate 20 is provided with introduction holes 21 and discharge holes 22 penetrating in the thickness direction at positions corresponding to both ends of the groove 11 of the flow path substrate 10. The introduction hole 21 guides the reactant from the vaporizer 203 to the reaction flow path, and the discharge hole 22 discharges the product from the reaction flow path facing the groove 11 and the lid substrate 20 facing the groove 11, thereby removing the carbon monoxide remover. Guide to 205.
As the lid substrate 20, for example, a stainless steel substrate, a glass substrate, a silicon substrate, a ceramic substrate, or the like can be used.

Next, the manufacturing method of the reactor 1 is demonstrated. The reactor 1 can be manufactured by, for example, the following three types of manufacturing methods. Hereinafter, three types of manufacturing methods will be described with reference to FIGS.
<First manufacturing method>
As shown in FIG. 13, a dry film photoresist 30 is pasted on the surface of the flow path substrate 10 (FIG. 13A) in which the grooves 11 are formed in a predetermined shape by sandblasting or the like in advance. It is attached (FIG. 13 (b)). Next, the portion corresponding to the groove 11 of the dry film photoresist 30 is removed by photolithography (FIG. 13C).

  Next, the upper surface of the flow path substrate 10 is coated with a catalyst solution 102a to be a composite catalyst layer 102 made of a Pd / ZnO catalyst and a film-like zinc oxide (FIG. 13 (d)).

When the coated catalyst solution 102a is dried, the dry film photoresist 30 is peeled off from the flow path substrate 10 using a peeling (peeling) method (FIG. 13 (e)). The dried catalyst layer on the dry film photoresist 30 is lifted off together with the dry film photoresist 30 leaving a catalyst layer adhering to the surface of the groove 11. After peeling, if necessary, a slight residue (scum) of the dry film photoresist 30 left by the peeling method is removed by plasma ashing (discum), and then the catalyst layer is baked.
Thereafter, the lid substrate 20 is bonded to the upper surface of the flow path substrate 10 (FIG. 13 (f)). The flow path substrate 10 and the lid substrate 20 can be bonded by, for example, a bonding method such as anodic bonding or brazing.

  Thus, the reactor 1 is formed. The thin film heater may be provided on the outer surface of the flow path substrate 10 or the lid substrate 20 after the step of FIG. 13 (e) or after the step of FIG. 13 (f). Further, a groove may be provided on the surface of the lid substrate 20 facing the groove 11, a support layer may be formed on the surface of the lid substrate 20 facing the groove 11, and the surface of the lid substrate 20 facing the groove 11. Alternatively, the composite catalyst layer 102 may be formed.

<Second production method>
As shown in FIG. 14, the dry film photoresist 30 is affixed on the upper surface of the flow path substrate 10 in which the groove 11 is not yet formed (FIG. 14 (a)). Next, the dry film photoresist 30 at a position corresponding to a portion where the groove 11 of the flow path substrate 10 is formed is removed by photolithography (FIG. 14B). Next, the grooves 11 are formed in the flow path substrate 10 by a sandblast method, a chemical etching method, or the like.
Thereafter, the reactor 1 is formed in the same manner as in the first production method (FIGS. 14 (d), (e), (f)).

<Third production method>
As shown in FIG. 15, the lid substrate 20 is bonded to the surface of the flow path substrate 10 (FIG. 15A) in which the grooves 11 are formed in advance (FIG. 15B). The flow path substrate 10 and the lid substrate 20 can be bonded by a bonding method such as anodic bonding.

  Next, the above-described catalyst solution 102a is caused to flow from the introduction hole 21 or the discharge hole 22 into the flow path formed by joining the flow path substrate 10 and the lid substrate 20 (FIG. 15 (c)).

  Next, the flow path substrate 10 and the lid substrate 20 are placed in a manufacturing apparatus furnace, and the furnace is heated or heat treatment is performed by heat generated by the thin film heater 13, and the metal oxide precursor is baked to form a metal oxide. To do.

  When the catalyst solution 102a is caused to flow into the flow path, the catalyst solution 102a is dried and fired (FIG. 15 (d)). At least one of the drying and baking is achieved by placing the flow path substrate 10 and the lid substrate 20 in the production apparatus furnace and heating the inside of the furnace or performing heat treatment by heat generation of the thin film heater 13. Thus, the composite catalyst layer 102 is formed, and the reactor 1 is formed.

When the reactor 1 is heated to 250 to 400 ° C. by the thin film heater 13 and a mixture of fuel such as methanol, water, and an oxidizing agent such as oxygen and hydrogen peroxide is introduced from the introduction hole 21, Reactions represented by the following chemical reaction formulas (2) and (3) occur, and hydrogen gas, carbon dioxide gas and the like are discharged from the discharge hole 22.
CH ₃ OH + H ₂ O → 3H ₂ + CO ₂ (2)
CH ₃ OH + 1/2 · O ₂ → 2H ₂ + CO ₂ (3)

A combustor for heating the reactor 1 may be provided adjacent to the reactor 1. The combustor can be provided in the same manner as the reactor 1 by forming a layer of a combustion catalyst such as Pt / Al ₂ O _{3 in} the flow path. In this case, heat can be efficiently generated by introducing the hydrogen generated in the reactor 1 after being supplied to the fuel cell as the fuel for the combustor.

<< Power generation equipment >>
Next, the power generator 200 using the reactor 1 will be described.
FIG. 16 is a block diagram of the power generation device 200. The power generation device 200 is provided in a notebook personal computer, a mobile phone, a PDA (Personal Digital Assistant), an electronic notebook, a wristwatch, a digital still camera, a digital video camera, a game device, a game machine, and other electronic devices. Yes, it is used as a power source for operating the electronic device main body 210.

The power generation apparatus 200 is supplied from a fuel container 201 that stores fuel such as methanol and water separately or in a mixed state, a vaporizer 202 that vaporizes the fuel and water supplied from the fuel container 201, and the vaporizer 202. A reformer (reactor) 203 for generating hydrogen from the mixed gas of fuel and water by the above chemical reaction formula (3), and carbon monoxide as a by-product in the mixture supplied from the reformer 203 The carbon monoxide remover 204 that removes carbon monoxide from the air-fuel mixture by oxidation as shown in the following chemical reaction formula (4), and the hydrogen gas and the outside air out of the air-fuel mixture supplied from the carbon monoxide remover 204 A power generation cell 205 that generates electric energy by an electrochemical reaction with oxygen gas, and a combustion catalyst that heats the reformer 203 and sets the temperature to a temperature necessary for satisfactorily performing the reaction of the chemical reaction formula (3). Established And it comprises a catalytic combustor 206, the outside air of the air pump (not shown) for supplying the sucked air into the carbon monoxide remover 204, and fuel cell type power generation cell 205 sucks the air or the like.
2CO + O ₂ → 2CO ₂ (4)

  The above reactor 1 can be used as the reformer 203 in which the reaction represented by the chemical reaction formula (3) occurs.

  As the fuel stored in the fuel container 201, an organic compound containing hydrogen atoms in the composition of alcohols such as ethanol, ethers such as dimethyl ether, gasoline, or the like can be used instead of methanol.

Although not shown, the power generation cell 205 includes a fuel electrode carrying catalyst fine particles, an air electrode carrying catalyst fine particles, a film-like solid polymer electrolyte membrane interposed between the fuel electrode and the air electrode, It has. A mixture of products is supplied from the carbon monoxide remover 204 to the fuel electrode of the power generation cell 205, and air is supplied from an air pump to the air electrode of the power generation cell 205. At the fuel electrode, as shown in the electrochemical reaction formula (5), hydrogen in the gas mixture is separated into hydrogen ions and electrons by the action of the catalyst particles of the fuel electrode. Hydrogen ions are conducted to the oxygen electrode through the solid polymer electrolyte membrane, and electrons are taken out by the fuel electrode. In the oxygen electrode, as shown in the electrochemical reaction formula (6), hydrogen ions that have passed through the solid polymer electrolyte membrane, electrons that have moved from the fuel electrode to the oxygen electrode through an external circuit, and oxygen in the air are Reaction produces water. The movement of electrons at this time becomes electric energy. On the fuel electrode side, a large amount of unreacted hydrogen is sent to the catalytic combustor 206 as off-gas and burned, and used as energy for the reforming reaction.
H ₂ → 2H ⁺ + 2e ⁻ (5)
2H ⁺ + 1 / 2O ₂ + 2e ⁻ → H ₂ O (6)

As shown in FIG. 16, the power generation apparatus 200 includes a DC / DC converter 207 that converts electrical energy generated by the power generation cell 205 into an appropriate voltage, and a secondary battery 208 that is connected to the DC / DC converter 207. And a control unit 209 for controlling them.
The DC / DC converter 207 converts the electric energy generated by the power generation cell 205 into an appropriate voltage and then supplies the electric energy to the electronic device main body 210. In addition, the DC / DC converter 207 converts the electric energy generated by the power generation cell 205 into the secondary battery 208. When the power generation cell 205 side is not operated, the electronic device main body 220 can also function to supply electric energy from the secondary battery 208 side. The controller 209 includes a vaporizer 202, a reformer 203, a carbon monoxide remover 204, a catalytic combustor 206, pumps and valves (not shown) necessary for operating the power generation cell 205, heaters, DC / DC Control is performed so that electric energy is stably supplied to the electronic device main body 210 by controlling the converter 207 and the like.

As described above, since the composite catalyst layer 102 includes the substantially particulate catalyst 103 and the base film 104 that is a layered porous body, the base film 104 acts as a binder of the catalyst 103, whereby the catalyst 103 Adhesive strength is improved as compared with a single body, and it is possible to reliably adhere to a support having a smooth surface. In addition, since the catalyst 103, which is a Pd / ZnO catalyst having better catalytic characteristics than the ZnO film that is the material of the base film 104, is contained compared to the single body that is the base film 104, the reaction rate can be improved. It becomes possible.
In addition, in order to improve the adhesion strength, when forming a plate-type catalyst for methanol reforming using the sol-gel method described above, if alumina that can be easily adjusted by the alkoxide method is used, the catalyst There was a possibility that the acid property of the alumina formed in the layer acted to produce ether by dehydration reaction of methanol, and this ether hindered the methanol reforming reaction. On the other hand, in the configuration of the material of the composite catalyst layer 102, alumina is not used as the support, and therefore, the catalytic reaction expected when alumina is used does not occur and the performance of the Pd / ZnO catalyst can be exhibited. Excellent reaction efficiency.
In particular, in the sol-gel method using zinc acetate as a starting material as a catalyst solution, in addition to the fact that the storage stability of the catalyst solution is high by using an alcohol as the solvent, an industrially stable catalyst layer can be formed. The thickness of the catalyst layer can be controlled by adding additives such as thickeners and dispersants.

[Modification]
FIG. 17 is a schematic side view showing a modification in which an intermediate layer 107 is formed between the support 101 and the composite catalyst layer 102.
As shown in FIG. 17, by providing a ZnO film as the intermediate layer 107 between the support 101 and the composite catalyst layer 102, the adhesion strength of the composite catalyst layer 102 to the support 101 can be further increased. The ZnO film of the intermediate layer 107 is obtained by coating and baking a zinc salt solution, for example, the above-described zinc acetate solution on the support 101 similar to the above-described support 101, and further, on this ZnO film, The composite catalyst layer 102 described above is formed by coating and baking the above-described catalyst solution.
Although the reactor 1 has a structure including the groove 11, the present invention is not limited thereto, and a wall for partitioning the flow path is formed in the internal space of the reactor 1, and the composite catalyst layer 102 is formed on the surface of this wall. Good.

  Hereinafter, the present invention will be described in more detail with reference to examples.

(Invention Example 1)
According to the flowchart shown in FIG. 2, by adding 0.2 to 0.3 ml of monoethanolamine as a proton extractant and 8 to 10 ml of 2-methoxyethanol as a solvent to 1 g of zinc acetate dihydrate, hydrolysis of zinc acetate is performed. A zinc acetate solution was prepared.
Next, a Pd / ZnO catalyst was prepared using the coprecipitation method described above. An aqueous solution of palladium nitrate having a palladium content of 50 g / L and zinc nitrate hexahydrate were mixed with 100 ml of distilled water to obtain a mixed solution. A mixed solution of zinc nitrate / hexahydrate and palladium nitrate was adjusted so that the content of palladium in the obtained catalyst was 15% by weight. Moreover, 0.76 mol / L sodium carbonate aqueous solution was produced as a precipitant. Then, while maintaining the temperature at 40 ° C., a mixed solution of zinc nitrate hexahydrate and palladium nitrate and a precipitating agent were simultaneously added dropwise to produce a precipitate. A precipitate was formed while maintaining the pH of the mixed solution after dropping at 7.3 to 7.7. Thereafter, stirring was continued for 1 hour, and the mixture was allowed to stand for 12 hours, followed by filtration.
Next, the washing process of adding distilled water to the filtrate, stirring at 40 ° C. for 20 minutes, and performing filtration again was repeated three times. The precipitate obtained after the fourth filtration was dried at 100 ° C. for 12 hours, and then subjected to a calcination treatment at 500 ° C. for 1 hour in an N ₂ stream to obtain a Pd / ZnO catalyst.
Next, 0.1 g of hydroxyethyl cellulose (HEC) as a thickener is added to 1 g of Pd / ZnO catalyst to obtain a mixed powder. The mixed powder is added to 15 to 20 g of the zinc acetate solution as the mother liquor, and the zinc acetate solution is further added. 3-5g was dripped. At this time, 0.5 g of polyethylene glycol (PEG) was added and mixed as a dispersant to prepare a catalyst solution.
Thereafter, the stainless steel substrate was immersed in the catalyst solution, and the immersed stainless steel substrate was pulled up and dried at room temperature, followed by firing at 500 ° C. in an air stream. In this way, a composite catalyst layer having a thickness of about 50 μm was formed.

(Comparative example)
As a comparative example, a Pd / ZnO catalyst prepared by using a coprecipitation method in the same manner as the present invention described above and pelletized to a size of 0.5 mm to 1.0 mm was used.

表１及び図１８の結果より、比較例の触媒（Ｐｄ／ＺｎＯ触媒単身）の性能と比較して本発明例１の複合触媒層は、触媒重量当たりのメタノール反応速度がほぼ同じ値であり、特に３５０℃〜４００℃では若干転化率が向上した。したがって、本発明例１で用いた複合触媒層中のＺｎＯ膜はＰｄ／ＺｎＯ触媒の性能を阻害することなく触媒付着強度を向上させる効果があることが認められる。 Next, the adhesion strength and catalytic activity of the catalysts layer formed on the support was evaluated by the following methods.
(Adhesion strength)
To evaluate the adhesion strength of the prepared catalysts layers were air blow test. Using an air nozzle on one side of the Pd / ZnO catalyst film, compressed air of about 0.5 MPa from a height of 5 cm was blown for 10 seconds, and the weight of the catalyst before and after blowing was measured.
As a result, while the lack of the catalyst layer was visible in the comparative example, the weight reduction rate of the composite catalyst layer of Example 1 of the present invention was hardly reduced to 1.36 to 1.87%.
(Catalytic activity)
An oxidative steam reforming reaction using methanol, water, and oxygen as raw materials was performed using the prepared composite catalyst layer and the catalyst of the comparative example. Specifically, a mixed solution of methanol and water was passed through the prepared catalyst under the condition of GHSV (Gas Hourly Space Velocity) = 100000 / h. The mixing ratio of methanol and water was 1: 2 (molar ratio). The reaction temperature was maintained at 250 ° C., 300 ° C., 350 ° C., and 400 ° C., the methanol flow rate at the outlet of the reactor was measured, and the methanol conversion per catalyst weight was calculated. The relationship between the methanol conversion reaction temperature and the methanol conversion rate is shown in Table 1 and FIG.

From the results of Table 1 and FIG. 18, the composite catalyst layer of Example 1 of the present invention has substantially the same methanol reaction rate per catalyst weight as compared with the performance of the catalyst of the comparative example (Pd / ZnO catalyst alone), In particular, the conversion rate slightly improved at 350 ° C to 400 ° C. Therefore, it is recognized that the ZnO film in the composite catalyst layer used in Example 1 of the present invention has an effect of improving the catalyst adhesion strength without hindering the performance of the Pd / ZnO catalyst.

(Invention Example 2)
A zinc acetate solution and a Pd / ZnO catalyst were prepared in the same manner as in the above-mentioned Invention Example 1, and further a catalyst solution was prepared from a zinc acetate solution, a Pd / ZnO catalyst, a thickener and a dispersing agent. Next, the stainless steel substrate was immersed in a zinc acetate solution, dried and fired, and further immersed in a catalyst solution, followed by drying and firing. In this way, an intermediate layer and a composite catalyst layer were formed on the support. In this way, a composite catalyst layer having a thickness of about 50 μm and an intermediate layer having a thickness of about 2 μm were formed.
In the present invention example 1 in which no intermediate layer is provided and in the present invention example 2 in which an intermediate layer is provided, the surface of the composite catalyst layer is evaluated by a scanning electron microscope. In Example 1), cracks that did not cause separation of the composite catalyst layer occurred in some places, whereas in the composite catalyst layer (Invention Example 2) provided with an intermediate layer, the occurrence of cracks was suppressed. It was confirmed that

It is a schematic sectional side view of the support body 101 in which the composite catalyst layer 102 was formed. It is the flowchart which showed the adjustment method of a zinc acetate solution. It is the flowchart which showed the adjustment method of a Pd / ZnO catalyst. It is the flowchart which showed the adjustment method of a Pd / ZnO catalyst. It is the flowchart which showed the adjustment method of a catalyst solution. 2 is a perspective view showing the front, side, and plane of the reactor 1. FIG. It is arrow sectional drawing at the time of cut | disconnecting along the cutting line VII-VII of FIG. 3 is a top view of a flow path substrate 10. FIG. It is arrow sectional drawing at the time of cut | disconnecting along the cutting line VIIII-VIIII of FIG. 2 is a bottom view of a flow path substrate 10. FIG. 3 is a top view of the lid substrate 20. FIG. It is arrow sectional drawing at the time of cut | disconnecting along the cutting line XII-XII of FIG. 1 is a schematic diagram showing a first production method for a reactor 1. FIG. 3 is a schematic diagram showing a second manufacturing method of the reactor 1. FIG. FIG. 3 is a schematic diagram showing a third manufacturing method for reactor 1. 2 is a block diagram of a power generation device 200. FIG. FIG. 6 is a schematic side view showing a modified example in which an intermediate layer 107 is formed between a support 101 and a composite catalyst layer 102. It is the figure which showed the relationship between the methanol addition rate and reaction temperature in this invention example 1 and a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reactor 101 Support body 102 Composite catalyst layer 103 Catalyst 104 Base film 107 Intermediate layer

Claims (6)

A reactor for reforming alcohol,
And support,
A composite catalyst comprising: a base film that is formed on the support and contains ZnO and is a porous catalyst; and catalyst particles containing Pd / ZnO that are dispersed in the base film and contribute to the reforming reaction Layers,
Reactor, wherein the Ru with the. The reactor according to claim 1, wherein the composite catalyst layer is polycrystalline. The reactor according to claim 1 or 2 , wherein a crystal lattice diameter of the catalyst particles of the composite catalyst layer and a pore diameter of the base film which is the porous catalyst are substantially equal. The intermediate layer is further formed between the said support body and the said composite catalyst layer, The said intermediate layer is comprised with the same material as the said base film, The statement to any one of Claims 1-3 characterized by the above-mentioned. The reactor described. In the manufacturing method of the reactor which manufactures the reactor as described in any one of Claims 1-4 ,
A composite catalyst layer is formed by applying a catalyst solution in which the catalyst material is dispersed in a solution of a material to be a base film on the support, and then performing a calcination treatment. Production method. An intermediate layer is formed by applying a solution having a material to be an intermediate layer on the support,
The method for producing a reactor according to claim 5 , wherein the catalyst solution is applied to the intermediate layer and then subjected to a calcination treatment to form the composite catalyst layer on the intermediate layer.

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