JP2009090184A - Catalyst for water-gas-shift reaction and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalyst for water-gas-shift reaction, which has a high activity even in a small amount of noble metals, and can suppress a deactivation due to an exposure to water and steam at low temperatures. <P>SOLUTION: The catalyst for water-gas-shift reaction is characterized in that Pt is present in a solid solution of oxides of zirconium and cerium with iron and/or yttrium, and at the same time, particles of one or more kinds of metal elements A selected from Au, Ag, Cu, Fe, Pd, Ni, Ir, Rh, Co, Os, and Ru are present by being partly buried in the oxide solid solution. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a catalyst that can be suitably used for a water gas shift reaction.

The water gas shift reaction (CO + H ₂ O → CO ₂ + H ₂ ) changes the ratio of CO and H ₂ O contained in water gas obtained from hydrocarbons and steam such as coke and natural gas, or production of H ₂ , etc. Therefore, it is a very important reaction used in the chemical industry process.

  In addition, when hydrogen, which is the fuel of fuel cells that has been attracting attention in recent years, is obtained by reforming city gas or the like, the by-produced CO poisons the fuel cell electrode, reducing power generation efficiency. Attention has been focused on a highly active water gas shift reaction as a reaction for reducing the generated CO. As a catalyst for such a water gas shift reaction, a copper-zinc system or a platinum / alumina system is generally used at a low temperature of about 150 to 230 ° C., and an iron-chromium system is used at a high temperature of about 350 to 450 ° C.

  The copper-zinc catalyst has a problem of being deactivated in a short time due to oxidation or sintering with water or oxygen. Although the heat resistance of the iron-chromium catalyst is high, there is a problem that the CO concentration of the equilibrium gas composition does not fall below a certain standard because the reaction temperature is high. Chromium is a harmful metal and its use is being regulated rapidly in recent years. In addition, when a molded body such as a bead is used, high heat treatment cannot be performed in order to avoid deterioration of the catalytic activity, and the molded body is weak and powdered, resulting in clogging of the catalyst reaction tube and reaction field pressure. There is also a drawback that the rise of the is likely to occur.

  On the other hand, although the heat resistance of the platinum / alumina catalyst is high, there is a problem that the catalyst itself becomes very expensive because it is necessary to increase the amount of platinum supported in order to exhibit high activity. Furthermore, there are concerns about problems such as resource depletion due to the use of a large amount of rare elements and further price increases.

One of the driving methods for household fuel cells that has been attracting attention in recent years is an operation method called Daily Start-up and Shutdown (DSS) that starts only during the day and stops when power consumption is low at night. . In this operation method with start-up and stop, the catalyst is repeatedly exposed to water and water vapor in the low temperature range at the start-up (start-up) or shutdown (stop), so that the catalytic active metal is sintered and the catalyst activity is deteriorated. End up.

  If a highly durable and highly active water gas shift reaction catalyst that does not use a large amount of noble metal that overcomes the above problems is obtained, not only a chemical industry process under a certain condition but also a fuel cell system with a large fluctuation range of operating conditions in particular. Can be used with confidence.

  Catalysts having Pt, Pd, Rh, etc. supported on zirconium and cerium or their solid solutions are well known as exhaust gas treatment catalysts for automobiles, but are also known to exhibit activity as catalysts for water gas shift reactions. (Patent Documents 1 to 3).

  In the exhaust gas treatment catalyst for automobiles, as a method for preventing active metal sintering, methods for fixing active metal by arranging various elements around the active metal have been devised (Patent Documents 4 to 6).

  Further, since a catalyst is usually used as a molded body, it is necessary to produce the molded body by some method, and a method in which catalyst powder is packed in a mold and pressure is applied is widely used.

  As another method for producing a molded article, a method for producing a catalyst molded article by allowing a cerium aqueous solution to penetrate into a molded article such as alumina is also described (Patent Document 7).

JP 2004-89908 A JP 2004-97948 A International Publication No. 00/48261 Pamphlet JP-A-2005-305300 JP-A-8-131830 JP-A-2005-185556 JP 2003-144925 A

  A catalyst having high activity even with a small amount of noble metal and having resistance to water and water vapor is currently most demanded, but a catalyst for a water gas shift reaction that satisfies this requirement has not yet been provided.

  That is, the techniques described in Patent Documents 1 to 7 are hardly useful as a catalyst used in a water gas shift reaction because of low catalytic activity and / or lack of resistance to water and water vapor.

  Patent Document 6 has an embodiment using nitric acid, which is expected to have an effect of lowering the slurry viscosity at the time of honeycomb coating by addition of acid. In Patent Document 6, nitric acid is added to the catalyst slurry when adhering the catalyst slurry to the carrier, but the catalyst viscosity is lowered to the carrier (honeycomb) by adding nitric acid to lower the pH by lowering the pH. It is for easy application, and the effect is clearly different from the addition of the acid of the present invention.

  The present invention has been made in view of the current state of the prior art described in Patent Documents 1 to 7, and the main object thereof is an oxide solid solution containing at least zirconium, cerium, iron and / or yttrium. Pt is present, and one or more metal elements A selected from Au, Ag, Cu, Fe, Pd, Ni, Ir, Rh, Co, Os, and Ru are present with respect to Pt. It is to provide a catalyst having both resistance to water and water vapor and high activity, and a method for producing the same, by embedding particles of Pt and the metal element A in the oxide solid solution.

  The technical problem can be achieved by the present invention as follows.

  That is, the present invention allows Pt to exist in an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium, and Au, Ag, Cu, Fe, Pd, Ni, Ir, Rh, Co to Pt. , Os, Ru, one or more metal elements A are present in an amount of 0.001 to 500% by weight, and Pt and particles of the metal elements A are embedded in the oxide solid solution. The water gas shift reaction catalyst (Invention 1).

  Further, the present invention allows Pt to be present in an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium, and Au, Ag, Cu, Fe, Pd, Ni, Ir, Rh, Co to Pt. , Os, Ru, a catalyst in which 0.001 to 500% by weight of one or more metal elements A selected from the group consisting of Os, Ru is present, and the catalytic activity does not decrease by more than 10% in the deterioration test method of the catalyst. It is a catalyst for water gas shift reaction (Invention 2).

In the present invention, the content of iron constituting the catalyst is 5.0% by weight or less in terms of iron oxide (Fe ₃ O ₄ ), and the content of yttrium is in terms of yttrium oxide (Y ₂ O ₃ ). It is a catalyst for water gas shift reaction characterized by being 10 wt% or less (Invention 3).

  Further, the present invention provides the catalyst according to any one of the present invention, wherein one or more selected from Pt and Au, Ag, Cu, Fe, Pd, Ni, Ir, Rh, Co, Os, and Ru. Water gas shift characterized in that metal element A is present in an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium, and Pt and metal element A are supported in an amount of 0.001 to 40% by weight with respect to the catalyst. This is a catalyst for the reaction (Invention 4).

  Further, the present invention provides the catalyst according to the present invention 1, wherein Pt is present in an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium, and Au, Ag, Cu, Fe, Pd, When one or more metal elements A selected from Ni, Ir, Rh, Co, Os, and Ru are present in an amount of 0.001 to 500% by weight, an acid is added, followed by drying. The method for producing a catalyst for water gas shift reaction according to claim 1, wherein the dried product is calcined (Invention 5).

  Further, in the present invention, an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium is present on the support material, and further, Pt is present and Au, Ag, Cu, Fe, Pd, One or two or more metal elements A selected from Ni, Ir, Rh, Co, Os, and Ru are present in an amount of 0.001 to 500% by weight, and Pt and particles of the metal element A are present. A catalyst body for a water gas shift reaction characterized by being embedded in the oxide solid solution (Invention 6).

  In the present invention, a slurry containing an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium is applied to the surface of the support material, and then fired and coated, and then Pt and Au, Ag, Cu, Fe, Pd. , Ni, Ir, Rh, Co, Os, Ru, in the presence of one or more metal elements A, an acid is added and then dried, and the resulting dried product is fired. This is a method for producing a catalyst for water gas shift reaction (Invention 7).

  Moreover, this invention is the reaction method of the water gas shift reaction using the catalyst in any one of this invention 1-4, or 6 (this invention 8).

  The catalyst for water gas shift reaction according to the present invention comprises Pt in an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium, and Au, Ag, Cu, Fe, Pd, Ni, One or more metal elements A selected from Ir, Rh, Co, Os, and Ru are present, and Pt and the particles of the metal elements A are embedded in the oxide solid solution, thereby causing a water gas shift. There is an excellent effect that the reaction can be performed more efficiently.

  In addition, when the catalyst is present in the support material according to the sixth aspect of the invention, almost the entire amount of the catalyst can contribute to the water gas shift reaction, so that the function of the catalyst can be sufficiently exhibited.

  The configuration of the present invention will be described in more detail as follows.

  The catalyst for the water gas shift reaction according to the present invention comprises a solid solution oxide composed of at least zirconium, cerium, iron and / or yttrium, Pt, Au, Ag, Cu, Fe, Pd, Ni, Ir, Rh, Co, Os. , Ru, a catalyst for water gas shift reaction in which one or more metal elements A selected from Ru are present, and Pt and metal particles of the metal elements A are embedded in the oxide solid solution.

  In the catalyst for water gas shift reaction according to the present invention, cerium, zirconium, iron and / or yttrium is an oxide in which a solid solution is formed. That is, it is made of any one of a composite oxide of Ce—Zr—Fe, a composite oxide of Ce—Zr—Y, or a composite oxide of Ce—Zr—Fe—Y. In the present invention, when the element does not form a solid solution, the ability to store and release oxygen decreases. Moreover, when iron and / or yttrium do not form a solid solution, the specific surface area decreases, and the function as a catalyst for the water gas shift reaction is not sufficient.

  The catalyst for water gas shift reaction according to the present invention is obtained by embedding Pt and metal particles of the metal element A in the oxide solid solution. In the present invention, when some of the particles of Pt and the metal element A are not embedded in the oxide solid solution, the resistance to water and water vapor at a low temperature is low, the metal particles are sintered and deactivated, The function as a catalyst for the water gas shift reaction is not sufficient.

The content of cerium constituting the catalyst for the water gas shift reaction according to any one of the present inventions 1 to 4 is 10 to 70% by weight in terms of cerium oxide (CeO ₂ ), and the content of zirconium is in terms of zirconium oxide (ZrO ₂ ). 30 to 90% by weight, the iron content is 0 to 5.0% by weight in terms of iron oxide (Fe ₃ O ₄ ), and the yttrium content is 0 to 10% by weight in terms of yttrium oxide (Y ₂ O ₃ ) It is preferable to be within the range. When cerium, zirconium, yttrium, and iron are out of the above ranges, the intended effect of the present invention cannot be obtained. More preferably, the cerium content is 20 to 60% by weight, the zirconium content is 40 to 75% by weight, the iron content is 0.01 to 4.5% by weight, and the yttrium content is 0.01 to It is in the range of 9.0% by weight. Even more preferably, the iron content is in the range of 0.1 to 4.5% by weight and the yttrium content is in the range of 1.0 to 9.0% by weight.

  The abundance of the metal element A is 0.001 to 500% by weight with respect to Pt. When the abundance of the metal element A is outside the above range, sufficient activity cannot be obtained. The abundance of the metal element A is more preferably 0.001 to 300% by weight, still more preferably 0.001 to 200% by weight.

  The amount of Pt present in the catalyst for water gas shift reaction according to the present invention is preferably 0.001 to 40% by weight with respect to the catalyst. When the amount of Pt present is outside the above range, sufficient activity is obtained. I can't. The amount of Pt present is more preferably 0.01 to 30% by weight, still more preferably 0.01 to 10% by weight.

The BET specific surface area of the catalyst for water gas shift reaction according to any one of the present inventions 1 to 4 is preferably 15 m ² / g or more, more preferably 50 m ² / g or more. The upper limit is about 350 m ² / g.

  The catalyst for water gas shift reaction according to the present invention is one whose catalytic activity does not decrease by 10% or more by the deterioration test method described later. A catalyst having a decrease in catalytic activity of more than 10% easily causes sintering, and does not stably have sufficient activity for a water gas shift reaction. Preferably, the rate at which the catalyst activity decreases is 8% or less.

  The CO conversion rate before and after the deterioration test of the catalyst for water gas shift reaction according to any one of the present inventions 1 to 4 is preferably 50% or more, more preferably 70% or more, in the evaluation method described later.

  You may shape | mold the catalyst which concerns on either of this invention 1 thru | or 4 according to each use to be used. The shape and size are not particularly limited, but may be, for example, a spherical shape, a cylindrical shape, a tubular shape, or a shape applied to a honeycomb body. In general, the size of a catalyst body having a spherical, cylindrical, or tubular shape is preferably about 0.1 to 30 mm. Depending on conditions, the strength and pore distribution density of the molded body may be adjusted by adding various binders such as organic substances and inorganic substances.

  In the catalyst body according to the sixth aspect of the present invention, an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium is present on the support material, and further, Pt is present and the metal element A is 0.001 with respect to Pt. The catalyst is present in a state of ˜500% by weight, in which the particles of Pt and the metal element A are embedded in the oxide solid solution.

The state of the catalyst body according to the present invention 6 is as follows.
1) A state in which any of the catalysts according to the first to fourth aspects of the present invention is attached and coated on a support material. In this case, Pt and the inside of secondary particles (aggregated particles) of the oxide solid solution and in the vicinity of the surface thereof The metal element A is present.
2) An oxide solid solution composed of iron and / or yttrium together with zirconium and cerium is adhered and coated on the support material, and Pt and metal element A are present in the vicinity of the secondary particle (aggregated particle) surface of the oxide solid solution. It is in a state.

  The support material in the present invention is a molded body made of iron plate, SUS tube, mullite, alumina, silica, cordierite or the like, and preferably silica, alumina, cordierite or the like.

  In the present invention, the surface of the support material may be coated in advance with an oxide or hydroxide of silicon, aluminum, zirconium or the like.

  The smaller the difference in linear expansion coefficient between the support material and the catalyst according to the present invention, the more ideal it is, and preferably ± 6% or less, more preferably ± 3% or less.

  The catalyst body according to the sixth aspect of the present invention has an active metal element A loading of 0.0001 to 40% by weight based on the catalyst. More preferably, the catalyst is supported by 0.01 to 30% by weight. The total content of active metal elements in the catalyst body (total amount of Pt and active metal element A) is preferably 0.1 to 30% by weight.

  Further, the catalyst body according to the present invention 6 can reduce the amount of expensive zirconium and cerium used by allowing the catalyst of any one of the present invention 1 to 4 to be present in the support material, thereby reducing the cost of the catalyst. Can be made.

  Next, a method for producing a catalyst for water gas shift reaction according to the present invention will be described.

The catalyst for water gas shift reaction according to the present invention is prepared by mixing and aging an alkaline solution and a solution containing zirconium, cerium, iron and / or yttrium, followed by filtration, washing and drying, and then 100 to 1300. An oxide solid solution of the above elements is obtained by heating in the temperature range of ° C. When Pt and the metal element A are supported on the oxide solid solution, an acid is added, washed with water and dried. It can be obtained by firing in a temperature range of ˜1300 ° C.
Part of the active metal can be covered with the oxide containing cerium by the manufacturing method, and the metal particles of Pt and metal element A are buried. As a result, sintering of the active metal particles can be suppressed. Moreover, it is speculated that by adding an acid, a part of the oxide containing cerium of the carrier is dissolved and baked, whereby a strong bond like Pt-Ce can be formed and sintering is suppressed. .

  The pH during aging is not particularly limited, but is preferably 4 to 13.5, and more preferably 6 to 13.

  Since the oxide solid solution composed of zirconium, cerium, iron and / or yttrium is simultaneously mixed and aged with an aqueous solution containing zirconium, cerium, iron and / or yttrium, the produced precipitated particles have a uniform elemental composition. It becomes particles and each element is highly dispersed, and a solid solution is easily formed. In the present invention, since it is an oxide in which iron and / or yttrium is dissolved together with zirconium and cerium, it has a high catalytic activity.

  Moreover, when synthesizing an oxide in which iron and / or yttrium is dissolved together with zirconium and cerium, Pt may be supported on the oxide obtained by mixing the metal element A by an impregnation method. That is, an alkaline solution and a solution containing zirconium, cerium, iron and / or yttrium, and metal element A are mixed and aged, then filtered, washed with water, dried, and then heated in a temperature range of 100 to 1300 ° C. When an oxide solid solution of the element is obtained and Pt is supported on the oxide solid solution, an acid is added and dried, and the resulting dried product can be fired at a temperature range of 100 to 1300 ° C. .

  In the present invention, an acid is added when Pt and metal element A are present and supported. The type of acid to be added is not particularly limited. For example, perchloric acid, sulfuric acid, fuming sulfuric acid, sulfurous acid, hydrochloric acid, hydroiodic acid, hydrobromic acid, nitric acid, fuming nitric acid, nitrous acid, king Water, mixed acid, methanesulfonic acid, benzenesulfonic acid, fluorosulfonic acid, chlorosulfonic acid, iodic acid, bromic acid, chloric acid and the like are preferable. As a method of using the acid, one kind or a mixture of two or more kinds may be used.

  Usually, Pt nitrate, dinitrodiammine Pt solution, chloroplatinic acid or the like is used as the Pt source, all of which are acidic but relatively low in acidity. For example, in the case of a dinitrodiammine Pt solution, Pt is usually dissolved with concentrated nitric acid, but at most, concentrated nitric acid having a weight about five times that of Pt is used, and the acid is used to dissolve Pt. Therefore, the acidity is not strong enough to dissolve the oxide solid solution of the carrier. Separately, a catalyst having the intended effect of the present invention cannot be obtained unless concentrated nitric acid having a weight several tens of times that of an active metal such as Pt is added. This is the same as in the case of Pt in the metal element A source.

  The acid to be added preferably has a higher concentration. For example, in the case of sulfuric acid, hydrochloric acid, hydrobromic acid, nitric acid, aqua regia, chlorosulfonic acid, etc., the amount of acid is 100 parts by weight of the catalyst, excluding the acid contained in the solution of Pt and metal element A. Thus, it is preferable to add an amount such that the amount of acid other than a solvent such as moisture is 0.5 to 40 parts by weight. If the amount is less than 0.5 parts by weight, the oxide solid solution of the carrier cannot be sufficiently dissolved to obtain the effects of the present invention. If the amount exceeds 40 parts by weight, the oxide solid solution is excessively dissolved and Pt becomes an oxide solid solution. Since it is completely covered with, the activity decreases. The amount of acid added is more preferably 1 to 20 parts by weight.

  As for heating temperature, 100-800 degreeC is more preferable. The heating atmosphere is preferably in the air.

  Usually, the catalyst is often used as a catalyst body obtained by molding the catalyst, and its production methods are diverse. As a general method for producing a catalyst body, a method in which a catalyst powder is packed in a mold and pressure-molded, a method in which a cake-like catalyst is extruded by an extruder and then calcined, or a catalyst powder is placed in a pan and rolled. The method of granulating etc. is mentioned.

  However, when a catalyst is actually used, the gas used for the catalytic reaction reacts mainly near the surface of the catalyst body and hardly penetrates into the catalyst body. Therefore, the catalyst component inside the catalyst body cannot sufficiently contribute to the catalytic reaction. In particular, when the catalyst is made of an expensive material, the catalyst inside the catalyst body is wasted.

  Accordingly, in the present invention, a slurry containing the catalyst according to any one of the present inventions 1 to 4 is applied to the surface of a support material such as ceramics or metal together with a slurry containing ceramics, if necessary, and coated to be coated. Can be used. The obtained catalyst body is in a state in which any of the catalysts according to the first to fourth aspects of the present invention is attached to and coated on a support material, and is an oxide solid solution (Ce—Zr—Fe / Y composite oxide). In this state, Pt and metal element A are present inside and near the surface of the next particle (aggregated particle). Therefore, the phase of the catalyst component can be formed on the surface of the support material, and the catalyst component can be effectively utilized.

  In the present invention 7, on the surface of a support material such as ceramics or metal, a slurry containing an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium is applied, fired and coated together with a slurry containing ceramics, if necessary. Then, Pt and metal element A are made to exist. In the catalyst body obtained by the above-described manufacturing method, an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium is adhered and coated on a support material, and the secondary particle (aggregated particle) surface of the oxide solid solution is near the surface. Pt and metal element A are present. Therefore, the active metal component can be supported on the surface of the support material, and the active metal can be used more effectively.

  In the present invention, the support material is coated with ceramics such as alumina, and then the catalyst according to any one of the present inventions 1 to 4 is coated, or the catalyst according to any one of the present inventions 1 to 4 is coated. After that, the ceramics may be coated very thinly, or may be further coated in multiple layers. The catalyst can be more firmly coated on the support material by coating the catalyst on any one of the present inventions 1 to 4 after coating the ceramic on the support material.

  Although the coating can be performed by the method described in Patent Document 7, it is difficult to increase the thickness of the catalyst layer because it is immersed in a metal aqueous solution, and the catalyst layer is easily pulverized. Due to the chemical reaction between the support element and the catalyst raw material, another phase is generated and the activity is deteriorated more than expected. Further, sufficient catalytic activity cannot be obtained unless the catalyst layer has a certain thickness. However, since the slurry is applied in the present invention, the catalyst layer can be easily thickened and powdering can be suppressed.

  In the catalyst body according to the sixth aspect of the present invention, when any of the catalysts according to the first to fourth aspects of the present invention is coated on the support material, it may be performed by an ordinary method. For example, the present invention is applied to a honeycomb carrier made of cordierite. Any one of the catalysts 1 to 4 may be made into a slurry, coated, dried, and fired to form a catalyst body.

  In the catalyst body according to the present invention 7, when the support material is coated with an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium, it may be performed by an ordinary method, for example, a cordierite honeycomb carrier. The oxide solid solution is slurried and coated. Thereafter, by allowing the metal element A to be present together with Pt, the active metal component is supported on the surface of the support material, dried and fired to obtain a catalyst body.

  Next, the water gas shift reaction using the catalyst according to the present invention will be described.

  Hydrogen and carbon dioxide are obtained by reacting water and carbon monoxide in the temperature range of 100 ° C. to 800 ° C. in the presence of the catalyst according to the present invention. The presence ratio of the catalyst is preferably 100 / h or more in terms of gas space velocity in which water and carbon monoxide are combined.

<Action>
In the present invention, a catalyst in which Pt is present in a support made of an oxide solid solution containing zirconium, cerium and iron and / or yttrium, and a metal element A is present with respect to Pt exhibits higher activity.
Further, in the present invention, by dissolving iron and / or yttrium in a solid solution of zirconia and ceria, the specific surface area is increased or the oxygen of the catalyst is increased with respect to the catalyst which is added without dissolving iron or yttrium. High catalytic activity is achieved by improving the storage and release capacity of the catalyst.

  It is presumed that when zirconium and cerium form a solid solution, the ability to store and release oxygen is improved, and the water gas shift reaction can be performed efficiently.

  In addition, it is generally well known that when the specific surface area increases, the supported Pt and the metal element of the metal element A are highly dispersed, the active sites are easily increased, and the activity is easily improved. It is surmised that the improvement of the releasing ability can be a factor of the improvement of the catalytic activity in the water gas shift reaction which is supposed to be achieved by the movement of oxygen atoms.

  As a method for supporting a metal element of Pt and metal element A in a solid solution such as zirconia, impregnation is performed by immersing a composite such as zirconia in an aqueous solution containing a salt of the metal element of Pt and metal element A and evaporating to dryness. In the present invention, the active metal element may be similarly supported by the impregnation method. However, in the present invention, an acid is added when the active metal element is supported.

  In the present invention, as described above, Pt is present in an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium, and 0.001 to 500% by weight of metal element A is present with respect to Pt. At the same time, an acid is added, dried as it is, and calcined to dissolve a part of the oxide solid solution of the support, and then a part of the active metal (Pt and metal element A) is covered with an oxide containing cerium. The present inventor presumes that the sintering of the active metal can be suppressed.

  Patent Document 7 also describes a method for producing a catalyst molded body by infiltrating a cerium aqueous solution into a molded body such as alumina. However, since the aqueous solution is infiltrated, the catalyst layer is formed on the molded body such as alumina. It is difficult to attach a thick and firm, and pulverization tends to occur. On the other hand, the amount of expensive zirconium or cerium used can be reduced by coating the catalyst of any one of the present inventions 1 to 4 on the surface of an inexpensive support material (molded body such as silica), An inexpensive catalyst can be produced. Furthermore, a catalyst molded body can be obtained in which the catalyst layer can be easily thickened and hardly pulverized.

  Hereinafter, the present invention will be described in detail based on examples.

  The content of the metal elements constituting the catalyst, zirconium, cerium, yttrium, iron, Au, Ag, Cu, Pt, Pd, Ni, Ir, Rh, Co, Os, Ru, is obtained by dissolving the catalyst with an acid. Plasma emission spectroscopy analyzer SPS4000 (Seiko Electronics Co., Ltd.) "

  The BET specific surface area value was measured by the BET method using nitrogen.

  The phase was identified by X-ray diffraction measurement. The X-ray diffractometer is “X-ray diffractometer RINT-2500 (manufactured by Rigaku Corporation)” (tube: Cu, tube voltage: 40 kV, tube current: 300 mA, goniometer: wide angle goniometer, sampling width: 0. 020 °, scanning speed: 2 ° / min, divergence slit: 1 °, scattering slit: 1 °, light receiving slit: 0.50 mm).

The concentration of the acid used in the examples of the present invention is as follows. In the examples, “acid A”, “acid B”, “acid C”, “acid D”, “acid E”, “acid F” are used. ".
Acid A: sulfuric acid (concentration 96 wt%)
Acid B: Hydrochloric acid (concentration 35 wt%)
Acid C: nitric acid (concentration 61 wt%)
Acid D: hydrobromic acid (concentration 47 wt%)
Acid E: aqua regia (volume ratio, concentrated hydrochloric acid (35 wt%): concentrated nitric acid (61 wt%) = 3: 1 mixed)
Acid F: Chlorosulfonic acid (concentration 50 wt%)

Example 1
A solution obtained by adding pure water to a mixed aqueous solution of a cerium chloride aqueous solution, a zirconium oxychloride aqueous solution and a ferric chloride aqueous solution to make 500 ml is a solution 1-1, and caustic soda is dissolved in water to make 500 ml. 2. The solution 1-2 was heated to 60 ° C. and stirred, and the solution 1-1 was added thereto and aged at 80 ° C. for 3 hours. The resulting precipitate was filtered, washed and baked at 120 ° C. for 1 hour. The weight ratio of zirconium oxide, cerium oxide, and iron oxide was 72.1: 25: 2.5.
To this, 10 parts by weight of acid A with respect to the entire catalyst, dinitrodiammine platinum nitrate aqueous solution, ruthenium nitrate solution was used to support platinum and ruthenium by an impregnation method, calcined at 400 ° C for 1 hour, and then hydrogenated at 200 ° C. Reduction was performed.
The weight ratio of zirconium oxide, cerium oxide, and iron oxide was 72.1: 25: 2.5. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.
Of the lattice constants of the catalyst determined by XRD measurement, the a-axis length is 3.64189 mm, which is larger than that of Example 6 to be described later, and no peak due to the iron compound is observed. It was confirmed that

Example 2
Synthesis was performed in the same manner as in Example 1, and the amount of acid A added was 15 parts by weight with respect to the total catalyst, the weight ratio of zirconium oxide, cerium oxide, and iron oxide was 72.1: 25: 2.5, and ruthenium nitrate. Instead of, rhodium nitrate was used. The supported amount of platinum was 0.4 wt%, and the supported amount of rhodium was 0.001 wt%.

Example 3
Synthesis was performed in the same manner as in Example 1, and the weight ratio of zirconium oxide, cerium oxide, and iron oxide was 72.1: 25: 2.5, and copper nitrate was used instead of ruthenium nitrate. The supported amount of platinum was 0.4 wt%, and the supported amount of copper was 0.001 wt%.

Example 4
Synthesis was performed in the same manner as in Example 1, and the amount of acid A added was 12 parts by weight with respect to the total catalyst, the weight ratio of zirconium oxide, cerium oxide, and iron oxide was 72.1: 25: 2.5, and ruthenium nitrate. In addition, rhodium nitrate was used. The supported amount of platinum was 0.4 wt%, the supported amount of ruthenium was 0.001 wt%, and the supported amount of rhodium was 0.001 wt%.

Example 5
Synthesis was performed in the same manner as in Example 1, and the weight ratio of zirconium oxide, cerium oxide, and iron oxide was 49.6: 47.5: 2.5. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.

Example 6
Synthesis was performed in the same manner as in Example 1, and the acid to be added was changed from acid A to acid B, so that the amount was 30 parts by weight based on the total catalyst, and the weight ratio of zirconium oxide, cerium oxide, and iron oxide was 73.6: 25: It was set to 1. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.
Of the lattice constants of the catalyst determined by XRD measurement, the a-axis length is 3.6391 mm, which is larger than that of Comparative Example 1 to be described later, and no peak due to the iron compound is observed. It was confirmed that

Example 7
Synthesis was performed in the same manner as in Example 1, and the amount of acid added was changed from acid A to acid B to 35 parts by weight with respect to the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and iron oxide was 70.6: 25: It was set to 4. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.
Of the lattice constants of the catalyst determined by XRD measurement, the a-axis length is 3.65211, which is larger than that of Example 1 and no peak due to the iron compound is observed, so that iron is in solid solution. It was confirmed.

Example 8
It was synthesized in the same manner as in Example 1, and the acid added was changed from acid A to acid B to make the amount 30 parts by weight with respect to the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and iron oxide was 72.1: 25: 2.5. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.01 wt%.

Example 9
Synthesis was performed in the same manner as in Example 1, and the acid to be added was changed from acid A to acid B to make the amount 20 parts by weight with respect to the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and iron oxide was 71.1: 25: 2.5. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 1 wt%.

Example 10
Synthesis was performed in the same manner as in Example 1 except that yttrium nitrate was used instead of ferric chloride. The acid to be added was changed from acid A to acid B so that the amount was 30 parts by weight with respect to the total catalyst, and the weight ratio of zirconium oxide, cerium oxide, and yttrium oxide was 72.6: 25: 2. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.
Of the lattice constants of the catalyst determined by XRD measurement, the a-axis length is 3.64289 mm which is larger than that of Comparative Example 1 and no peak due to the yttrium compound is observed. It was confirmed that

Example 11
Synthesis was carried out in the same manner as in Example 10, and the acid added was changed from acid B to acid C, so that the amount was 15 parts by weight based on the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and yttrium oxide was 72.6: 25: 2, rhodium nitrate was used instead of ruthenium nitrate. The supported amount of platinum was 0.4 wt%, and the supported amount of rhodium was 0.001 wt%.

Example 12
Synthesis was carried out in the same manner as in Example 10, and the acid added was changed from acid B to acid C to make the amount 20 parts by weight with respect to the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and yttrium oxide was 72.6: 25: 2 and copper nitrate was used instead of ruthenium nitrate. The supported amount of platinum was 0.4 wt%, and the supported amount of copper was 0.001 wt%.

Example 13
Synthesis was carried out in the same manner as in Example 10, and the acid added was changed from acid B to acid C, so that the amount was 15 parts by weight based on the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and yttrium oxide was 72.6: 25: 2 and copper nitrate was used in addition to ruthenium nitrate. The supported amount of platinum was 0.4 wt%, the supported amount of ruthenium was 0.001 wt%, and the supported amount of copper was 0.001 wt%.

Example 14
It was synthesized in the same manner as in Example 10, and the acid added was changed from acid B to acid C to make the amount 10 parts by weight based on the total catalyst, and the weight ratio of zirconium oxide, cerium oxide, yttrium oxide was 52.6: 45: 2. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.

Example 15
Synthesis was carried out in the same manner as in Example 10, and the acid added was changed from acid B to acid C, so that the amount was 15 parts by weight based on the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and yttrium oxide was 69.6: 25: It was set to 5. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.
Of the lattice constants of the catalyst determined by XRD measurement, the a-axis length is 3.64979 mm, which is larger than Example 10, indicating that yttrium is in solid solution.

Example 16
Synthesis was carried out in the same manner as in Example 10, and the acid added was changed from acid B to acid D to make the amount 15 parts by weight based on the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and yttrium oxide was 66.6: 25: It was set to 8. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.
Of the lattice constants of the catalyst determined by XRD measurement, the a-axis length is 3.65588 mm, which is larger than Example 15, indicating that yttrium is in solid solution.

Example 17
Synthesis was performed in the same manner as in Example 10, and the acid added was changed from acid B to acid D to make the amount 20 parts by weight based on the total catalyst, and the weight ratio of zirconium oxide, cerium oxide, yttrium oxide was 72.6: 25: 2. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.01 wt%.

Example 18
Synthesis was carried out in the same manner as in Example 10, and the acid added was changed from acid B to acid D to make the amount 15 parts by weight based on the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and yttrium oxide was 71.6: 25: 2. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 1 wt%.

Example 19
It was synthesized in the same manner as in Example 1, and the acid added was changed from acid B to acid D to make the amount 10 parts by weight based on the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and iron oxide was 71.7: 25: 2.5. The supported amount of platinum was 0.8 wt%, and the supported amount of ruthenium was 0.001 wt%.

Example 20
Synthesis was carried out in the same manner as in Example 10, and the acid added was changed from acid B to acid D to make the amount 15 parts by weight based on the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and yttrium oxide was 72.2: 25: 2. The supported amount of platinum was 0.8 wt%, and the supported amount of ruthenium was 0.001 wt%.

Example 21
Yttrium nitrate was added and synthesized in the same manner as in Example 1. The acid added was changed from acid A to acid E, so that the amount was 15 parts by weight with respect to the total catalyst, and the weight of zirconium oxide, cerium oxide, yttrium oxide, and iron oxide The ratio was 70.1: 25: 2: 2.5. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.

Example 22
Rhodium nitrate was added and synthesized in the same manner as in Example 21. The amount of acid added was 20 parts by weight with respect to the total catalyst, and the weight ratio of zirconium oxide, cerium oxide, yttrium oxide, and iron oxide was 70.1: 25: 2: 2.5. The supported amount of platinum was 0.4 wt%, the supported amount of ruthenium was 0.001 wt%, and the supported amount of rhodium was 0.001 wt%.

Example 23
Copper nitrate was added and synthesized in the same manner as in Example 21, and the weight ratio of zirconium oxide, cerium oxide, yttrium oxide, and iron oxide was 65.6: 25: 5: 4. The supported amount of platinum was 0.4 wt%, the supported amount of ruthenium was 0.001 wt%, and the supported amount of copper was 0.001 wt%.

Example 24
It was synthesized in the same manner as in Example 1, and the acid added was changed from acid A to acid E to make the amount 10 parts by weight with respect to the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and iron oxide was 72.1: 25: 2.5. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.

Example 25
It was synthesized in the same manner as in Example 1, and the acid added was changed from acid A to acid E, so that the amount was 15 parts by weight based on the total catalyst, and the weight ratio of zirconium oxide, cerium oxide, iron oxide was 72.1: 25: 2.5. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.

Example 26
It was synthesized in the same manner as in Example 1, and the acid added was changed from acid A to acid F to make the amount 15 parts by weight based on the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and iron oxide was 72.1: 25: 2.5. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.

Example 27
Synthesis was performed in the same manner as in Example 1, and the acid added was changed from acid A to acid F to make the amount 20 parts by weight with respect to the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and iron oxide was 72.1: 25: 2.5. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.

Example 28
Synthesis was performed in the same manner as in Example 1, and the acid to be added was changed from acid A to acid F so that the amount was 15 parts by weight with respect to the total catalyst, yttrium was used instead of iron, and the weight of zirconium oxide, cerium oxide, and yttrium oxide. The ratio was 71.6: 25: 2, the platinum loading was 0.4 wt%, and the ruthenium loading was 1 wt%.

Example 29
Synthesis was performed in the same manner as in Example 28, and the amount of acid added was 10 parts by weight with respect to the total catalyst, copper was used instead of ruthenium, and the weight ratio of zirconium oxide, cerium oxide, and iron oxide was 47.5: 25: 2.5, the supported amount of platinum was 5 wt%, and the supported amount of copper was 20 wt%.

Example 30
It was synthesized in the same manner as in Example 28, using copper in addition to ruthenium, the weight ratio of zirconium oxide, cerium oxide, and iron oxide was 57.5: 25: 2.5, the supported amount of platinum was 3 wt%, The supported amount was 2 wt%, and the supported amount of copper was 10 wt%.

Example 31
It was synthesized in the same manner as in Example 28, using rhodium instead of ruthenium, the weight ratio of zirconium oxide, cerium oxide, and iron oxide was 62.5: 25: 2.5, the supported amount of platinum was 5 wt%, rhodium The supported amount was 5 wt%.

Example 32
It was synthesized in the same manner as in Example 28, and the weight ratio of zirconium oxide, cerium oxide, and iron oxide was 67.5: 25: 2.5, the supported amount of platinum was 5 wt%, and the supported amount of ruthenium was 0.0001 wt%. did.

Comparative Example 1
Synthesis was performed in the same manner as in Example 1 except that the weight ratio of zirconium oxide and cerium oxide was 74.6: 25 without adding ruthenium and iron. The supported amount of platinum was 0.4 wt%. Of the lattice constants of the catalyst determined by XRD measurement, the a-axis length was 3.6267 mm.

Comparative Example 2
The acid to be added is changed from acid A to acid B so that the amount is 30 parts by weight with respect to the whole catalyst, and without adding ruthenium, the weight ratio of zirconium oxide, cerium oxide and iron oxide is 72.1: 25: 2. 5 and synthesized in the same manner as in Example 1. The supported amount of platinum was 0.4 wt%.

Comparative Example 3
The acid to be added is changed from acid B to acid C to make the amount 15 parts by weight with respect to the whole catalyst, and without adding ruthenium, the weight ratio of zirconium oxide, cerium oxide, yttrium oxide is 50.1: 47.5: 2 and synthesized in the same manner as in Example 10. The supported amount of platinum was 0.4 wt%.

Comparative Example 4
Pure water is added to a mixed aqueous solution of a cerium chloride aqueous solution and a zirconium oxychloride aqueous solution to make 500 ml, and the mixture is thoroughly stirred to make a solution 2-1, and caustic soda dissolved in water to make 500 ml is made a solution 2-2. The solution 2-2 was heated to 60 ° C. and stirred, and the solution 2-1 was added thereto and aged at 80 ° C. for 3 hours. The resulting precipitate was filtered, washed and baked at 120 ° C. for 1 hour. This is designated as Carrier 2-1.
Separately, pure water is added to the ferric chloride aqueous solution to make 500 ml, and the mixture is thoroughly stirred to make solution 2-3, and caustic soda dissolved in water to make 500 ml is made solution 2-4. The solution 2-4 was heated to 60 ° C. and stirred, and the solution 2-3 was added thereto, followed by aging at 80 ° C. for 3 hours. The resulting precipitate was filtered, washed and baked at 120 ° C. for 1 hour. This is designated as Carrier 2-2.
The carrier 2-1 and the carrier 2-2 are mixed well, and the acid D is mixed with 15 parts by weight of the total catalyst, dinitrodiammine platinum nitric acid aqueous solution, ruthenium nitrate solution, and platinum and ruthenium are impregnated by an impregnation method. After supporting and baking at 400 ° C. for 1 hour, hydrogen reduction was performed at 200 ° C.
The weight ratio of zirconium oxide, cerium oxide, and iron oxide was 72.1: 25: 2.5. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.
Of the lattice constants of the catalyst determined by XRD measurement, the a-axis length is 3.6271 mm, which is almost the same as in Comparative Example 1, and thus it can be seen that iron is not dissolved.

Comparative Example 5
Pure water is added to a mixed solution of a cerium chloride aqueous solution and a zirconium oxychloride aqueous solution to make 500 ml, and the mixture is thoroughly stirred to make solution 3-1, and caustic soda dissolved in water to make 500 ml is made solution 3-2. The solution 3-2 was heated to 60 ° C. and stirred, and the solution 3-1 was added thereto and aged at 80 ° C. for 3 hours. The resulting precipitate was filtered, washed and baked at 120 ° C. for 1 hour. This is designated as Carrier 3-1.
Separately, pure water was added to an aqueous yttrium nitrate solution to make 500 ml, and the mixture was thoroughly stirred to make solution 3-3. Solution obtained by dissolving caustic soda in water to make 500 ml was made solution 3-4. The solution 3-4 was heated to 60 ° C. and stirred, and the solution 3-3 was added thereto and aged at 80 ° C. for 3 hours. The resulting precipitate was filtered, washed and baked at 120 ° C. for 1 hour. This is designated as Carrier 3-2.
The carrier 3-1 and the carrier 3-2 are mixed well, and the acid E is mixed with 15 parts by weight of the whole catalyst and a dinitrodiammine platinum nitrate aqueous solution and a ruthenium nitrate solution. After supporting and baking at 400 ° C. for 1 hour, hydrogen reduction was performed at 200 ° C.
The weight ratio of zirconium oxide, cerium oxide, and yttrium oxide was 72.6: 25: 2. The supported amount of platinum was 0.4 wt%.
Of the lattice constants of the catalyst determined by XRD measurement, the a-axis length is 3.6276 mm, which is almost the same as in Comparative Example 1, so that it can be seen that yttrium is not dissolved.

Comparative Example 6
γ-alumina was loaded with platinum by an impregnation method using 15 parts by weight of acid F and dinitrodiammine platinum nitric acid aqueous solution based on the whole catalyst, calcined at 400 ° C. for 1 hour, and then hydrogen reduced at 200 ° C. . The supported amount of platinum was 0.4 wt%.

Comparative Example 7
A solution obtained by adding pure water to a zirconium oxychloride aqueous solution to 500 ml and stirring well is designated as Solution 4-1, and a solution obtained by dissolving caustic soda in water to obtain 500 ml is designated as Solution 4-2. The solution 4-2 was heated to 60 ° C. and stirred, and the solution 4-1 was added thereto and aged at 80 ° C. for 3 hours. The resulting precipitate was filtered, washed and baked at 120 ° C. for 1 hour. The catalyst was loaded with platinum by an impregnation method using 15 parts by weight of acid F with respect to the entire catalyst and an aqueous solution of dinitrodiammine platinum nitrate, calcined at 400 ° C. for 1 hour, and then hydrogen reduced at 200 ° C. The supported amount of platinum was 0.4 wt%.

Comparative Example 8
A solution obtained by adding pure water to a cerium chloride aqueous solution to 500 ml and stirring well is designated as Solution 5-1, and a solution obtained by dissolving caustic soda in water to obtain 500 ml is designated as Solution 5-2. The solution 5-2 was heated to 60 ° C. and stirred, and the solution 5-1 was added thereto and aged at 80 ° C. for 3 hours. The resulting precipitate was filtered, washed and baked at 120 ° C. for 1 hour. To this, 10 parts by weight of acid A with respect to the whole catalyst and a dinitrodiammine platinum nitric acid aqueous solution were used to support platinum by an impregnation method, calcined at 400 ° C. for 1 hour, and then subjected to hydrogen reduction at 200 ° C. The supported amount of platinum was 0.4 wt%.

Comparative Example 9
A solution obtained by adding pure water to an aqueous cerium chloride solution and an aqueous yttrium chloride solution to 500 ml and stirring well is designated as solution 6-1, and a solution obtained by dissolving caustic soda in water to obtain 500 ml is designated as solution 6-2. Solution 6-2 was heated to 60 ° C. and stirred, and then solution 6-1 was added thereto and aged at 80 ° C. for 3 hours. The resulting precipitate was filtered, washed and baked at 120 ° C. for 1 hour. To this, 30 parts by weight of acid B with respect to the whole catalyst and dinitrodiammine platinum nitrate aqueous solution and ruthenium nitrate aqueous solution were used to support platinum by impregnation method, calcined at 400 ° C for 1 hour, and then hydrogen reduced at 200 ° C. went. The weight ratio of cerium oxide and yttrium oxide was 97.6: 2. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.

Comparative Example 10
Using an aqueous solution of dinitrodiammine platinum nitrate on γ-alumina, platinum was supported by an impregnation method, calcined at 400 ° C. for 1 hour, and then subjected to hydrogen reduction at 200 ° C. The supported amount of platinum was 0.4 wt%.

Comparative Example 11
The synthesis was performed in the same manner as in Example 1 without adding the acid A, with the weight ratio of zirconium oxide, cerium oxide, and iron oxide being 72.1: 25: 2.5. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.

Comparative Example 12
The synthesis was performed in the same manner as in Example 1 without adding the acid A, with the weight ratio of zirconium oxide, cerium oxide, and iron oxide being 72.1: 25: 2.5. The supported amount of platinum was 0.4 wt%, and the supported amount of rhodium was 0.001 wt%.

Comparative Example 13
The synthesis was performed in the same manner as in Example 1 without adding the acid A, and the weight ratio of zirconium oxide, cerium oxide, and iron oxide was 49.6: 47.5: 2.5. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.

Comparative Example 14
The synthesis was carried out in the same manner as in Example 1 without adding acid A, with the weight ratio of zirconium oxide, cerium oxide, and iron oxide being 47.5: 25: 2.5. The supported amount of platinum was 5 wt%, and the supported amount of copper was 20 wt%.

Comparative Example 15
The synthesis was performed in the same manner as in Example 1 without adding the acid A, with the weight ratio of zirconium oxide, cerium oxide, and iron oxide being 62.5: 25: 2.5. The supported amount of platinum was 5 wt%, and the supported amount of rhodium was 5 wt%.

Comparative Example 16
The synthesis was carried out in the same manner as in Example 1 without adding acid A, with the weight ratio of zirconium oxide, cerium oxide, and iron oxide being 67.5: 25: 2.5. The supported amount of platinum was 5 wt%, and the supported amount of ruthenium was 0.0001 wt%.

Comparative Example 17
Without adding acid A, the weight ratio of zirconium oxide, cerium oxide, and yttrium oxide was 69.6: 25: 5, and synthesis was performed in the same manner as in Example 1. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.

Example 33
The amount of acid A added was 5 parts by weight with respect to the total catalyst, and the weight ratio of zirconium oxide, cerium oxide, and iron oxide was 72.5: 25: 2.5. The supported amount of platinum was 0.02 wt%, and the supported amount of ruthenium was 0.0001 wt%.

Example 34
The acid to be added was changed from acid A to acid B, the amount was 10 parts by weight, and the weight ratio of zirconium oxide, cerium oxide and yttrium oxide was 69.9: 25: 5. Synthesized. The supported amount of platinum was 0.1 wt%, and the supported amount of ruthenium was 0.0001 wt%.

Example 35
The acid to be added was changed from acid A to acid C, the amount was 5 parts by weight based on the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and iron oxide was 72.5: 25: 2.5. It synthesized similarly. The supported amount of platinum was 0.02 wt%, and the supported amount of rhodium was 0.0001 wt%.

Example 36
The acid to be added was changed from acid A to acid D, the amount was 5 parts by weight based on the total catalyst, and the weight ratio of zirconium oxide, cerium oxide and iron oxide was 62.5: 25: 2.5. It synthesized similarly. The supported amount of platinum was 5 wt%, and the supported amount of rhodium was 5 wt%.

Example 37
The acid to be added is changed from acid A to acid E, the amount is 5 parts by weight with respect to the whole catalyst, and the weight ratio of zirconium oxide, cerium oxide and iron oxide is 72.5: 25: 2.5. It synthesized similarly. The supported amount of platinum was 0.02 wt%, and the supported amount of ruthenium was 0.0001 wt%.

Example 38
The acid to be added was changed from acid A to acid F, and the amount was 5 parts by weight with respect to the total catalyst, and the weight ratio of zirconium oxide, cerium oxide, and iron oxide was 50: 47.5: 2.5. It synthesized similarly. The supported amount of platinum was 0.02 wt%, and the supported amount of ruthenium was 0.0001 wt%.

Example 39
The amount of acid A added was 15 parts by weight with respect to the total catalyst, and the weight ratio of zirconium oxide, cerium oxide, and iron oxide was 67.5: 25: 2.5. The supported amount of platinum was 5 wt%, and the supported amount of ruthenium was 0.0001 wt%.

Example 40
The acid to be added is changed from acid A to acid B, the amount is 30 parts by weight with respect to the whole catalyst, and the weight ratio of zirconium oxide, cerium oxide and yttrium oxide is 66.6: 25: 8, and the same as in Example 1. Synthesized. The supported amount of platinum was 0.4 wt%, and the supported amount of ruthenium was 0.001 wt%.

Comparative Example 18
The acid to be added is changed from acid B to acid C to make the amount 5 parts by weight based on the total catalyst, and without adding ruthenium, the weight ratio of zirconium oxide, cerium oxide, yttrium oxide is 50.5: 47.5: 2 and synthesized in the same manner as in Example 10. The supported amount of platinum was 0.02 wt%.

Comparative Example 19
Using 5 parts by weight of acid D to γ-alumina and dinitrodiammine platinum nitric acid aqueous solution based on the whole catalyst, platinum was supported by an impregnation method, calcined at 400 ° C. for 1 hour, and then reduced at 200 ° C. with hydrogen. . The supported amount of platinum was 0.02 wt%.

Comparative Example 20
The nitric acid was not added, and the weight ratio of zirconium oxide, cerium oxide, and iron oxide was set to 72.5: 25: 2.5. The supported amount of platinum was 0.02 wt%, and the supported amount of ruthenium was 0.001 wt%.

Comparative Example 21
The nitric acid was not added, and the weight ratio of zirconium oxide, cerium oxide, and iron oxide was 62.5: 25: 2.5. The supported amount of platinum was 5 wt%, and the supported amount of rhodium was 5 wt%.

Comparative Example 22
The nitric acid was not added, and the weight ratio of zirconium oxide, cerium oxide, and iron oxide was set to 67.5: 25: 2.5. The supported amount of platinum was 5 wt%, and the supported amount of ruthenium was 0.0001 wt%.

These catalysts were sized to 1 to 2 mm. The catalyst layer of this catalyst is heated in an electric furnace, and at a predetermined temperature, a gas containing 33% by volume of CO and 67% by volume of water vapor is 200 ° C., space velocity (GHSV-wet base) 10000 h ⁻¹ and 350 ° C., 20000 h ^{− 1} was distributed. The outlet gas composition at this time was measured with a gas chromatograph, and this was measured with CO Conv. It was.

Hereinafter, the deterioration test method is shown.
Deterioration test method 1) A gas having 4.3% by volume of CO, 16% by volume of water vapor, and 79.7% by volume of N ₂ was circulated at 250 ° C., and the CO conversion rate was within a range of 90% ± 0.5%. The space velocity was adjusted so that This is the CO CONV. It was.
2) Then, at 60 ° C., a gas having 4.3% by volume of CO, 16% by volume of water vapor, and 79.7% by volume of N ₂ was allowed to flow at a space velocity (GHSV-wet base) 2000 h ⁻¹ for 3 hours, The catalyst was deteriorated.
3) Further, after that, a gas having 4.3% by volume of CO, 16% by volume of water vapor, and 79.7% by volume of N ₂ was circulated at the same space velocity and 250 ° C. as in 1), and the CO conversion was measured. . After this deterioration test, CO CONV. It was.
The decrease in the catalyst activity in the catalyst according to the present invention 2 indicates the change before and after the deterioration test in Tables 2 and 4, which is the CO CONV. To CO CONV. It is the value which subtracted.

  Before the deterioration test, CO CONV. The reason why the range of 90% ± 0.5% is that when the conversion rate reaches chemical equilibrium or is too low, deterioration of the catalyst cannot be confirmed in the form of conversion rate.

For each catalyst, the weight ratio of zirconium oxide, cerium oxide, iron oxide and yttrium oxide, specific surface area, supported metal type, supported amount, parts by weight of coated oxide solid solution, parts by weight of added acid, 200 ° C., ( Table 2 shows the CO conversion rate at GHSV-wet base) 10000h ^{−1 and} the CO conversion rate before and after the deterioration test. Table 2 shows the CO conversion rate at 350 ° C. (GHSV-wet base) 20000h ⁻¹ and the CO conversion before and after the deterioration test. The rates are shown in Table 4.

  The reason why the CO conversion rate does not reach 100% is that it depends on the reaction equilibrium.

As shown in Table 2, it was confirmed that all the catalysts according to the present invention have a high CO conversion rate even when the reaction temperature is 200 ° C.
That is, the catalyst according to the present invention has a high CO conversion rate of 70% or more under the conditions of 200 ° C. and space velocity (GHSV-wet base) 10,000 h ⁻¹ .

From Table 4, it has a high CO conversion even at a high reaction temperature of 350 ° C.
That is, the catalyst according to the present invention has a high CO conversion rate of 70% or more under conditions of 350 ° C. and space velocity (GHSV-wet base) 20000 h ⁻¹ .

  Even if the weight ratio of the catalyst of the present invention and the constituent elements is the same, high activity is not exhibited unless the solid solution contains zirconium, cerium and iron or yttrium.

  Since a solution or oxide solid solution containing zirconium, cerium and iron and / or yttrium is coated or nitric acid is added and a part of the active metal particles is not buried in the support, it is deactivated after the deterioration test. The effect of cannot be obtained.

Example 41
The catalyst of Example 1 was silkwormed to give a 20% slurry. The alumina compact was immersed in this slurry, and after supporting the catalyst component, the compact was lifted from the slurry, excess slurry was blown off, dried, fired at 400 ° C., and then hydrogen reduced at 200 ° C. .

Example 42
The oxide solid solution described in Example 1 before adding platinum, ruthenium and nitric acid was silkwormed to give a 20% slurry. The alumina compact was immersed in this slurry, and after supporting the catalyst component, the compact was pulled up from the slurry, excess slurry was blown off, dried, and fired at 120 ° C. Nitric acid is supported on platinum and ruthenium by an impregnation method using 15 parts by weight of the total solid oxide solution, dinitrodiammine platinum nitric acid aqueous solution and ruthenium nitrate solution, and calcined at 400 ° C. for 1 hour. Hydrogen reduction was performed.

Comparative Example 23
The molded body of alumina was immersed in an aqueous cerium nitrate solution, and after supporting cerium, the molded body was lifted from the aqueous cerium nitrate solution, dried, and fired at 400 ° C. A dinitrodiammine platinum nitric acid aqueous solution was used for this, and platinum was supported by an impregnation method. After baking at 400 ° C. for 1 hour, hydrogen reduction was performed at 200 ° C.

In Comparative Example 23, since the aqueous solution is infiltrated, it is difficult to attach the catalyst layer on the alumina molded body thickly and firmly, and pulverization is likely to occur. On the other hand, in Example 41, since the catalyst slurry is applied to the surface of the alumina molded body, the catalyst layer can be easily thickened, and a catalyst molded body that hardly adheres to powder can be obtained.
As a result, the catalyst bodies obtained in Examples 41 and 42 showed a CO conversion rate comparable to that in Example 1 and a deterioration rate in the catalyst deterioration test.

  In the catalyst according to the present invention, a catalyst in which an active metal element is present in an oxide solid solution containing zirconium, cerium, iron and / or yttrium, and if necessary mixed with alumina or the like, has a water gas shift reaction as compared with a conventional catalyst. It is more efficient and has excellent effects. Moreover, a practical catalyst molded body can be obtained by using the method for producing a catalyst molded body of the present invention.

Claims (8)

Pt is present in an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium, and in relation to Pt, in Au, Ag, Cu, Fe, Pd, Ni, Ir, Rh, Co, Os, and Ru. One or more metal elements A selected from the group consisting of 0.001 to 500% by weight, Pt and particles of the metal element A are embedded in the oxide solid solution, for water gas shift reaction Catalyst. Pt is present in an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium, and in relation to Pt, in Au, Ag, Cu, Fe, Pd, Ni, Ir, Rh, Co, Os, and Ru. A catalyst for water gas shift reaction in which 0.001 to 500% by weight of one or more metal elements A selected from the above is present, and the catalytic activity does not decrease by 10% or more by the deterioration test method of the catalyst . The content of iron constituting the catalyst according to claim 1 or 2 is 5.0% by weight or less in terms of iron oxide (Fe ₃ O ₄ ), and the content of yttrium is yttrium oxide (Y ₂ O ₃ ). A catalyst for water gas shift reaction, characterized in that it is 10% by weight or less in terms of conversion. The catalyst according to any one of claims 1 to 3, wherein Pt and one or more metals selected from Au, Ag, Cu, Fe, Pd, Ni, Ir, Rh, Co, Os, and Ru are used. Water gas shift reaction characterized in that element A is present in an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium, and the Pt and metal element A are supported in an amount of 0.001 to 40% by weight with respect to the catalyst. Catalyst. The catalyst according to claim 1, wherein Pt is present in an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium, and Au, Ag, Cu, Fe, Pd, Ni, Ir, Rh, When 0.001 to 500% by weight of one or more metal elements A selected from Co, Os, and Ru are present in an amount of 0.001 to 500% by weight, the acid is added and then dried, and the resulting dried product is fired. The method for producing a catalyst for a water gas shift reaction according to claim 1, wherein An oxide solid solution composed of iron and / or yttrium together with zirconium and cerium exists on the support material, and further, Pt is present and Au, Ag, Cu, Fe, Pd, Ni, Ir, Rh, One or two or more metal elements A selected from Co, Os, and Ru are present in an amount of 0.001 to 500% by weight, and particles of Pt and the metal elements A are embedded in the oxide solid solution. A catalytic body for a water gas shift reaction, wherein The surface of the support material is coated with a slurry containing an oxide solid solution composed of iron and / or yttrium together with zirconium and cerium, fired and coated, and then coated with Pt, Au, Ag, Cu, Fe, Pd, Ni, Ir, Rh. , Co, Os, Ru, in the presence of one or more metal elements A, an acid is added, and the resulting dried product is calcined. A method for producing a catalyst. The reaction method of the water gas shift reaction using the catalyst in any one of Claims 1-4 and 6.