WO2016148062A1 - Metal composite oxide catalyst for exhaust gas purification and method for producing same - Google Patents

Abstract

The present invention provides a metal composite oxide catalyst for exhaust gas purification, which is represented by formula (I). M¹/M²Fe_xMn_1-xO₃ (I) (In the formula, M¹ represents a noble metal selected from the group consisting of Pd, Rh and Pt; M² represents a rare earth element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y; and x represents a number of 0.2-1.0. In this connection, M²Fe_xMn_1-xO₃ represents a metal composite oxide carrier, and M¹ is supported by the carrier.)

Description

Metal composite oxide catalyst for exhaust gas purification and method for producing the same

The present invention relates to a metal composite oxide catalyst for purifying exhaust gas and a method for producing the same, and more particularly to the development of a novel composite oxide catalyst with a reduced precious metal superposition aimed at purifying automobile exhaust gas and a method for producing the same.

Currently, precious metal species such as Pd and Rh are mainly used as automobile exhaust gas purification catalysts. It is known that Pd has a high oxidation activity under rich conditions (oxygen-diluted conditions), and Rh exhibits an extremely high NO _x reduction activity (Non-patent Document 1). Precious metal species show high activity as an automobile exhaust gas purification catalyst and are indispensable elements for automobiles. However, since these noble metal species are rare elements, there is a problem that price fluctuations are severe. In recent years, research for replacing noble metals has been actively conducted, and it has been clarified that Cu exhibits high activity for NO selective reduction among transition metals (Non-patent Document 2). In particular, it is well known that a Cu ²⁺ ion exchange ZSM-5 zeolite catalyst is effective in NO _x selective reduction reaction using hydrocarbon (HC) as a reducing agent (Non-patent Document 3). This laboratory has also reported that Cu / Al ₂ O ₃ is most effective as a result of optimization of combinations of various carriers and various active metal components (Non-patent Document 4). However, Cu-based catalysts have a problem that the NO purification efficiency at low temperatures is extremely low and is not suitable for exhaust gas purification in the cold. Therefore, the addition of noble metal species is indispensable for improving the purification efficiency at low temperatures.

Muraki Hideaki, Sakai Catalyst, 1992, 34, 225. V. Parvulescu, P. Grange, B. Delmon, Catal. Today 1998, 46, 233. H. Yahiro, M. Iwamoto, Appl. Catal. A-Gen. 2001, Gen222, 163. T. Yamamoto, T. Tanaka, R. Kuma, S. Suzuki, F. Amano, Y. Shimooka, Y. Kohno, T. Funabiki, S. Yoshida., Phys. Chem. Chem. Phys., 2002, 4, 2449.

The main object of the present invention is to realize removal of precious metal or reduction of precious metal by developing a novel catalyst with a reduced amount of precious metal used.

The present invention provides the following metal complex oxide catalyst for exhaust gas purification and a method for producing the same.
Item 1. Formula (I)
M ¹ / M ² Fe _x Mn _1-x O ₃ (I)
(Wherein M ¹ represents a noble metal selected from the group consisting of Pd, Rh and Pt. M ² represents a rare earth element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y. _X is 0.2 to 1.0, M ² Fe _x Mn _1-x O ₃ represents a metal composite oxide support, and M ¹ is supported on the support.
A metal composite oxide catalyst for exhaust gas purification represented by
Item 2. M ¹ is Pd, the exhaust gas purifying metal composite oxide catalyst according to claim 1.
Item 3. M ² is Yb, the exhaust gas purifying metal composite oxide catalyst according to claim 1 or 2.
Item 4. Item 4. The metal composite oxide catalyst for exhaust gas purification according to any one of Items 1 to 3, wherein x is 0.4 to 0.8.
Item 5. Item 5. The exhaust gas purifying metal composite oxide catalyst according to Item 4, wherein x is 0.6 to 0.8.
Item 6. The noble metal M ¹ is M ² Fe _x Mn _1-x O ₃ (M ² represents a rare earth element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y. x is 0.2 to 0.2). Item 6. The metal composite oxide catalyst for purifying exhaust gas according to any one of Items 1 to 5, which is contained in an amount of 0.01 to 2% by mass with respect to the carrier represented by 1.0.
Item 7. The noble metal M ¹ is M ² Fe _x Mn _1-x O ₃ (M ² represents a rare earth element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y. x is 0.2 to 0.2). Item 10. The metal complex oxide catalyst for exhaust gas purification according to Item 6, which is contained by 0.1 to 1.0% by mass with respect to the complex oxide represented by 1.0).
Item 8. Item 8. The metal complex oxide catalyst for exhaust gas purification according to any one of Items 1 to 7, wherein the crystal structure of the metal complex oxide support is a hexagonal crystal structure.
Item 9. M ¹ is Pd, and, M ² is Yb, the exhaust gas purifying metal composite oxide catalyst according to claim 1.
Item 10. Item 10. The metal complex oxide catalyst for purifying exhaust gas according to any one of Items 1 to 9, wherein the metal complex oxide support is synthesized by a solvothermal method.
Item 11. A rare earth element compound, Fe compound, or Mn compound selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y is dissolved or suspended in a solvent and heated to the following formula (II)
M ² Fe _x Mn _1-x O ₃ (II)
(In the formula, M ² represents a rare earth element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y. x is 0.2 to 1.0.)
And a step of contacting the obtained carrier with a Pd compound, Rh compound or Pt compound solution and calcining it.
M ¹ / M ² Fe _x Mn _1-x O ₃ (I)
(Wherein M ¹ represents a noble metal selected from the group consisting of Pd, Rh and Pt. M ² represents a rare earth element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y. _X is 0.2 to 1.0, M ² Fe _x Mn _1-x O ₃ represents a metal composite oxide support, and M ¹ is supported on the support.
The manufacturing method of the metal complex oxide catalyst for exhaust gas purification represented by these.
Item 12. Item 12. The method for producing a metal composite oxide catalyst for exhaust gas purification according to Item 11, wherein the solvent is 1,4-butanediol.

According to the present invention, a noble metal (M ¹ ) support selected from the group consisting of Pd, Rh and Pt is used as M ² Fe _x Mn _1-x O ₃ (M ² , x is as defined above). Thus, even if the amount of M ¹ supported is reduced, excellent performance as an exhaust gas purifying metal composite oxide catalyst can be exhibited. In addition, as shown in the examples, the catalyst supporting 0.5% by mass of Pd is CO and propylene oxidized, NOx compared to the Al ₂ O ₃ supported noble metal catalyst supporting 1.0% by mass of Rh or Pd. The reduction temperature (T50) is low, and the performance is superior to conventional Rh-containing catalysts and Pd-containing catalysts.

Comparison of catalytic activity of hexagonal YbFe _0.6 Mn _0.4 O ₃ (ST) supported Pd catalyst and γ-Al ₂ O ₃ supported noble metal catalyst. The effect of the amount of hexagonal YbFe _0.6 Mn _0.4 O ₃ (ST) supported Pd catalyst. Effect of preparation method and addition effect of Mn _. Measurement results of XRD patterns and specific surface areas of various catalysts. From the XRD pattern, it was confirmed that the crystal structure of the carrier used in the present invention was a hexagonal crystal structure. Moreover, the specific surface area described in FIG. 4 is a BET specific surface area. 1 schematically shows a normal pressure fixed bed flow type reactor.

In the exhaust gas purifying metal composite oxide catalyst of the present invention, a noble metal selected from the group consisting of Pd, Rh and Pt is represented by the following formula (II):
M ² Fe _x Mn _1-x O ₃ (II)
(In the formula, M ² represents a rare earth element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y. x is 0.2 to 1.0. M ² Fe _x Mn _{1− x} O ₃ represents a metal composite oxide support, and Pd is supported on the support.
It is carried on a metal composite oxide carrier represented by

The amount of the noble metal M ¹ supported is preferably about 0.01 to 2%, more preferably about 0.05 to 2%, still more preferably about 0.1 to 1%, based on the mass of the carrier represented by the formula (II). Preferably, it is about 0.1 to 0.5%. The smaller the amount of the precious metal supported, the lower the cost, but it is preferable. However, if the amount is too small, there is a risk that the NO reduction activity is lowered and exhaust gas purification is not performed sufficiently when used for a long time.

The noble metal M ¹ supported on the support includes at least one selected from the group consisting of Pd, Rh and Pt, preferably Pd, Rh or Pt, more preferably Pd, Rh, most preferably Pd. It is.

Examples of the rare earth element represented by M ² include Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y, and one or more of these can be used. Preferred rare earth elements are Er, Tm, Yb, Lu, or Y, more preferably Yb, Lu, and particularly preferably Yb.

The crystal structure of the carrier of the present invention includes a hexagonal crystal structure.

The carrier represented by the general formula (II) of the present invention can be produced by a solvothermal method (ST method), a complex polymerization method (PC method) or the like, and the ST method is preferred.

The ST method is a method in which a rare earth element (M ² ) compound, an Fe compound, and optionally a Mn compound are dissolved or suspended in a solvent in a sealed container and heated, and the carrier represented by the formula (II) is: It forms as a precipitate. As the solvent, one or more of polyhydric alcohols such as 1,4-butanediol, alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, and glycerin can be used. A preferred solvent is 1,4-butanediol. The reaction is preferably carried out in a closed system. The reaction is preferably performed in an atmosphere substituted with an inert gas (such as nitrogen or argon). The reaction temperature is about 50 to 350 ° C, preferably about 100 to 350 ° C. The reaction pressure is about 0.1 to 10 MPa, preferably about 1.0 to 5.0 MPa. The reaction time is about 30 minutes to 24 hours, preferably about 1 to 12 hours. In the reaction, the total amount of the Fe compound and the Mn compound is about 0.5 to 1.5 mol, preferably about 0.8 to 1.2 mol, per 1 mol of the rare earth element (M ² ) compound. Further, the obtained sample is calcined at 200 to 800 ° C. for 0.2 to 24 hours, whereby the carrier of the formula (II) used in the present invention can be obtained.

As the rare earth element (M ² ) compound dissolved / suspended in the solvent, a complex compound in which a ligand such as acetylacetone or alkoxide (methoxide, ethoxide, tert-butoxide, etc.) is coordinated with the rare earth element, or a rare earth element Examples include organic acid salts such as nitrates and acetates, carbonates, halides (fluorides, chlorides, bromides, iodides), and coordination such as acetylacetone and alkoxides (methoxide, ethoxide, tert-butoxide, etc.) A complex compound coordinated with a child, an organic acid salt such as acetate, and a carbonate can be preferably used. Rare earth element (M ²⁾ compounds can be used alone or in combination of two or more.

Fe compounds include complex compounds in which ligands such as acetylacetone and alkoxide (methoxide, ethoxide, tert-butoxide, etc.) are coordinated to Fe ions (divalent or trivalent), and organic acid salts such as nitrates and acetates. , Carbonate, halide (fluoride, chloride, bromide, iodide) Organic acid salts such as salts can be preferably used. Fe compounds can be used alone or in combination of two or more.

Mn compounds include complex compounds in which ligands such as acetylacetone and alkoxide (methoxide, ethoxide, tert-butoxide, etc.) are coordinated to Mn ions (divalent or trivalent), and organic acid salts such as nitrates and acetates. , Carbonates, halides (fluorides, chlorides, bromides, iodides), etc., and complex compounds coordinated by ligands such as acetylacetone and alkoxides (methoxide, ethoxide, tert-butoxide, etc.), acetic acid Organic acid salts such as salts can be preferably used. Mn compounds can be used alone or in combination of two or more.

In the PC method, an Fe compound, and if necessary, a Mn compound is further dissolved in an aqueous solution in which citric acid is dissolved, and the rare earth element (M ² ) compound (for example, a rare earth element carbonate) is added to the mixture at 60 to 90 ° C. For 1 to 5 hours, add ethylene glycol, react at 100 to 150 ° C. for 3 to 8 hours, and heat. Thereafter, the precursor product of the carrier of the formula (II) can be obtained by calcination at 200 to 500 ° C. for 2 to 6 hours. In the reaction, the total amount of the Fe compound and the Mn compound is about 0.5 to 1.5 mol, preferably about 0.8 to 1.2 mol, per 1 mol of the rare earth element (M ² ) compound. Furthermore, the carrier of the formula (II) used in the present invention can be obtained by baking at 700 to 900 ° C. for 0.2 to 5 hours. The PC method can be performed in an open system.

The catalyst of the present invention is contacted by impregnating or immersing a carrier represented by the formula (II) in a solution containing a noble metal compound, or by applying a solution containing the noble metal compound to the carrier by spraying, and then calcining. Can be manufactured. As noble metal compounds, platinum compounds such as hexachloroplatinic acid, tetrachloroplatinic acid, potassium tetrachloroplatinate, sodium tetrachloroplatinate, platinum chloride, dinitrodiamineplatinum; palladium chloride, palladium nitrate, palladium sulfate, palladium acetate, etc. Palladium compounds; rhodium compounds such as rhodium chloride, rhodium sulfate, rhodium nitrate, rhodium hydroxide and acetylacetonatodium. The firing temperature is about 400 to 1000 ° C., preferably about 450 to 600 ° C. The firing time is about 10 minutes to 8 hours, preferably about 30 minutes to 2 hours. Firing can be performed under air flow.

The calcined catalyst may be used as it is as an exhaust gas purification catalyst, but a hydrogen reduction treatment may be further performed after the calcining. The hydrogen reduction treatment can be performed by heating in the presence of hydrogen. The temperature of the hydrogen reduction treatment is about 150 to 850 ° C., more preferably about 500 to 800 ° C., and the treatment time is about 30 minutes to 12 hours, preferably about 1 to 6 hours.

Since the catalyst of the present invention can treat NOx at a low temperature, it is particularly excellent as a three-way catalyst for automobile exhaust gas purification.

Hereinafter, although the present invention will be described in more detail with reference to examples, it goes without saying that the present invention is not limited to these examples.

Production Example 1: Preparation of carrier by solvothermal method (ST method) Ytterbium acetate tetrahydrate (Yb (OAc) ₃ · 4H ₂ O, 15 mmol), trisacetylacetonatoiron (III) (Fe (acac) ₃ , 9 mmol) and trisacetylacetonatomanganese (III) (Mn (acac) ₃ , 6 mmol) were ground in a mortar, and then 1,4-butanediol (1,4 -BG) Suspended in 120 ml. The total amount of Fe (acac) ₃ and Mn (acac) ₃ was 15 mmol (Fe 9 mmol, Mn 6 mmol). This suspension was transferred to an autoclave reaction tube, charged into an autoclave (300 mL), and 30 ml of 1,4-BG was added to the gap. After the atmosphere in the autoclave was replaced with nitrogen, the temperature was raised from room temperature to 315 ° C at 2.3 ° C / min and reacted for 2 hours. The product was washed with methanol and air-dried to obtain hexagonal YbFe _0.6 Mn _0.4 O ₃ . This was calcined in air at 500 ° C for 30 min to obtain a catalyst and catalyst support.

Hexagonal YbFeO ₃ containing no Mn was synthesized in the same manner as described above, with Fe (acac) ₃ of 15 mmol (Mn (acac) ₃ of 0 mmol).

Production Example 2: Preparation of carrier by complex polymerization method (PC method) Ytterbium carbonate n-hydrate (Yb ₂ (CO ₃ ) ₃ · nH ₂ O, 5 mmol), iron nitrate nonahydrate (Fe (NO ₃ )) ₃ · 9H ₂ O, 6 mmol) and manganese nitrate hexahydrate (Mn (NO ₃ ) ₂ · 6H ₂ O, 4 mmol) were dissolved in ion-exchanged water (180 ml) containing 400 mmol of citric acid. The total amount of Fe (NO ₃ ) ₃ · 9H ₂ O and Mn (NO ₃ ) ₂ · 6H ₂ O was 10 mmol. This solution was stirred at 80 ° C. for 2 h, ethylene glycol (400 mmol) was added, and the mixture was stirred at 130 ° C. for 5 h to obtain a gel product. This gel product was calcined at 350 ° C. for 4-5 h to obtain a powder, and further calcined at 800 ° C. for 30 min to obtain hexagonal YbFe _0.6 Mn _0.4 O ₃ .

Example 1 and Comparative Example 1: Preparation of hexagonal YbFe _0.6 Mn _0.4 O ₃ supported Pd catalyst and γ-Al ₂ O ₃ supported noble metal catalyst by impregnation method Hexagonal YbFe _0.6 Mn _0.4 O ₃ supported Pd catalyst was produced in Production Example 1. Or palladium (II) acetate (Pd (OAc) ₂ , 0.0021-0.0211 g) so that Pd (metal) is 0.1-1.0wt% with respect to hexagonal YbFe _0.6 Mn _0.4 O ₃ (0.99 g) prepared in ₂ . Was impregnated and supported at room temperature, dried, and fired in air at 500 ° C for 30 min. In addition, 9 ml of acetone was used as a solvent.

γ-Al ₂ O ₃ supported noble metal catalyst is precious metal (Pd, Rh, Pt) against γ-Al ₂ O ₃ (reference catalyst ALO-7 (180 m ² / g), provided by the Catalysis Society of Japan, 1.00 g) Palladium (II) acetate (Pd (OAc) ₂ , 0.0211 g), dinitrodiamine platinum aqueous solution (4.64 wt% Pt (NO ₂ ) ₂ (NH ₃ ) ₂ aq., 0.2154 g) or Trisacetylacetonatodium (III) (Rh (acac) ₃ , 0.0389 g) was added to various solvents, impregnated and supported, dried, and calcined in air at 500 ° C for 3 hours. In addition, 9 ml of acetone was used as a solvent for carrying Pd, and 9 ml of water was used for carrying Pt. For loading Rh, 9 ml of ethyl acetate was used.

Test Example 1: Catalytic Reaction The reaction was carried out using an atmospheric pressure fixed bed flow type reactor schematically shown in FIG. A catalyst (200 mg) was packed in a quartz reaction tube, and as a pretreatment, He was circulated at 30 mL min ^-1 at 500 ° C for 1 h. As a reaction gas, a mixed gas of NO: 1000 ppm, CO: 1000 ppm, C ₃ H ₆ : 250 ppm, O ₂ : 1125 ppm, He: balance was circulated through the catalyst layer at 100 mL min ⁻¹ . The outlet gas analysis was performed from 100 ° C to 500 ° C and held for 20 min every 50 ° C before the outlet gas analysis was performed. The analysis of the reaction gas was performed with two TCD-GC8A (MS-5A and Porapak Q manufactured by Shimadzu) and a NOx meter (PG-350 manufactured by Horiba). C ₃ H ₆ , CO, CO ₂ , N ₂ and N ₂ O were measured with _two TCD-GC8A (MS-5A and Porapak Q), and NO and NO ₂ were measured with a NOx meter.

Results and Discussion Figure 1 shows the amount of CO ₂ produced from CO and C ₃ H ₆ and NO _x from hexagonal YbFe _0.6 Mn _0.4 O ₃ supported Pd catalyst and Al ₂ O ₃ supported noble metal (Rh, Pd, Pt) catalyst. N ₂ production amount is shown. Tables 1 and 2 show T50 (temperature at 50% oxidation / reduction) of oxidation and NO reduction of C ₃ H ₆ and CO.

Despite the same amount of Pd supported, the oxidation of C ₃ H ₆ and CO by Pd / YbFe _0.6 Mn _0.4 O ₃ catalyst is much lower than that of any precious metal / Al ₂ O ₃ catalyst (T ₅₀ = 135 ° C) ). As for NO reduction activity, among the noble metal / Al ₂ O ₃ catalysts, the Rh / Al ₂ O ₃ catalyst showed a stable and high activity in the temperature range above 300 ° C. However, the NO reduction activity of the Pd / YbFe _0.6 Mn _0.4 O ₃ catalyst was higher at lower temperatures than the Rh / Al ₂ O ₃ catalyst. Furthermore, in the case of Pd / Al ₂ O ₃ catalyst, N ₂ O formation may be confirmed in the reaction temperature range of 350 ° C to 500 ° C, but Pd / YbFe _0.6 Mn _0.4 O ₃ catalyst has a temperature of 250 ° C or higher. By-products such as N ₂ O were not found even in the temperature range, and all NO in the reaction gas was reduced to N ₂ .

FIG. 2 shows the activity of Pd / YbFe _0.6 Mn _0.4 O ₃ catalysts with different Pd loadings. Although the NO reduction activity is reduced by reducing the loading, the NO reduction activity of the 0.5 wt% Pd / YbFe _0.6 Mn _0.4 O ₃ catalyst is the same as that of the Rh / Al ₂ O ₃ catalyst and Pd / Al _It was higher than that of ₂ O ₃ catalyst. Furthermore, the oxidation activity of C ₃ H ₆ and CO remained high even in the 0.1 wt% Pd / YbFe _0.6 Mn _0.4 O ₃ catalyst.

From the above results, it is considered that the catalyst developed in this study succeeded in reducing the amount of noble metal used and replacing or reducing the most expensive and rare Rh catalyst among the noble metal elements compared to conventional catalysts.

FIG. 3 shows the activities of the Pd / YbFe _0.6 Mn _0.4 O ₃ and the catalyst without addition of Mn with different preparation methods. The catalyst using sorbothermally synthesized YbFe _0.6 Mn _0.4 O ₃ as the support showed higher activity than that synthesized by the complex polymerization method. The catalyst using YbFeO ₃ synthesized by solvothermal as the catalyst support remained less active than that of YbFe _0.6 Mn _0.4 O ₃ . We have reported that solvothermally synthesized YbFe _0.6 Mn _0.4 O ₃ has a hexagonal plate shape, and that synthesized by complex polymerization has an irregular shape (S Hosokawa, Y. Masuda, T. Nishimura, K. Wada, R. Abe, M. Inoue, Chem. Lett., 2014, 43, 874.). We also found that the specific surface area (78 m ² / g) of the solvothermally synthesized product is much higher than that of the complex polymerized method (25 m ² / g) (S. Hosokawa, Y. Masuda, T. Nishimura, K. Wada, R. Abe, M. Inoue, Chem. Lett., 2014, 43, 874). In addition, the addition of Mn decreased the crystallite size of YbFeO ₃ and improved the specific surface area. From these results, it is considered that the physical properties unique to solvothermally synthesized YbFe _0.6 Mn _0.4 O ₃ are one of the factors that brought about high activity.

Claims (12)

Formula (I)
M ¹ / M ² Fe _x Mn _1-x O ₃ (I)
(Wherein M ¹ represents a noble metal selected from the group consisting of Pd, Rh and Pt. M ² represents a rare earth element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y. _X is 0.2 to 1.0, M ² Fe _x Mn _1-x O ₃ represents a metal composite oxide support, and M ¹ is supported on the support.
A metal composite oxide catalyst for exhaust gas purification represented by The metal complex oxide catalyst for exhaust gas purification according to claim 1, wherein M ¹ is Pd. M ² is a Yb, metal for purification of exhaust gas according to claim 1 or 2 composite oxide catalyst. The exhaust gas purifying metal composite oxide catalyst according to any one of claims 1 to 3, wherein x is 0.4 to 0.8. The metal complex oxide catalyst for exhaust gas purification according to claim 4, wherein x is 0.6 to 0.8. The noble metal M ¹ is M ² Fe _x Mn _1-x O ₃ (M ² represents a rare earth element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y. x is 0.2 to 0.2). The metal composite oxide catalyst for exhaust gas purification according to any one of claims 1 to 5, which is contained in an amount of 0.01 to 2% by mass with respect to the carrier represented by 1.0). The noble metal M ¹ is M ² Fe _x Mn _1-x O ₃ (M ² represents a rare earth element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y. x is 0.2 to 0.2). The metal complex oxide catalyst for exhaust gas purification according to claim 6, which is contained in an amount of 0.1 to 1.0% by mass with respect to the complex oxide represented by 1.0. The metal composite oxide catalyst for exhaust gas purification according to any one of claims 1 to 7, wherein a crystal structure of the metal composite oxide support is a hexagonal crystal structure. The metal composite oxide catalyst for exhaust gas purification according to claim 1, wherein M ¹ is Pd and M ² is Yb. The exhaust gas purifying metal composite oxide catalyst according to any one of claims 1 to 9, wherein the metal composite oxide support is synthesized by a solvothermal method. A rare earth element compound, Fe compound, or Mn compound selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y is dissolved or suspended in a solvent and heated to the following formula (II)
M ² Fe _x Mn _1-x O ₃ (II)
(In the formula, M ² represents a rare earth element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y. x is 0.2 to 1.0.)
And a step of contacting the obtained carrier with a Pd compound, Rh compound or Pt compound solution and calcining it.
M ¹ / M ² Fe _x Mn _1-x O ₃ (I)
(Wherein M ¹ represents a noble metal selected from the group consisting of Pd, Rh and Pt. M ² represents a rare earth element selected from the group consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y. _X is 0.2 to 1.0, M ² Fe _x Mn _1-x O ₃ represents a metal composite oxide support, and M ¹ is supported on the support.
The manufacturing method of the metal complex oxide catalyst for exhaust gas purification represented by these. The method for producing a metal composite oxide catalyst for exhaust gas purification according to claim 11, wherein the solvent is 1,4-butanediol.

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