JPH0576762A - Catalyst for catalytic reduction of nitrogen oxide - Google Patents

Abstract

PURPOSE:To increase the purification efficiency of a ternary catalyst for simultaneous removal of NOx, hydrocarbon compds. and CO in exhaust gas within a wide range of fuel-air ratio by supporting a perovskite type multiple oxide represented by a specified formula on a solid acid carrier. CONSTITUTION:A perovskite type multiple oxide represented by a formula AxB1-xCyC1-yO3 is supported on zeolite or other solid acid carrier to obtain a catalyst for simultaneous removal of NOx, hydrocarbon compds. and CO in exhaust gas. In the formula, A is La or Ce, B is Ba, Sr, Ca, Mg, Pb, Zn or Co, C is Fe, Ni, Cr, Cu, V, Mo, W, Ti, Zr, Nb, Pd, Rh, Ru or Pt, 0<=x<=1 and O<=y<=1. When the catalyst is used, NOx and hydrocarbon in exhaust gas are efficiently removed within a wide range of fuel-air ratio.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalyst for catalytic reduction of nitrogen oxides, and more specifically, it simultaneously removes harmful nitrogen oxides, hydrocarbons and carbon monoxide contained in exhaust gas emitted from factories, automobiles and the like. The present invention relates to a three-way catalyst used when removing.

2. Description of the Related Art A reaction for simultaneously removing harmful components such as NO _X , HC and CO in exhaust gas is a reaction for reducing NO _X to N ₂ and a reaction for reducing HC and CO.
Since the reaction that oxidizes carbon dioxide into water and water progresses at the same time, the ratio of the amounts of oxidizing components such as oxygen and NO _x contained in the exhaust gas to reducing components such as HC and CO is extremely important. Exhaust gas treatment is performed under conditions close to the stoichiometric air-fuel ratio. However, operation at the stoichiometric air-fuel ratio contributes to deterioration of fuel efficiency, and development of a catalyst with a wide window has been desired. As conventional three-way catalyst components, platinum-rhodium, palladium-rhodium, and platinum-palladium-rhodium catalysts have shown high activity, and catalysts in which platinum-rhodium is supported on alumina have been put to practical use. Further, since these noble metal catalysts are expensive, perovskite-type composite oxides or catalysts containing palladium in them have been proposed as alternative catalysts. However, each of these catalysts showed high activity only at or near the stoichiometric air-fuel ratio. (Wide window width) Therefore, it has been desired to develop a catalyst having a wide window without sacrificing fuel efficiency. The present invention has been made in view of the above circumstances, and the purpose thereof is to be a three-way catalyst having a wide window, in other words, to be effective even under exhaust gas conditions with a large deviation from the stoichiometric air-fuel ratio. It is to provide a functional three-way catalyst.

A catalyst for catalytic reduction of nitrogen oxides using a hydrocarbon and / or an oxygen-containing compound according to the present invention as a reducing agent is a perovskite type complex oxide represented by the following formula (2). , Zeolite, crystalline aluminum silicate phosphate (SAPO), crystalline aluminum phosphate (A
LPO), crystalline aluminum metal phosphate (MAPO),
It is supported on a solid acid carrier such as alumina, titania, zirconia, or silica-alumina. A _X B _1-X C _Y C _1-Y O ₃ (2) (In the formula, A is La or Ce, B is Ba, Sr, Ca, M
g, Pb, Zn or Ag, C is Mn or Co, C is F
e, Ni, Cr, Cu, V, Mo, W, Ti, Zr, N
b, Pd, Rh, Ru or Pt, and 0 ≦ X ≦
1, 0 ≦ Y ≦ 1. ) The solid acid carrier in the present invention refers to a carrier that exhibits solid acidity in the temperature range in which it is used. Solid acidity can be confirmed by the temperature programmed desorption method using ammonia, or ins using ammonia or pyridine.
It is done by the in-FTIR method. Examples of the solid acid carrier include the following zeolite-based solid acid carriers and oxide-based solid acid carriers. (I) Zeolite-based solid acid carrier includes zeolite having excellent heat resistance such as Na-mordenite, Na-ZSM-5, Na-USY (USY: Ultrastable Y-type zeolite), an aqueous solution of ammonium salt such as ammonium sulfate, or sulfuric acid. Of the alkali metal in the zeolite and ion-exchanged with ammonium ion (NH ⁴⁺ ) or hydrogen ion (H ⁺ ). In the case of the method of ^performing ion exchange with NH ⁴⁺ , a calcination process is finally required. The zeolite-based solid acid carrier is, for example, an acid-type mordenite obtained by subjecting a mordenite-type zeolite represented by the following formula (3) to an acid treatment, and having a SiO ₂ / Al ₂ O ₃ molar ratio of 13 to 20: There, and _the molar ratio of SiO 2 / _Al 2 _{O 3} is 25 to 20
The acid type mordenite which is 0 or a part or all of the ion M in the zeolite represented by the following formula (4) is Ti ⁴⁺ , Z
Zeolite obtained by ion exchange with r ⁴⁺ or Sn ⁴⁺ may be mentioned. M ₂ [(AlO ₂ ) _2r (SiO ₂ ) ₁₀ ] .ZH ₂ O (3) (where M is an alkali metal ion and r is a value that varies depending on the synthesis conditions of the zeolite) M ′ _A [(AlO ₂ ) _p (SiO ₂ ) _q ] · Z′H ₂ O (4) (In the formula, the ion M ′ is an alkali metal ion, an alkaline earth metal ion or a hydrogen ion, and nA = p (n
Is the valence of the ion M), and q / p ≧ 5. ) (Ii) As oxide-based solid acid carriers, Al ₂ O ₃ , T
^{_{iO 2, TiO 2 / SO 4}} -, ZrO 2, ZrO 2 /
SO ₄ ^- single metal oxides such _or, SiO 2 / _Al 2 O
₃ , complex oxides such as TiO ₂ / Al ₂ O ₃ , TiO ₂ / ZrO _{2 and the} like can be mentioned. Among these, Al ₂ O ₃ , ZrO ₂ , and SiO ₂ / Al ₂ O ₃ are preferable in terms of heat resistance. (Iii) Other examples of the solid acid carrier include a kind of crystalline aluminum phosphate (ALPO) having a zeolite-like porous structure or a layered structure, and crystalline aluminum silicate phosphate (SAPO) and ALPO which are closely related substances. Part of phosphorus or phosphorus-aluminum of titanium, iron, magnesium,
Examples thereof include crystalline metal aluminum phosphate (MAPO) substituted with a metal such as zinc, manganese, or cobalt. A
The LPO type phosphate is a combination of the above-mentioned phosphoric acid source and metal source,
Using a hydrothermal synthesis method under conditions similar to those for synthesizing zeolite from a raw material in which a so-called template such as amine or quaternary ammonium is mixed with a desired combination selected from silica, silica sol, sodium silicate, etc. It can be adjusted. The main difference from the case of synthesizing zeolite is that it is generally synthesized at a higher temperature (about 150 ° C. or higher) in a pH acidic region. The composition of an ALPO type phosphate is generally Al ₂ O _3. (0.8 to 1.2).
It is represented by P ₂ O ₅ .nH ₂ O. Also, SAPO or M
In the case of APO, the maximum amount of silica and metal to be replaced is about 1/10 of the total amount of aluminum and phosphorus, but in the present invention, those which do not necessarily fall within this composition range, that is, amorphous You may use the thing containing. When the ALPO type phosphate obtained by the hydrothermal synthesis method is used as a carrier, it is generally used after being washed with water, dried and then calcined in air to remove the remaining template by incineration. The catalyst according to the present invention can be prepared, for example, by the method (1), (2) or (3) shown below. (1) La and C are added to a slurry in which a solid acid carrier is dispersed.
e, Ba, Sr, Ca, Mg, Pb, Zn, Ag, M
n, Co, Fe, Ni, Cr, Cu, V, Mo, W, T
The water-soluble salts such as nitrates of i, Zr, Nb, Pd, Rh, Ru, or Pt, and the method of introducing an alcohol solution into these alkoxides and neutralizing or hydrolyzing them are used as the solid acid carrier. A perovskite compound precursor such as a hydroxide of a composite metal species is supported. Then, filtration, washing with water, and repulping are repeatedly performed, followed by drying and firing. (2) The solid acid carrier and the separately prepared perovskite compound are thoroughly wet-milled and mixed by a planetary mill or the like. (3) A precursor such as a water-soluble salt or hydroxide of a solid acid carrier, and La, Ce, Ba, Sr, Ca, Mg, Pb, Z
n, Ag, Mn, Co, Fe, Ni, Cr, Cu, V,
Mo, W, Ti, Zr, Nb, Pd, Rh, Ru or P
A precipitate is formed by a method of neutralizing or hydrolyzing a solution obtained by homogeneously mixing a water-soluble salt such as a nitrate of t or an alcohol solution of these alkoxides. Next, this precipitate is repeatedly filtered, washed with water and repulped, then dried and calcined. In the above method, it is preferable that the production temperature of the perovskite compound is low. The reason is that as the production temperature is lower, a perovskite compound having a larger specific surface area is obtained, and the solid acid carrier and the elements constituting the perovskite compound react to change the solid acidity of the solid acid carrier, or the perovskite compound. This is because it is possible to avoid a decrease in the activity of the catalyst due to a decrease in the production amount of. Therefore, Al ₂
In the case of using a solid acid carrier having high reactivity with an element forming the perovskite compound such as O ₃ or TiO ₂ , homogeneity of the element forming the solid acid carrier and the element forming the perovskite compound The method (3) for increasing the value is not preferable. Generally, the method (1) is preferable, but the method (2) can also give a catalyst having a considerably high activity. A suitable amount of the perovskite compound supported is 1.0 to 50% by weight based on the total weight of the perovskite compound and the solid acid carrier. 50% by weight
If not less than that, not only the effect of addition corresponding to the increase in amount cannot be obtained, but also in the reaction system in which oxygen coexists, the purification rate of hydrocarbons and carbon monoxide by oxygen becomes high, but the purification rate of NO _X significantly decreases. On the other hand, if less than 1.0% by weight, N
It is not possible to sufficiently improve the purification rate of any of O, hydrocarbons and CO. The catalyst according to the present invention can be molded into various shapes such as a honeycomb shape and a spherical shape by a conventionally known molding method. At the time of this molding, a molding aid, a molded body reinforcing material, an inorganic fiber, an organic binder and the like may be appropriately mixed. It is also possible to carry the coating on a preformed base material by a wash coating method or the like. Other,
It is also possible to use a conventionally known catalyst preparation method. The optimum temperature at which the catalyst according to the present invention exhibits purifying activity for nitrogen oxides, hydrocarbons and carbon monoxide varies depending on the catalyst species,
The temperature is usually 100 to 800 ° C., and in this temperature range, it is preferable to flow the exhaust gas at a space velocity (SV) of about 500 to 100,000. A more suitable operating temperature range is 200 to 800 ° C. The air-fuel ratio (A / F) at which the catalyst according to the present invention effectively functions is 14.0.
-60, preferably 14.0-40, more preferably 14.0-30.

EXAMPLES The present invention will be described in more detail based on the following examples.
However, the present invention is not limited to the following examples.
Rather, change as appropriate within the scope of not changing the gist
It can be carried out. (1) Adjustment of catalyst Example 1 La (NO_Three)_Two・ 6H_TwoO, Mn (Ac)_Two・ 4H_Two
O (Ac: CH_ThreeCOOH, the same below), Sr (NO
_Three)_Two, Co (NO_Three)_Two・ 6H_TwoO for 101.
05g, 28.60g, 74.08g, 135.83g
Weighed and dissolved in 500 ml of water. Enough for this solution
121g / l NaOH aqueous solution was added to
The pH was adjusted to 10. After completion of the neutralization reaction, stir for 18 hours
And continued aging. Then, filter, wash, repulp
Until the conductivity of the filtered water is almost the same as the repulping water.
Repeated. The filter cake obtained is heated at 120 ° C. at 18:00.
And dried at 700 ° C. for 3 hours. Got
As a result of obtaining the XRD of the fired product, the perovskite crystal phase was found to be
It turned out that it was generating. Also, BET of this baked product
The specific surface area by the method (the following specific surface areas are also by the same method),
23.7m^Two/ G (La_0.4Sr_0.6Co
_0.8Mn_0.2O_Three). Perovs thus obtained
Obtained by 30g of Kite compound and titanium oxide process of sulfuric acid method
Metatitanic acid (TiO_Two・ H_TwoO) at 600 ° C for 3 o'clock
Activated titanium oxide obtained by calcining (specific surface area: 104.2
m^Two/ G) to a mixture with 100 g, add 100 g of water,
Grind and mix for 30 minutes with a planetary mill, and adjust the viscosity with water.
A slurry for washcoat was obtained. This slurry
For 1.25 mm pitch cordierite honeycomb
Apply to support catalyst and obtain prototype sample (A-1)
It was The coating amount of the slurry at this time is 1 cc of honeycomb.
It was 0.116 g. Example 2 La (NO_Three)_Two・ 6H_TwoO and Mn (Ac)_Two・ 4H_Two
89.5 g and 50.66 g of O are weighed, and then
Then, in the same manner as in Example I, the perovskite compound
(LaMnO_Three) Got. Of this perovskite compound
Specific surface area is 29.1m^Two/ G. Like this
30 g of the perovskite compound obtained by
To a mixture with 100 g of γ-alumina, add 100 g of water
Obtain a slurry and then apply it to the same honeycomb as in Example 1.
To support the catalyst and form a 1.25 mm pitch honeycomb
A prototype sample (A-2) was obtained. Slurry at this time
Coating amount is 0.094 g per 1 cc of honeycomb
It was. Example 3 La (NO_Three)_Two・ 6H_TwoO, Pb (NO_Three)_Two, Mn
(Ac)_Two・ 4H_Two71.60 g and 13.6 O respectively
Weigh 9g, 50.66g and mix, then 800 ° C
By the same method as in Example I except that it was baked for 3 hours.
The perovskite compound (La_0.8Pb_0.2Mn
O_Three) Got. Specific surface area of this perovskite compound
Is 23.7m^Two/ G. The bae obtained in this way
30 g of the Robskite compound and γ-Al manufactured by Sumitomo Chemical Co., Ltd.
Add 100g of water to a mixture with 100g of Mina and add slurry
And then coating the same honeycomb as in Example 1 to obtain the catalyst.
Supporting 1.25mm pitch honeycomb prototype
A sample (A-3) was obtained. Application of slurry at this time
The amount was 0.117 g per cc of honeycomb. Example 4 La (NO_Three)_Two・ 6H_TwoO, Co (NO_Three)_Two・ 6H
_Two88.07g and 59.19g of O are respectively weighed and mixed.
And then fired at 800 ° C. for 3 hours.
In the same manner as in I, the perovskite compound (LaCo
O_Three) Got. Specific surface area of this perovskite compound
Is 17.47m^Two/ G. Got this way
30 g of perovskite compound and H type model made by Nippon Kagaku
To a mixture with 100 g of rudenite (HM-23), water 1
00 g was added to obtain a slurry, and then the same procedure as in Example 1 was performed.
1.25mm pitch by applying to Nicam to support catalyst
A honeycomb-shaped prototype sample (A-4) was obtained. this
At this time, the coating amount of the slurry was 0.
It was 113 g. Example 5 Ce (NO_Three)_Two・ 6H_TwoO, Ba (NO_Three)_Two, Co
(NO_Three)_Two・ 6H_TwoO, 70.65 g, 10.
63 g, 59.19 g, then weighed as in Example 1.
The perovskite compound (Co_0.8Ba
_0.2CoO_Three) Got. Of this perovskite compound
Specific surface area is 23.0m^Two/ G. Like this
30 g of the perovskite compound obtained by
H-type mordenite (trade name "HM-23") 100g
100 g of water was added to the mixture of above to obtain a slurry, and
The same honeycomb as in Example 1 was applied to support a catalyst,
Prototype sample (A-
5) was obtained. The coating amount of the slurry at this time is 1
It was 0.130 g per cc. Example 6 La (NO_Three)_Two・ 6H_TwoO, Mn (Ac)_Two・ 4H_Two
O, TiCl_FourAqueous solution (Ti as 14.82 g / 10
0 ml aqueous solution), 90.84 g, 25.7 respectively
Weigh 1 g, 339.0 ml, then as in Example I
Method, the perovskite compound (LaMn_0.5T
i_0.5O_Three) Got. The ratio of this perovskite compound
Surface area is 25.3m^Two/ G. In this way
10 g of the obtained perovskite compound and Nippon Arosil
Silica-alumina (trade name "COK-84") 100
To the mixture with g, add 100 g of water to obtain a slurry, then
Then, the same honeycomb as in Example 1 was applied to support the catalyst.
1.25mm pitch honeycomb prototype sample
(A-6) was obtained. The coating amount of the slurry at this time is
It was 0.098 g per 1 cc of Nicam. Example 7 <Preparation of perovskite compound> La manufactured by Shiramizu Chemical Co., Ltd.
Ethoxide solution in ethanol (La_TwoO_ThreeAs 73g
/ L concentration solution), the company's Ba ethoxide ethanol
Solution (79 g / l concentration solution as BaO), manufactured by the same company
Ethanol solution of Ni ethoxide (67 g as NiO
/ L concentration solution), ethanol solution of Co ethoxide
(Solution of 91 g / l concentration as CoO)
0.0 ml, 21.74 ml, 49.95 ml, 9.2
2 ml is weighed and mixed.
Ammonia aqueous solution was gradually added dropwise for hydrolysis. Next
Then, evaporate it to dryness with uniform mixing at 600 ° C.
After firing for 3 hours, the perovskite compound (La_0.8Ba
_0.2Co_0.8Ni_0.2O_Three) Got. This perov
Specific surface area of the skylite compound is 36.9m^Two/ G
It was <Preparation of SAPO-34> Do not stir in 129.6 g of water.
Finely ground aluminum isopropoxide 90.
7 g was added little by little and mixed with stirring until uniform. This
51.3 g of 85% phosphoric acid aqueous solution was added dropwise to the mixed solution of
50% silica sol after stirring and mixing until it becomes 1
16.0 g was added and thoroughly mixed with stirring. Then hydroxylation
Add 81.6 g of tetraethylammonium and stir well.
Mix with stirring. Charge this mixture into an autoclave,
After reacting with stirring at 200 ° C. for 24 hours, the product was filtered off.
Separate, wash with water and dry, then air at 500 ° C for 3 hours.
Calcination in to obtain SAPO-34. This SAPO-3
4, Si, Al and P are 9.5, 18.0 and 1 respectively.
The composition contained 9.0% by weight. in this way
25 g of the perovskite compound obtained by
To the mixture with APO-34, 100 g of water was added and the slurry was added.
And then coated on the same honeycomb as in Example 1 and touched.
A medium-supported 1.25 mm pitch honeycomb-shaped sample
A working sample (A-7) was obtained. Slurry coating at this time
The amount of cloth was 0.138 g per 1 cc of the honeycomb. Example 8 La (NO_Three)_Three・ 6H_TwoO, Sr (NO_Three)_Two, Co
(NO_Three)_Two・ 6H_TwoO, Fe (NO_Three)_Two・ 6H_TwoO
Respectively 101.05 g, 74.08 g, 135.83
g and 33.60 g were weighed and mixed, and the same as in Example 1
The perovskite compound (La_0.4Sr
_0.6Co_0.8Fe_0.2O_Three) Got. This perov
Specific surface area of the skylite compound is 21.6m^Two/ G
It was 30 g of the perovskite compound thus obtained
And a mixture of 100 g of γ-alumina manufactured by Sumitomo Chemical Co., Ltd.
To 100 g of water to obtain a slurry.
It is applied to the same honeycomb to support the catalyst, 1.25m
Obtained a m-pitch honeycomb-shaped prototype sample (A-8)
It was The coating amount of the slurry at this time is 1 cc of honeycomb.
It was 0.098 g. Example 9 La (NO_Three)_Three・ 6H_TwoO, Zn (NO_Three)_Two・ 6H
_TwoO, Co (NO_Three)_Two・ 6H_TwoO, Cu (NO_Three)_Two
・ 3H_TwoO is 202.10 g, 28.41 g, 1
35.83 g and 28.19 g were weighed and mixed, and
In the same manner as in 1, the perovskite compound (La
_0.8Zn_0.2Co_0.8Cu_0.2O_Three) Got.
The specific surface area of this perovskite compound is 17.3 m.^Two
/ G. The perovskite compound thus obtained
Of 30 g and 100 g of γ-alumina manufactured by Sumitomo Chemical Co., Ltd.
To the mixture, add 100 g of water to obtain a slurry, then carry out
The same honeycomb as in Example 1 was applied to support a catalyst, and
25 mm pitch honeycomb-shaped prototype sample (A-
9) was obtained. The coating amount of the slurry at this time is
It was 0.083 g per cc. Example 10 La (NO_Three)_Three・ 6H_TwoO, AgNO_Three, Co (NO
_Three)_Two・ 6H_TwoO, Zr (NO_Three)_Four・ 5H_TwoO for each
202.10g, 19.82g, 135.83g, 6
9.87 g were weighed and mixed, and the same procedure as in Example 1 was performed.
The perovskite compound (La_0.8Ag_0.2Co
_0.8Zr_0.2O_Three) Got. This perovskite conversion
The specific surface area of the compound is 17.3m^Two/ G. This
30 g of the perovskite compound thus obtained and Sumitomo Chemical
100 g of water in a mixture with 100 g of γ-alumina manufactured by the company
In addition, a slurry was obtained, and then the same honeycomb as in Example 1 was obtained.
To support the catalyst and apply 1.25 mm pitch
A cam-shaped prototype sample (A-10) was obtained. At this time
The amount of slurry applied is 0.09 per cc of honeycomb.
It was 7 g. Example 11 La (NO_Three)_Three・ 6H_TwoO, Sr (NO_Three)_Two, Co
(NO_Three)_Two・ 6H_TwoO, Cr (NO_Three)_Three1 for each
01.05 g, 74.08 g, 135.83 g, 27.
79 g were weighed and mixed, and in the same manner as in Example 1,
Perovskite compound (La_0.4Sr_0.6Co
_0.8Cr_0.2O_Three) Got. This perovskite conversion
Specific surface area of compound is 20.3m^Two/ G. <Preparation of ALPO-5> 69.2 g of 85% phosphoric acid and 17 parts of water
Pseudo-boehmite powder (alumina 67
%, Acetic acid 9.5%) 45.8 g added little by little
And mixed with stirring until uniform. To this solution,
Add 43.8 g of pyramine and stir to mix until uniform
did. This mixture was placed in an autoclave and heated to 150 ° C.
After reacting with stirring for 70 hours, the product is separated by filtration and washed with water.
After washing and drying, calcination in air at 500 ° C for 3 hours A
LPO-5 was obtained. This ALPO-5 contains Al and P.
Of which the composition contains 18.0 and 22.0% by weight, respectively
there were. The perovskite compound 30 thus obtained
g and 100 g of ALPO-5 in a mixture, water 100
g to obtain a slurry, and then the same honeycomb as in Example 1
Applied to the aluminum plate to support the catalyst, and the
A Nicam-shaped prototype sample (A-11) was obtained. This and
The coating amount of mushroom slurry is 0.1 per 1 cc of honeycomb.
It was 04 g. Example 12 <Preparation of perovskite compound> La (NO_Three)_Two・ 6
H_TwoO, Sr (NO_Three)_Two, Co (NO_Three)_Two・ 6H_Two
O, NbCl₅(Hydrochloric acid aqueous solution, 50 g / l concentrated as Nb
101.05 g, 74.08 g, 1
35.83g, 216.81ml Weigh and mix,
In the same manner as in Example 1, the perovskite compound (La_0.4
Sr_0.6Co_0.8Nb_0.2O_Three) Got. This pen
The specific surface area of the rovskite compound is 18.9 m^Two/ G
there were. <Preparation of MAPO-5> 4.9 g of manganese acetate and vinegar
4.1 g of cupric acid and 129 g of water are stirred in a liquid
While finely crushed aluminum isopropoxide 5
Add 6.3 g little by little, stir and mix until uniform
It was To this solution, 55.4 g of 85% phosphoric acid, diethyl ethano
A mixture of 56.3 g of water amine and 55.5 g of water is stirred.
While adding little by little, the mixture was stirred and mixed until uniform. This
Charge the solution in an autoclave and let it stand at 200 ° C for 25 hours.
After reaction, the product is separated by filtration, washed with water and dried,
MAPO-5 was obtained by baking in air at 500 ° C. for 3 hours.
It was This MAPO-5 contains Al, P, Mn, Cu
Contains 19.0, 19.0, 2.8 and 4.4% by weight, respectively.
The composition was Perovska obtained in this way
Mixing 25 g of ito compound with 100 g of MAPO-5
100 g of water was added to the product to obtain a slurry, and then Example 1
Coated on the same honeycomb as above to support the catalyst, 1.25
Prototype sample of honeycomb shape with mm pitch (A-12)
Got The coating amount of the slurry at this time is the honeycomb 1c.
It was 0.116 g per c. Example 13 In Example 1, instead of activated titanium oxide, zirconium hydroxide was used.
ZrO obtained by firing conium at 600 ° C. for 3 hours_Two(ratio
Surface area: 148.3m^Two/ G) was used except that
A prototype sample (A-13) was obtained in the same manner as in Example 1. This
In this case, the coating amount of the slurry is 1 cc of honeycomb.
It was 0.139 g. Example 14 <Preparation of perovskite compound> La (NO_Three)_Two・ 6
H_TwoO, Sr (NO_Three)_Two, Co (Ac)_Two・ 4H_TwoO
88.07 g, 10.76 g and 50.66 g, respectively.
Weighed and dissolved in 500 ml of water. 121 g / l Na
Add the OH solution dropwise with sufficient stirring to adjust the pH of the solution.
It was set to 10. After completion of the neutralization reaction, continue stirring for 18 hours for aging
I went. After that, filtration, washing with water, and re-pulsing the filtered water.
Repeat until the conductivity is about the same as that of the water for repulsion.
After returning, the filter cake was dried at 120 ° C. for 18 hours.
This dried product is crushed and dissolved in vanadyl oxalate.
Liquid (100 g / l concentration aqueous solution as V) 25.90 m
1 kneaded well and evaporated to dryness.
For 3 hours and then calcined at 850 ° C for 3 hours to give Perovska
Ito compound (La_0.8Sr_0.2Co_0.8V_0.2
O_Three) Got. Specific surface area of this perovskite compound
Is 12.8m^Two/ G. <Silica-zirconia
Preparation> Nissan Chemical Co., Ltd. silica sol O type (SiO_TwoAs 20 layers
% Concentration) and zirconium chloride (ZrCl_Four)
Weigh 100.0 g and 97.20 g respectively and fill while stirring.
The components were mixed, and the total amount was adjusted to 500 ml with water. In this liquid,
121 g / l NaOH aqueous solution was added dropwise to adjust the pH to 10.
did. After completion of the neutralization reaction, stirring was continued for 18 hours and then filtered.
Repeat filtration, washing with water and re-pulp to obtain a filter cake.
The filter cake is dried at 120 ° C for 18 hours and calcined for 3 hours
It was The specific surface area of the obtained fired product is 297 m.^Two/ G
It was. Perovskite compound 3 thus obtained
In a mixture of 0 g and 100 g of the above fired product, 100 g of water
, And dry pulverize and mix with a planetary mill for 30 minutes, and then add water
The viscosity was adjusted with to obtain a washcoat slurry. This
Slurries of 1.25 mm pitch manufactured by Cordierite
Samples are applied by coating on the honeycomb of
(A-14) was obtained. The coating amount of the slurry at this time is
It was 0.127 g per 1 cc of honeycomb. Example 15 <Preparation of perovskite compound> In Example 14,
Ammonium molybdate instead of vanadyl oxalate solution
Ammonia aqueous solution of um (MoO_TwoAs 25 g / l
(Concentration of aqueous solution) except that 260.22 ml was added
In the same manner as in Example 14, the perovskite compound (La
_0.8Sr_0.2Co_0.8Mo_0.2O_Three) Got. <Preparation of Zr-mordenite> Namol manufactured by Nippon Kagaku Co., Ltd.
Denit (NM-100P) 100 g with zirconyl nitrate
Aqueous solution (ZrO_TwoAs 100 g / l concentration)
While soaking and stirring, hold at 70 ° C for 1 hour to convert Na into Zr
Ion-exchanged. Zeolite case obtained by filtration and washing with water
After the ki was dried, it was baked at 650 ° C. for 4 hours. This zeolite
The content of Zr in (Zr-mordenite) is 3.3 weight.
%, And the specific surface area is 391 m^Two/ G. This
30 g of the perovskite compound obtained by
-To a mixture with 100 g of mordenite, add 100 g of water.
E, pulverize and mix with a planetary mill for 30 minutes, then add viscosity with water
A slurry for washcoat was prepared. This slur
Lee is a 1.25 mm pitch cordierite Hani
The sample was coated on the cam to support the catalyst, and a prototype sample (A-1
5) was obtained. The coating amount of the slurry at this time is
It was 0.135 g per cc. Example 16 Instead of the vanadyl oxalate aqueous solution in Example 14,
Ammonium metatungstate aqueous solution (WO_ThreeAs
50% by weight aqueous solution) except that 23.58 g was added.
In the same manner as in Example 14, the perovskite compound (La
_0.8Sr_0.2Co_0.8M_0.2O_Three) Got. This
The specific surface area of the perovskite compound is 13.6 m^Two/
It was g. Perovskite compound thus obtained
30 g and γ-alumina manufactured by Sumitomo Chemical Co., Ltd. (trade name “A-
11 ") Add 100 g of water to a mixture with 100 g
Dry and pulverize for 30 minutes in a star mill, and then adjust the viscosity with water.
A slurry for washcoat was obtained. This slurry
For 1.25 mm pitch cordierite honeycomb
Apply the catalyst to support the catalyst and make a prototype sample (A-16).
Obtained. The coating amount of the slurry at this time is 1 cc of the honeycomb.
It was 0.135 g per unit. Example 17 La (NO_Three)_Three・ 6H_TwoO, Sr (NO_Three)_Two, Co
(NO_Three)_Two・ 6H_TwoO, H_TwoPtCl₆・ 6H_TwoO
173.20 g, 126.98 g, 276.48 respectively
g, weigh 25.90 g and dissolve in 1000 ml of water
It was 121g / l NaOH aqueous solution was added to this water solution.
While dropping, the pH was adjusted to 10. End of hydrolysis reaction
After that, stirring was continued for 18 hours. Then, in the same manner as in Example 1,
The perovskite compound (La_0.4Sr_0.6Co
_0.95Pt_0.05O_Three) Got. This perovsky
The specific surface area of the compound is 27.6 m^Two/ G. This
30 g of the perovskite compound obtained as described above and Sumitomo
Γ-Alumina (trade name "A-11") manufactured by Kagaku Co., Ltd. 100
Add 100g of water to the mixture with 30g and add 30g with a planetary mill.
Pulverize and mix for 1 minute, adjust the viscosity with water and wash
A slurry for polishing was obtained. Add this slurry to a 1.25 mm
Coated on a cordierite honeycomb manufactured by
It was carried to obtain a trial sample (A-17). At this time
The amount of slurry applied is 0.12 per cc of honeycomb.
It was 3 g. Example 18 In Example 17, H_TwoPtCl₆・ 6H_TwoInstead of O
Rh (NO_Three)_Three・ 2H_Two16.25 g of O was used
Except for the above, carry out the same method as in Example 17 to give Perovska.
Ito compound (La_0.4Sr_0.6Co_0.95Rh
_0.05O_Three) Got. The ratio of this perovskite compound
Surface area is 29.6m^Two/ G. In this way
30 g of the obtained perovskite compound and γ manufactured by Sumitomo Chemical Co., Ltd.
-Mixture with 100 g of alumina (trade name "A-11")
To the above, add 100g of water and crush and mix for 30 minutes with a planetary mill
Then, adjust the viscosity with water and wash slurry for wash coat.
I got it. Use this slurry with a 1.25 mm pitch cord
It was applied to a Ulite honeycomb to support the catalyst and then tested.
A working sample (A-18) was obtained. Of the slurry at this time
The coating amount was 0.129 g per cc of honeycomb.
It was Example 19 In Example 17, H_TwoPtCl₆・ 6H_TwoInstead of O
PdCl_TwoExample 1 except that 8.67 g was used.
In the same manner as in 7, the perovskite compound (La_0.4S
r_0.6Co_0.95Pd_0.05O_Three) Got. this
The specific surface area of the perovskite compound is 28.5 m^Two/ G
Met. Perovskite compound 3 thus obtained
0 g and γ-alumina manufactured by Sumitomo Chemical Co., Ltd. (trade name “A-1
1 ”) Add 100 g of water to a mixture with 100 g
Grind for 30 minutes in a mill and adjust the viscosity with water.
A slurry for washcoat was obtained. This slurry
For 1.25 mm pitch cordierite honeycomb
Apply the catalyst to support the catalyst and make a prototype sample (A-19).
Obtained. The coating amount of the slurry at this time is 1 cc of the honeycomb.
It was 0.122 g per unit. Example 20 In Example 17, H_TwoPtCl₆・ 6H_TwoInstead of O
RuCl_Four・ 5H_TwoSince 16.15 g of O was used
Except that the perovskite compound (L
a_0.4Sr_0.6Co_0.95Ru_0.05O_Three)
Obtained. The specific surface area of this perovskite compound is 25.
3m^Two/ G. Perovsky obtained in this way
Compound of 30 g and γ-alumina manufactured by Sumitomo Chemical Co., Ltd.
100 g of water in a mixture with 100 g of name "A-11")
In addition, pulverize and mix with a planetary mill for 30 minutes, and then further mix with water.
To prepare a slurry for washcoat. This
The rally is a cord made by the cordierite company of 1.25mm pitch.
The sample was coated on Nicam to support the catalyst, and a prototype sample (A-
20) was obtained. The amount of slurry applied at this time is
It was 0.129 g per 1 cc of mu. Example 21 In Example 3, the perovskite compound (LaCoO 2
_Three) And H-type mordenite manufactured by Nippon Kagaku Co., Ltd.
M-23 ") and 1g and 100g respectively
Is the same as in Example 3 and has a 1.25 mm pitch
A prototype sample (A-21) having a worm shape was obtained. At this time
The amount of slurry applied is 0.929 per cc of honeycomb.
It was g. Example 22 In Example 3, the perovskite compound (LaCoO 2
_Three) And H-type mordenite manufactured by Nippon Kagaku Co., Ltd.
M-23 ") and 10 g and 100 g respectively were used.
Except for this, in the same manner as in Example 3, a 1.25 mm pitch
A Nicam-shaped prototype sample (A-21) was obtained. This and
The amount of mushroom slurry applied is 0.9 per 1 cc of honeycomb.
It was 48 g. Example 23 In Example 3, the perovskite compound (LaCoO 2
_Three) And H-type mordenite manufactured by Nippon Kagaku Co., Ltd.
M-23 ") and 50 g and 100 g respectively
Except for this, in the same manner as in Example 3, a 1.25 mm pitch
A trial sample (A-23) having a Nicam shape was obtained. This and
The coating amount of mushroom slurry is 0.1 per 1 cc of honeycomb.
It was 09 g. Example 24 In Example 3, the perovskite compound (LaCoO 2
_Three) And H-type mordenite manufactured by Nippon Kagaku Co., Ltd.
M-23 ") and 50 g and 100 g respectively
Except for this, in the same manner as in Example 3, a 1.25 mm pitch
A prototype sample (A-24) having a Nicam shape was obtained. This and
The coating amount of mushroom slurry is 0.1 per 1 cc of honeycomb.
It was 22 g. Example 25 Compositional formula: Nax [(AlO_Two)_X・ (SiO_Two)_Y]
ZH_TwoCommercial product of sodium-type mordenite represented by O
(Nippon Mobile Co., product name "ZSM-5", Y / X-
35) 100 g of 0.025 mol / l TiOSO_Fourwater
It was immersed in 1 liter of the solution and stirred thoroughly. This
Temperature rising rate of 100 ° C / hour while stirring in an autoclave
Temperature and hold at 125 ° C for 1 hour._FourTo
After hydrolyzing and ion-exchanging Na with Ti,
Separately, it was washed with water to obtain a zeolite cake. Then this
After drying the cake, bake at 650 ° C for 4 hours and zeola
I got it. The content of Ti in this zeolite is TiO
_TwoWas 2.4% by weight. Got this way
Use Ti-ZSM-5 instead of H-type mordenite
In the same manner as in Example 3 except for and,
A honeycomb-shaped prototype sample (A-25) was obtained. this
At this time, the coating amount of the slurry was 0.
It was 110 g. Comparative Example 1 In Example 1, without using active titanium oxide, perov
Skytite compound (La_0.4Sr_0.6Co_0.8Mn
_0.2O_Three) Only for washcoat slurry
Other than the above, in the same manner as in Example 1, a 1.25 mm
A honeycomb-shaped comparative sample (B-1) was obtained.
The coating amount of the slurry at this time is 1 cc of honeycomb.
It was 0.132 g. (2) Evaluation test The samples (A-1) to (A-25) and the comparative sample
For pull (B-1), set A / F to 1 under the following test conditions.
Nitrogen oxide by changing the range of 4.0-40
CO and C_ThreeH₆A purification test of contained gas was performed. (Test conditions) (1) Gas composition NO 1000ppm CO 1% C_ThreeH₆ 1000ppm CO_Two 10% A / F 14-40 (2) Space velocity 10000 l / Hr (3) Reaction temperature 300 ° C, 400 ° C, 500
C or 600 C The results are shown in Tables 1 to 3. From Tables 1 and 2, the catalyst according to the present invention [prototype sample (A
-1) to (A-25)] are all nitrogen oxides and CO
And C_ThreeH₆The purification rate of
Comparative samples (B-1) and (B-2)] are generally
It can be seen that the purification rate is low.

As described in detail above, the three-way catalyst according to the present invention can efficiently purify nitrogen oxide CO and hydrocarbons in exhaust gas in a wide A / F range. The present invention has excellent unique effects.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B01J 23/80 A 8017-4G 23/85 A 8017-4G 23/89 A 8017-4G 29/04 A 6750-4G 29/18 A 6750-4G 29/28 A 6750-4G

Claims (1)

[Claims] 1. A nitrogen oxide, a hydrocarbon compound and carbon monoxide in exhaust gas are simultaneously removed, which is characterized in that a perovskite type complex oxide represented by the following formula (1) is supported on a solid acid carrier. Catalyst for doing. A _X B _1-X C _Y C _1-Y O ₃ (1) (In the formula, A is La or Ce, B is Ba, Sr, Ca,
Mg, Pb, Zn or Ag, C is Mn or Co, C is F
e, Ni, Cr, Cu, V, Mo, W, Ti, Zr, N
b, Pd, Rh, Ru or Pt, and 0 ≦ X ≦
1, 0 ≦ Y ≦ 1. )