JPH07289910A - Catalyst for purifying exhaust gas - Google Patents

Abstract

PURPOSE:To provide a catalyst for purifying exhaust gas effectively acting even within a lean burn region wherein the air/fuel ratio of an internal combustion engine such as a car engine is low and excellent in heat resistance and durability even when the catalyst is used for a long time at high temp. CONSTITUTION:In a catalyst for purifying exhaust gas obtained by further adding at least one kind of a metal component selected from a group consisting of alkali metal, alkaline earth metal and rare earth metal to a catalyst obtained by adding a copper(Cu) component and a phosphorous(P) component to inorg. matter based on crystalline aluminosilicate, the contents of Cu and P are respectively set to 4-15wt.% and 0.01-1.7wt.% with respect to crystalline aluminosilicate from which adsorbed water is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying catalyst, and in particular, it works effectively even when the air-fuel ratio of an internal combustion engine such as an automobile engine is in the lean burn region.
Moreover, the present invention relates to an exhaust gas-purifying catalyst that has excellent heat resistance and durability even when used at high temperatures for a long time.

[0002]

2. Description of the Related Art Conventionally, as a catalyst for purifying exhaust gas from an internal combustion engine, activated alumina is generally used as Pd, Pt and R.
Those carrying a noble metal component such as h are used. This catalyst is called a three-way catalyst because it can remove hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NO _x ) at once.

However, this catalyst is effective only when the internal combustion engine is operated under conditions close to the stoichiometric air-fuel ratio (stoichiometric ratio), the oxygen content is high, and the internal combustion engine is operated under lean conditions with better fuel economy. In this case, there is a drawback that a sufficient NO _x removal performance cannot be obtained.

Under such lean conditions, it is known that a catalyst composed of a zeolite carrying metal ion exchange is effective for removing NO _x [eg, Iwamoto,
Proceedings of a brief discussion “Catalyst Technology for Nitrogen Oxide Reduction”
p71 (1990)]. In particular, a Cu-zeolite catalyst in which Cu is supported on zeolite by an ion exchange method exhibits excellent performance in a high gas space velocity (GHSV) and a relatively wide temperature range.

However, when this catalyst is exposed to a high temperature of 600 ° C. or higher, it undergoes rapid thermal deterioration, cannot withstand long-term use, and has not been put to practical use. It is considered that the main cause of the activity deterioration when the above catalyst is exposed to high temperature is that Cu ions retained at the ion exchange sites in zeolite move by heat and cause sintering. For this reason, methods for stabilizing Cu ions by various additives have been vigorously studied and proposed.
It is hard to say that we are still getting sufficient results.

Japanese Unexamined Patent Publication (Kokai) No. 3-131345 proposes a highly durable catalyst in which zeolite is loaded with at least one alkaline earth metal selected from the group consisting of Cu, Ca, Sr and Ba. ing. According to this patent publication, among these alkaline earth metals, particularly Ba has a remarkable effect of improving the catalyst durability even though the addition thereof reduces the Cu content of the active ingredient. . Further, regarding Ca, it is said that the durability of the catalyst can be enhanced without lowering the Cu content.

Japanese Unexamined Patent Publication (Kokai) No. 3-202157 proposes a highly durable catalyst in which zeolite is loaded with Cu and at least one alkaline earth metal and at least one rare earth metal. Since the conditions of the catalyst activity evaluation in this publication are the same as those in the above-mentioned JP-A-3-131345, when comparing the effects of various added metals, the effect of Ba in the above publication is remarkable.
In this publication, the addition of is described as an opposite effect. Further, this publication is interpreted as an improvement of the above-mentioned Japanese Patent Laid-Open No. 3-131345, but the catalyst that actually exhibits the highest performance is the catalyst in which Cu and Ca are combined and supported in the above publication, The effect of the composite support of alkaline earth metal and rare earth metal is unclear.

Further, in Japanese Laid-Open Patent Publication No. 3-135437, Cu is added to zeolite, and Fe (iron), Co (cobalt), Ni (nickel), V (vanadium), Mn (manganese), W (tungsten), Mo (molybdenum),
Cr (chromium), Ti (titanium), Nb (neobium)
A highly durable catalyst supporting at least one variable valence metal selected from the group consisting of is proposed. The conditions for the catalyst activity evaluation in this publication are the same as those in the above-mentioned 2 publications (Japanese Patent Laid-Open No. Hei 3 (1999) -311).
(-131345 gazette and Japanese Patent Laid-Open No. 3-202157).

However, the deterioration treatment conditions of the catalyst of this publication are relaxed as compared with the conditions of the above-mentioned publications 2. However, comparing the performances of the comparative catalysts, the treatment of this publication shows a rather severe result. Therefore, the performance level of the catalyst of the examples and the effect of adding the variable valence metal are unclear.

As described above, whether or not the durability of the catalyst can be truly improved by the method of simply adding and supporting the alkaline earth metal, the rare earth metal or the variable valence metal on the Cu-zeolite catalyst can be achieved. It is unclear as to what. In addition to the above-mentioned catalyst, for example, JP-A-4-4045
As can be seen from the publication, a catalyst added with a large number of components has been proposed, but it is not clear whether or not this catalyst is expected to have a significant effect in improving the heat resistance and durability of the catalyst.

For this reason, the present inventors have extensively and in detail studied the effect of adding various components, and as a result,
Focusing on a series of components such as B, P, Sb, and Bi, and proposing a catalyst with significantly improved heat resistance and durability by adjusting the addition amount of these components and the ratio with Cu within a specific range. (JP-A-5-170325, etc.).

[0012]

However, even with the catalyst according to the above publication, it cannot be said that the heat resistance and durability of the catalyst are sufficient in a more severe environment such as automobile exhaust gas. Development was desired. Therefore, the present invention is less deteriorated even when used at high temperature for a long time,
It is intended to provide a catalyst having excellent heat resistance and durability.

[0013]

Means and Actions for Solving the Problems The present inventors have
As a result of diligent studies to solve the above problems, as a result, an inorganic substance containing a crystalline aluminosilicate as a main component, a catalyst body containing a copper (Cu) component and a phosphorus (P) component, an alkali metal, an alkali In an exhaust gas purifying catalyst containing at least one metal component selected from the group consisting of earth metals and rare earth metals, when Cu and P are limited to a specific range, use at high temperature for a long time However, they have found that a catalyst that is less deteriorated and has excellent heat resistance and durability can be obtained, and has reached the present invention.

The above object of the present invention is to provide a catalyst body containing an inorganic material mainly composed of crystalline aluminosilicate, a copper (Cu) component and a phosphorus (P) component, and further an alkali metal or alkaline earth. In a catalyst for purification of exhaust gas, which contains at least one metal component selected from the group consisting of group metals and rare earth metals, the crystalline aluminosilicate in a state in which water having Cu and P contents adsorbed is removed. In contrast, the exhaust gas purifying catalyst is characterized in that the ranges are 4 to 15% by weight and 0.01 to 1.7% by weight, respectively. Hereinafter, the present invention will be described in more detail.

The Cu- zeolitic catalyst can be removed efficiently NO _X even in the lean region, 6
When exposed to a temperature of 00 ° C. or higher, Cu, which is an active ingredient, is sintered and deteriorates in a short time. This C
There are two possible factors in the sintering of u. One is the ease of sintering Cu and the other is the Cu holding power of the zeolite carrier. Regarding the former, C
u itself needs to be stable. Regarding the latter, since the site that retains Cu (ion exchange site) collapses due to the dealumination phenomenon of zeolite, it is important to stabilize aluminum in the zeolite skeleton.

The exhaust gas purifying catalyst of the present invention comprises a P component and at least one metal component selected from the group consisting of alkali metals, alkaline earth metals and rare earth metals, whereby the above Cu ions and zeolite are combined. It is considered that the ion exchange site is efficiently stabilized. That is, P component is Li, Na, K, Rb, C
Remarkable effects are exhibited by coexisting and interacting with metal components such as s, Mg, Ca, Sr, Ba, Ce and La.

Although the detailed mechanism described above is not clear, P
Not only the components, but also Ca, Mg, Sr and other components also have the effect of suppressing dealumination of the zeolite. Furthermore,
As a notable effect, the P component has the effect of strongly interacting with the Cu component to stabilize it, but if the interaction is too strong, the catalytic activity will decrease. It is considered that the components such as Ca, Mg, and Sr can make the interaction between the Cu component and the P component have an appropriate strength, and as a result, the thermal stability of the Cu component and the catalytic activity can both be achieved. The amount and ratio of the components are important parameters for obtaining such an effect, and the feature of the present invention is to find out the interaction effect of the P component and the components such as Ca, Mg and Sr and the range of the appropriate parameter. There is something.

The crystalline aluminosilicate used in the present invention is a zeolite, which can be appropriately selected and used from known zeolites, and the pentasil type is particularly effective. Examples of such zeolites include mordenite, ferrierite, and ZS.
M-5, ZSM-11 and the like are mentioned, and among these, S
The molar ratio of iO ₂ / Al ₂ O ₃ is preferably in the range of 20-60. SiO ₂ / Al ₂ O ₃ molar ratio is 20
If it is less than the above range, dealumination phenomenon is likely to occur, and the thermal stability is not sufficient, resulting in low catalyst durability. On the other hand, when the molar ratio exceeds 60, the amount of the active metal component supported on the zeolite becomes small and the catalytic activity becomes insufficient. In addition, zeolite has a crystal having higher crystallinity due to hydrothermal treatment, re-synthesis, or the like, and when stabilized, a catalyst having higher durability can be obtained.

In the present invention, the content of the P component is in the range of 0.01 to 1.7% by weight with respect to the crystalline aluminosilicate excluding the adsorbed water, and Ca,
The content of at least one metal component selected from the group consisting of Mg and Sr is in the range of 0.01 to 4% by weight. If the content of these is less than 0.01% by weight, the effect of the present invention is not sufficiently obtained, and conversely, the content of both components is in the above range, that is, P component is 1.7% by weight, and Ca, M
When the metal component such as g or Sr exceeds 4% by weight and becomes excessive, Cu is excessively stabilized by the P component, and thus C
The inactivation of u, or the metal components such as Ca, Mg and Sr cause a decrease in catalytic activity, which is considered to be due to the coating effect of Cu. In order to maximize the effect of the P component while suppressing the excessive stabilization of Cu by the P component, P / C
It is also important to control u (molar ratio), and in the case of the present invention, when it exceeds 0.5, inactivation of Cu becomes remarkable and the catalytic activity is lowered.

As the raw material of the P component or the metal component such as Ca, Mg and Sr, various compounds such as nitrates, inorganic acid salts, oxides, organic acid salts, chlorides, carbonates, sodium salts and ammonium salts are used. can do. The method of supporting and impregnating these components on zeolite is not limited to a special method, and various known methods such as ion exchange method, impregnation method and kneading method can be used, and further, physically. Various methods such as mixing salt can be used.

The amount of Cu supported on the zeolite is 4 to 4 with respect to the crystalline alumina silicate without adsorbed water.
It is in the range of 15% by weight. If the supported amount of Cu is less than 4% by weight, the amount of the active ingredient is not sufficient, and conversely 15% by weight.
If it exceeds, excess copper oxide (CuO) left on the surface of the catalyst becomes excessive, which causes adverse effects such as blocking of pores of the zeolite.

The raw materials of Cu are acetate, nitrate, chloride,
Various things such as ammine complex compounds can be used,
The supporting method is not limited to a special method, and a general method such as an ion exchange method or an impregnation method is used. In addition, Cu component, P component, or Ca for zeolite,
The order of loading the metal components such as Mg and Sr is not particularly limited, and several types of components may be added at once.

The shape of the catalyst of the present invention is not particularly limited, but it is usually preferable to use it in a honeycomb shape, and the catalyst powder is applied to various honeycomb-shaped base materials for use.
As the honeycomb material, a cordierite material is generally used, but a honeycomb made of a metal material can be used, and the catalyst powder itself may be formed into a honeycomb shape. By making the shape of the catalyst honeycomb, the contact area between the catalyst and the exhaust gas becomes large and the pressure loss can be suppressed, which is extremely advantageous when used for automobiles.

[0024]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto.

Example 1 H-type ZSM-5 having a SiO ₂ / Al ₂ O ₃ molar ratio of about 30.
Zeolite powder was impregnated with an aqueous solution containing orthophosphoric acid (H ₃ PO ₄ ), and 0.42% by weight of P component was supported on the zeolite powder in a state where adsorbed water was removed. The obtained P component-containing zeolite powder is stirred in a copper acetate aqueous solution,
After loading Cu component by ion exchange method, 120 ℃
And dried for 8 hours or more. The obtained dry powder was impregnated with an aqueous solution of calcium acetate, and 1.1 wt% of Ca was supported on the zeolite powder in a state where the adsorbed water was removed, and then dried at 150 ° C. for 8 hours or more.

The obtained powder was heated in the atmosphere at 550 with an electric furnace.
Z containing Cu, P and Ca components after firing at ℃ for 2 hours
SM-5 catalyst powder was obtained. Cu loading in this catalyst (Cu
(As of) 5.2% by weight. This catalyst is described as follows. Cu (5.2) -P (0.42) -Ca (1.1) / Z
SM-5 (P / Cu = 0.17)

2250 g of this catalyst powder was placed in a ball mill pot together with 1250 g of silica sol (solid content 20%) and 1500 g of water, and pulverized for 4 hours to obtain a slurry. This slurry was made of cordierite honeycomb (capacity 0.7
L), dried in a hot air drier at 120 ° C. for 1 hour, and then calcined at 400 ° C. for 1 hour to obtain a catalyst (1) of Example 1. The coating amount of the catalyst powder at this time was 170 g / L.

Example 2 The same H-type ZSM-5 zeolite as in Example 1 was stirred in an aqueous solution of calcium nitrate for 8 hours, and C was added by an ion exchange method.
After carrying 0.72% by weight of a, it was dried in a dryer at 150 ° C. for 2
It was dried for 4 hours. Then, the raw material of P was replaced with sodium pyrophosphate (Na ₄ P ₂ O ₇ ), and 0.012% by weight of P was loaded in exactly the same manner as in Example 1, and then Cu was loaded in the same manner to obtain the next catalyst powder. Obtained. Thereafter, in the same manner as in Example 1, a honeycomb catalyst (2) represented as follows was obtained. Cu (4.2) -P (0.012) -Ca (0.72)
/ ZSM-5 (P / Cu = 0.006)

Example 3 A honeycomb catalyst (3) represented as follows was obtained in exactly the same manner as in Example 1 except that the amount of P added was 0.83% by weight. Cu (5.7) -P (0.83) -Ca (1.08) /
ZSM-5 (P / Cu = 0.30)

Example 4 P was added in an amount of 1.66% by weight, and the Cu component and Ca component were loaded on the zeolite in the same manner as in Example 1,
Further, a honeycomb catalyst (4) represented as follows was obtained in exactly the same manner as in Example 1 except that the amount of Cu component supported was 6.9% by weight by impregnation with an aqueous solution of copper acetate. Cu (6.9) -P (1.66) -Ca (1.01) /
ZSM-5 (P / Cu = 0.49)

Example 5 A honeycomb catalyst (5) having a Cu component and a Ca component supported on zeolite was obtained in exactly the same manner as in Example 4, except that the amount of P added was 0.54% by weight. In the present embodiment, the Cu component loading amount is 14.8% by weight, and the Ca component loading amount is 3.89% by weight.
Increased. Cu (14.8) -P (0.54) -Ca (3.89)
/ ZSM-5 (P / Cu = 0.075)

Example 6 A honeycomb catalyst (6) was obtained in the same manner as in Example 1 except that the amount of P added was 0.45% by weight. In this embodiment,
The loading amount of the Ca component was 0.012% by weight. Cu (5.4) -P (0.45) -Ca (0.012)
/ ZSM-5 (P / Cu = 0.17)

Example 7 A honeycomb catalyst (7) was obtained in the same manner as in Example 1 except that magnesium acetate was used instead of calcium acetate. Cu (5.3) -P (0.41) -Ca (1.23) /
ZSM-5 (P / Cu = 0.16)

Example 8 Except that lithium nitrate was used instead of calcium acetate,
A honeycomb catalyst (8) was obtained in exactly the same manner as in Example 1. Cu (4.8) -P (0.38) -Li (0.87) /
ZSM-5 (P / Cu = 0.16)

Example 9 A honeycomb catalyst (9) was obtained in exactly the same manner as in Example 1 except that strontium nitrate was used instead of calcium acetate. Cu (4.8) -P (0.38) -Sr (1.1) / Z
SM-5 (P / Cu = 0.17)

Example 10 Except that potassium acetate was used instead of calcium acetate,
A honeycomb catalyst (10) was obtained in exactly the same manner as in Example 1. Cu (5.0) -P (0.38) -K (0.68) / Z
SM-5 (P / Cu = 0.16)

Example 11 Barium acetate was used instead of calcium acetate,
A honeycomb catalyst (11) was obtained in exactly the same manner as in Example 1. Cu (5.1) -P (0.41) -Ba (0.12) /
ZSM-5 (P / Cu = 0.16)

Example 12 Except that cesium nitrate was used instead of calcium acetate,
A honeycomb catalyst (12) was obtained in exactly the same manner as in Example 1. Cu (5.2) -P (0.40) -Cs (0.24) /
ZSM-5 (P / Cu = 0.16)

Example 13 Except that cerium nitrate was used instead of calcium acetate,
A honeycomb catalyst (13) was obtained in exactly the same manner as in Example 1. Cu (5.0) -P (0.38) -Ce (1.43) /
ZSM-5 (P / Cu = 0.16)

Example 14 Except that lanthanum nitrate was used instead of calcium acetate,
A honeycomb catalyst (14) was obtained in exactly the same manner as in Example 1. Cu (5.3) -P (0.38) -La (0.97) /
ZSM-5 (P / Cu = 0.15)

Example 15 A honeycomb catalyst (15) was obtained in exactly the same manner as in Example 1 except that sodium nitrate was used instead of calcium acetate. Cu (5.4) -P (0.36) -Na (0.44) /
ZSM-5 (P / Cu = 0.14)

Example 16 A honeycomb catalyst (16) was obtained in the same manner as in Example 1 except that rubidium nitrate was used instead of calcium acetate. Cu (5.3) -P (0.35) -Rb (0.32) /
ZSM-5 (P / Cu = 0.14)

Example 17 A honeycomb catalyst (17) was obtained in the same manner as in Example 1 except that a mixed aqueous solution of calcium acetate and magnesium acetate was used instead of the calcium acetate aqueous solution. Cu (5.0) -P (0.4) -Ca (0.31) ・ M
g (0.2) / ZSM-5 (P / Cu = 0.16)

Example 18 A honeycomb catalyst (18) was obtained in exactly the same manner as in Example 17, except that strontium nitrate was further added to the mixed aqueous solution of calcium acetate and magnesium acetate to use the mixed aqueous solution of three components. Cu (4.6) -P (0.35) -Ca (0.25) ・
Mg (0.17) ・ Sr (0.12) / ZSM-5 (P
/Cu=0.16)

Example 19 A honeycomb catalyst (19) was obtained in exactly the same manner as in Example 18 except that barium acetate was used instead of strontium nitrate. Cu (4.5) -P (0.32) -Ca (0.25) ・
Mg (0.22) ・ Ba (0.07) / ZSM-5 (P
/Cu=0.15)

Example 20 A honeycomb catalyst (20) was obtained in the same manner as in Example 18 except that cesium nitrate was used instead of strontium nitrate. Cu (5.0) -P (0.41) -Ca (0.22) ・
Mg (0.27) ・ Cs (0.11) / ZSM-5 (P
/Cu=0.17)

Example 21 A honeycomb catalyst (21) was obtained in the same manner as in Example 18 except that lanthanum nitrate was used instead of strontium nitrate. Cu (5.1) -P (0.38) -Ca (0.26) ・
Mg (0.2) ・ La (0.36) / ZSM-5 (P /
Cu = 0.15)

Example 22 H-type ZSM-5 having a SiO ₂ / Al ₂ O ₃ molar ratio of about 30.
Instead of zeolite, the SiO ₂ / Al ₂ O ₃ molar ratio is about 3
A honeycomb catalyst (22) was obtained in exactly the same manner as in Example 1 except that the H-type mordenite of 4 was used. Cu (5.5) -P (0.44) -Ca (0.9) / mordenite (P / Cu = 0.16)

Comparative Example 1 The H-type ZSM-5 used in Example 1 was stirred in an aqueous solution of copper acetate for 12 hours, supported with Cu by an ion exchange method, and then dried in a dryer at 120 ° C. for 8 hours or more. After firing
A slurry was prepared in the same manner as in Example 1 to obtain a honeycomb catalyst.
I got (23). Cu (3.2) / ZSM-5

Comparative Example 2 A honeycomb catalyst (24) was obtained in exactly the same manner as in Example 1 except that the Ca component was not added. Cu (5.0) -P (0.44) / ZSM-5 (P / C
u = 0.18)

Comparative Example 3 A Ca component was added to the catalyst powder obtained in Comparative Example 1 in the same manner as in Example 1, and the honeycomb catalyst (25) was obtained in the same manner.
Got Cu (3.2) -Ca (1.2) / ZSM-5 (P / C
u = 0)

Comparative Example 4 A honeycomb catalyst (26) was obtained in exactly the same manner as in Example 4, except that the amount of P added was 1.73% by weight. Cu (7.0) -P (1.73) -Ca (0.96) /
ZSM-5 (P / Cu = 0.51)

Comparative Example 5 A honeycomb catalyst (27) was obtained in exactly the same manner as in Example 1 except that the amount of Ca added was 4.3% by weight. Cu (5.1) -P (0.44) -Ca (4.3) / Z
SM-5 (P / Cu = 0.18)

Comparative Example 6 A honeycomb catalyst (28) was obtained in exactly the same manner as in Example 4 except that the amount of P added was 0.51% by weight and the amount of Cu supported was 15.4% by weight. . Cu (15.4) -P (0.51) -Ca (0.81)
/ ZSM-5 (P / Cu = 0.068)

Test Example With respect to the catalysts obtained in the above Examples and Comparative Examples, the actual exhaust gas of the engine was treated under the following conditions, and the durability performance of the catalyst was evaluated.

Activity evaluation conditions Evaluation device: atmospheric pressure fixed bed flow type reaction device Catalyst capacity: 0.05 L (cut out from a 0.7 L size catalyst) Gas space velocity: about 40,000 h ⁻¹ Exhaust gas composition: Total hydrocarbons = about 2,000 ppm (converted to C1) NO = about 400 ppm CO = 1,000 ppm O ₂ = 7.5% CO ₂ = 12% H ₂ O = 8.5% N ₂ = balance rapid endurance treatment condition catalyst Inlet exhaust gas temperature: 630 ° C Engine: Nissan V8 cylinder 4400c
c Engine use Average air-fuel ratio (A / F): Approximately 15 (with fuel cut) Fuel: Unleaded regular gasoline Treatment time: 30 h NO of catalyst obtained in Examples and Comparative Examples at catalyst inlet temperature of 370 ° C. after durability test _{The X} removal performance is shown in Table 1.

[0057]

[Table 1]

From the results shown in Table 1, the catalyst of the present invention is 600 ° C.
It can be seen that the high NO _x removal activity is maintained even after the rapid endurance treatment at a temperature exceeding 2,000 ° C., and the heat resistance and durability are excellent. Further, the content of the Ca component in the catalyst is 0.32-1.
NO when the content of P component is changed within the range of 1% by weight
Looking at the _X removal rate, the effect appears when the P component is 0.01% by weight or more, and a large effect is obtained in the range of 0.4 to 0.9% by weight, but when it exceeds 1.7% by weight, it is rather It turns out that it is the opposite effect.

Further, looking at the NO _x removal rate when the content of the Ca component in the catalyst is changed, the effect appears when the Ca component is 0.01 wt% or more, and when the Ca component is 0.3 to 3.0 wt%. It can be seen that a clear effect can be obtained, but when it exceeds 4.0% by weight, the opposite effect is obtained. Alkali metals such as Ca, Mg, and Sr, alkaline earth metals, and rare earth metal components have no particular adverse effect even when multiple components such as two or three components coexist.
The same effect can be obtained.

[0060]

The exhaust gas purifying catalyst of the present invention is
It is possible to efficiently purify NO _{X in} exhaust gas containing much oxygen such as burn engine exhaust gas,
Since it has heat resistance and durability that can be used for a long time even at a temperature of 600 ° C or higher, environmental pollution is extremely low,
It is possible to provide a fuel-efficient car.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B01D 53/36 102 H (72) Inventor Takashi Katsuno 1280 Kamizumi, Sodegaura-shi, Chiba Idemitsu Kosan Co., Ltd. Company (72) Inventor Hiroshi Akama 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Inventor Goji Masuda 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Inventor, Kanasaka Hiroyuki 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd.

Claims (4)

[Claims] 1. A catalyst body comprising a crystalline aluminosilicate as a main component, a copper (Cu) component and a phosphorus (P) component, and an alkali metal, an alkaline earth metal or a rare earth metal. An exhaust gas-purifying catalyst containing at least one metal component selected from the group consisting of 4 parts of each of the crystalline aluminosilicates in a state in which water having adsorbed Cu and P contents is removed. ~ 15
%, And 0.01 to 1.7% by weight. 2. The alkali metal, alkaline earth metal and rare earth metal components are lithium (Li) and sodium (N
a), potassium (K), rubidium (Rb), cesium (Cs), magnesium (Mg), calcium (C
The exhaust gas purifying catalyst according to claim 1, which is a), strontium (Sr), barium (Ba), cerium (Ce), or lanthanum (La). 3. A ratio of P and Cu [P / Cu (molar ratio)]
Is more than 0 and 0.5 or less, The exhaust gas purifying catalyst according to claim 1. 4. Li, Na, K, Rb, Cs, Mg, C
The content of at least one metal component selected from the group consisting of a, Sr, Ba, Ce, and La is 0.01 to 4 with respect to the crystalline aluminosilicate in the state where the adsorbed water is removed.
An exhaust gas-purifying catalyst characterized by being in a weight% range.