JPS6099340A - Catalyst for treating exhaust gas - Google Patents

Abstract

PURPOSE:To improve the catalytic activity of a titled catalyst by coating a mixed slurry of a granular catalyst deposited a novel metal dispersively, a metallic oxide powder and an aq. soln. of nitric acid on an inorganic granular carrier composed essentially of activated alumina. CONSTITUTION:After an inorganic granular carrier composed essentially of activated alumina is impregnated by an impregnating method into the acidic aq. soln. of nitric acid of a novel metal such as platinum and rhodium by using the aq. soln. of nitirc acid by such amount that the pH of said soln. is regulated to <=1.0, the novel metal is fixed into said granular carrier in the form of a sulfide by using the aq. soln. of sodium thiosulfate and the carrier is dried and calcined at the temperature of 550 deg.C. A rare earth metallic nitrate and rare earth metallic oxide are added to said granular catalyst and the mixture is crushed and kneaded together with the aq. soln. of nitric acid by usig a pot mill or the like to obtain the slurry. Said slurry is coated on cordierite-one body type carrier composed essentially of silica, alumina and magnesia, and the carrier is dried and calcined.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical field to which the invention relates) This invention is directed to the treatment of hydrocarbons (OH), -carbon oxides (GO), and nitrogen oxides (N
This invention relates to an exhaust gas treatment catalyst for removing ox) at 181 o'clock.

(Prior art) As a conventional catalyst for this type of exhaust gas treatment, U.S. Pat.
．． As disclosed in No. 665.880, platinum, rhodium, etc. are supported on a support obtained by coating a cordierite monolithic support with activated alumina using an impregnation method. Catalysts have been proposed in which platinum or rhodium is supported using an impregnation method on a catalyst or a carrier obtained by coating activated alumina containing cerium in advance.

However, in such conventional exhaust gas treatment catalysts, platinum, rhodium, etc. are dispersed and supported on the surface of activated alumina that is deposited on an integrated carrier.
Sintering of platinum, rhodium, etc. due to the thermal deterioration of alumina itself is promoted, resulting in a decrease in the number of catalyst active sites, making it impossible to maintain durability. Since the impregnation method is used for this process, the distribution of platinum, rhodium, etc. is not uniform in response to changes in the alumina layer, so there is a problem in that sufficient catalytic activity cannot be brought out.

(Disclosure of the Invention) The present invention has been made by focusing on such conventional problems. A slurry, which is a suspension obtained by simultaneously mixing and pulverizing a granular catalyst on which more than one noble metal is dispersed, a rare earth metal nitrate, a rare earth metal oxide powder, and an aqueous nitric acid solution, is used. The purpose is to solve the above-mentioned problems by using a catalyst formed by coating, drying and calcining a cordierite monolithic carrier containing magnesia as a main component.

The catalyst of the present invention is produced by coating an integrated carrier with a slurry obtained by simultaneously mixing and pulverizing the granular catalyst in which the noble metal is dispersedly supported, a rare earth metal nitrate, a rare earth metal oxide powder, and an aqueous nitric acid solution, and then drying the slurry. The granular catalyst is characterized by being formed by firing one or two noble metals selected from the group consisting of platinum, rhodium, and palladium on an inorganic granular carrier mainly composed of activated alumina. The granular catalyst can be obtained by supporting it on a granular carrier by any conventional production method, but it is particularly preferable to adjust the hydrogen ion concentration (PH
) is 1.0 or less, and the precious metal nitrate is impregnated by the impregnation method, and then the noble metal is impregnated in the form of sulfide into the granular carrier using an aqueous sodium thiosulfate solution. It is preferably produced by fixing, drying, and then firing in a steam atmosphere, preferably at 550° C. for 2 hours. In this method for preparing a granular catalyst, a granular support containing activated alumina as a main component is impregnated with a nitrate of a noble metal by the above-mentioned impregnation method. By doing so, it is possible to achieve a particularly high degree of dispersion on activated alumina which provides effective catalytic active sites on the granular support, and then sulfidation is performed using an aqueous sodium thiosulfate solution in order to prevent movement of the noble metal on the alumina. Thereafter, after drying as described above, noble metal particles are fixedly supported in a highly dispersed state in the granular catalyst obtained by calcining at 550° C. in a stream of steam to remove sulfur in the sulfide.

The granular catalyst thus obtained, rare earth metal nitrate, and rare earth metal oxide are contained in an amount of 5 to 50% by weight based on the total solid content as rare earth metal, and the ratio of the rare earth metal oxide added as nitrate to alumina is 5 to 50% by weight based on the total solid content. An amount of 1 to 10% by weight is added, and a slurry is obtained by pulverizing and kneading together with an aqueous nitric acid solution using a pot mill or the like.

The rare earth metal oxides mentioned above are added to improve the heat resistance of the noble metal highly dispersed granular catalyst and activated alumina.The rare earth metal nitrates added to the activated alumina are converted into rare earth metal oxides with excellent heat resistance by calcination. It is decomposed, but at this time it forms a solid solution with alumina, improving the heat resistance of alumina. The amount of the rare earth metal nitrate added is such that the rare earth metal oxide obtained by firing is 1-5% by weight of the alumina as a metal. This is because if the amount exceeds the weight percentage, the heat resistance will improve, but the specific surface area of alumina will be relatively reduced.

Next, the above-mentioned rare earth oxides simultaneously support the so-called oxygen (0,) storage effect, which adsorbs oxygen when the atmosphere in which the catalyst of the present invention is used is excessive, and desorbs oxygen when oxygen is insufficient. It is added to obtain a catalytic effect, and the amount of the rare earth metal added as a rare earth metal oxide is 5 to 50% relative to the total solid content in the slurry as a metal.
If the amount is less than 5% by weight, no sufficient effect can be expected, whereas if it exceeds 50% by weight, the specific surface area will decrease due to a relative decrease in the amount of alumina in the coating layer, which is not preferable.

Next, the slurry obtained as described above is coated on a cordierite monolithic support mainly composed of silica, alumina, and magnesia, dried, and then calcined in an air atmosphere to form a catalyst. The firing temperature at this time is 600℃~7
50℃, maintain the temperature range for 1 to 8 hours, and
It is desirable to perform firing in a temperature increasing and slow cooling pattern from a temperature of 0°C or less. The amount of noble metal supported in the catalyst of the present invention is such that the total amount of one or more noble metals among platinum, rhodium, and palladium is 0.05 to 0.22% by weight, and when rhodium is included, the amount of the other noble metals and rhodium is 0.05 to 0.22% by weight. Preferably, the ratio is in the range 1=1 to 20:l. Precious metals are 0.05%
If it is less than 0.22% by weight, the purification efficiency will be lowered, and even if it exceeds 0.22% by weight, improvement of the blade of the purification vehicle will hardly be expected. As for the ratio of metals, if rhodium is more abundant than other noble metals, the purification of hydrocarbons will be low.

The catalyst of the present invention is characterized by having the above-mentioned structure, and as a result, low-temperature activity and durability are significantly improved, the amount of precious metals supported is small, and the catalyst is highly effective. This makes it possible to simultaneously remove harmful components HC, 00 and NOx from exhaust gases from internal combustion engines, especially motor vehicles. This means that conventional catalysts for the simultaneous removal of the three harmful components mentioned above are required to have a high level of treatment performance, especially excellent durability, while on the other hand, precious metals such as platinum and rhodium used for exhaust gas treatment are expensive. This is an epoch-making achievement in the current situation where there are natural restrictions on the use of fiK, and the development of high-performance catalysts with low amounts of precious metals is awaited.

(Examples of the Invention) The present invention will be explained in detail using the following Examples, Comparative Examples, and Test Examples.

Example 1 Activated alumina granular carrier manufactured by Rhone-Poulenc, France (
5(38-79) 800011 as platinum 17.
A nitric acid acidic solution of platinum containing 969 and 1 as rhodium.
．． A rhodium nitrate solution containing 796# was mixed, ion-exchanged water was added to bring the volume to 1800 vlIl, and then a 10% nitric acid solution was added until the hydrogen ion concentration (PH) reached a peak of 1.0 or less. Using a heater, heat the liquid and immerse it while keeping the temperature at 45°C, and after 10 minutes.

Ammonium thiosulfate was added so that the molar ratio of platinum, rhodium and sulfur was 1:2, and after reacting for 15 minutes, the carrier was pulled out and fluidized in an oven at 150°C to ensure uniform drying of the carrier. While drying, drying was carried out until the amount of water-containing 1O taken up was less than %. The mixture was then calcined at 550° C. for 90 minutes in a stream of steam to obtain a granular catalyst supported on platinum and rhodicum. This catalyst contained 0.6987% by weight of platinum and 0.0599% by weight of rhodium in terms of metal.

A porcelain bot mill was filled with 1419 g of the granular catalyst obtained above, 86.1 g of cerium nitrate, 108.9 g of cerium oxide powder, and 2478 J of ion-exchanged water containing nitric acid No. 8, lI, and pulverized and mixed to form a slurry liquid. I got it. Using this slurry liquid, a cordierite monolithic carrier ('1.
J, 400 cell) K coating was applied, dried and calcined to obtain catalyst 1. This catalyst 1 contains 187.711/l of alumina, 14.497g of ceria (Gens), and 1.1211/l of platinum (0.11211/l) on an island-wide basis.
1 of rhodium.

Example 2 In Example 1, the activated alumina granular support aooog was treated with an acidic solution of platinum in nitric acid containing 7.269 as autologous;
1.21 as rhodium! Catalyst 2 was obtained in the same manner except that a rhodium nitrate solution containing i+ was mixed and ion-exchanged water was added to make a total volume of 1800 ml.

Is this catalyst 2 18? ,? 11/l (7) 7 Lumina, ceria of 14.411/It and 0.
It contained 454 y/l of platinum and 0.07601/l of rhodium.

Example 8 In Example I, activated alumina granular support 800019
A nitric acid solution of platinum containing 19.22 g of platinum and a rhodium nitrate solution containing 1,922.9 g of rhodium were mixed, ion-exchanged water was added to make the solution 1800 m, and the same procedure was followed except that the solution was impregnated. Particulate catalyst 18 prepared by
．． 16.9 and 86.1 # cerium nitrate A, watt
Catalyst 8 was obtained in the same manner except that a porcelain bot mill was filled with 47819 grams of ion-exchanged water containing 84.1 grams of cerium oxide powder and 84.1 grams of nitric acid.

This catalyst 8 contains % 175.411/l alumina, 2
6.511/l ceria and metal equivalent 1.1211
It contained 0.11211/l of platinum and 0.11211/l of rhodium.

Example 4 In Example I, a nitric acid acid solution of platinum containing 20.66 g of platinum and a rhodium nitrate solution containing 2.066 # of rhodium were mixed in activated alumina granular carrier 80009, and ion-exchanged water was added. Granular catalyst 1218.9 prepared in the same manner except that it was impregnated after being adjusted to 1800 d.
Catalyst 4 was obtained in the same manner except that a porcelain bot mill was filled with 2478 g of ion-exchanged water containing 86.1.9 of cerium nitrate, l'101 g of cerium oxide powder, and nitric acid of 84.1.9.

This catalyst 4 has lan, z Filg (+ri alumina, 8B, ceria of 711/l and 1.12 in terms of metal)
1/l platinum.

It contained 0.1129/l of rhodium.

Example 5 In Example 1, activated alumina granular carrier ROO0,9
, a solution of platinum in nitric acid containing 2 g, 84.9 as platinum, and 2.2841 of rhodium! A granular catalyst 111 was prepared in the same manner, except that a rhodium nitrate solution containing ion-exchanged water was added, the mixture was adjusted to 1800 at, and then impregnated.
A catalyst was obtained in the same manner except that a porcelain bot mill was filled with 2478 g of ion-exchanged water containing 0 g of cerium nitrate, 86.1 g of cerium nitrate, 418 JI of cerium oxide powder, and nitric acid R4,1 II.

This catalyst 5 consists of 1IiO, 91//l of alumina, 50
．． 81/l ceria and metal conversion, 1.121/l
) platinum and 0.1181/l rhodium.

Example 6 In Example I, a nitric acidic solution of platinum containing 26.7 # as platinum and rhodium L6? A granular catalyst 908II prepared in the same manner except that a rhodium nitrate solution containing g was mixed, ion-exchanged water was added to make it 1800-g, and then impregnated.
．． 1 # of cerium nitrate, 619II cerium oxide powder and 24” 1 of deionized water containing 84.1 N of nitric acid
Catalyst 6 was obtained in the same manner except that 8.9 was filled into a porcelain bot mill.

This catalyst 6 is Ii6. g i/l alumina,? 5.
011/l ceria and metal conversion 1.121/It
platinum - 0.11211 rhodium/l.

Example ? In Example I, activated alumina granular support 8000 I
Prepared in the same manner except that a nitric acid acid solution of platinum containing 48.64 Ii as platinum and a rhodium nitrate solution containing 864 N as platinum were mixed with I, and ion-exchanged water was added to make the solution 1800 d, followed by impregnation. Granular catalyst 4911
I and 86. I II cerium nitrate, 10821 cerium oxide powder and nitrate B4. Sample a7 was obtained in the same manner except that 2,478.9 g of ion-exchanged water containing II was filled into a porcelain bot mill.

This catalyst 7 contains 77.2 g/l alumina, 12B,
611/l ceria and metal equivalent 1.12. l/l
of platinum and 0.11 fillOa of dium.

Example 8 In Example 1, granular catalysts 1419.9 and 108.
81! Catalyst 8 was obtained under the same pressure except that cerium nitrate of 10BIi and cerium oxide powder of 10BIi were used.

This catalyst 8 is made of 187.7 till alumina, 18
．． 511/l ceria and metal equivalent 1.1211/l
It contained 0.11211/l of rhodium and 0.11211/l of platinum.

Example 9 Catalyst 9 was obtained using the same pressure as in Example 8 except that 108.8.9 cerium nitrate was mixed.

This catalyst 9 contains 175.411/l alumina, 80.8
It contained 11/l of ceria, 1.12 &/l of platinum and 0.1121/l of rhodium in metal terms.

Example i.

Catalyst 10 was obtained in the same manner as in Example 1 except that 108.89% of cerium nitrate was mixed.

This catalyst lO is 16B, S IIl alumina, 42
．． 211/l f) Ceria, 1.12 ti in metal equivalent
1/l of platinum and 0.11211/l of rhodium.

Example 11 Catalyst 11 was obtained in the same manner as in Example 5, except that 108.811 cerium nitrate was mixed.

This catalyst 11 was made of alumina of 150.99/It, 54
．． 11/It ceria and metal equivalent 1.12 p/
It contained 1% platinum and 0.11211/II rhodium.

°Example 12 In Example 1, activated alumina granular carrier aooog
A solution of platinum in nitric acid containing 24.8.9% of platinum and 2.8.9% of rhodium. 1007 g of a granular catalyst prepared in the same manner except that rhodium nitrate solution containing +8 and
Catalyst 12 was obtained in the same manner except that a porcelain bot mill was filled with 2478.9 of ion-exchanged water containing 08.8.9 cerium nitrate, 516II cerium oxide powder, and 134.1 # of nitric acid.

This catalyst 12 contains 188.511/l alumina, 65
．． 811/l ceria and metal conversion 1.1211/
1 of platinum and 0.1121/l of rhodium.

Example 18 Catalyst 18 was obtained in the same manner as in Example 6, except that 108.8 N of cerium nitrate was mixed.

This catalyst 1B is 126.21/l cD 7 #mina,
77.61/l ceria and metal equivalent 1.1211
It contained 0.1129/l of platinum and 0.1129/l of rhodium.

°Example 14 In Example 1, activated alumina granular carrier 800019
A nitric acid solution of platinum containing 88.129 platinum and a rhodium nitrate solution containing 8.812.9 rhodium were mixed, ion-exchanged water was added to make the solution 1800 m, and the solution was then impregnated in the same manner. 697g of granular catalyst and 108g
．． Ion exchange water containing 8.9 cerium nitrate, 82611 cerium oxide powder and 84.1.9 nitric acid 247
Catalyst 14 was obtained in the same manner except that 8.9' was filled into a porcelain bot mill.

This catalyst 14 contains 101.811/l alumina, 10
1.411/II ceria and metal conversion 1.12
It contained 0.1121171 g/l of platinum and 0.1121171 g/l of rhodium.

Example 15 Catalyst 15 was obtained in the same manner as in Example 7, except that 108.89 g of cerium nitrate was mixed.

This touch (115 is '11.21/l (7)7 #
Me? -11 g Contained 5.01/l ceria, 1.121171 platinum and 0.1121/l rhodium in metal terms.

° Example 16 In Example 1, a nitric acid acid solution of platinum containing 64.09 g of platinum and a rhodium nitrate solution containing 6.409.9 g of rhodium were mixed into the activated alumina granular carrier aooooy, and ion-exchanged water was added. 284 g of granular catalyst prepared in the same manner except that it was added to make 1800 ml and then impregnated.
Catalyst 16 was obtained in the same manner except that ion-exchanged water B478II containing ios, ag of cerium nitrate, 12887F of cerium oxide powder, and 84.111 of nitric acid was charged into a porcelain bot mill.

This catalyst 16 is made of 5L61/l alumina, 148.6
It contained ceria of 1/l, platinum of 1.12171/l and rhodium of 0.11211/l in metal terms.

Example 17 Catalyst 17 was obtained in the same manner as in Example 1 except that 180 J and 9 of cerium nitrate were mixed.

This catalyst 17 is 187. ? fill alumina, 2
．． It contained 1.12971 of platinum and 0.112 fill of rhodium in terms of Liao δ and gold IIA in 2.611/l.

°Example 18 Catalyst 18 was obtained in the same manner as in Example Q except that 180.5.9 cerium nitrate was mixed.

This catalyst 18 contains 175.4 p/l alumina, 84.
It contained 211/l of ceria, 1.121/l of platinum and 0.11211/l of rhodium in metal terms.

Example 19 Catalyst 19 was obtained in the same manner as in Example 4, except that 180.5 g of cerium nitrate was mixed.

This catalyst 19 was made of 16B, 29/l alumina, 45.
811/l ceria and gold conversion is 1.121171
of platinum and 0.11211/l of rhodium.

Example 20 Catalyst 20 was obtained in the same manner as in Example 5, except that 180.5.9 cerium nitrate was mixed.

This catalyst zO is 150.911/l (D7 Lumina, b7.8 II/73 ceria and metal equivalent)
．． 121! It contained 1/1 platinum and 0.11211/l rhodium.

Example 21 Catalyst 21 was obtained in the same manner as in Example 12, except that 180.6.9 cerium nitrate was mixed.

This catalyst zl contains 188.51/l (1 l 7 lumina, 68.811/II ceria and 1.1 l in terms of metal).
It contained 1211/It of platinum and 0.11 B Ill of rhodium.

Catalyst z2 was obtained in the same manner as in Example 6, except that 180.59 cerium nitrate was heated.

Cono catalyst 22 is alumina of lB6.211/l, 80
．． 811/l ceria and metal conversion 1.1211/
It contained 11 Ill of platinum and 0.112 Ill of rhodium.

Example 28 The same pressure as in Example 14 was repeated except that 180.5.9 cerium nitrate was mixed to obtain catalyst 28.

This catalyst z8 contains 101.81/l alumina, 108
．． 41/l ceria and metal equivalent 1. ls If1
of platinum and 0.1129/A of rhodium.

Example 24 Catalyst z4 was obtained in the same manner as in Example 7, except that 180.511 cerium nitrate was mixed.

What is this catalyst z4? ? , 211/l (Dfulmi f,'
126.511/l (1 in terms of D ceria and metals)
．． It contained 121,171 parts of platinum and 0.1111,711 parts of rhodium.

Example 25 In Example 8, platinum is 7.7? A catalyst 25 was prepared under the same pressure except that a nitric acid acid solution of platinum containing 1.2 g of rhodium was mixed with a rhodium nitrate solution containing 1.29 g of rhodium.
I got it.

This catalyst 25 contains 175.4 p/l alumina, 26
．． 0.4541 in ceria and metal equivalent of 5 i/ll
It contained 71% platinum and 0.0761/l rhodium.

Example 26 The catalyst 26 was prepared under the same pressure as in Example 4, except that a nitric acid acid solution of platinum containing 8.85.9 as platinum and a rhodium nitrate solution containing 1.89.9 as rhodium were mixed.
I got it.

This catalyst z6 is 16B, 7/l/min of 21/It, 8
8.711/l ceria and metal equivalent, 0.454
It contained 11,711 parts of platinum and 0.07+511 parts of rhodium/l.

Example 27 In the same manner as in Example 5, catalyst z
I got a 7.

This catalyst 27 contains 150.9 p/l alumina, 50.
81/It is ceria and metal equivalent is 0.45411/
1 of platinum and 0.0-611/l of rhodium.

Catalyst z8 was obtained in the same manner as in Example 6, except that a nitric acid acidic solution of platinum containing 10.79 If as platinum and a rhodium nitrate solution containing 1.80.9 If as rhodium were mixed.

This catalyst 28 is 126. fl Ill alumina,?
5.011/l of ceria and 0.0 in terms of metal. Urn 541
/1 platinum, 0. (Contained 17,611/l of rhodium.

Example 29 Catalyst 29 was prepared in the same manner as in Example 7, except that a nitric acid acid solution of platinum containing 17.64.9 as platinum and a rhodium nitrate solution containing L94N as rhodium were mixed.
I got it.

This catalyst 29 is made of 77.2 Ill alumina, 128
．． 61/l ceria and metal equivalent 0.45411/
It contained 1' of platinum and 0.07611/l of rhodium.

Example 80 Catalyst 8 was prepared in the same manner as in Example 8, except that a platinum acidic nitric acid solution containing 7.26 N as platinum and a rhodium nitrate solution containing 1.21 If as rhodium were mixed.
I got 0.

This catalyst 80 was made of 187.71/l alumina, 18.
It contained 51/l of ceria, 0.4541/1 of platinum in metal terms, and 0.0-6.9/l of rhodium.

Catalyst 81 was obtained in the same manner as in Example 9, except that a platinum acidic nitric acid solution containing 7.77.9 as platinum and a rhodium nitrate solution containing lJ9# as rhodium were mixed.

This catalyst 81 is 175. + 1/l alumina, 80.
81/II ceria and metal equivalent 0.454 Il
of platinum and 0.07611/l of rhodium.

Example 82 Catalyst 8 was prepared in the same manner as in Example 10, except that a nitric acid acid solution of platinum containing 8.85 g of platinum and a rhodium nitrate solution containing 1.89 g of rhodium were mixed.
I got z.

This catalyst 82 is made of 168.21/l alumina, 4L2
It contained 11/l of ceria, 0.454171 of platinum, and 0.0761171 of rhodium in metal terms.

Example 88 A catalyst 88 was prepared in the same manner as in Example 11, except that a nitric acid acid solution of platinum containing 9.081 as platinum was mixed with a rhodium nitrate bath solution containing 1.50 g of rhodium.
I got it.

This catalyst 88 contains 150.911/l alumina, 546
111/l ceria and metal conversion o, QM Iil
It contained O platinum and 0.0761711 rhodium.

Example 84 Catalyst 8 was prepared in the same manner as in Example 12, except that a nitric acid acid solution of platinum containing 9.82.9 as platinum and a rhodium nitrate solution containing 1.687 g as rhodium were mixed.
I got 4.

This catalyst B4 contained 188.59/l alumina, 65.8
It contained 9/l of ceria, 0.45411/l of platinum and 0.07697130 dium in metal terms.

Example 85 Catalyst 8 was prepared in the same manner as in Example 18, except that a nitric acid acid solution of platinum containing 10.79.9 as platinum and a rhodium nitrate solution containing 1.80 g as rhodium were mixed.
Got 5.

This catalyst 85 is 126.211/l alumina, ? ? ,
69/l ceria and metal equivalent 0.43411/l
of platinum and 0.67611/l of rhodium.

Example 86 Catalyst 8 was prepared in the same manner as in Example 14, except that a nitric acid acid solution of platinum containing 18.89 g as platinum and a rhodium nitrate solution containing L28.9 as rhodium were mixed.
I got 6.

This catalyst 86 contains iol, 81/l of alumina, 101
．． 411/l ceria and metal conversion o, +b+9/
1 of platinum and 0.0769/It of rhodium.

Example n7 Catalyst 87 was obtained in the same manner as in Example 15, except that a platinum acidic nitric acid solution containing 17.64.9 as platinum and a rhodium nitrate solution containing z and 94I as rhodium were mixed.

Cono catalyst 87 is 11. B 11/l alumina, 12
6.011/l ceria and metal equivalent 0.4541
It contained 171% platinum and 0.07611/l rhodium.

Example 88 Catalyst 88 was obtained in the same manner as in Example 16, except that a nitric acid acidic platinum solution containing 25.90 g of platinum and a rhodium nitrate solution containing 4.815 g of rhodium were mixed.

Cono catalyst 88 was made of 6L611/l alumina, 148.
611/l ceria and metal 4! 0.454 for J crime.
It contained 9/AI of platinum and 0.07611/l of rhodium.

Example 89 In Example 17, a platinum nitrate solution containing 7.2 (S Ii) as platinum and 1 as rhodium
．． Catalyst 89 was obtained in the same manner except that a rhodium nitrate bath solution containing 21 g was mixed.

This catalyst 89 is 187. ? 11/l alumina, 2
2.61171 O- to rear and metal conversion 0.45
It contained 4171 parts of platinum and 0.0 to 611 parts of rhodium/l.

Example 40 Example 11 was carried out in the same manner as in Example 18, except that a nitric acid acidic solution of platinum containing 7.77 Ii as platinum and a rhodium nitrate solution containing 1.291 as rhodium were mixed.
I got 140.

This catalyst 40 is made of 176.41171 alumina, 84.
z9/l ceria and metal conversion o, +5+ Iil
of platinum and 0.07611/l of rhodium.

Example 41 Catalyst 41 was prepared in the same manner as in Example 19, except that a nitric acid acidic solution of platinum containing 8.851i as platinum and a rhodium nitrate solution containing 1.89I as rhodium were mixed.
I got it.

This catalyst 41 is 16B, 21/l of 7A/min, 45.
81/II ceria and metal equivalent 0.454 El
It contained 0.07611/l of platinum and 0.07611/l of rhodium.

Example 4z Catalyst 4 was prepared in the same manner as in Example 20, except that a nitric acid acid solution of platinum containing ρ, oa Ii as platinum and a rhodium nitrate solution containing 1.50 g as rhodium were mixed.
I got 2.

This catalyst 4z contains 150.911/l alumina, 57.
89/l ceria and metal equivalent 0.45411/l
of platinum and 0.0761/l of rhodium.

In Example 21, a nitric acid acidic solution of platinum containing 9.1Fa 9 as platinum and 1.687 I as rhodium
Catalyst 48 was obtained in the same manner except that a rhodium nitrate solution containing i was mixed.

This catalyst 4B consists of 188.51711 alumina, 68
．． 8971 ceria and metal equivalent 0.4549/1
of platinum and 0.0 to 6.9/l of rhodium.

Catalyst 4 was prepared in the same manner as in Example 22, except that a nitric acid acid solution of platinum containing 10.7911 as platinum and a rhodium nitrate solution containing 1.809 as rhodium were mixed.
I got 4.

This catalyst 44 contains 126.211/l alumina, 80
．． 811/l ceria and metal equivalent 0.4349/
1 of platinum and 0.0761/l of rhodium.

Example 45 Catalyst 4 was prepared in the same manner as in Example 2B, except that a nitric acid acid solution of platinum containing is, ao p as platinum and a rhodium nitrate solution containing 2480 g as rhodium were mixed.
Got 5.

This catalyst 45 is made of 101.81/l alumina, 108.
49/l ceria and metal equivalent 0.45411/l
of platinum and 0.07611711 of rhodium.

Example 46 In Example 24, a nitric acid acidic solution of platinum containing 17.64 Ji' as platinum and 2.041 Ji' as rhodium
Catalyst 46 was obtained in the same manner except that a rhodium nitrate solution containing .

This catalyst 46 is made of 77.211/l alumina, 126.
0.454 Il in terms of 5fill of ceria and metals
1 of platinum and 0.07611/l of rhodium.

Example 47 In Example I, activated alumina granular support 8000,!
i+ was mixed with a platinum nitric acid acidic solution containing 19.81.9 as platinum and a rhodium nitrate solution containing 1.98 g as rhodium, and ion-exchanged water was added to the solution to 1800 t.
Granular catalyst 1826.9 prepared in the same manner except that it was impregnated after being made into sl, and cerium nitrate of 86.1.9,
197.0.9 lanthanum oxide powder and nitric acid 84.1
．． Catalyst 47 was obtained in the same manner except that 2478 g of ion-exchanged water containing 9 was filled into a porcelain bot mill.

This catalyst 47 was made of 17-year old, 511/l alumina, 1.
911/II ceria, 2B,'a 9/l lantana (La O) and 1.12 Ill (D
It contained platinum and 0.11211711° rhodium.

Example 48 Granular catalyst +11!1128# obtained in the same manner as in Example 47 except that a nitric acid acid solution of platinum containing 22.26.9 as platinum and a rhodium nitrate solution containing 2.28 g as rhodium were mixed. and 86.1.917) cerium nitrate, 894.0.9 lanthanum oxide powder and nitric acid 8
Catalyst 48 was obtained in the same manner except that 2478.9% of ion-exchanged water containing 4.19% of ion-exchanged water was filled into a porcelain bot mill.

This catalyst 48 consists of 161.411/l alumina, 1.
611/If) Celia, 46.91/11 (1) U7
Tana, 1.1 in metal equivalent! 11/l platinum, 0.11
It contained 211/It of rhodium.

Example 49 Granular catalyst 1B+! was obtained in the same manner as in Example 47, except that a nitric acid acidic platinum solution containing 19.75 II as platinum and a rhodium nitrate solution containing 1.98 I as rhodium were mixed. Catalyst 49 was obtained in the same manner except that 16 Jil, 108.8 N of cerium nitrate, and 197.09 N of lanthanum oxide powder were used.

This catalyst 49 consists of 170.7 IIIt alumina, 5
．． 8El/13 ceria, 211.611/l lantana and 1.121171 platinum in metal equivalent, 0.1
It contained 1211/l of rhodium.

Example 50 In Example 47, a platinum nitrate f11 acidic solution containing 24.62 g as platinum and 2.46 I as rhodium
Granular catalysts 1080.9 and 108.8.9 obtained in the same manner except that rhodium nitrate solution containing rhodium nitrate solution 17
Catalyst 5o was obtained in the same manner except that a lanthanum oxide powder of 49Lfl and 9 was used.

This catalyst 50 contains 186.911/l alumina,
11/l ceria, 58.61/l lantana and metal equivalent "r 1.12 Iil (D platinum, 0.112
It contained 11/l of rhodium.

In Example 47, 1825 g of a granular catalyst obtained in the same manner as in Example 47 except that a nitric acid acid solution of platinum containing @0.2.9 as platinum and a rhodium nitrate solution containing 2.021 as rhodium were mixed, and 180.519 of cerium nitrate, 1
Catalyst 51 was obtained in the same manner except that 97.01i lanthanum oxide was used.

This catalyst 51 is 166.81/l (D 7 lumi f,
14. It contained a11/l of ceria, 28.511/l of lanthana and 1.121 till (7) platinum with metal sandwich, 0.11211/l (D rhodium).

Actual gun example 52 Example 4? Particulate catalysts 108011 and 180.511 (D cerium nitrate, 492.1) obtained in the same manner except that a platinum nitric acid solution containing 2L42 Ii as platinum and a rhodium nitrate solution containing 2.42 g as rhodium were mixed. Catalyst 52 was obtained in the same manner except that 6N lanthanum oxide powder was used.

The catalyst 52 contains 188.9 g/II alumina, 7.
611/l of ceria, 58.61/it of lantana and metal equivalent of 1.121/It (7) Platinum, 0.11
It contained 29/l OIfdium.

Example 58 Granular catalysts 18Z1g and 86 were obtained in the same manner as in Example 47, except that a platinum nitrate m solution containing io, sdg as platinum and a rhodium nitrate solution containing 1.941 as rhodium were mixed. .1.9 cerium nitrate, io
Catalyst 5a was obtained in the same manner except that 2 g of cerium oxide powder and 98.5 g of lanthanum oxide powder were used.

This catalyst 58 is made of 174.111/l alumina, 14J
77/A' Celia, 11. '711/l of lantana and metal equivalent of 1.1211/l of platinum, 0.1121
/l of rhodium.

Example 54 1119 g and 86.1 g of granular catalysts were obtained in the same manner as in Example 47, except that a nitric acid acid solution of platinum containing 22.421 as platinum and a rhodium nitrate solution containing 2.42I as rhodium were mixed. of cerium nitrate 206.
Except for using 4.9 cerium oxide powder and 197.0.9 lanthanum oxide powder (iJ (a), catalyst 54 was obtained.

Co catalyst 54 Ha 150.41/l 17) 7 k
Mi f, 26. ceria of z1/11, lantana of 28.51/II and 1.12 M/l of metal equivalent (D platinum,
It contained 0.11211/l of rhodium.

Example 55 Granular catalysts 1821.9 and 108 were obtained in the same manner as in Example 47, except that a nitric acid acid solution of platinum containing 19.80 g of platinum and a rhodium nitrate solution containing 1.98y of rhodium were mixed. .8.9 Cerium Nitrate%
Catalyst 66 was obtained in the same manner except that 10B, 2.9 cerium oxide powder and 98.51 lanthanum oxide powder were used.

This (D catalyst 55 Ha1'20.29/l I) lk mina, ceria of 18.19/l, lantana of 11.71/l and platinum of lA2.11/l in metal terms, 0.11
It contained 2171 rhodium.

In Example 47, 1016 g of a granular catalyst obtained in the same manner as in Example 47 except that a nitric acid acid solution of platinum containing 24.91 g of platinum and an adium nitrate solution containing 2.49 g of rhodium were obtained and 108 J 9 of cerium nitrate , 80
Catalyst 56 was obtained in the same manner except that 9.1511 cerium oxide powder and 197.09 lanthanum oxide powder were used.

This catalyst 56 was made of 185.81/l alumina, 41.
81/l (7) Ceria, 28.5 g/l of laninotana and 1. l @ 11/l of platinum, 0.
It contained 1121/l of rhodium.

Example 57 In Example 471C, platinum was 120. ．． 26.9
A nitric acidic solution of platinum containing as rhodium 2.08
The procedure was the same except that a granular catalyst 1821N obtained in the same manner as above was mixed with a rhodium nitrate solution containing g, 180.5 # of cerium nitrate, 1OL of 2.9 cerium oxide powder, and 98.5 g of lanthanum oxide powder. A catalyst 57 was obtained.

This catalyst 57 contains 166.411/l alumina, 21
．． Celia of 99/It, 11. ? 11/l lantern and gold Jjl calculation te 1.12111/l (D platinum, 0
．． 11S! I/l (D Cl rhodium cargo).

Example 58 Granular catalyst 1016II obtained in the same manner as in Example 47 except that a nitric acid acidic solution of platinum containing 25.4819 as platinum and a rhodium nitrate solution containing 2.55 g as rhodium were mixed, and 180. Is, 9 O cerium nitrate, 809.577 cerium oxide powder, 197.
Catalyst 68 was obtained in the same manner except that 0.9% lanthanum oxide powder was used.

This catalyst 58 contains 182.811/l alumina, 44.
Ceria of 811/II, 2B, lantana of 59/II and metal equivalent Te 1.129/l (7) Platinum, 0.11
It contained 29/l O rhodium.

Example 69 In Example 47, a solution of platinum in nitric acid containing 19.42 Jil as platinum and 1694 g as rhodium
The granular catalysts 1816.9 and cerium nitrate of 86.111, mixed rare earth phthalide (mesi metal oxide) powder of lB106Ii, were obtained in the same manner except that a rhodium nitrate solution containing ? Catalyst 59 was obtained in the same manner except that it was used.

This catalyst 59 contains 178.511/l of alumina, 26.5 E/l of ceria equivalent and mixed earth oxide of 1.121/l (D platinum, 0.11211/l of metal equivalent).
(D Contains rhodium.

Example 60 In Example 47, a solution of platinum in nitric acid containing 22.5819 as platinum and 2.2677 as rhodium
Particulate catalyst 111ON obtained in the same manner except that a rhodium nitrate solution containing 86.1 N of cerium nitrate 4 was mixed.
18JFf) Catalyst 6o was obtained in the same manner except that mixed earth oxide powder was used.

This catalyst 60 contains 149.811/l alumina, 5Q ceria equivalent, 89/l mixed earth oxide and metal equivalent r
1.121! /11 No platinum, 0.111a 11/
l (7) *Contained dicum.

Example 61 Granular catalysts 1816JI and 108.8 were obtained in the same manner as in Example 47, except that a nitric acid acid solution of platinum containing 19.87 # as platinum and a rhodium nitrate solution containing 1.99 g as rhodium were mixed. Catalyst 61 was obtained in the same manner except that cerium nitrate from JiJ and mixed earth oxide powder from 206I were used.

This catalyst 61 is 169. fl 11/l alumina,
Mixed rare earth ends of 80.811/l in terms of SE17-r and 1.1211/l in terms of gold pA (7) Platinum, 0.
It contained 1121/l OCl rhodium.

Example 62 Granular catalysts 1007.9 and 108 were obtained in the same manner as in Example 47, except that a nitric acid acid solution of platinum containing 25.11 g of platinum and a rhodium nitrate solution containing 2.519 g of rhodium were mixed. .811 cerium nitrate,
Catalyst 62 was obtained in the same manner except that 51611 mixed earth oxide powder was used.

This catalyst 62 is made of 1B+, 29/l alumina, and has a ceria equivalent value of 1. It contained 11/l of platinum and 0.1129/l of rhodium.

Example 6B Granular particles 41118161! were obtained in the same manner as in Example 47, except that a nitric acid acid solution of platinum containing 20.88 N as platinum and a rhodium nitrate solution containing 2.08 g as rhodium were mixed. and 180.5.17 (Cerium nitrate D, catalyst 68 was obtained in the same manner except that mixed earth oxide powder of 206I was used.

This catalyst 6B had alumina of 165.81/l and 84.0% in terms of ceria. a 11/II mixed soil oxide and metal equivalent 1. lB E/l of platinum, 0.11a II/
1 of rhodium.

Example 64 Particulate catalyst 1007. was obtained in the same manner as in Example 47 except that a nitric acid acid solution of platinum containing 25.67 # of platinum and a rhodium nitrate solution containing 2.57 g of rhodium were mixed. r and 180.551 cerium nitrate,
Catalyst 64 was obtained in the same manner except that 516.9 mixed earth oxide powder was used.

This catalyst 64 has alumina of 181.811/l, which is 68.8% in terms of ceria. It contained a mixed earth oxide of Fl 97I and 1.121/l of platinum and 6.1121/l of rhodium in metal terms.

Example 65 In Example 47, as platinum? Catalyst 65 was obtained in the same manner except that a nitric acid acidic solution of platinum contained in , 80.9' and a rhodium nitrate solution containing 1.80 g of rhodium were mixed.

This contact fi1i65 contains 174.5.9/l alumina, 1.911/l ceria, 2B, 511/l lantana, and 0.454 Fl/l platinum in metal terms, (
j, 0'? It contained 61/l of rhodium.

Example 66 Catalyst 6 was prepared in the same manner as in Example 48, except that a nitric acid acid solution of platinum containing 9.0 g of platinum and a rhodium nitrate solution containing 1.50 Ji' of rhodium were mixed.
I got 6.

This catalyst 66 is 151. ΦFl/l alumina, 1.6
JJ/l ceria, 46.911711 lantana and metal equivalent 0.454 E/l platinum, 0.0761
/l of rhodium.

Example 6? Catalyst 67 was prepared in the same manner as in Example 49, except that a nitric acid acid solution of platinum containing 7.98 # as platinum and a rhodium nitrate solution containing 1.881 # as rhodium were mixed.
I got it.

This catalyst 67 contains 170.711/l alumina, 5.
8"11/I ceria, 28.511/l lantana and metal equivalent 0.45411/l platinum, 0.07
It contained 611/l of rhodium.

Example 68 In Example 50, 9.95 II was included as platinum.
A nitric acid solution of platinum was mixed with a rhodium nitrate solution containing 1.66 g of rhodium.
I got 68.

This catalyst 68 contains 186.91/l alumina, 4.51
1/l ceria, 58.611/l lantana and 0.454.971 platinum in metal terms, 0.0?611
/l of rhodium.

Example 69 Catalyst 69 was obtained in the same manner as in Example 51, except that a nitric acid acidic platinum solution containing 8.17.9 as platinum and a nitrate glPIlffdium solution containing 1.86I as rhodium were mixed.

This catalyst 69 consisted of 166.811/l alumina, 9.
71/l ceria, 28.59/l lantana and 0.454 g/l platinum in metal terms, 0.0769/l
It contained rhodium.

Example 70 Catalyst 7 was prepared in the same manner as in Example 52, except that a platinum acidic nitric acid solution containing 10.179 as platinum and a rhodium nitrate solution containing 1.701 as rhodium were mixed.
I got 0.

This catalyst 70 contains 188.91/lg of alumina, 7.5
g/l ceria, 5s, e&, i lantana and metal equivalents 0.454971 cv platinum, 0.07611
It contained 7% rhodium.

Example 71 Catalyst 7 was prepared in the same manner as in Example 58, except that a nitric acid acid solution of platinum containing 7.82 II as platinum and a rhodium nitrate solution containing 1.30 g as rhodium were mixed.
I got 1.

This catalyst 71 contains 174.11/lg of alumina, 14.
211/lt ceria, 11.7117g lantana and 0.45411/e platinum in metal equivalent, 0.076
It contained 97g of rhodium.

Example 72 Catalyst 72 was prepared in the same manner as in Example 54, except that a nitric acid acidic solution of platinum containing 9.06 g of platinum and a rhodium nitrate solution containing 1.511 g of rhodium were mixed.
I got it.

This catalyst 72 is made of 150.4 Vg alumina, 26.2
Vl ceria, 28.597 g lantana and metal equivalent 0.454 g/6 cr) platinum, 0.076 V
Contains rhodium (・ta).

Example 78 The catalyst 73 was prepared under the same pressure as in Example 65 except that a nitric acid acid solution of platinum containing s, oo g as platinum and a rhodium nitrate solution containing 1.88 g as rhodium were mixed.
I got it.

This catalyst 73 contains 170.2117 g of alumina, 18.
1υe of ceria, 11.71//g of lantana and 0.454 g/g in metal terms (7) Platinum, U-076
It contained 51 Ig of rhodium.

Example? 4 In Example 56, platinum was 10.0? , 9 was mixed with a rhodium nitrate solution containing 1.68y as rhodium. Catalyst 74 was obtained in the same manner.

This catalyst 74 has an ia5. a 114 alumina, 41.
89/e ceria, 2a, 511Ig lantana and metal equivalent 0.454 g/l platinum, 0.076 g
/g (1) Contained dicum.

Example 75 A granular catalyst obtained in the same manner as in Example 57 was used except that a nitric acid acid solution of platinum containing 8.19 g of platinum and a rhodium nitrate solution containing 1.86 y of rhodium were mixed. Catalyst 75 was obtained.

This catalyst 75 is made of 166.4 Vg alumina, 21.9
11/e ceria, 11.71yl lantana and metal conversion nte 0.454117g (r) Platinum, 0.07
61//g (7) Contained Rosi 17A.

Example 76 A granular catalyst obtained in the same manner as in Example 58 was used, except that a nitric acid acid solution of platinum containing 10.89 as platinum and a rhodium nitrate solution containing 1.72I as 10dium were mixed. I got 76.

This catalyst 76 contained 182.8117 g of alumina, 44.
8g/lt ceria, ga, s Vtt lantana and metal equivalent te 0.45411Ig platinum, 0.076
Contained 17g f) odium.

Example 77 Same as in Example 59 except that a platinum acidic nitric acid solution containing 7.859 as platinum and a rhodium nitrate solution containing 1.811 as rhodium were mixed. Catalyst 77 was obtained in the same manner using the obtained granular catalyst.

This catalyst 17 has lvs, 51 Ig of alumina, n 26.511 Ig of ceria as a mixed clay oxide, and 0.454 f as metal! /6 f) Platinum Contained 0.07617 g of rhodium.

Example 78 A granular catalyst obtained in the same manner as in Example 60 was used except that a nitric acid acid solution of platinum containing 9.1217 as platinum and a rhodium nitrate solution containing 1.529 as rhodium were mixed. I got 78.

This catalyst 78 contains 149.3 I/1 of aluminum, so, s in terms of ceria, mixed clay oxide of 11/it and 0.454 Vg in terms of metal (1) Platinum, 0.076
g/g of rhodium.

Example 79 A granular catalyst obtained in the same manner as in Example 61 was used except that a nitric acid acid solution of platinum containing s, oa, and p as platinum and a rhodium nitrate solution containing 1.84 g as rhodium were mixed. Catalyst 79 was obtained.

This catalyst? No. 9 contained 169.6 Vg alumina, ceria equivalent ao, a g/g mixed clay oxide and metal equivalent 0.4549/g platinum and 0.07617 g rhodium.

Hide IL ahead! In Example 62, catalyst 80 was prepared in the same manner using a granular catalyst obtained in the same manner except that a nitric acid acidic solution of platinum containing 10.15.9 as platinum and a rhodium nitrate solution containing 1.69I as rhodium were mixed. I got it.

This catalyst 80 contains 134°2 Vg of alumina, 65.9117g of mixed rare earth oxide in terms of ceria, and 0 in terms of metal.
．． It contained 454 Vg of platinum and 0.07697 g of rhodium.

Example 81 In Example 68, a granular catalyst obtained in the same manner was used except that a nitric acid acid solution of platinum containing 8.21 g as platinum and a rhodium nitrate solution containing 1 (711) as rhodium were mixed. Catalyst 81 was obtained.

This catalyst 81 is 165.81! /g of alumina, ceria equivalent: 84.2 /l/i of mixed fabric oxide and metal equivalent: TE: 0.4541! /g (7) Platinum, 0.076
It contained 7i/6 rhodium.

Example 82 A granular catalyst obtained in the same manner as in Example 64 was used except that a nitric acid acid solution of platinum containing 10.889 as platinum and a rhodium nitrate solution containing 1.789 as rhodium were mixed. I got 82.

This catalyst 82 has 131.8 g/g of alumina, which is 68.8 g/g in terms of ceria. li'/6 mixed rare earth oxide and metal equivalent: 0.454 g/g (1) Platinum, 0.076
Contained 117g Noodium.

Example 88 In Example 1, the activated alumina granular carrier aoooy was mixed with an acidic solution of palladium in nitric acid containing 17.011 as palladium and rhodium nitrate containing 2.84 Ii as rhodium, and ion-exchanged water was added to give a solution of 1800
Catalyst 88 was obtained in the same manner except that the amount was changed to mg.

This catalyst 88 contained 187.7117 g of alumina, 14.
4 ceria, metal equivalent i, oa g/g palladium, 0.1771! /l of rhodium.

Example 84 In Example 1, activated alumina granular support aooo,v
A solution of palladium in nitric acid containing 1.26 g of palladium was mixed with rhodium nitrate containing 1.2177 g of rhodium, and 1800 g of ion-exchanged water was added.
Catalyst 84 was obtained in the same manner except that the amount was changed to mg.

This catalyst 84 consisted of 187.7717 g of alumina, 14
．． It contained 4 g/g ceria, 0.454 Vg of palladium, and o, o7ao Vg of rhodium in terms of metal.

Example 85 In Example 1, the activated alumina granular support aooog was mixed with an acidic solution of platinum in nitric acid containing 12.089 p as platinum, an acidic solution of palladium in nitric acid containing 6.01 lI as palladium, and 1.796 p as rhodium. Mix rhodium nitrate containing it, add ion-exchanged water and boil for 1800m.
Catalyst 86 was obtained in the same manner except that 1 was changed.

;Cf) Catalyst C 187.7 g/g Noah Lumina, 1
4.4 g/e ceria, 0. '151/g
of platinum, 0.8'151/lt of palladium, 0.11
Contains 2 Vl of rhodium.

Example 86 In Example 1, an acidic solution of platinum in nitric acid containing 4.861i as platinum, an acidic solution of palladium in nitric acid containing 2.419 as palladium, and 1.21 as rhodium.
Catalyst 86 was obtained in the same manner except that rhodium nitrate containing g was mixed and ion-exchanged water was added to make the total amount to 1800 mg.

This catalyst 86 contained 187.7117 g of alumina, 14
．． 4 Vg (1) *Rear, 0. in metal equivalent. aoa
Vg f) Platinum, 0.150 &/g Palladium, 0
．． Contains 07617g of rhodium.

Comparative Example 1 Activated alumina granular carrier 14a7.017 and alumina sol (10% by weight suspension of boehmite alumina)
Sol obtained by adding HNO3) 25
After filling 6L09 into a bot mill and pulverizing it for 6 hours, the resulting slurry was attached to a one-piece carrier (1,7 it, 400 cells) mainly composed of cordierite.
It was baked at 0°C for 2 hours.

The amount of adhesion at this time was set to a+OVx pieces.

Next, this alumina-attached carrier was immersed in a mixed aqueous solution of chloroplatinic acid and rhodium chloride to support the platinum and rhodium so that the amount of platinum and rhodium attached was 1.9117 Pt and 191 I Pt, and then heated at 600°C. The catalyst was calcined for 2 hours to obtain catalyst A.

Comparative Example 2 Activated alumina granular carrier 1487.09 carrying 5% by weight of cerium in terms of cerium metal and alumina sol 25
63. Catalyst B was prepared in the same manner as in Comparative Example 1 except that Og was used.
I got it. However, the amount of deposited platinum and rhodium is 1 on the integrated carrier.
The platinum i, toy, and rhodium were set at 0.19117 per piece.

Comparative Example 3 Activated alumina granular carrier 454.89 and alumina sol 2 carrying cerium in an amount of 50Ji in terms of cerium metal
Catalyst C was obtained in the same manner as Comparative Example 1 except that 5689 was used. However, the adhesion amounts of platinum and rhodium were set to 1.919 platinum, rhodium o, and iot g per one integrated carrier.

Comparative Example 4 Chloroplatinic acid, rhodium chloride, and cerium oxide were added to an alumina slurry containing boehmite alumina as the main component (40%) and also viarite alumina and amorphous alumina hydroxide, and hydrogen sulfide (H, S ) After treatment, dry and sinter at 340°C. US Pat. No. 8,56
5, No. 880, according to the method of Example xm), a catalyst was obtained.

This catalyst is 1.12 Ve of platinum, 0.1121! i
71 rhodium, 14.4 Vl ceria and 81
It contained Vg alumina.

Test Examples Catalysts 1 to 86 obtained in Examples 1 to 86 and Comparative Example 1-4
The catalysts A-D obtained in the above were subjected to actual vehicle durability (engine durability) under the following conditions, and the purification rate of 1O mode emissions was measured, and the purification rate was VηOOXη.

As shown in Table 1.

Engine durability conditions Catalyst Integrated precious metal catalyst Catalyst outlet temperature 750°C Space velocity Approximately 70,000 Hr-1 Durability time 100 hours Engine exhaust volume 2200cc (Effects of the invention) As explained above, the catalyst of this invention has a catalyst metal A slurry obtained by simultaneously mixing and pulverizing a supported granular catalyst, a rare earth metal nitrate, a rare earth metal oxide powder, and an aqueous nitric acid solution is coated on an integrated carrier, dried, and fired. As is clear from Table 1, the purification rate is significantly improved compared to the conventional integrated precious metal catalyst, and the durability is improved, resulting in an equivalent or higher level of purification compared to the conventional catalyst, even with a low amount of wrinkled metal. This shows the purification rate. In addition, when the catalyst is compared with the catalyst of the example which supports an inward-like noble metal, the purification rate of the catalyst is significantly lower, but since the main component is boehmite alumina, the Pt1 ribs are sintered during the transformation to gamma alumina. This is considered to be because the dispersion of Pt1 and other substances on alumina decreases. On the other hand, in the catalyst of the present invention, since pt and others are highly dispersed on gamma alumina which has already been stabilized, reduction in the surface area of noble metals due to sintering of Pt5Rb etc. is prevented.

Claims (1)

[Claims] L: 1 selected from the group consisting of platinum, rhodium, and palladium on an inorganic granular carrier mainly composed of activated alumina.
A slurry obtained by simultaneously mixing and pulverizing a granular catalyst carrying more than one noble metal dispersed thereon, a rare earth metal nitrate, a rare earth metal oxide powder, and an aqueous nitric acid solution is coated on an integrated carrier, dried, and fired. An exhaust gas treatment catalyst for removing hydrocarbons, carbon oxides and silicon oxides from the exhaust gas of an internal combustion engine.