WO2001033057A2

WO2001033057A2 - Method of manufacturing a catalytic converter and after-treating apparatus of exhaust gas using the catalytic converter

Info

Publication number: WO2001033057A2
Application number: PCT/KR1999/000657
Authority: WO
Inventors: Moon-Chan Kim
Original assignee: Kim Moon Chan
Priority date: 1999-11-03
Filing date: 1999-11-03
Publication date: 2001-05-10
Also published as: AU1080300A

Abstract

An after-treating apparatus of exhaust gas and a catalyst converter installed therein is disclosed. The after-treating apparatus of exhaust gas primarily removes the exhaust gas in a first filtering device and a second filtering device, and secondarily purifies within the catalyst converter. The first filtering device and the second filtering device are controlled by opening and closing a valve through a time control part. That is, when particulate of the exhaust gas is collected in the first filtering device, the second filtering device burns the collected particulate by means of an electric heater. Further, the catalytic converter is prepared by coating a honeycomb supported on a supporter of alumina (Al2O3) and chromic oxide (Cr2O3) with a composite consisting of platinum, nickel and a promoter metal, or serially combining a honeycomb (a) and a honeycomb (b) in the order of (a) + (b) or (b) + (a). The honeycomb (a) is supported on a supporter of alumina (Al2O3) and coated with a composite consisting of platinum and nickel and a promoter metal. The honeycomb (b) is supported on a supporter of chromic oxide (Cr2O3) and coated with a composite consisting of platinum, nickel, and a promoter metal. Only the catalytic converters prepared by the above-stated method are used for treating exhaust gas.

Description

METHOD OF MANUFACTURING A CATALYTIC CONVERTER

AND AFTER-TREATING APPARATUS OF EXHAUST GAS

USING THE CATALYTIC CONVERTER

Technical Field

1. Field of the Invention This invention relates to an after-treating apparatus of exhaust gas, and more particularly to an after-treating apparatus which firstly burns particulate of the exhaust gas collected in a ceramic filter, and secondly oxidizes CO into CO2, HC into CO2 and H2O, and reduces NOx into N2 by a catalytic converter installed in the apparatus.

Background Art

Generally, a method of and an apparatus for burning particulate collected by only a filter through heat wires or burner has been used. This is the method of mounting pressure sensors on a front side and a rear side of the filter, heating through the burner when the applied pressure is above the predetermined pressure, supplying air through a blower, and burning the particulate deposited in the filter.

However, the method shortens the life of the filter by rapidly raising the temperature due to burning the particulate or hydrocarbon in a short time. Also, smoke of exhaust gas can be removed to some degree, but the particulate is hard to remove above 80% thereof only through the ceramic filter because above 90% of the particulate are small particles having l μ m and less size. HC , CO, and NOx are seldom removed, but rather it may happen that they are increased by back pressure of the ceramic filter.

Meanwhile, the methods of wash-coating a catalyst in the prior ceramic filter are under consideration to solve these problems. However, these methods have drawbacks that the temperature rises during regeneration of the ceramic filter, a crack occurs in the ceramic filter due to a difference of a coefficient of thermal expansion between the ceramic filter and metallic oxides coated thereon, and life of the ceramic filter is greatly shortened. Further, because of the temperature rise, the coated catalyst generates a sintering phenomenon above 700 , and activity of the catalyst abruptly deteriorates. Also, in the filtering operation of the exhaust gas, a fouling phenomenon in which the smoke of the exhaust gas covers the catalyst is generated, so the exhaust gas is not treated efficiently.

Furthermore, in a prior catalyst containing noble metals, one makes an effort to coat fire-resistant inorganic oxides such as active alumina(Al2θ3) with the noble metals in a higher dispersion. However, the catalyst coating the noble metals in the higher dispersion has drawbacks that the initial activity is high, but under strict conditions such as high temperature and oxidization atmosphere, particles of the noble metals grow, a supporter is apt to react with the noble metals and promoter metals, and thus durability of the activity deteriorates.

A method of supporting noble metals on a supporter containing alumina and zirconia in order to acquire a catalyst having a good heat-resistance and a stable special property is disclosed in Japanese Patent Nos. S57-29215(B2) and S57- 153737(A) . However, in the above method, because the noble metals are substantially high-dispersed on the alumina, activity is reduced. Further, methods of using zirconia or α -alumina as a supporter not reacting with noble metals in high temperature and oxidization atmosphere are disclosed in U. S. Patent Nos. 4 ,233, 189 and 4, 172 ,047, respectively.

Disclosure of Invention

Accordingly, to solve the above problems, it is a first object of the present invention to provide a catalytic converter having a good durability under strict conditions and high purifying capacity for harmful components of exhaust gas, and a method of preparing the same. It is a second object of the present invention to provide an after-treating apparatus of exhaust gas, having at least two filtering devices and a catalytic converter in order to substantially increase purifying capacity of the exhaust gas without applying high load to an engine.

To obtain these objects, a catalytic converter of the present invention includes: one honeycomb 1 or two honeycombs 2 and 3 serially combined with each other; a supporter A coated on the honeycomb 1 , the supporter A consisting of a mixture of alumina (AI2O3) and chromic oxide (Cr2U3) ; a supporter B coated on the honeycomb 2 , the supporter B consisting of alumina (AI2O3) ; and a supporter C coated on the honeycomb 3 , the supporter C consisting of chromic oxide (Cr θ3) ; a catalyst supported on the supporter A, the catalyst containing platinum and nickel with at least one promoter metal Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au; a catalyst supported on the supporter B, the catalyst containing platinum and nickel with at least one promoter metal selected from Pd, Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au; and a catalyst supported on the supporter C, the catalyst containing platinum and nickel, with at least one promoter metal selected from Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au. In addition, there is provided a method of preparing a catalytic converter comprising the steps of: (a) in a case of using one honeycomb 1 , mixing alumina (AI2O3) and chromic oxide (Cr2θ3) and wet-pulverizing the mixture to produce a supporter of aqueous slurry, and in a case of using two honeycombs 2 and 3, wet-pulverizing alumina to produce a supporter of aqueous slurry for the honeycomb 2 and wet-pulverizing chromic oxide to produce a supporter of aqueous slurry for the honeycomb 3; (b) dipping the honeycombs having a plurality of cells in the aqueous slurry of the supporters; (c) drawing out the dipped honeycombs and blowing extra slurry in the cells by compressed air; (d) drying the blown honeycombs at 120 C for 2 hours; (e) dipping the dried honeycomb 1 in a mixed aqueous solution consisting of a platinum-containing aqueous solution of platinum chloride , nickel-containing nickel chloride, and a catalytic composite consisting of at least one element selected from Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au; (f) dipping the dried honeycomb 2 in a mixed aqueous solution consisting of platinum and nickel and a catalytic composite consisting of at least one element selected from Pd, Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au; (g) dipping the dried honeycomb 3 in a mixed aqueous solution consisting of a platinum and nickel, with a catalytic composite consisting of at least one element selected from Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au; and (h) drawing out the dipped honeycombs, drying the honeycombs at 120 C for 12 hours, and calcining the dried honeycombs at 600 C for 2 hours.

An after-treating apparatus of exhaust gas using the catalyst converter according to the present invention comprises a main pipe connected to an engine; a first duct extended from the main pipe into one side and having a first inlet port for inflow of the exhaust gas; a second duct extended from the main pipe into the other side and having a second inlet port for inflow of the exhaust gas; a first filtering device integrally formed in a center portion of the first duct, the first filtering device having a first ceramic filter inside and a first electric heater mounted on one end of the first ceramic filter facing the engine; a second filtering device integrally formed in a center portion of the second duct, the second filtering device having a second ceramic filter inside and a second electric heater mounted on one end of the second ceramic filter facing the engine; a valve for selectively opening and closing the first inlet port and the second inlet port; a time control part for operating the valve in a predetermined time and simultaneously applying electric power on the electric heater selected from the first electric heater and the second electric heater for a predetermined time; and a catalytic converter having a housing connected to the first duct and the second duct, and a catalyst converter received in the housing.

Brief Description of Drawings

This invention will be better understood and its various obj ects and advantages will be more fully appreciated from the following description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a schematic view showing an after-treating apparatus of exhaust gas according to a preferred embodiment of the present invention,

Fig. 2 is an enlarged sectional view of a catalyst converter according to the present invention, and

Fig. 3 is an schematic view showinng of another embodiment of a catalyst device according to the present invention

Best Mode for Carrying Out the Invention

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the drawings . Fig. 1 is a schematic view showing an after-treating apparatus of exhaust gas according to a preferred embodiment of the present invention. In the drawings a hood side having an engine 70 is located in a front portion, and a trunk side is located in a rear portion with reference to a vehicle body.

As shown in Fig. 1 , the after-treating apparatus of the exhaust gas includes a main pipe 10 connected to the engine 70, a first and a second filtering devices 30,40 as a primary filtering means, and a catalytic device 60 as a secondary filtering means.

For inflow of the exhaust gas from the engine 70, a first duct 3 1 extended from the main pipe 10 into one side of the vehicle s rear portion has a first inlet port 25, and a second duct 4 1 extended from the main pipe 10 into the other side of the vehicle s rear portion has a second inlet port 27. Also, a valve 20 is installed between the main pipe 10 and the first and the second inlet ports 25,27 in order to selectively open and close the first inlet port 25 and the second inlet port 27.

The first filtering device 30 is integrally mounted in a center portion of the first duct 31 . A first ceramic filter 35 for filtering particulate of the exhaust gas and a first electric heater 33 for burning the particulate collected in the first ceramic filter 35 are installed in the first filtering device 30. A filter material of 7.5in. - outer diameter and 8in. -length is used as a material of the first ceramic filter 35. The first electric heater 33 is installed adjacent to the first ceramic filter 35 between the first duct 3 1 and the first ceramic filter

35.

The second filtering device 40 has a second duct 4 1 , a second electric heater 43 , and a second ceramic filter 45 , which is the same with the structure of the first filtering device 30 , and is installed parallel to the first filtering device 30. Accordingly, description for the constituting elements of the second filtering device 40 will be omitted. The first and the second filtering device 30 ,40 communicates with a housing 63 of the catalytic device 60 by the first duct 3 1 and the second duct 4 1 . Also , a catalyst converter 65 is received in the housing 63 in order to remove gaseous substances and hydrocarbon of the exhaust gas flowing into the housing 63 again. The catalyst converter 65 is formed of a honeycomb structure or a pellet structure, and preferably is formed of a honeycomb structure .

Fig. 2 is an enlarged sectional view of a catalyst converter according to the present invention. As shown in Fig. 2 , the catalyst converter 65 comprises a honeycomb( l 10) , a supporter( 120) coated on the honeycomb .

The supporter is consisted of ;

1 ) a mixture of aluminafAbOs) and chromic oxide(Cr2θ3) , and a catalyst containing platinum and nickel and at least one promoter metal selected from Ir, Co, Sn, Fe, Mn, Cu, V,

Zn, Ba, Ag, and Au;

2) alumina (AI2O3) and a catalyst containing platinum and nickel and at least one promoter metal selected from Pd, Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au;

3) chromic oxide (Cr2θ3) and a catalyst containing platinum and nickel at least one promoter metal selected from

Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au.

Furthermore, a time control part 50 for controlling an opening and closing time of the valve 20 and an operating time of the first electric heater and the second electric heater is installed at a predetermined position. The time control part 50 has a timer(not shown) inside for constantly maintaining the total operating time of the valve by memorizing the operating time in spite of non-operating state of the engine.

Hereinafter, an operation of the after-treating apparatus of the exhaust gas according to the present invention will be described.

When the valve 20 opens the first inlet port 25 and closes the second inlet port 27, the exhaust gas emitted from the engine 70 is collected in the first ceramic filter 35 via the first duct 31 , in which the particulate of the exhaust gas is substantially collected. At this time, the collecting time of the exhaust gas, that is, the operating time of the valve 20 is controlled by the time control part 50 , is preferably 90- 150 minutes, and more preferably 120 minutes. When the operating time of the valve 20 exceeds 150 minutes, adhesion of hydrocarbon and particulate increases and back pressure of the filtering device becomes high , thereby applying a great load to the engine . When the operating time of the valve 20 is smaller than 120 minutes , consumption of the electric power increases. At the same time, in the second filtering device 40 , electric power is applied to the second heater 43 and thus the particulate collected in the second ceramic filter 45 is burned, in which the burning time is controlled by the time control part 50 , and preferably is approximately 20 minute s . When the burning time exceeds 20 minutes , the second ceramic filter 45 is damaged by heat. When the burning time is smaller than 20 minutes, the second electric heater 45 does not perfectly burn the collected particulate , thereby increasing back pressure of the second ceramic filter. Meanwhile , when the opening time of the first inlet port

25 reaches 120 minutes, the valve 20 closes the first inlet port 25 and opens the second inlet port 27 by control of the time control part 50. Accordingly, as mentioned above , the exhaust gas emitted from the engine 70 is collected in the second ceramic filter 45 via the second duct 4 1 for 120 minutes, and the particulate previously collected in the first ceramic filter 35 is burned by the first electric heater 33 for 20 minutes .

The above operation is continuously repeated during operation of the engine . Even though the engine does not operate , the continuous timer of the time control part 50 memorizes the collecting time of the exhaust gas, and thereby constantly maintains the operating time of the valve 20 in a re-operating state of the engine. The exhaust gas primarily filtered by the first filtering device 30 and the second filtering device 40 flowing into the housing 63 of the catalytic device 60. The exhaust gas flowed in the housing 63 substantially includes harmful gaseous substances, such as HC, CO , NOx. The harmful gaseous substances pass through the catalyst converter 65 in the housing 63 , and are purified by generating oxidation and reduction with platinum, nickel, and promoter metal coated on the catalyst converter 65.

As mentioned above, the after-treating apparatus of the exhaust gas firstly removes the particulate of the exhaust gas by the filtering devices 30,40 and secondly removes the gaseous substances and hydrocarbon by the catalyst converter 65 of the catalytic device 60, thereby increasing the purifying capacity of the exhaust gas . Hereinafter, the catalyst converter 65 and the preparing method of the same according to the present invention will be described.

The catalyst converter 65 according to the present invention is prepared by wash-coating an active substrate on the honeycomb( l 10) , in which the active substrate( 120) is formed by supporting platinum, nickel, and promoter metal on the supporter of alumina and chromic oxide.

A honeycomb 1 comprises a supporter consisting of a mixture of alumina (AI2O3) and chromic oxide (Cr2θ3) . The supporter is coated with a platinum-containing aqueous solution of platinum chloride, nickel-containing nickel chloride, and a catalytic composite containing at least one element selected from Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au.

Also, a honeycomb 2 comprises an alumina (AI2O3) supporter coated with a catalytic composite consisting of platinum and nickel and at least one element selected from Pd, Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au. Also a honeycomb 3 comprises a chromic oxide (Cr₂O3) supporter coated with a catalyst composite consisting of platinum and nickel, and at least one element selected from Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au.

Alunima and chromic oxide is mixed at the weight ratio of 99 : 1 to 1 :99 , and the mixture is prepared to easily coat on the honeycomb 1 during a wash coating step.

A source of platinum of the honeycombs 1 , 2 and 3 is preferably selected from the group consisting of platinum chloride, dinitrodiamine platinum, platinum sulphate complex salt, and platinum tetramine chloride, and a source of nickel of the honeycombs 1 , 2 and 3 is preferably selected from nickel nitrate and nickel chloride.

Platinum and nickel have synergy effect reciprocally, and are preferably mixed to have a weight ratio of [nickel/ (nickel+platinum) = 0.02 - 0.8] . When only either one of platinum and nickel is used, the oxidization conversion rate of the particulate material, HC and Co as well as the reduction conversion rate of NOx deteriorate even with the weight ratio of platinum and nickel being larger than 0.8 or smaller than 0.02.

Furthermore, in the honeycombs 1 , 2 and 3 , platinum and nickel are preferably supported on the mixture of alumina and chromic oxide, or chromic oxide at the ratio of

0.05-5 wt.% . When the weight ratio is smaller than 0.05 wt.%, it is difficult to have sufficient activity, and when the weight ratio is larger than 5 wt.%, particle growth between metal particles is accelerated, thereby deteriorating activity.

The promoter metal maintaining a strong activity oxidizes hydrocarbon and carbon monoxide and reduces nitrogen oxide. Also, the promoter metal is preferably contained in the honeycombs 1 , 2 and 3 by 0.01 - 15 weight%, and more preferably by 0. 1 - 10 weight% about the supporter consisting of alumina and chromic oxide, the alumina supporter, or the chromic oxide supporter. The above-mentioned honeycombs have a round or oval type monolith structure, and is preferably made from a material selected from a group consisting of cordierite, mordenite, mullite, α -alumina, β -alumina, aluminosilicate, spinel, zirconia, titania, titan phosphate, aluminum titanate, ferrite, and magnesium silicate. More preferably, the honeycomb used in a diesel vehicle is made from cordierite.

The active substrate is coated on honeycomb with a concentration of 10 - 350g/ dm³, and preferably a concentration of 30 - 200g/ dm³. The above mentioned catalyst converter may be used in a vehicle, ship, train, and internal combustion engine for industry.

Hereinafter, examples and comparative examples of the catalyst converter and the preparing method of the same according to the present invention will be described.

The purifying capacity of the after-treating apparatus of exhaust gas in diesel engine is examined in Examples 1 to 13 and Comparative Examples 1 to 10, and that of the catalytic converter is examined in Examples 14 to 16.

An engine of the diesel vehicle is a 4-stroke engine of straight-vertical type, and combustion type of the engine is a direct injection type. The specification of the engine is as follows:

Six-cylinders in which the inner diameter of cylinder X stroke is 123mm X 155mm, Stroke volume is l l ,051 cc,

Compression ratio is 17. 1 : 1 ,

Maximum torque/velocity of engine is 81.5Kgm/ 1400rpm, and

Maximum output/velocity of engine is 780Nm/ 2 ,200rpm.

The catalyst converter for the engine having the above specification uses for 100 hours under the condition that temperature of the after-treating apparatus of the exhaust gas is 450 ^°C in normal operating state .

An examiner compares the results of a base test with those of a test using the catalytic converter and the after-treating apparatus of the present invention in the D- 13 mode, so as to measure a removable rate of total particulate matter (TPM) , total hydrocarbon (THC) , CO and NO in the respective modes 3 , 4 , 5, 6 and 8.

Table 1 indicates constituting components of the honeycomb coating the catalyst, and Table 2 indicates a performance of the after-treating apparatus of the exhaust gas.

Example 1 A catalyst converter according to the present invention is prepared bymixing 400g-alumina(γ -AI2O3) having specific surface of 2 10m²/ g and 40g-chromic oxide(Cr2θ3) , wet-pulverizing the mixture through a ball mill for 20 hours, and producing a supporter of aqueous slurry, dipping the four monolith honeycomb on the supporter, the honeycomb having a plurality of gas communicating cells formed of about 400cells/in² and being made from cordierite of 5.66in. -outer diameter and 6in. -length, drawing out the dipped honeycomb, blowing extra slurry in the cells by compressed air, and drying the honeycomb in 120 ^°C for 12 hours, dipping the dried honeycomb in a mixed aqueous solution consisting of platinum chloride containing 4.0g-platinum, nickel chloride containing 0.4g-nickel, and copper chloride containing 0.4g-copper, and drying the honeycomb in 120 ^°C for 12 hours, and calcining in 600 ^°C for 2 hours.

Accordingly, the catalyst converter is prepared by coating an active substrate on the honeycomb, the active substrate being formed by supporting platinum, nickel, and copper on the supporter consisting of alumina and chromic oxide . A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2.

Example 2

A catalyst converter and a preparing method of the same according to Example 2 is the same as that of Example 1 except that the (E) component of Table 1 is 0.4g-Ag. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2.

Example 3

A catalyst converter and a preparing method of the same according to Example 3 is the same as that of Example 1 except that the (E) component of Table 1 is 0.4g-Sn . A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2.

Example 4 A catalyst converter and a preparing method of the same according to Example 4 is the same as that of Example 1 except that the (E) component of Table 1 is 0.4g-Fe . A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2. Example 5

A catalyst converter and a preparing method of the same according to Example 5 is the same as that of Example 1 except that the (E) component of Table 1 is 0.4g-Mn. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2.

Example 6 A catalyst converter and a preparing method of the same according to Example 6 is the same as that of Example 1 except that the (E) component of Table 1 is 0.4g-V. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2.

Example 7

A catalyst converter and a preparing method of the same according to Example 7 is the same as that of Example 1 except that the (E) component of Table 1 is 0.4g-Zn. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2.

Example 8 A catalyst converter and a preparing method of the same according to Example 8 is the same as that of Example 1 except that the (E) component of Table 1 is 0.4g-Ba. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table

2.

Example 9

A catalyst converter and a preparing method of the same according to Example 9 is the same as that of Example 1 except that the (E) component of Table 1 is 0.4g-Au. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2.

Example 10 A catalyst converter and a preparing method of the same according to Example 10 is the same as that of Example 1 except that the (E) component of Table 1 is 0.4g-Ag and 0.4g-V. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2.

Example 1 1 A catalyst converter and a preparing method of the same according to Example 1 1 is the same as that of Example 1 except that the (E) component of Table 1 is 0.4g-Ag and 0.4g-Cu. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2. Example 12 A catalytic converter of the present invention is prepared by:

(a) wet-pulverizing 220g-alumina having specific surface of 2 10 m²/ g for a honeycomb 1 and 220g-chromic oxide (Cr2U3) for a honeycomb 2 , separately, through a ball mill for 20 hours, and producing supporters of aqueous slurry;

(b) dipping four monolith honeycombs in the aqueous slurry, the honeycombs having a plurality of gas communicating cells formed of about 400 cells/ in² and being made from cordierite of 5.66 inches in outer diameter and 3 inches in length,

(c) drawing out the dipped honeycombs, blowing extra slurry in the cells through compressed air, and drying the honeycombs at 120 °C for 2 hours,

(d) dipping the dried honeycomb 1 in a mixed aqueous solution consisting of platinum chloride containing

2.0g-platinum, nickel chloride containing 0.2g-nickel, and palladium chloride containing 0.2g-palladium, drying the honeycomb 1 at 120 ^°C for 12 hours, and calcining the dried honeycomb 1 at 600 ^°C for 2 hours, thereby obtaining a catalytic converter a , and

(e) dipping the dried honeycomb 2 in a mixed aqueous solution consisting of platinum chloride containing 2.0g-platinum, nickel chloride containing 0.2g-nickel, and copper chloride containing 0.2g-copper, drying the honeycomb 2 at 120 ^°C for 12 hours , and calcining the dried honeycomb 2 at 600 ^°C for 2 hours, thereby obtaining a catalytic converter b .

Thus obtained catalytic converters are serially combined with each other in the order of a and b . A performance of the after-treating apparatus of the exhaust gas using the catalytic converters is listed on Table 2.

Example 13

A procedure of Example 13 is the same as that of Example 12 except that the catalytic converters are combined in the order of b and a .

A performance of the after-treating apparatus of the exhaust gas using the catalytic converters is listed on Table 2.

Example 14

A procedure of Example 14 is the same as that of Example 12 excepting that only the catalytic converter is used.

A performance of the after-treating apparatus of the exhaust gas using only the catalytic converter is listed on Table 2.

Example 15 A procedure of Example 15 is the same as that of Example 13 except that only the catalytic converter is used. A performance of the after-treating apparatus of the exhaust gas using only the catalytic converter is listed on Table 2. Example 16

A procedure of Example 16 is the same as that of Example 1 except that only the catalytic converter is used.

Comparative Example 1 A catalyst converter and a preparing method of the same according to Comparative Example 1 is the same as that of Example 1 except that the (B) component of Table 1 is not contained. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2.

Comparative Example 2 A catalyst converter and a preparing method of the same according to Comparative Example 2 is the same as that of Example 1 except that the (B) component of Table 1 contains 0.5g. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2.

Comparative Example 3 A catalyst converter and a preparing method of the same according to Comparative Example 3 is the same as that of Example 1 except that the (C) component of Table 1 is not contained. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table

2.

Comparative Example 4

A catalyst converter and a preparing method of the same according to Comparative Example 4 is the same as that of

Example 1 except that the (C) component of Table 1 contains 0.5g. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2.

Comparative Example 5 A catalyst converter and a preparing method of the same according to Comparative Example 5 is the same as that of Example 1 except that the (D) component of Table 1 is not contained. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2.

Comparative Example 6 A catalyst converter and a preparing method of the same according to Comparative Example 6 is the same as that of Example 1 except that the (D) component of Table 1 contains 0.04g. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on

Table 2.

Comparative Example 7 A catalyst converter and a preparing method of the same according to Comparative Example 7 is the same as that of Example 1 except that the (D) component of Table 1 contains 20g. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2.

Comparative Example 8 A catalyst converter and a preparing method of the same according to Comparative Example 8 is the same as that of Example 1 except that the (D) component of Table 1 contains 0.4g and the (E) component of Table 1 is not contained. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2.

Comparative Example 9 A catalyst converter and a preparing method of the same according to Comparative Example 9 is the same as that of Example 1 except that the (D) and (E) components of Table 1 are not contained. A performance of the after-treating apparatus of the exhaust gas using the catalyst converter is listed on Table 2. Comparative Example 10

An after-treating apparatus of exhaust gas which wash-coats the catalyst components of Example 1 on ceramic filters without using the catalyst converter of Example 1 is used. A performance of the after-treating apparatus of the exhaust gas is listed on Table 2.

Table 1 . Components of active substrate

Table 2. A performance of after-treating apparatus of exhaust gas

As indicated in Table 2 regarding the removable rate of harmful substances of the exhaust gas, the removable rate of Examples 1 to 16 is greater than that of Comparative

Examples 1 to 10, and particularly the removable rate of NOx is quite excellent. This demonstrates that the catalytic converters of Examples 1 to 16 have a high removable rate of the harmful substances.

As mentioned above, the after-treating apparatus of the exhaust gas alternately uses the first filtering device and the second filtering device, thereby increasing durability of the filtering devices and purifying capacity. Also, the apparatus is installed with the catalytic converter having the catalyst converter at the rear portion of the filtering devices separately, and thereby greatly reduces the harmful substances of the exhaust gas. Furthermore , the catalyst converter according to the present invention has good durability under strict conditions such as high temperature and oxidization atmosphere, and high purifying capacity for the harmful substances at a low temperature state .

While this invention has been particularly shown and described with reference to particular embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be effected therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method of manufacturing a catalyst converter comprising the steps of: mixing alumina (AI2O3) and chromic oxide (Cr2θ3) , wet-pulverizing the mixture, and producing a supporter of water slurry; dipping a honeycomb having a plurality of cells in the supporter; drawing out the honeycomb, and blowing the extra slurry in the cells through compressed air; drying the blown honeycomb; dipping the dried honeycomb in a mixing solution consisting of aqueous platinum chloride solution containing platinum, aqueous nickel chloride solution containing nickel, and catalytic composite containing at least one element selected from Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au; and drying and calcining the honeycomb.

2. A catalyst converter comprising: a honeycomb; a supporter coated on the honeycomb, the supporter consisting of a mixture of alumina (AI2O3) and chromic oxide (Cr O ) ; and a catalyst supported on the supporter, the catalyst containing platinum and nickel with at least one promoter metal selected from Ir, Co, Sn, Fe , Mn, Cu, V, Zn, Ba, Ag, and

Au.

3. A method of manufacturing a catalytic converter comprising the steps of: wet-pulverizing alumina (AI2O3) , and producing a supporter of aqueous slurry; dipping a honeycomb having a plurality of cells in the supporter; drawing out the honeycomb, and blowing the extra slurry in the cells of the honeycomb through compressed air; drying the blown honeycomb; dipping the dried honeycomb in a mixed aqueous solution consisting of a platinum-containing aqueous solution of platinum chloride and a catalytic composite containing at least one element selected from Ni, Ir, Pd, Co , Sn, Fe, Mn, Cu,

V, Zn, Ba, Ag, and Au; and drawing out the honeycomb, and drying and calcining the drawn honeycomb.

4. A catalytic converter comprising: a honeycomb; a supporter coated on the honeycomb, the supporter consisting of alumina (AI2O3) ; and a catalyst coated on the supporter, the catalyst consisting of platinum and nickel with at least one promoter metal selected from Ir, Pd, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au.

5. A method of manufacturing a catalytic converter comprising the steps of: wet-pulverizing chromic oxide (Cr2θ3) , and producing a supporter of aqueous slurry; dipping a honeycomb having a plurality of cells in the supporter; drawing out the honeycomb, and blowing the extra slurry in the cells of the honeycomb through compressed air; drying the blown honeycomb; dipping the dried honeycomb in a mixed aqueous solution consisting of a platinum-containing aqueous solution of platinum chloride, nickel-containing nickel chloride, and a catalytic composite containing at least one element selected from Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au; and drawing out the honeycomb, and drying and calcining the drawn honeycomb.

6. A catalytic converter comprising: a honeycomb; a supporter coated on the honeycomb, the supporter consisting of chromic oxide (Cr2θ3) ; and a catalyst coated on the supporter, the catalyst consisting of platinum and nickel with at least one promoter metal selected from Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au.

7. The catalyst converter according to claim 2, wherein weight ratio of Al₂O₃ : Cr₂0₃ includes 99 : 1 to 1 :99.

8. The catalytic converter according to any one claim 2 , 4 or 6, wherein the supporter comprises at least one material selected from the group consisting of cordierite, mordenite, mullite, α -alumina, -alumina, aluminosilicate, spinel, and magnesium silicate.

9. The catalytic converter according to claim 2 , 4 or 6, wherein the supporter and the catalyst have a concentration of 10 - 350 g/ dm³ with respect to the honeycomb.

10. The catalytic converter according to claim 2 , 4 or 6, wherein the platinum and the nickel have a weight ratio of Ni/ (Ni+Pt) = 0.02 - 0.8.

1 1. The catalytic converter according to claim 2 , 4 or 6, wherein the platinum and the nickel are supported on the supporter at the ratio of 0.05 - 5 wt.%.

12. The catalytic converter according to claim 2 , 4 or 6 , wherein the supporter comprises 0. 1 - 20 wt.% of promoter metal.

13. An after-treating apparatus of exhaust gas comprising:a main pipe connected to an engine; a first duct extended from the main pipe into one side and having a first inlet port for inflow of the exhaust gas; a second duct extended from the main pipe into the other side and having a second inlet port for inflow of the exhaust gas; a first filtering device integrally formed in a center portion of the first duct, the first filtering device having a first ceramic filter inside and a first electric heater mounted on one end of the first ceramic filter facing the engine; a second filtering device integrally formed in a center portion of the second duct, the second filtering device having a second ceramic filter inside and a second electric heater mounted on one end of the second ceramic filter facing the engine; a valve for selectively opening and closing the first inlet port and the second inlet port; a time control part for operating the valve in a predetermined time and simultaneously applying electric power on the electric heater selected from the first electric heater and the second electric heater for a predetermined time; and a catalytic device having a housing connected to the first duct and the second duct, and a catalyst converter received in the housing.

14. The after-treating apparatus of exhaust gas according to claim 13 , wherein the catalyst converter comprises: a honeycomb; a supporter coated on the honeycomb , the supporter consisting of a mixture of alumina (AI2O3) and chromic oxide (Cr2θ3) ; and a catalyst supported on the supporter, the catalyst containing platinum and nickel with at least one promoter metal selected from Sn , Fe, Mn, Cu, V, Zn, Ba, Ag, and Au.

15. The after-treating apparatus according to claim 13 , wherein the after-treating apparatus uses catalytic converters (a) and (b) serially combined in the order of (a) + (b) or (b) + (a) , the catalytic converter (a) comprising: a honeycomb; a supporter coated on the honeycomb, the supporter consisting of alumina (AI2O3) ; and a catalyst coated on the supporter, the catalyst consisting of platinum and nickel with at least one promoter metal selected from Ir, Pd, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au; the catalytic converter (b) comprising: a honeycomb; a supporter coated on the honeycomb, the supporter consisting of chromic oxide (Cr2θ3) ; and a catalyst coated on the supporter, the catalyst consisting of platinum and nickel with at least one promoter metal selected from Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au.

16. An after-treating apparatus of exhaust gas comprising: a main pipe connected to an engine; a catalytic device having a housing connected to the main pipe , and a catalyst converter received in the housing.

1 7. The after-treating apparatus of exhaust gas according to claim 16, wherein the catalyst converter comprises : a honeycomb; a supporter coated on the honeycomb, the supporter consisting of a mixture of alumina (AI2O3) and chromic oxide (Cr2θ3) ; and a catalyst supported on the supporter, the catalyst containing platinum and nickel with at least one promoter metal selected from Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au.

18. The after-treating apparatus according to claim 16, wherein the after-treating apparatus uses catalytic converters (a) and (b) serially combined in the order of (a) + (b) or (b) + (a) , the catalytic converter (a) comprising: a honeycomb; a supporter coated on the honeycomb, the supporter consisting of alumina (AI2O3) ; and a catalyst coated on the supporter, the catalyst consisting of platinum and nickel with at least one promoter metal selected from Ir, Pd, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au; the catalytic converter (b) comprising: a honeycomb; a supporter coated on the honeycomb, the supporter consisting of chromic oxide (Cr2U3) ; and a catalyst coated on the supporter, the catalyst consisting of platinum and nickel with at least one promoter metal selected from Ir, Co, Sn, Fe, Mn, Cu, V, Zn, Ba, Ag, and Au.