TW201639624A - Use of Cu-ferrite in manufacturing three-way catalyst of automotive engine for treating exhaust gas - Google Patents

Abstract

The invention relates to a use of Cu-ferrite in manufacturing a three-way catalyst of an automotive engine for treating exhaust gas. The Cu-ferrite contains a 1:2 to 1:10 molar ratio of copper and iron. The Cu-ferrite can be used to effectively remove waste gas such as nitrogen oxides, carbon monoxides and hydrocarbons, and remove surface carbon deposit by itself.

Description

Copper ferrite magnets are used as three-effect catalyst for automobile engine exhaust gas treatment

The invention relates to the use of a copper ferrite magnet (Cu-ferrite) as a three-effect catalyst for automobile engine exhaust gas treatment, in particular to the use of a copper ferrite magnet to produce a three-way catalyst for effectively removing pollutants from automobile exhaust gas. By this, the traditional use of precious metal catalysts can be solved to make the catalyst converters expensive.

According to the automobile emissions of nitrogen oxides (NO _X ), carbon monoxide (CO) and hydrocarbons (HC), the main murderers of urban air pollution, countries around the world have formulated regulations to regulate pollutant emissions and are becoming stricter. During the operation of the vehicle engine can not be generated by complete combustion of CO gas of HC, and nitrogen at elevated temperature with oxygen to generate NO _x generation is a main reason for these contaminants. Decades of experience have pointed out that only improvements in fuel composition and engine combustion design have reached the limit but are not environmentally friendly. The only viable technology available today is the addition of a catalytic converter to the exhaust pipe of the car. A commonly used catalyst for treating automobile exhaust is Three-Way Catalyst, or a three-way catalyst. A typical three-way catalyst is a combination of cerium oxide (CeO ₂ ) on a ceramic honeycomb support containing alumina (Al ₂ O ₃ ) powder, and adding palladium (Pd), platinum (Pt), rhodium (Rh). A precious metal is used as an active catalyst. Among them, platinum (Pt) and palladium (Pd) are oxidation catalysts, which can convert CO and HC into harmless carbon dioxide (CO ₂ ) and water (H ₂ O); 铑 (Rh) is a reduction catalyst, which can be NO _{X is} converted to harmless nitrogen (N ₂ ).

At present, a variety of catalysts have been developed to solve the pollution caused by exhaust gas. For example, the Republic of China Patent Publication No. I346172 "catalytic carrier for catalytic converters installed near an engine, catalytic converter, exhaust The system and the vehicle having the catalyst carrier, that is, a catalyst carrier suitable for use in an exhaust system near an internal combustion engine, having a plurality of passages, the plurality of passages being available for an air flow And extending between each other between an inlet side and an outlet side; in order to allow efficient and permanent installation of an exhaust gas treatment device that can be subjected to high thermal and dynamic loads, the catalyst carrier has at least one metal A sheet having a proof stress Rp0.2 of at least 50 Newtons per square inch at a temperature of 900 °C. In addition, the Republic of China Patent Publication No. I316421 discloses a "catalyst material for high-performance catalytic combustion and its application", which can be self-comparted in a very short time by a noble metal catalyst dispersed on a supporting material. The temperature rises to the required high temperature, and moreover, the method also discloses a method of dispersing a precious metal catalyst for a catalytic combustion reaction to increase the specific surface area of the catalyst, thereby accelerating the catalytic combustion reaction. In addition, the case also discloses a material comprising a boron nitride supported precious metal catalyst, a substrate for dispersing the catalyst, and a material for dispersing the support material of the substrate in which the catalyst is dispersed, so that the total amount of the catalyst The surface area can therefore be increased, and the catalytic combustion reaction can also be initiated in a very short time. However, the above-mentioned invention has the disadvantage that precious metals such as platinum, rhodium and palladium are required to be used. Since the production of precious metals is low and the price is high, the price of the catalyst products is very expensive, which is not conducive to air pollution prevention, so there is inevitably a cheap catalyst active ingredient. Demand.

Ferrite, also known as ferrite magnet, ferrite lattice, ferrite, ferrite or magnet spinel, generally refers to the oxidation of composite metals composed of iron oxides and other metal oxides. Things. In addition to natural ones, the preparation methods are roughly classified into two types: wet synthesis techniques for reaction in aqueous solutions or alcohol solutions, and powder metallurgy techniques for solid phase reactions using high temperatures. In order to produce ferrite magnets of different nature, there are many skill changes in various methods. The ferrite magnet is a spinel structure of a face-centered cubic system and can be of the general formula: MO. M' ₂ O ₃ represents, where M represents the position at which the divalent cation should be filled, and M' represents the position at which the trivalent cation should be filled. If M is completely ferrous ion, M' is completely ferric ion, which is magnetite FeO. Fe ₂ O ₃ (generally abbreviated as Fe ₃ O ₄ ). The divalent metal cation of the non-ferrous ion can be filled in the position of M by a synthetic method, and the trivalent metal cation of the non-ferrous ion can also be filled in the position of M'. Ferromagnetic magnets of different properties can be obtained by varying the types and proportions of doped metals. According to common practice, if the non-ferrous element in the ferrite magnet is mainly copper, it is called Cu-ferrite, but other metal doping is allowed in the crystal lattice. In fact, this structure is a very important factor in adjusting the properties of the catalyst. Ferrite magnets are known to be widely used, including electromagnetic wave emitting elements, electromagnetic wave absorbing materials, water treatment adsorbents, magnetic coagulation magnetic species, etc. How to use ferrite magnets to develop a better three-effect catalyst for automobile exhaust gas treatment, It is the direction that the inventor thought.

Today, the inventor is still in the light of the tireless spirit of the existing three-effect catalyst in actual implementation, and is improved by its rich professional knowledge and years of practical experience. And based on this, the present invention was developed.

The main object of the present invention is to provide a catalyst made of a copper ferrite magnet or a copper ferrite magnet containing a part of other metals as a main active component; thereby, the nitrogen oxide in automobile exhaust gas can be effectively treated. (NO _X ), carbon monoxide (CO) and hydrocarbons (HC), and have the function of self-cleaning surface area carbon.

In order to achieve the above-mentioned object, the present invention relates to a copper ferrite magnet for use as a three-effect catalyst for automobile engine exhaust gas treatment, wherein the Cu-ferrite system comprises a molar ratio of 1:2 to 1:10. Copper and iron are used to remove nitrogen oxides, carbon monoxide and hydrocarbons from exhaust gases, as well as self-cleaning surface area carbon.

Another object of the present invention is to provide a three-effect catalyst for automobile engine exhaust gas treatment made of a copper ferrite magnet, wherein the copper ferromagnetic system used has a copper ratio of 1:2 to 1:10. iron.

In an embodiment of the invention, the copper ferrite magnet is selectively doped during synthesis, such as manganese, titanium, cobalt, zinc, nickel, strontium, calcium, magnesium, chromium, aluminum, strontium, cerium, lanthanum and cerium. One or more of the non-copper metals, and the ratio of the total amount of the non-copper metal doping metal to the iron molar ratio is 1:2 to 1:10.

In an embodiment of the invention, the copper ferrite magnet is prepared by a ferrite process, and the performing step comprises: (a) mixing a ferrous ion solution and a copper ion solution to obtain a mixed solution in which a ferrous ion solution is a ferrous sulfate or a ferrous chloride solution, a copper ion solution is a copper sulfate, a copper nitrate, a copper chloride solution or an industrially recovered copper waste liquid; (b) the mixed solution is adjusted to The pH is between 7 and 14 and is heated to 50 to 100 ° C for a period of time; (c) supplying oxygen or air to the adjusted pH mixture solution for reaction to obtain a solid primary product; and (d) The product is separated, dried, ground, and sieved to form a powdered copper ferrite magnet. A metal other than copper or iron is mixed with the solution of the metal in the step (a). The copper ferrite magnet produced by this method has a particle size distribution between 20 and 150 nm and can be adjusted by changing the reaction parameters.

In an embodiment of the invention, the copper ferromagnetic system is prepared by a co-precipitation method, and the performing step comprises: (a) preparing a solution of iron ions (for example, iron sulfate, iron nitrate or chlorine) Iron solution), a ferrous ion solution (for example, ferrous sulfate or ferrous chloride solution) and a copper ion solution (for example, copper sulfate, copper nitrate, copper chloride solution or industrially recovered copper waste liquid) Mixing to obtain a mixed solution; (b) heating in a water bath to raise the temperature of the solution to 70-100 ° C, and introducing nitrogen gas for several minutes; (c) adding ammonia water and stirring and heating for 1 to 3 hours to obtain a solid initial And (d) separating the solid primary product, drying, grinding, and sieving to form a powdery copper ferrite magnet. The metal other than the copper-iron is mixed with the solution of the metal in the step (a). The copper ferrite magnet produced by this method has a particle size distribution of about 2 to 25 nm.

It is worth noting that there are many methods that can be used to synthesize copper ferrite magnets, including ferrite processes, hydrothermal synthesis, sol-gel methods, and coprecipitation methods. (co-precipitation method) and solid reaction method. The embodiments of the invention should not be construed as limiting the application of the invention. In fact, it is necessary to synthesize copper ferrite magnets of different particle sizes by various methods, and then mix them in an appropriate ratio to obtain a copper ferrite magnet material having an optimum particle size distribution (not particularly limited to 2 to 150 nm). Further production of a three-effect catalyst converter.

In an embodiment of the invention, the copper ferromagnetic system is further provided with a fixing agent to form a honeycomb (honeycomb) catalyst body, or may be coated on a honeycomb metal or ceramic carrier to form a honeycomb. Catalyst blank. The honeycomb-like catalyst body is dried and placed in an inert atmosphere (nitrogen, argon or helium) to form a honeycomb-like three-way catalyst.

In one embodiment of the invention, the honeycomb three-way catalyst can be filled into a metal casing to form a three-effect catalyst converter and connected between the automobile engine and the exhaust port. The catalytic bed of the three-effect catalytic converter is divided into a front-stage catalyst bed and a rear-stage catalyst bed, and a secondary air is introduced in the middle of the two sections, and the secondary air amount is 0-30% of the exhaust gas.

The inventors' research found that copper ferrite magnets can reduce nitric oxide to harmless nitrogen at a low oxygen concentration using carbon monoxide or hydrocarbons as a reducing agent. Since the gasoline engine is an oxygen-poor combustion system, the oxygen concentration in the exhaust gas is very low and contains a large amount of carbon monoxide and hydrocarbons. Therefore, the copper ferrite magnet catalyst of the present invention can achieve the foregoing reaction by using only the temperature of the engine exhaust gas. Nitric oxide in the exhaust gas.

The inventors' research found that copper ferrite magnets can react this small amount of oxygen with carbon monoxide or hydrocarbons even at very low oxygen concentrations. Since the gasoline engine is an oxygen-poor combustion system, the oxygen concentration in the exhaust gas is very low and contains a large amount of carbon monoxide and hydrocarbons, so the removal of nitrogen monoxide in the front-stage catalyst bed will inevitably deplete the oxygen. Based on this, the practice of the present invention involves introducing a small amount of secondary air between the front and rear catalyst beds to remove residual carbon monoxide and hydrocarbons. This reaction can be carried out using only the temperature of the engine exhaust.

It can be seen from the above research results that the copper ferrite magnet has the functions of reducing nitrogen monoxide and oxidizing carbon monoxide and hydrocarbons, that is, it has bidirectional catalytic performance, which is the copper ferrite magnet of the invention as a three-effect touch of automobile engine exhaust gas treatment. The principle of the use of the media.

The inventors' research found that doping some of the other metals in the synthesis of copper ferrite magnets can enhance their properties. For example, doping zinc can increase the high temperature tolerance of the catalyst, doping manganese can enhance the oxidizing power, and doping rare earth can lower the light-off temperature.

The inventors' research found that copper ferrite magnets can oxidize their surface area to carbon dioxide when exposed to air, and can initiate the reaction even at room temperature. Therefore, the air entering the catalytic converter by the exhaust pipe or other passages when the engine is stopped is sufficient to cause the catalyst surface area carbon reaction to be removed, so the present invention has the characteristics of self-cleaning surface area carbon.

Therefore, the use of a copper ferrite magnet as a three-way catalyst does not require the use of precious metals such as palladium (Pd), platinum (Pt), rhodium (Rh), or rhodium (Ru), and has the advantages of low cost and fast reaction speed. .

The object of the present invention and its structural and functional advantages will be explained in conjunction with the specific embodiments according to the structure shown in the following drawings, so that the reviewing committee can have a more in-depth and specific understanding of the present invention.

The invention relates to a copper ferrite magnet for use as a three-effect catalyst for automobile engine exhaust gas treatment, wherein a copper ferrite magnet (Cu-ferrite) comprises copper and iron with a molar ratio of 1:2 to 1:10. To remove nitrogen oxides, carbon monoxide and hydrocarbons in the exhaust gas, and self-cleaning surface area carbon; copper ferrite magnets are also selectively doped such as manganese, titanium, cobalt, zinc, nickel, strontium, calcium, magnesium, chromium, A non-copper metal of one or more of aluminum, lanthanum, cerium, lanthanum and cerium, and the ratio of the total amount of non-copper metal doped to the molar ratio of iron is 1:2 to 1:10.

The invention also provides an automobile engine exhaust gas treatment three-effect catalyst prepared from a copper ferrite magnet, wherein the copper ferromagnetic system used comprises copper and iron with a molar ratio of 1:2 to 1:10. The copper ferrite magnet is also selectively doped with a non-copper metal such as manganese, titanium, cobalt, zinc, nickel, lanthanum, calcium, magnesium, chromium, aluminum, lanthanum, cerium, lanthanum and cerium. The ratio of the total amount of non-copper metal doped to the molar ratio of iron is 1:2~1:10.

The copper ferrite magnet can be prepared, for example, by the following steps, comprising: (a) a ferrous ion solution (which may be, for example, a ferrous sulfate or ferrous chloride solution) and a copper ion solution (for example, Copper sulfate, copper nitrate, copper chloride solution or industrially recovered copper waste liquid) are mixed to obtain a mixed solution; (b) the mixed solution is adjusted to a pH of 7 to 14, and heated to 50 to 100 ° C for a period of time (c) supplying oxygen or air to the adjusted pH mixture solution for heating to obtain a solid primary product; and (d) separating, drying, grinding, and sieving the solid primary product, To make a powdered copper ferrite magnet. The metal other than the copper-iron is mixed with the solution of the metal in the step (a). The copper ferrite magnet produced by this method has a particle size distribution between 20 and 150 nm and can be adjusted by changing the reaction parameters.

The copper ferrite magnet can also be prepared, for example, by the following steps, comprising: (a) an iron ion solution (for example, iron sulfate, iron nitrate or ferric chloride solution), a ferrous ion solution (for example, a solution of ferrous sulfate or ferrous chloride) and a copper ion solution (for example, copper sulfate, copper nitrate, copper chloride solution or industrially recovered copper waste liquid) to obtain a mixed solution; (b) water bath heating The temperature of the solution was raised to 70-100 ° C and nitrogen was introduced for several minutes. (c) adding ammonia water and heating for 1 to 3 hours to obtain a solid primary product; and (d) separating, drying, grinding, and sieving the solid primary product to form a powdery copper ferrite magnet. The metal other than the copper-iron is mixed with the solution of the metal in the step (a). The copper ferrite magnet produced by this method has a particle size distribution of about 2 to 25 nm.

By synthesizing different sizes of copper ferrite magnets by different methods, the copper ferrite magnets with the best particle size distribution can be prepared by mixing in an appropriate ratio, and the final particle size distribution range is preferably 2 to 150 nm. The particle size range of the copper ferrite magnet is not limited, and the copper ferrite magnet having a particle diameter larger than 150 nm can also be used as a three-effect catalyst, but the reaction effect is poor.

Further, the copper ferrite magnet may further be added with a fixing agent to form a honeycomb-shaped catalyst body, or may be coated on a honeycomb metal or ceramic carrier to form a honeycomb-shaped catalyst body. The fixing agent is prepared by using materials such as clay, alumina, kaolin, ceria, calcium sulfate, and paraffin. The honeycomb-shaped catalyst body is dried and then sintered at 200 to 800 ° C in an inert atmosphere of nitrogen, argon or helium to obtain a honeycomb-type three-effect catalyst. The honeycomb three-effect catalyst is filled into a metal casing to form a three-effect catalyst converter, and is connected between the automobile engine and the exhaust port. The catalytic bed of the three-effect catalytic converter is divided into a front-stage catalyst bed and a rear-stage catalyst bed, and a secondary air is introduced in the middle of the two sections, and the secondary air amount is 0-30% of the exhaust gas.

It is worth noting that the catalyst with copper as the active center is often discussed in the paper, but the actual application is not much. The main reason is that copper will gradually aggregate and lose its dispersion at high temperature, which leads to effective catalysis. The surface area is reduced and the function of the catalyst is thus greatly reduced. In the invention, a copper ferrite magnet is used as an active component of the catalyst, and the copper is fixed in the crystal structure of the spinel, thereby overcoming the aforementioned problems; if the auxiliary metal element is further added, the catalytic performance and thermal stability can be assisted. In addition, when the catalytic converter is used to treat automobile exhaust gas, there is often a problem of catalyst surface area carbon, and as the use time increases, the carbon accumulation gradually decreases the catalytic effect. In addition to the function of the three-way catalyst, the catalyst of the invention has the powerful catalytic ability to utilize the air entering from the exhaust pipe or other passages when the engine is stopped to promote the combustion of the surface area carbon to generate carbon dioxide, and the reaction only needs to be at room temperature. The invention can be started up, so the invention has the characteristics of self-cleaning carbon.

In addition, the scope of the invention may be further exemplified by the following specific examples, which are not intended to limit the scope of the invention.

Example 1: Synthesis of copper-iron oxide magnet catalyst (Cu/Fe=1/2.5)

This embodiment provides two methods for preparing copper-iron oxide magnet catalysts of different particle diameters:

(1) According to the required molar ratio (Cu ²⁺ /Fe ²⁺ = 1/2.5), weigh the correct amount of CuSO ₄ and FeSO ₄ into the reactor, add 1 liter of deionized water and stir to completely dissolve; Sodium hydroxide (NaOH) at a concentration of 6 N was added to adjust the pH to 9.5, and then the temperature was raised to 80 ° C by heating. After the temperature and pH were stabilized, air was supplied to the solution at a rate of 3 L/min, and the reaction conditions were maintained until the oxidation-reduction potential (ORP) meter reading rapidly turned to obtain a copper ferrite magnet solid initial product. The copper ferrite magnet obtained by this method has a particle size distribution of about 20 to 150 nm.

(2) According to the required molar ratio (Cu ²⁺ /Fe ²⁺ /Fe ³⁺ =1/0.167/2.333), weigh the correct amount of CuSO ₄ , FeCl ₂ and FeCl ₃ into the reactor and add 1 liter. Deionized water and stirred to completely dissolve; heating in a water bath to raise the temperature of the solution to 80 ° C, and nitrogen gas for 5 minutes; adding ammonia to completely precipitate the metal and stirring and heating for 2 hours to obtain a copper ferrite magnet solid initial product . The copper ferrite magnet obtained by this method has a particle size distribution of about 2 to 25 nm.

Please refer to the first figure, separate the solid primary product, dry it, grind it, and sieve it to make a powdery copper ferrite magnet. Zooming in with 30,000 times by electron microscope, each catalyst powder is actually made up of many sizes. The nano-scale ferrite magnet crystals are gathered together.

Example 2: Exploring the efficiency of copper-iron oxide magnet catalyst to remove carbon monoxide under low oxygen concentration

Referring to the second figure, the copper ferrite magnet can be removed by converting carbon monoxide to carbon dioxide at a temperature of 160 ° C even at an oxygen concentration of only 1%.

Example 3: Exploring the efficiency of copper-iron-oxygen magnet catalyst to remove hydrocarbons under low oxygen concentration

Referring to the third figure, the copper ferrite magnet can remove hydrocarbons at temperatures up to 270 °C even at oxygen concentrations of only 1%.

Example 4: Exploring the efficiency of copper-iron oxide magnet catalyst for removing nitric oxide

Referring to the fourth figure, the copper ferrite magnet can be removed by converting the nitrogen monoxide into nitrogen at a temperature of 270 ° C using a gasoline component.

Example 5: Exploring the removal effect of copper ferrite magnets on nitrogen oxides (NO _x ), carbon monoxide (CO) and hydrocarbons (HC) emitted by automobiles

(1) Making copper-iron oxide magnet catalyst powder into honeycomb catalyst

A preferred method is to apply a copper ferrite magnet catalyst powder additive to a ceramic honeycomb carrier to form a honeycomb-like catalyst body. Another preferred method is to prepare a copper ferrite magnet catalyst powder mixed with clay, alumina, kaolin, cerium oxide, calcium sulfate, paraffin, etc., and then extrude by a mold to form a honeycomb-shaped catalyst body. . The honeycomb-shaped catalyst body was dried and sintered at 600 ° C in an inert atmosphere of nitrogen to obtain a honeycomb structure catalyst.

(2) Air pollutant removal test

The catalyst was loaded into the experimental equipment and tested by introducing simulated exhaust gas formulated with nitrogen, air, CO, NO and 95 unleaded gasoline. The reaction conditions were: space velocity 24000 h ^-1 ; inlet oxygen concentration 1%; inlet CO, NO concentrations were 1.0%, 1000 ppm, respectively; inlet HC concentration was equivalent to 8000 ppm isooctane (calculated by FID). Referring to the fifth figure, the catalytic bed of the three-effect catalytic converter is divided into a front-stage catalyst bed and a rear-stage catalyst bed, and introduces secondary air in the middle of the front-stage catalyst bed and the rear-stage catalyst bed, and the secondary air introduction amount. It is 15% of the volume of the exhaust gas. When the engine is running, the front-stage catalyst bed firstly combusts the carbon monoxide and hydrocarbons in the exhaust gas from the outlet end of the engine, thereby reducing the oxygen concentration of the exhaust gas to a very low level. Next, the catalyst can reduce nitrogen oxides to nitrogen at a low oxygen concentration with carbon monoxide and hydrocarbons as reducing agents. Finally, secondary air is introduced at the front end of the rear catalyst bed, which acts to completely remove the remaining carbon monoxide and hydrocarbons. Please refer to FIG Sixth, it was found that the temperature can be only 300 ℃ NO _X, CO and HC clear, can be seen the present invention, the catalyst does have a three-way catalyst function.

Example 6: Carbon self-cleaning test

The simulated exhaust gas formulated with nitrogen, air, CO and 95 unleaded gasoline was introduced into a reactor filled with copper ferrite magnet catalyst powder and maintained at a temperature of 300 °C. When the system is stabilized, the air is suddenly turned off. At this time, due to the lack of oxygen in the exhaust gas, CO and HC cannot be burned smoothly, and a large amount of carbon deposit is rapidly generated on the catalyst surface. After 1 hour, the simulated exhaust gas and heater were turned off, and only nitrogen gas was introduced to remove residual flammable gas and allowed to stand while waiting for the reactor temperature to fall back to room temperature. Next, by shutting off the nitrogen gas and introducing air, it was observed that the temperature inside the reactor rose rapidly and a large amount of CO _{2 was} detected at the outlet, which is evidence that the carbon deposition was catalytically burned. In addition, if the reactor is poured out after the reactor temperature drops back to room temperature, it can be found that the original dark brown copper ferrite magnet is black due to being covered with carbon. In the next few minutes, the carbon deposits were quickly removed by oxidation to reveal the original dark brown color of the catalyst. Please refer to the seventh figure. The catalyst is poured out at room temperature. The reaction heat of burning off the carbon can even ignite the photocopying paper laid on the ground, showing that the catalytic performance is very strong.

It can be seen from the above description that the present invention has the following advantages compared with the prior art:

1. In addition to the function of the three-way catalyst, the invention also solves the shortcomings of the traditional use of precious metal catalysts because of the low production rate and the high cost of the catalyst. Therefore, the invention has the copper ferrite magnet as the three-acting catalyst active ingredient. Significantly reduce costs.

2. The copper ferrite magnet of the invention has strong catalytic ability to utilize the air sucked by the exhaust pipe or other passages when the engine is stopped to promote the reaction of the surface area carbon into carbon dioxide, thereby having the characteristics of self-cleaning carbon, and the performance is generally The ternary catalyst cannot be achieved, and thus the present invention has the advantage of being durable.

In summary, the use of the copper ferrite magnet of the present invention as a three-effect catalyst for automobile engine exhaust gas treatment can indeed achieve the intended use efficiency by the above disclosed embodiments, and the present invention has not been disclosed in the application. Before, Cheng has fully complied with the requirements and requirements of the Patent Law.爰Issuing an application for a patent for invention in accordance with the law, and asking for a review, and granting a patent, is truly sensible.

The illustrations and descriptions of the present invention are merely preferred embodiments of the present invention, and are not intended to limit the scope of the present invention; those skilled in the art, which are characterized by the scope of the present invention, Equivalent variations or modifications are considered to be within the scope of the design of the invention.

No

First Figure: An electron micrograph of a copper-iron oxide magnet catalyst in accordance with a preferred embodiment of the present invention.

Second: The effect of the copper-iron-oxygen magnet catalyst on the removal of carbon monoxide (CO) at different oxygen concentrations in the preferred embodiment of the present invention.

Third: The effect of the copper-iron oxide magnet catalyst of the preferred embodiment of the invention on the removal of hydrocarbons (HC) at different oxygen concentrations.

Fourth: The effect of the copper-iron oxide magnet catalyst of the preferred embodiment of the invention on the removal of nitrogen oxides (NO _x ) at different oxygen concentrations.

Figure 5 is a schematic view showing the construction of a three-effect catalytic converter for gasoline engine exhaust gas treatment according to a preferred embodiment of the present invention.

Fig. 6 is a view showing the effect of the copper-iron oxide three-effect catalytic converter of the preferred embodiment of the present invention on the removal of nitrogen oxides (NO _x ), carbon monoxide (CO) and hydrocarbons (HC).

Figure 7 is a schematic view showing the surface area carbon burned by the copper-iron oxide magnet catalyst powder after contact with air according to a preferred embodiment of the present invention.

Claims (10)

A copper ferrite magnet is used as a three-effect catalyst for automobile engine exhaust gas treatment, wherein a copper ferrite magnet (Cu-ferrite) contains copper and iron with a molar ratio of 1:2 to 1:10, which is used for removing Nitrogen oxides, carbon monoxide and volatile organic compounds in the exhaust gas, as well as self-cleaning surface area carbon. The use according to claim 1, wherein the copper ferromagnetic system doping is selected from the group consisting of manganese, titanium, cobalt, zinc, nickel, lanthanum, calcium, magnesium, chromium, aluminum, lanthanum, cerium, lanthanum and cerium. One or more of the non-copper metals, and the ratio of the total amount of the non-copper metal to the molar amount of iron is 1:2 to 1:10. The use according to claim 1, wherein the copper ferrite magnet has a particle diameter of 2 to 150 nm. The use according to claim 1, wherein the copper ferromagnetic system is further added with a fixing agent to form a honeycomb (honeycomb) catalyst body, or is further coated with a honeycomb metal or ceramic. The honeycomb-shaped catalyst body is formed on the support, and the honeycomb-shaped catalyst body is dried, and then fired at 200 to 800 ° C in an inert atmosphere of nitrogen, argon or helium to prepare a three-way catalyst. The use of claim 4, wherein the three-way catalyst is further used as a catalytic converter. The utility model relates to an automobile engine exhaust gas treatment three-effect catalyst prepared by a copper ferrite magnet, wherein the copper ferrite magnet (Cu-ferrite) comprises copper and iron with a molar ratio of 1:2 to 1:10. The automobile engine exhaust gas treatment three-effect catalyst prepared by the copper ferrite magnet according to the sixth aspect of the patent application, wherein the copper ferromagnetic system doping is selected from the group consisting of manganese, titanium, cobalt, zinc, nickel, antimony, A non-copper metal of one or more of calcium, magnesium, chromium, aluminum, lanthanum, cerium, lanthanum and cerium, and the ratio of the total amount of the non-copper metal to the molar ratio of iron is 1:2 to 1:10. The automobile engine exhaust gas treatment three-effect catalyst prepared by the copper ferrite magnet according to the sixth aspect of the patent application, wherein the copper ferrite magnet has a particle diameter of 2 to 150 nm. The automobile engine exhaust gas treatment three-effect catalyst prepared by the copper ferrite magnet according to the sixth aspect of the patent application, wherein the copper ferromagnetic system further adds a fixing agent to form a honeycomb (honeycomb) contact The medium body is further coated on the honeycomb metal or ceramic support to form a honeycomb-shaped catalyst body, and the honeycomb-shaped catalyst body is dried and then subjected to an inert atmosphere of nitrogen, argon or helium. It is made into a three-effect catalyst by firing at 200~800 °C. The automotive engine exhaust gas treatment three-effect catalyst prepared by the copper ferrite magnet according to claim 9 is further used as a catalytic converter.