CN116618044A - Catalyst with noble metal loaded on grain boundary and surface, and preparation method and application thereof - Google Patents

Catalyst with noble metal loaded on grain boundary and surface, and preparation method and application thereof Download PDF

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Publication number
CN116618044A
CN116618044A CN202210135425.8A CN202210135425A CN116618044A CN 116618044 A CN116618044 A CN 116618044A CN 202210135425 A CN202210135425 A CN 202210135425A CN 116618044 A CN116618044 A CN 116618044A
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noble metal
catalyst
cerium
honeycomb
composite oxide
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侯永可
黄小卫
崔梅生
张永奇
赵政
翟志哲
陈东明
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Hebei Xiongan Rare Earth Functional Material Innovation Center Co ltd
Grirem Advanced Materials Co Ltd
Grirem Hi Tech Co Ltd
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Hebei Xiongan Rare Earth Functional Material Innovation Center Co ltd
Grirem Advanced Materials Co Ltd
Grirem Hi Tech Co Ltd
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Priority to CN202210135425.8A priority Critical patent/CN116618044A/en
Priority to PCT/CN2023/075765 priority patent/WO2023151688A1/en
Publication of CN116618044A publication Critical patent/CN116618044A/en
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    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
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    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/89—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with noble metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/89—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with noble metals
    • B01J23/8933—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with noble metals also combined with metals, or metal oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/894—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with noble metals also combined with metals, or metal oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with rare earths or actinides
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    • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
    • B01J27/06—Halogens; Compounds thereof
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    • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
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    • B01J35/50—Catalysts, in general, characterised by their form or physical properties characterised by their shape or configuration
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    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
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    • F23G7/00—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
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Abstract

The invention relates to a catalyst with noble metal supported on grain boundary and surface, a preparation method and application thereof, wherein the catalyst supports the noble metal on the grain boundary and surface of an active coating containing alumina and/or cerium-zirconium composite oxide, improves the anchoring effect of the noble metal, avoids migration, agglomeration and growth of noble metal particles, maintains the catalytic activity and high-temperature stability of the noble metal catalyst, and reduces the consumption of the noble metal.

Description

Catalyst with noble metal loaded on grain boundary and surface, and preparation method and application thereof
Technical Field
The invention relates to the technical field of noble metal catalysts, in particular to a catalyst with noble metal supported on grain boundaries and surfaces, and a preparation method and application thereof.
Background
According to researches, with the annual increase of global automobile conservation, automobile exhaust pollution has become a primary pollution source of urban atmospheric pollution, and environmental problems caused by automobile exhaust emission are increasingly serious. The automobile exhaust catalytic converter is an effective solution for purifying automobile exhaust, and the core of the automobile exhaust catalytic converter is a three-way catalyst loaded with noble metals. In general, the three-way catalyst for automobile exhaust is composed of a honeycomb carrier, noble metal, an active coating and the like, the service life of the three-way catalyst is mainly determined by an active coating material of the three-way catalyst and a preparation process, the active coating material comprises cerium-zirconium composite oxide, aluminum oxide and the like, and the noble metal is supported on the active coating. Because the three-way catalyst for automobile exhaust is in a severe environment in practical application, the three-way catalyst not only contains water vapor, but also has higher temperature which can reach more than 900 ℃ sometimes, and the catalyst, coating materials, noble metals and the like are required to have high-temperature stability. Therefore, in order to ensure the conversion efficiency of the automobile exhaust catalyst and maintain the catalytic activity of the cerium-zirconium composite oxide supported noble metal catalyst, the high-temperature aging phenomenon of the coating material containing the cerium-zirconium supported noble metal in a high-temperature environment should be prevented as much as possible: on one hand, cerium and zirconium should be prevented from sintering at high temperature as much as possible, and on the other hand, noble metal particles should be prevented from migrating, agglomerating and growing at high temperature or being wrapped by coating materials such as cerium, zirconium, aluminum oxide and the like to reduce or lose catalytic activity. Oxidation catalysts for catalytic combustion of natural gas, treatment of organic waste gas, and the like also require noble metal catalysts having high-temperature stability.
Disclosure of Invention
Based on the above circumstances of the prior art, an object of the present invention is to provide a catalyst with noble metal supported on grain boundaries and surfaces, and a preparation method and application thereof, by dispersing noble metal at grain boundaries and surfaces of alumina and/or cerium-zirconium composite oxide to prevent or slow down element diffusion between grains and at surfaces, inhibit migration, agglomeration and growth of noble metal particles at high temperature, and prepare a cerium-zirconium-based noble metal catalyst which is more resistant to high temperature and stable; the alumina and/or cerium-zirconium composite oxide grain boundary and surface-supported noble metal catalyst prepared according to the method is used for preparing honeycomb noble metal catalyst slurry, and then the slurry is coated on a honeycomb to prepare the honeycomb noble metal catalyst, so that the high-temperature stability of the honeycomb noble metal catalyst is effectively improved, the catalytic activity of the catalyst under the condition of long-term use at high temperature is maintained, and the noble metal dosage is reduced.
In order to achieve the above object, according to a first aspect of the present invention, there is provided a catalyst having a noble metal supported on grain boundaries and surfaces, the catalyst comprising a noble metal G dispersed at the grain boundaries and surfaces of alumina and/or cerium-zirconium composite oxide having a chemical formula of G/Ce x Zr y M z O 2-α D δ The method comprises the steps of carrying out a first treatment on the surface of the Wherein,,
m is a cation doping element, and D is an anion doping element;
x is more than or equal to 0 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 1, z is more than or equal to 0 and less than 0.5, and x, y and z meet x+y+z=1;
0≤α≤0.1；0≤δ≤0.1。
according to a second aspect of the present invention, there is provided a honeycomb noble metal catalyst comprising a honeycomb carrier, a noble metalG and an active coating layer containing alumina and/or cerium-zirconium composite oxide Ce x Zr y M z O 2-α D δ The method comprises the steps of carrying out a first treatment on the surface of the The noble metal G is dispersed at the grain boundary and the surface of the aluminum oxide and/or the cerium-zirconium composite oxide; wherein,,
m is a cation doping element, and D is an anion doping element;
x is more than or equal to 0 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 1, z is more than or equal to 0 and less than 0.5, and x, y and z meet x+y+z=1;
0≤α≤0.1；0≤δ≤0.1。
further, the cerium-zirconium composite oxide accounts for 0 to 100% of the total mass of the active coating, and is preferably 30 to 70%.
Further, the noble metal G at the grain boundaries and surfaces is in a metallic state, or in a metallic state and in an oxidized state.
Further, the noble metal G includes one or more combinations of Pt, pd, rh, ir, os, ru, au and Ag, preferably one or more combinations of Pt, pd, rh and Ru. Further, the doping element M comprises one or more than one of Mg, ca, sr, ba, al, ga, si, ti, mn, sc, fe, co, ni, bi, cu, zn, nb, sn, hf, W, mo and non-cerium rare earth elements, preferably one or more than one of Sr, ba, al, si, ti, mn, fe, ni, cu, nb, sn, la, pr, nd, sm, eu, gd, er, tm, yb and Y; the doping element D includes one or a combination of more than one of anions N, F and P.
Further, the honeycomb carrier is made of porous ceramic or metal.
Further, the loading of the noble metal G in the catalyst is 0.01% -3%, preferably 0.1% -2% by mass.
Further, the loading of the noble metal G in the catalyst is 0.01 to 2.8G/L, preferably 0.1 to 2G/L.
According to a third aspect of the present invention, there is provided a method for preparing a catalyst having noble metal supported on grain boundaries and surfaces according to the first aspect of the present invention, comprising the steps of:
s1, uniformly mixing cerium-zirconium composite oxide and/or activated alumina with liquid salt of noble metal G;
s2, carrying out heat treatment on the product obtained in the step S1 once or twice;
s3, carrying out one-time or two-time reduction roasting on the product obtained in the step S2 in air or a reducing atmosphere to obtain the cerium-zirconium composite oxide and/or the active alumina grain boundary and the catalyst with the surface loaded with noble metal.
According to a fourth aspect of the present invention, there is provided a method for producing a honeycomb-type noble metal catalyst according to the second aspect of the present invention, the honeycomb-type noble metal catalyst being coated stepwise with one or more coating materials which are one or two of cerium-zirconium composite oxide, aluminum oxide, grain boundary and surface noble metal-supported cerium-zirconium composite oxide, grain boundary and surface noble metal-supported aluminum oxide, grain boundary and surface noble metal-supported cerium-zirconium composite oxide and aluminum oxide, comprising the steps of:
B1, uniformly mixing the coating material, an adhesive, an acidity regulator and water in one step or multiple steps to prepare coating slurry;
b2, coating the coating slurry obtained in the step B1 on a honeycomb carrier in one step or multiple steps, or coating the coating slurry on the honeycomb carrier in a zoning or layering manner, and drying;
and B3, carrying out heat treatment or/and roasting on the product obtained in the step B2 in air or reducing atmosphere to obtain the noble metal honeycomb catalyst.
According to a fifth aspect of the present invention, there is provided a method for preparing a honeycomb noble metal catalyst according to the second aspect of the present invention, wherein cerium-zirconium composite oxide or alumina or cerium-zirconium composite oxide and alumina, noble metal, binder, acidity regulator and water are uniformly mixed in one or more steps to prepare a coating slurry; coating the obtained product on a honeycomb carrier through one or more steps, or coating the product on the honeycomb carrier in a zoning or layering manner, and drying; and carrying out heat treatment or/and reduction roasting on the dried honeycomb carrier in a reducing atmosphere to obtain the honeycomb noble metal catalyst.
Further, the heat treatment temperature is 200-800 ℃, and the heat treatment time is 0.5-24 hours; the heat treatment temperature is preferably 400-700 ℃, and the heat treatment time is preferably 1-12h.
Further, the roasting temperature is 400-700 ℃ and the roasting time is 0.5-24 hours; preferably the calcination temperature is 450-600 ℃, preferably the calcination time is 1-12 h.
Further, the reducing atmosphere comprises CO and H 2 One or more than one of the following.
Further, the liquid salt of the noble metal G comprises one or more of a molten salt or an aqueous solution of a chloride salt, a nitrate salt and an acetate salt.
According to a sixth aspect of the present invention there is provided the use of a catalyst according to the first and second aspects of the present invention in the fields of automotive exhaust gas purification, industrial organic waste gas treatment, catalytic combustion of natural gas, petrochemical industry, hydrogen energy and batteries.
In summary, the invention provides a catalyst with noble metal supported on grain boundaries and surfaces, a honeycomb noble metal catalyst, and a preparation method and application thereof. According to the grain boundary and surface supported noble metal catalyst and the honeycomb type noble metal catalyst, the noble metal G is dispersed at the grain boundary and surface of the aluminum oxide and/or cerium-zirconium composite oxide, so that the anchoring effect of the noble metal is improved, migration, agglomeration and growth of noble metal particles are avoided, the catalytic activity and high-temperature stability of the noble metal catalyst are maintained, and the consumption of the noble metal is reduced.
Drawings
FIG. 1 is a flow chart of a method for preparing a catalyst with noble metal supported on grain boundaries and surfaces according to an embodiment of the present invention;
FIG. 2 is a flow chart of a method for preparing a honeycomb noble metal catalyst according to an embodiment of the present invention.
Detailed Description
The objects, technical solutions and advantages of the present invention will become more apparent by the following detailed description of the present invention with reference to the accompanying drawings. It should be understood that the description is only illustrative and is not intended to limit the scope of the invention. In addition, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the present invention.
The embodiment of the invention provides a catalyst for loading noble metal on the grain boundary and the surface, which is characterized in that noble metal G is loaded on the grain boundary and the surface of aluminum oxide and/or cerium-zirconium composite oxide, wherein the chemical general formula of the cerium-zirconium composite oxide is G/Ce x Zr y M z O 2-α D δ The method comprises the steps of carrying out a first treatment on the surface of the M is a cation doping element, and D is an anion doping element; the range of values of each element is as follows:
x is more than or equal to 0 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 1, z is more than or equal to 0 and less than or equal to 0.5, and x, y and z meet x+y+z=1;
0≤α≤0.1；0≤δ≤0.1。
the embodiment of the invention also provides a honeycomb noble metal catalyst, which comprises a honeycomb carrier, noble metal G and an active coating, wherein the active coating contains alumina and/or cerium-zirconium composite oxide Ce x Zr y M z O 2-α D δ The noble metal G is dispersed in alumina and/or cerium-zirconium composite oxide Ce x Zr y M z O 2-α D δ The noble metal G is in a metallic state, or in a metallic state and an oxidized state, preferably in a metallic state, and is dispersed in alumina and/or cerium-zirconium composite oxide Ce x Zr y M z O 2-α D δ The active coating layer of (2) is in a metal state at the grain boundary and surface, which is more beneficial to the catalytic effect, the noble metal G can be one or more than one of Pt, pd, rh, ir, os, ru, au and Ag, preferably one or more than one of Pt, pd, rh, ru, and the loading of the noble metal G in the catalyst is 0.01-3% by mass percent, preferably 0.1-2%.
The doping element M can be one or more than one of Mg, ca, sr, ba, al, ga, si, ti, mn, sc, fe, co, ni, bi, cu, zn, nb, sn, hf, W, mo and non-cerium rare earth elements, preferably one or more than one of Sr, ba, al, si, ti, mn, fe, ni, cu, nb, sn, la, pr, nd, sm, eu, gd, er, tm, yb, Y; the doping element D may be one or a combination of more than one of anions N, F, P.
The embodiment of the invention also provides a preparation method of the catalyst with the noble metal supported on the grain boundary and the surface. FIG. 1 shows a flow chart of a preparation method of a catalyst with noble metal supported on grain boundaries and surfaces, which comprises the following steps:
S1, mixing alumina and/or cerium-zirconium composite oxide Ce according to a preset component proportion x Zr y M z O 2-α D δ Mixing with liquid salt of noble metal G; the liquid salt of the noble metal G comprises one or more of chloride, nitrate, and molten salt of acetate or a combination of more than one solution; the step of alumina and/or cerium-zirconium composite oxide Ce x Zr y M z O 2-α D δ The ratio of the catalyst to the noble metal G is 0.01 to 3 percent, preferably 0.1 to 2 percent, in terms of mass percent according to the load of the noble metal G.
S2, carrying out heat treatment on the product obtained in the step S1 once or twice; the temperature of the heat treatment can be 200-800 ℃ and the time is 0.5-24 hours; preferably, the heat treatment temperature is 400-700 ℃ and the heat treatment time is 1-12 h.
S3, carrying out one-time or two-time reduction roasting on the product obtained in the step S2 in air or a reducing atmosphere to obtain the aluminum oxide and/or cerium-zirconium composite oxide Ce x Zr y M z O 2-α D δ A catalyst for dispersing noble metals at grain boundaries and surfaces; the roasting temperature can be 400-800 ℃ and the time is 0.5-24 hours; preferably, the roasting temperature is 450-600 ℃ and the roasting time is 1-12 h; the reducing atmosphere may include CO, H 2 The reducing atmosphere may further contain a small amount of O 2 ，O 2 The volume percentage content is not more than 10 percent.
In the embodiment of the invention, when the heat treatment is carried out in the step S2, the grain boundary of the matrix is activated by controlling the proper temperature so as to become a channel for diffusing noble metal, and the depth and the distribution of the noble metal along the grain boundary can be controlled by controlling the heat treatment time. By controlling the reducing atmosphere in step S3The original temperature, reduction time may reduce or control partial reduction of the noble metal at the grain boundaries and surfaces. The noble metal is distributed at the grain boundary and the surface of the cerium-zirconium composite oxide through the steps S2 and S3, so that on one hand, the noble metal is used for preventing or slowing down the element diffusion between grains or on the surface of the cerium-zirconium composite oxide, preventing the sintering aging of the cerium-zirconium composite oxide and reducing the specific surface area, and the thermal stability of the cerium-zirconium composite oxide is improved; on the other hand, the anchoring effect of the grain boundary and the surface of the cerium-zirconium composite oxide on the noble metal slows down the migration, agglomeration and growth of noble metal particles at high temperature, and the alumina and/or cerium-zirconium composite oxide Ce with higher high temperature resistance and stability is prepared x Zr y M z O 2-α D δ And a catalyst with noble metal supported on the grain boundary and surface.
The embodiment of the invention also provides a preparation method of the honeycomb noble metal catalyst, the honeycomb noble metal catalyst is coated with one or more coating materials step by step, the coating materials are one or two of cerium-zirconium composite oxide, aluminum oxide, cerium-zirconium composite oxide with grain boundary and surface loaded with noble metal, aluminum oxide with grain boundary and surface loaded with noble metal, cerium-zirconium composite oxide with grain boundary and surface loaded with noble metal and aluminum oxide, and fig. 2 shows a flow chart of the preparation method of the honeycomb noble metal catalyst, which comprises the following steps:
B1, uniformly mixing the coating material, an adhesive, an acidity regulator and water in one step or multiple steps to prepare coating slurry;
b2, coating the coating slurry obtained in the step B1 on a honeycomb carrier in one step or multiple steps, or coating the coating slurry on the honeycomb carrier in a zoning or layering manner, and drying;
b3, carrying out heat treatment or/and roasting on the product obtained in the step B2 to obtain the noble metal honeycomb catalyst, wherein the heat treatment temperature in the step can be 200-800 ℃ and the time is 0.5-24 h; preferably, the heat treatment temperature is 400-700 ℃ and the heat treatment time is 1-12 h; the roasting temperature in the step can be 400-800 ℃ and the time is 0.5-24 hours; preferably, the roasting temperature is 450-600 ℃ and the roasting time is 1-12 h; the roasting atmosphere in this step can be air atmosphere roasting or air atmosphere roastingRoasting in original atmosphere, wherein the atmosphere for reduction roasting can be CO and H 2 One or more than one of the following.
The embodiment of the invention also provides another preparation method of the honeycomb noble metal catalyst, which comprises the following steps: one or two of cerium-zirconium composite oxide, aluminum oxide, cerium-zirconium composite oxide and/or active aluminum oxide grain boundary and catalyst with surface loaded with noble metal are coated on a honeycomb carrier, the honeycomb noble metal catalyst with noble metal G loaded at the grain boundary and surface of the aluminum oxide and/or cerium-zirconium composite oxide is obtained through a heat treatment step and a roasting step and by controlling the atmosphere, temperature and time of heat treatment and roasting, migration and growth of noble metal particles are avoided through the anchoring effect of the grain boundary and surface on the noble metal, so that the catalytic activity and high-temperature stability of the noble metal catalyst can be maintained, the thermal stability of the honeycomb noble metal catalyst under the long-term high-temperature environment working condition is improved, the catalytic activity of the catalyst is ensured, and the consumption of the noble metal is reduced.
The embodiment of the invention also provides the catalyst with noble metal supported on the grain boundary and the surface and the application of the honeycomb noble metal catalyst in the fields of motor vehicle tail gas purification, industrial organic waste gas treatment, natural gas catalytic combustion, petrochemical industry, hydrogen energy and batteries. The catalyst with noble metal supported on the grain boundary and the surface and the honeycomb noble metal catalyst provided by the embodiment of the invention have better high-temperature stability and can meet the application requirements of various related fields.
The invention is further illustrated by the following specific examples.
Comparative example 1
A certain volume of palladium nitrate, platinum nitrate solution and 200gCe are measured according to the load quantity of 0.9 percent of palladium and 0.3 percent of platinum 0.52 Zr 0.36 La 0.05 Y 0.07 O 2 And uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, and roasting the dried sample at 500 ℃ for 5 hours in an air atmosphere to obtain the cerium-zirconium-supported noble metal catalyst sample.
Taking a proper amount of cerium-zirconium composite oxide supported noble metal catalyst sample prepared by the method, and aging at 1000 DEG CAnd (5) carrying out the treatment for 4 hours. And then tabletting, crushing and sieving the cerium-zirconium composite oxide supported noble metal catalyst powder to obtain a 30-40-mesh granular cerium-zirconium composite oxide supported noble metal catalyst, and then carrying out a catalytic performance test on the granular catalyst. The catalytic test adopts simulated automobile exhaust mixed gas, and the content (volume ratio) of each component is as follows: CO content of 1.5%, NO content of 900ppm, HC content of 900ppm, O 2 The content is 1.2%, CO 2 The content is 12 percent, the rest is N 2 The method comprises the steps of carrying out a first treatment on the surface of the The space velocity was 50000/h. The light-off temperature (T50) of the test sample for the catalytic conversion of CO, NO and HC; as a result, the light-off temperature of CO was 325 ℃, the light-off temperature of NO was 339 ℃, and the light-off temperature of HC was 318 ℃.
Comparative example 2
200 to gCe are taken 0.52 Zr 0.36 La 0.05 Y 0.07 O 2 Mixing powder, 200g of active alumina and a proper amount of deionized water to form slurry, adding palladium nitrate and platinum nitrate according to the total mass of the active coating of the honeycomb carrier, adding palladium nitrate and platinum nitrate with the loading amount of 0.45 percent and 0.15 percent, uniformly mixing, then adding an adhesive, an acidity regulator and the like to prepare coating slurry, coating the prepared slurry on a ceramic honeycomb carrier according to the coating amount of 1.2g/L of the total loading amount of noble metal of the honeycomb catalyst, drying the coated honeycomb carrier for 4 hours at 110 ℃, and finally roasting the honeycomb carrier in an air atmosphere at 500 ℃ for 5 hours to obtain the honeycomb noble metal catalyst.
The prepared honeycomb noble metal catalyst is aged for 4 hours at 1000 ℃, then a small section of honeycomb noble metal catalyst sample with the diameter of 0.5-1 cm is cut, and then the cut small section of honeycomb noble metal catalyst sample is subjected to catalytic performance test. The catalytic test adopts simulated automobile exhaust mixed gas, and the content (volume ratio) of each component is as follows: CO content of 1.5%, NO content of 900ppm, HC content of 900ppm, O 2 The content is 1.2%, CO 2 The content is 12 percent, the rest is N 2 . The space velocity was 50000/h. The light-off temperature (T50) of the test sample for the catalytic conversion of CO, NO and HC; as a result, the light-off temperature of CO was 314 ℃, the light-off temperature of NO was 329 ℃, and the light-off temperature of HC was 311 ℃.
Comparative example 3
According to the load quantity of 1.2 percent of palladium and 0.2 percent of rhodium, a certain volume of palladium nitrate, rhodium nitrate solution and 200g of Ce are measured 0.16 Zr 0.78 La 0.02 Nd 0.04 O 2 And uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, and roasting the dried sample at 500 ℃ for 5 hours in an air atmosphere to obtain the cerium-zirconium-supported noble metal catalyst sample. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 1, and the test results were a light-off temperature of CO of 330 ℃, a light-off temperature of NO of 323 ℃, and a light-off temperature of HC of 331 ℃.
Comparative example 4
200g Ce is taken 0.16 Zr 0.78 La 0.02 Nd 0.04 O 2 Mixing powder, 200g of active alumina and a proper amount of deionized water to form slurry, adding palladium nitrate and rhodium nitrate according to the total mass of the active coating of the honeycomb carrier, adding the loading amount of 0.6 percent of palladium and 0.1 percent of rhodium, uniformly mixing, adding an adhesive, an acidity regulator and the like to prepare coating slurry, coating the prepared slurry on a ceramic honeycomb carrier according to the coating amount of 1.4g/L of the total loading amount of noble metal of the honeycomb catalyst, drying the coated honeycomb carrier for 4 hours at 110 ℃, and finally roasting the honeycomb carrier in an air atmosphere at 500 ℃ for 5 hours to obtain the honeycomb noble metal catalyst. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of CO of 326 ℃, a light-off temperature of NO of 319 ℃, and a light-off temperature of HC of 327 ℃.
Example 1
Measuring a certain volume of palladium nitrate, platinum nitrate solution and 200gCe according to the load quantity of 0.9 percent of palladium and 0.3 percent of platinum 0.52 Zr 0.36 La 0.05 Y 0.07 O 2 Uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, heat-treating the sample at 550 ℃ for 4 hours, and finally reducing and roasting the sample at 500 ℃ for 5 hours in a hydrogen atmosphere to obtain a cerium-zirconium composite oxide grain boundary and a catalyst sample PdPt/Ce with noble metals Pd and Pt supported on the surface 0.52 Zr 0.36 La 0.05 Y 0.07 O 2 . For the sampleThe catalytic performance test was conducted under the same conditions as in comparative example 1, and the test result was a light-off temperature of CO of 290℃and a light-off temperature of NO of 320℃and a light-off temperature of HC of 295 ℃.
Example 2
Taking a cerium-zirconium composite oxide supported noble metal catalyst PdPt/Ce prepared according to example 1 0.52 Zr 0.36 La 0.05 Y 0.07 O 2 200g and proper amount of alumina, a certain amount of adhesive, acidity regulator, deionized water and the like are prepared into coating slurry; then coating the prepared slurry on a ceramic honeycomb carrier according to the coating amount of 1.2g/L of the total noble metal loading amount of the honeycomb catalyst, drying the coated honeycomb carrier for 4 hours at 110 ℃, then carrying out heat treatment on the honeycomb carrier for 5 hours at 300 ℃, and finally roasting the honeycomb carrier for 5 hours at 500 ℃ to obtain the honeycomb noble metal catalyst; noble metals Pd and Pt are loaded at the grain boundary and the surface of the cerium-zirconium composite oxide and the alumina of the honeycomb noble metal catalyst. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of CO of 270 ℃, a light-off temperature of NO of 300 ℃, and a light-off temperature of HC of 284 ℃.
Example 3
Measuring a certain volume of palladium nitrate, rhodium nitrate solution and 200gCe according to the load quantity of 1.2 percent of palladium and 0.2 percent of rhodium 0.16 Zr 0.78 La 0.02 Nd 0.04 O 2 Uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, heat-treating the sample at 550 ℃ for 4 hours, and finally reducing and roasting the sample at 500 ℃ for 5 hours in a hydrogen atmosphere to obtain a cerium-zirconium composite oxide grain boundary and a catalyst sample PdRh/Ce with noble metals Pd and Rh supported on the surface 0.16 Zr 0.78 La 0.02 Nd 0.04 O 2 . The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 1, and the test results were a light-off temperature of CO of 278 ℃, a light-off temperature of NO of 279 ℃, and a light-off temperature of HC of 313 ℃.
Example 4
Taking cerium zirconium prepared according to example 3Composite oxide supported noble metal catalyst PdRh/Ce 0.16 Zr 0.78 La 0.02 Nd 0.04 O 2 200g and a proper amount of activated alumina, a certain amount of adhesive, acidity regulator, deionized water and the like are prepared into coating slurry; then coating the prepared slurry on a ceramic honeycomb carrier according to the coating amount of 1.4g/L of the total noble metal loading amount of the honeycomb catalyst, drying the coated honeycomb carrier for 4 hours at 110 ℃, then carrying out heat treatment on the honeycomb carrier for 5 hours at 300 ℃, and finally roasting the honeycomb carrier for 5 hours at 500 ℃ to obtain the honeycomb noble metal catalyst; noble metals Pd and Rh are loaded at the grain boundary and the surface of the cerium-zirconium composite oxide and the alumina of the honeycomb noble metal catalyst. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of CO of 261 ℃, a light-off temperature of NO of 250 ℃, and a light-off temperature of HC of 287 ℃.
Example 5
According to the load quantity of 0.4 percent of palladium, 0.3 percent of platinum and 0.01 percent of rhodium, a certain volume of palladium nitrate, platinum nitrate, rhodium nitrate solution and 200g of Ce are measured 0.38 Zr 0.53 La 0.071 Pr 0.01 Y 0.01 O 2 Uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, heat-treating the sample at 550 ℃ for 4 hours, and finally reducing and roasting the sample at 500 ℃ for 4 hours in a hydrogen atmosphere to obtain a cerium-zirconium composite oxide grain boundary and a catalyst sample PdPtRh/Ce with noble metals Pd, pt and Rh supported on the surface 0.38 Zr 0.53 La 0.071 Pr 0.01 Y 0.01 O 2 . The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 1, and the test results were a light-off temperature of CO of 260 ℃, a light-off temperature of NO of 287 ℃ and a light-off temperature of HC of 286 ℃.
Example 6
According to the load amounts of 0.7 percent of palladium, 0.2 percent of platinum and 0.1 percent of rhodium, a certain volume of palladium nitrate, platinum nitrate, rhodium nitrate solution and 200g of Ce are measured 0.33 Zr 0.58 La 0.033 Nd 0.032 Y 0.025 O 2 Mixing the powder uniformly, and then baking the sample at 110 DEG CDrying for 4 hours, heat-treating the sample at 200 ℃ for 4 hours, and finally reducing and roasting the sample at 500 ℃ for 4 hours in hydrogen atmosphere to obtain a catalyst sample PdPtRh/Ce with cerium-zirconium composite oxide grain boundary and surface loaded with noble metals Pd, pt and Rh 0.33 Zr 0.58 La 0.033 Nd 0.032 Y 0.025 O 2 . The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 1, and the test results were a light-off temperature of CO of 315℃and a light-off temperature of NO of 324℃and a light-off temperature of HC of 327 ℃.
Example 7
According to the load amounts of 0.7 percent of palladium, 0.2 percent of platinum and 0.1 percent of rhodium, a certain volume of palladium nitrate, platinum nitrate, rhodium nitrate solution and 200g of Ce are measured 0.33 Zr 0.58 La 0.033 Nd 0.032 Y 0.025 O 2 Uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, heat-treating the sample at 400 ℃ for 4 hours, and finally reducing and roasting the sample at 500 ℃ for 4 hours in a hydrogen atmosphere to obtain a cerium-zirconium composite oxide grain boundary and a catalyst sample PdPtRh/Ce with noble metals Pd, pt and Rh supported on the surface 0.33 Zr 0.58 La 0.033 Nd 0.032 Y 0.025 O 2 . The samples were subjected to catalytic performance testing under the same conditions as in comparative example 1, and the results of the test were a CO light-off temperature of 278℃and a NO light-off temperature of 310℃and a HC light-off temperature of 290 ℃.
Example 8
According to the load amounts of 0.7 percent of palladium, 0.2 percent of platinum and 0.1 percent of rhodium, a certain volume of palladium nitrate, platinum nitrate, rhodium nitrate solution and 200g of Ce are measured 0.33 Zr 0.58 La 0.033 Nd 0.032 Y 0.025 O 2 Uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, heat-treating the sample at 600 ℃ for 4 hours, and finally reducing and roasting the sample at 500 ℃ for 4 hours in a hydrogen atmosphere to obtain a cerium-zirconium composite oxide grain boundary and a catalyst sample PdPtRh/Ce with noble metals Pd, pt and Rh supported on the surface 0.33 Zr 0.58 La 0.033 Nd 0.032 Y 0.025 O 2 . Catalytic action on sampleThe sample preparation procedure and catalytic test conditions were the same as in comparative example 1, and the test result was that the light-off temperature of CO was 259 ℃, the light-off temperature of NO was 277 ℃, and the light-off temperature of HC was 278 ℃.
Example 9
Taking a cerium-zirconium composite oxide supported noble metal catalyst PdPtRh/Ce prepared according to example 8 0.33 Zr 0.58 La 0.033 Nd 0.032 Y 0.025 O 2 200g and a proper amount of activated alumina, a certain amount of adhesive, acidity regulator, deionized water and the like are prepared into coating slurry; then coating the prepared slurry on a ceramic honeycomb carrier according to the coating amount of 1g/L of the total noble metal loading amount of the honeycomb catalyst, drying the coated honeycomb carrier at 110 ℃ for 4 hours, heat-treating the honeycomb carrier at 400 ℃ for 12 hours, and finally roasting the honeycomb carrier at 500 ℃ for 5 hours to obtain the honeycomb noble metal catalyst; noble metals Pd, pt and Rh are loaded at the grain boundary and the surface of the cerium-zirconium composite oxide and the alumina of the honeycomb noble metal catalyst. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of CO of 257 ℃, a light-off temperature of NO of 283 ℃, and a light-off temperature of HC of 267 ℃.
Example 10
A certain volume of chloride liquid salt of palladium, platinum and rhodium and 200g of Ce are measured according to the load amounts of 0.7 percent of palladium, 0.2 percent of platinum and 0.1 percent of rhodium 0.33 Zr 0.58 La 0.033 Nd 0.032 Y 0.025 O 2 Uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, performing first heat treatment at 450 ℃ for 4 hours, performing second heat treatment at 800 ℃ for 4 hours, and finally reducing and roasting the sample at 500 ℃ for 4 hours in a hydrogen atmosphere to obtain a cerium-zirconium composite oxide grain boundary and a catalyst sample PdPtRh/Ce with noble metals Pd, pt and Rh supported on the surface 0.33 Zr 0.58 La 0.033 Nd 0.032 Y 0.025 O 2 . The samples were subjected to catalytic performance testing under the same conditions as in comparative example 1, the results of the test were a light-off temperature of 264℃for CO, 291℃for NO, and HCThe burning temperature was 275 ℃.
Example 11
200g of active alumina and a certain amount of adhesive, acidity regulator, deionized water and the like are taken to prepare coating slurry; then coating the alumina slurry on the ceramic honeycomb carrier according to the amount of 100g/L alumina contained in the honeycomb carrier, and drying the coated honeycomb carrier at 110 ℃ for 4 hours; taking a cerium-zirconium composite oxide supported noble metal catalyst PdPtRh/Ce prepared according to example 10 0.33 Zr 0.58 La 0.033 Nd 0.032 Y 0.025 O 2 200g and a certain amount of adhesive, acidity regulator, deionized water and the like are prepared into coating slurry; then coating the prepared slurry on the ceramic honeycomb carrier coated with alumina according to the coating amount of 1g/L of the total noble metal loading amount of the honeycomb catalyst, drying the coated honeycomb carrier at 110 ℃ for 4 hours, heat-treating the honeycomb carrier at 600 ℃ for 4 hours, and finally roasting the honeycomb carrier at 500 ℃ for 5 hours to obtain the honeycomb noble metal catalyst; noble metals Pd, pt and Rh are mainly loaded at the grain boundary and the surface of the cerium-zirconium composite oxide of the honeycomb noble metal catalyst, and a small amount of noble metals Pd, pt and Rh are loaded at the grain boundary and the surface of the cerium-zirconium composite oxide and the aluminum oxide. The samples were subjected to catalytic performance testing under the same conditions as in comparative example 2, and the results of the test were a light-off temperature of CO of 267℃and a light-off temperature of NO of 279℃and a light-off temperature of HC of 274 ℃.
Example 12
A certain volume of palladium nitrate, platinum nitrate solution and 200gCeO are measured according to the load quantity of 1% of palladium and 0.01% of platinum 2 Uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, heat-treating the sample at 500 ℃ for 4.5 hours, and finally reducing and roasting the sample at 400 ℃ for 24 hours in a hydrogen atmosphere to obtain cerium oxide grain boundaries and a catalyst sample PdPt/CeO with noble metals Pd and Pt supported on the surfaces 2 . The samples were subjected to catalytic performance testing under the same conditions as in comparative example 1, and the results of the test were a light-off temperature of 304℃for CO, 339℃for NO, and 317℃for HC.
Example 13
Taking cerium oxide-supported noble metal catalyst PdPt/CeO prepared according to example 12 2 200g and a proper amount of activated alumina, a certain amount of adhesive, acidity regulator, deionized water and the like are prepared into coating slurry; then coating the prepared slurry on a ceramic honeycomb carrier according to the coating amount of 0.61g/L of the total noble metal loading amount of the honeycomb catalyst, drying the coated honeycomb carrier for 4 hours at 110 ℃, then carrying out heat treatment on the honeycomb carrier for 18 hours at 300 ℃, and finally roasting the honeycomb carrier for 12 hours at 400 ℃ to obtain the honeycomb noble metal catalyst; noble metals Pd, pt are supported at the grain boundaries and surfaces of cerium oxide and aluminum oxide of the honeycomb-type noble metal catalyst. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of CO of 288 ℃, a light-off temperature of NO of 329 ℃, and a light-off temperature of HC of 303 ℃.
Example 14
According to the load of 1.2% of palladium and 0.08% of rhodium, a certain volume of acetate solution of palladium and rhodium and 200g of Ce are taken 0.3 8 Zr 0.53 La 0.045 Sm 0.03 Tm 0.015 O 2 Uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, then carrying out heat treatment on the sample at 600 ℃ for 4 hours, carrying out first reduction roasting on the sample at 500 ℃ for 5 hours under hydrogen atmosphere, and finally carrying out second reduction roasting on the sample at 650 ℃ for 2 hours under hydrogen atmosphere to obtain a cerium-zirconium composite oxide grain boundary and a catalyst sample PdRh/Ce with noble metals Pd and Rh supported on the surface 0.38 Zr 0.53 La 0.045 Sm 0.03 Tm 0.015 O 2 . The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 1, and the test results were a light-off temperature of CO of 254 ℃, a light-off temperature of NO of 257 ℃, and a light-off temperature of HC of 260 ℃.
Example 15
According to the load quantity of 1.9% of platinum and 0.1% of rhodium, a certain volume of platinum nitrate, rhodium nitrate solution and 200g of Ce are measured 0.13 Zr 0.64 La 0.03 Nd 0.03 Mn 0.17 O 2 Mixing the powder uniformly, and then placing the sample at 110 DEG CDrying for 4 hours, then carrying out heat treatment on the sample at 200 ℃ for 24 hours, finally carrying out reduction roasting on the sample at 700 ℃ for 0.5 hour in a CO atmosphere to obtain a catalyst sample PtRh/Ce with cerium-zirconium composite oxide grain boundaries and noble metals Pt and Rh supported on the surfaces 0.13 Zr 0.64 La 0.03 Nd 0.03 Mn 0.17 O 2 . The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 1, and the test results were a light-off temperature of CO of 286 ℃, a light-off temperature of NO of 280 ℃, and a light-off temperature of HC of 293 ℃.
Example 16
Taking a cerium-zirconium composite oxide supported noble metal catalyst PdRh/Ce prepared according to example 14 0.38 Zr 0.53 La 0.045 Sm 0.03 Tm 0.015 O 2 200g and a proper amount of activated alumina, a certain amount of adhesive, acidity regulator, deionized water and the like are prepared into coating slurry a; taking a cerium-zirconium composite oxide supported noble metal catalyst PtRh/Ce prepared according to example 15 0.13 Zr 0.64 La 0.03 Nd 0.03 Mn 0.17 O 2 200g and a proper amount of activated alumina, a certain amount of adhesive, acidity regulator, deionized water and the like are prepared into another coating slurry b; then coating the prepared slurry a on a half honeycomb carrier according to the coating amount of 0.64g/L of the total noble metal loading, and drying the half coated honeycomb carrier for 4 hours at 110 ℃; coating the prepared slurry b on the other half of the honeycomb carrier according to the coating amount of 1g/L of the total loading amount of the noble metal, and drying the coated honeycomb carrier for 4 hours at 110 ℃; then the honeycomb carrier is heat treated for 3 hours at 450 ℃, and finally the honeycomb carrier is roasted for 6 hours at 550 ℃ to obtain the honeycomb noble metal catalyst with the total noble metal loading of 1.64 g/L; noble metals Pd, pt and Rh are loaded at the grain boundary and the surface of the cerium-zirconium composite oxide and the alumina of the honeycomb noble metal catalyst. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of CO of 245 ℃, a light-off temperature of NO of 249 ℃, and a light-off temperature of HC of 247 ℃.
Example 17
A certain volume of rhodium nitrate solution and 200gCe are measured according to the load of 0.01 percent of rhodium 0.78 Zr 0.16 La 0.02 Y 0.02 Fe 0.02 O 2 Uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, heat-treating the sample at 300 ℃ for 20 hours, roasting the sample at 450 ℃ for 4 hours in an air atmosphere, and finally reducing and roasting the sample at 570 ℃ for 5 hours in a hydrogen atmosphere to obtain a cerium-zirconium composite oxide grain boundary and a catalyst sample Rh/Ce with noble metal rhodium loaded on the surface 0.78 Zr 0.16 La 0.02 Y 0.02 Fe 0.02 O 2 . The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 1, and the test results were a light-off temperature of CO of 313 ℃, a light-off temperature of NO of 291 ℃, and a light-off temperature of HC of 305 ℃.
Example 18
Taking a cerium-zirconium composite oxide supported noble metal catalyst Rh/Ce prepared according to example 17 0.78 Zr 0.16 La 0.02 Y 0.02 Fe 0.02 O 2 200g and a proper amount of activated alumina, a certain amount of adhesive, acidity regulator, deionized water and the like are prepared into coating slurry; then coating the prepared slurry on a ceramic honeycomb carrier according to the coating amount of 0.01g/L of the total noble metal loading amount of the honeycomb catalyst, drying the coated honeycomb carrier for 4 hours at 110 ℃, and finally roasting the honeycomb carrier for 5 hours at 500 ℃ to obtain the honeycomb noble metal catalyst; noble metal Rh is supported at the grain boundaries and surfaces of the cerium-zirconium composite oxide and alumina of the honeycomb-type noble metal catalyst. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of CO of 296 ℃, a light-off temperature of NO of 281 ℃, and a light-off temperature of HC of 293 ℃.
Example 19
A certain volume of palladium nitrate solution and 200gCe are measured according to the load amount of 0.5 percent of palladium 0.38 Zr 0.5 La 0.07 Pr 0.0 3 Y 0.01 Si 0.01 O 1.999 N 0.001 And 200g of active alumina powder are uniformly mixed, and thenDrying the sample at 110 ℃ for 4 hours, heat-treating the sample at 550 ℃ for 3 hours, and finally reducing and roasting the sample at 470 ℃ for 16 hours in a hydrogen atmosphere to obtain a catalyst sample Pd/Ce with noble metal Pd supported on grain boundaries and surfaces of cerium-zirconium composite oxide and aluminum oxide 0.38 Zr 0.5 La 0.07 Pr 0.0 3 Y 0.01 Si 0.01 O 1.999 N 0.001 &Al 2 O 3 . The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 1, and the test results were a light-off temperature of 265℃for CO, 270℃for NO, and 270℃for HC.
Example 20
Taking cerium-zirconium composite oxide prepared according to example 19 and alumina-supported noble metal catalyst Pd/Ce 0.38 Zr 0.5 La 0.07 Pr 0.03 Y 0.01 Si 0.01 O 1.999 N 0.001 &Al 2 O 3 200g and a proper amount of adhesive, acidity regulator, deionized water and the like are mixed into coating slurry; then coating the prepared slurry on a ceramic honeycomb carrier according to the coating amount of 1g/L of the total noble metal loading amount of the honeycomb catalyst, drying the coated honeycomb carrier for 4 hours at 110 ℃, then carrying out heat treatment on the honeycomb carrier for 1 hour at 750 ℃, and finally roasting the honeycomb carrier for 5 hours at 600 ℃ to obtain the honeycomb noble metal catalyst; the noble metal Pd is supported at the grain boundary and surface of the cerium-zirconium composite oxide and alumina of the honeycomb noble metal catalyst. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of CO of 260 ℃, a light-off temperature of NO of 263 ℃, and a light-off temperature of HC of 258 ℃.
Example 21
According to the load of 0.5 percent of palladium and 1.8 percent of platinum, a certain volume of palladium nitrate, platinum nitrate solution and 200g Ce are measured 0.18 Zr 0.64 La 0.03 Y 0.13 Yb 0.02 O 1.995 F 0.005 Mixing the powder uniformly, drying the sample at 110deg.C for 4 hr, heat treating the sample at 600deg.C for 4 hr, and heating the sample in hydrogenReducing and roasting for 4 hours at 600 ℃ in the atmosphere to obtain a catalyst sample PdPt/Ce with noble metal Pd and Pt supported on the grain boundary and the surface of the cerium-zirconium composite oxide 0.18 Zr 0.64 La 0.03 Y 0.13 Yb 0.02 O 1.995 F 0.005 . The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 1, and the test results were a light-off temperature of CO of 243 ℃, a light-off temperature of NO of 261 ℃, and a light-off temperature of HC of 242 ℃.
Example 22
According to the load quantity of 0.9% of platinum and 0.01% of rhodium, a certain volume of platinum nitrate, rhodium nitrate solution and 200g of Ce are measured 0.3 3 Zr 0.5 La 0.033 Nd 0.032 Y 0.025 Sr 0.04 Ba 0.04 O 2 Uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, heat-treating the sample at 600 ℃ for 6.5 hours, and finally reducing and roasting the sample at 500 ℃ for 12 hours in a hydrogen atmosphere to obtain a catalyst sample PtRh/Ce with cerium-zirconium composite oxide grain boundaries and noble metals Pt and Rh loaded on the surfaces 0.33 Zr 0.5 La 0.033 Nd 0.032 Y 0.025 Sr 0.04 Ba 0.04 O 2 . The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 1, and the test results were a light-off temperature of CO of 256 ℃, a light-off temperature of NO of 261 ℃, and a light-off temperature of HC of 263 ℃.
Example 23
The cerium-zirconium composite oxide supported noble metal catalyst PtRh/Ce prepared in example 22 was taken according to the content of cerium-zirconium of 90% and the content of alumina of 10% in the honeycomb noble metal catalyst coating 0.33 Zr 0.5 La 0.033 Nd 0.032 Y 0.025 Sr 0.04 Ba 0.04 O 2 200g and a proper amount of activated alumina, a certain amount of adhesive, acidity regulator, deionized water and the like are prepared into coating slurry; then coating the prepared slurry on a ceramic honeycomb carrier according to the coating amount of 1.64g/L of the total noble metal loading of the honeycomb catalyst, drying the coated honeycomb carrier for 4 hours at 110 ℃, and then carrying out heat treatment on the honeycomb carrier for 0.5 hour at 800 DEG CFinally, roasting the honeycomb carrier at 700 ℃ for 0.5 hour to obtain a honeycomb noble metal catalyst; noble metals Pt, rh are supported at the grain boundaries and surfaces of the cerium-zirconium composite oxide and alumina of the honeycomb-type noble metal catalyst. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of 265℃for CO, 271℃for NO, and 274℃for HC.
Example 24
According to the load quantity of 0.5% of platinum and 0.4% of rhodium, a certain volume of platinum nitrate, rhodium nitrate solution and 200gCe are measured 0.16 Zr 0.6 La 0.02 Nd 0.04 Mn 0.12 Ba 0.06 O 2 Uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, heat-treating the sample at 700 ℃ for 8 hours, and finally reducing and roasting the sample at 600 ℃ for 4 hours in a hydrogen atmosphere to obtain a cerium-zirconium composite oxide grain boundary and a catalyst sample PtRh/Ce with noble metals Pt and Rh supported on the surface 0.16 Zr 0.6 La 0.02 Nd 0.04 Mn 0.12 Ba 0.06 O 2 . The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 1, and the test results were a light-off temperature of CO of 251 ℃, a light-off temperature of NO of 248 ℃, and a light-off temperature of HC of 260 ℃.
Example 25
Taking a cerium-zirconium composite oxide supported noble metal catalyst PtRh/Ce prepared according to example 24 0.16 Zr 0.6 La 0.02 Nd 0.04 Mn 0.12 Ba 0.06 O 2 200g and a proper amount of activated alumina, a certain amount of adhesive, acidity regulator, deionized water and the like are prepared into coating slurry; then coating the prepared slurry on a ceramic honeycomb carrier according to the coating amount of 1.08g/L of the total noble metal loading amount of the honeycomb catalyst, drying the coated honeycomb carrier for 4 hours at 110 ℃, then carrying out heat treatment on the honeycomb carrier for 3 hours at 430 ℃, and finally roasting the honeycomb carrier for 6 hours at 650 ℃ to obtain the honeycomb noble metal catalyst; grain boundary and table of cerium-zirconium composite oxide and alumina of noble metals Pt and Rh supported on honeycomb noble metal catalystAt the face. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of CO of 247 ℃, a light-off temperature of NO of 242 ℃, and a light-off temperature of HC of 253 ℃.
Example 26
A volume of rhodium nitrate solution was taken with 200g Zr according to a rhodium loading of 0.1% 0.86 La 0.09 Y 0.04 Ti 0.01 O 2 Uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, heat-treating the sample at 420 ℃ for 6 hours, and finally reducing and roasting the sample at 630 ℃ for 4 hours in a hydrogen atmosphere to obtain a cerium-zirconium composite oxide grain boundary and a catalyst sample Rh/Zr with noble metal Rh supported on the surface 0.86 La 0.09 Y 0.04 Ti 0.01 O 2 . The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 1, and the test results were a light-off temperature of CO of 271 ℃, a light-off temperature of NO of 258 ℃, and a light-off temperature of HC of 277 ℃.
Example 27
The cerium-zirconium composite oxide loaded noble metal catalyst Rh/Zr prepared in example 26 is taken according to the content of cerium and zirconium in the honeycomb noble metal catalyst coating of 70 percent and the content of alumina of 30 percent 0.86 La 0.09 Y 0.04 Ti 0.01 O 2 200g and a proper amount of activated alumina, a certain amount of adhesive, acidity regulator, deionized water and the like are prepared into coating slurry; then coating the prepared slurry on a ceramic honeycomb carrier according to the coating amount of 0.14g/L of the total noble metal loading amount of the honeycomb catalyst, drying the coated honeycomb carrier for 4 hours at 110 ℃, then carrying out heat treatment on the honeycomb carrier for 3 hours at 550 ℃, and finally roasting the honeycomb carrier for 1.5 hours at 700 ℃ to obtain the honeycomb noble metal catalyst; the noble metal rhodium is supported at the grain boundary and surface of the cerium-zirconium composite oxide and alumina of the honeycomb noble metal catalyst. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of CO of 268 ℃, a light-off temperature of NO of 253 ℃, and a light-off temperature of HC of 272 ℃.
Example 28
According to the load quantity of 0.1 percent of palladium, 0.2 percent of platinum and 0.1 percent of rhodium, a certain volume of palladium nitrate, platinum nitrate, rhodium nitrate solution and 200gCe 0.25 Zr 0.6 La 0.05 Y 0.05 Nb 0.02 Sn 0.03 O 2 Uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, heat-treating the sample at 620 ℃ for 4 hours, and finally reducing and roasting the sample at 520 ℃ for 7 hours in a hydrogen atmosphere to obtain a cerium-zirconium composite oxide grain boundary and a catalyst sample PdPtRh/Ce with noble metals Pd, pt and Rh supported on the surface 0.25 Zr 0.6 La 0.05 Y 0.05 Nb 0.02 Sn 0.03 O 2 . The samples were subjected to catalytic performance testing under the same conditions as in comparative example 1, and the results of the test were a light-off temperature of CO of 276 ℃, a light-off temperature of NO of 257 ℃, and a light-off temperature of HC of 273 ℃.
Example 29
A volume of rhodium nitrate solution was taken with 200g Ce according to a rhodium loading of 0.1% 0.18 Zr 0.62 La 0.03 Y 0.13 Er 0.02 Ni 0.02 O 2 Uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, heat-treating the sample at 710 ℃ for 2 hours, and finally reducing and roasting the sample at 650 ℃ for 3 hours in a hydrogen atmosphere to obtain a cerium-zirconium composite oxide grain boundary and a catalyst sample Rh/Ce with noble metal Rh supported on the surface 0.18 Zr 0.62 La 0.03 Y 0.13 Er 0.02 Ni 0.02 O 2 . The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 1, and the test results were a light-off temperature of CO of 291 ℃, a light-off temperature of NO of 258 ℃, and a light-off temperature of HC of 285 ℃.
Example 30
A volume of palladium nitrate, platinum nitrate solution and 200g of Al were measured according to a load of 0.9% palladium and 0.5% platinum 0.48 Ce 0.175 Zr 0.3 La 0.018 Nd 0.018 Y 0.009 O 2 Mixing the powder uniformly, drying the sample at 110deg.C for 4 hr, heat treating the sample at 650deg.C for 5 hr, and finallyThe sample is reduced and roasted for 5 hours at 500 ℃ in hydrogen atmosphere to obtain a catalyst sample PdPt/Al of cerium-zirconium composite oxide grain boundary and surface loaded with noble metal Pd and Pt 0.48 Ce 0.175 Zr 0.3 La 0.018 Nd 0.018 Y 0.009 O 2 . The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 1, and the test results were a light-off temperature of CO of 273 ℃, a light-off temperature of NO of 285 ℃ and a light-off temperature of HC of 277 ℃.
Example 31
Taking cerium-zirconium composite oxide supported noble metal catalyst PdPt/Al prepared according to example 30 0.48 Ce 0.175 Zr 0.3 La 0.018 Nd 0.018 Y 0.009 O 2 200g and a proper amount of activated alumina, a certain amount of adhesive, acidity regulator, deionized water and the like are prepared into coating slurry; then coating the prepared slurry on a ceramic honeycomb carrier according to the coating amount of 1.4g/L of the total noble metal loading amount of the honeycomb catalyst, drying the coated honeycomb carrier for 4 hours at 110 ℃, then carrying out heat treatment on the honeycomb carrier for 4 hours at 250 ℃, and finally roasting the honeycomb carrier for 16 hours at 470 ℃ to obtain the honeycomb noble metal catalyst; noble metals Pd and Pt are loaded at the grain boundary and the surface of the cerium-zirconium composite oxide and the alumina of the honeycomb noble metal catalyst. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of CO of 253 ℃, a light-off temperature of NO of 264 ℃, and a light-off temperature of HC of 269 ℃.
Example 32
According to the load of 0.01 percent of palladium and 2 percent of platinum, a certain volume of palladium nitrate, platinum nitrate solution and 200g Ce are measured 0.30 Zr 0.61 La 0.044 Gd 0.04 Cu 0.006 O 2 Uniformly mixing the powder, drying the sample at 110 ℃ for 4 hours, heat-treating the sample at 270 ℃ for 12 hours, roasting the sample at 440 ℃ for 3 hours under air atmosphere for the first time, roasting the sample at 620 ℃ for the second time under air atmosphere for 3 hours to obtain cerium-zirconium composite oxide grain boundary and noble metal Pd and Pt loaded on the surfaceCatalyst sample PdPt/Ce 0.30 Zr 0.61 La 0.044 Gd 0.04 Cu 0.006 O 2 . The samples were subjected to catalytic performance testing under the same conditions as in comparative example 1, and the results of the test were a light-off temperature of CO of 283℃and a light-off temperature of NO of 272℃and a light-off temperature of HC of 278 ℃.
Example 33
A certain volume of platinum nitrate solution is measured according to the load of 0.5 percent of platinum and is uniformly mixed with 200g of active alumina powder, then the sample is dried for 4 hours at 110 ℃, then the sample is heat-treated for 7 hours at 350 ℃, finally the sample is reduced and roasted for 5 hours at 500 ℃ in hydrogen atmosphere, and the catalyst sample Pt/Al with alumina grain boundary and surface loaded with noble metal Pt is obtained 2 O 3 。
According to Pt/Al 2 O 3 And cerium-zirconium powder in a mass ratio of 4:1, respectively taking the prepared Pt/Al 2 O 3 320g、Ce 0.13 Zr 0.64 La 0.03 Nd 0.03 Mn 0.17 O 2 80g and a certain amount of adhesive, acidity regulator, deionized water and the like are prepared into coating slurry; then coating the prepared slurry on a honeycomb carrier according to the coating amount of 0.8g/L of the total noble metal loading amount of the honeycomb catalyst, drying the coated honeycomb carrier for 4 hours at 110 ℃, then carrying out heat treatment on the honeycomb carrier for 7 hours at 270 ℃, and finally roasting the honeycomb carrier for 5 hours at 500 ℃ to obtain the honeycomb noble metal catalyst; the noble metal Pt is supported at the grain boundaries and surfaces of the cerium-zirconium composite oxide and alumina of the honeycomb noble metal catalyst. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of CO of 277 ℃, a light-off temperature of NO of 273 ℃, and a light-off temperature of HC of 281 ℃.
Example 34
Taking a cerium-zirconium composite oxide supported noble metal catalyst PtRh/Ce prepared according to example 15 0.13 Zr 0.64 La 0.03 Nd 0.03 Mn 0.17 O 2 200g of Pt/Al prepared according to example 33 2 O 3 200g, ptRh/Ce 0.13 Zr 0.64 La 0.03 Nd 0.03 Mn 0.17 O 2 And Pt/Al 2 O 3 Preparing a certain amount of adhesive, acidity regulator, deionized water and the like into coating slurry; then coating the prepared slurry on a ceramic honeycomb carrier according to the coating amount of 2.5g/L of the total noble metal loading amount of the honeycomb catalyst, drying the coated honeycomb carrier for 4 hours at 110 ℃, then carrying out heat treatment on the honeycomb carrier for 3 hours at 400 ℃, and finally roasting the honeycomb carrier for 6 hours at 550 ℃ to obtain the honeycomb noble metal catalyst; noble metals Pt, rh are supported at the grain boundaries and surfaces of the cerium-zirconium composite oxide and alumina of the honeycomb-type noble metal catalyst. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of CO of 253 ℃, a light-off temperature of NO of 249 ℃, and a light-off temperature of HC of 255 ℃.
Example 35
Pt/Al prepared according to example 33 was taken 2 O 3 200g and a certain amount of adhesive, acidity regulator, deionized water and the like are prepared into coating slurry; then coating the alumina slurry on the ceramic honeycomb carrier according to the amount of 100g/L alumina contained in the honeycomb carrier, and drying the coated honeycomb carrier at 110 ℃ for 4 hours; cerium-zirconium composite oxide Ce 0.30 Zr 0.61 La 0.044 Gd 0.0 4 Cu 0.006 O 2 200g, ce 0.30 Zr 0.61 La 0.044 Gd 0.04 Cu 0.006 O 2 And a certain amount of adhesive, acidity regulator, deionized water and the like to prepare coating slurry; then Ce is contained 0.30 Zr 0.61 La 0.044 Gd 0.04 Cu 0.006 O 2 Is coated on the coated Pt/Al with the coating weight of 100g/L 2 O 3 Drying the coated honeycomb carrier for 4 hours at 110 ℃, then carrying out heat treatment on the honeycomb carrier for 7 hours at 530 ℃, and finally roasting the honeycomb carrier for 5 hours at 640 ℃ to obtain the honeycomb noble metal catalyst; the noble metal Pt is mainly supported on Pt/Al of the honeycomb noble metal catalyst 2 O 3 Is less loaded at the grain boundary and surfaceAt the grain boundaries and surfaces of the cerium-zirconium composite oxide and the alumina. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of CO of 293 ℃, a light-off temperature of NO of 288 ℃, and a light-off temperature of HC of 287 ℃.
Example 36
Respectively taking cerium-zirconium composite oxide Ce 0.3 Zr 0.6 La 0.05 Pr 0.05 O 2 200g of activated alumina and a certain amount of deionized water are added to be uniformly mixed, a certain amount of nitrate of palladium, platinum and rhodium is added into the slurry according to the loading amount of 0.45 percent of palladium, 0.13 percent of platinum and 0.01 percent of rhodium in the active coating of the honeycomb carrier, and then a certain amount of adhesive, acidity regulator, deionized water and the like are added to be prepared into coating slurry; then coating the prepared slurry on a ceramic honeycomb carrier according to the coating amount of 1.18g/L of the total noble metal loading amount of the honeycomb catalyst, drying the coated honeycomb carrier at 110 ℃ for 4 hours, heat-treating the honeycomb carrier at 650 ℃ for 4 hours, and finally reducing and roasting the honeycomb carrier at 550 ℃ for 6 hours in a hydrogen atmosphere to obtain the honeycomb noble metal catalyst; noble metals Pd, pt and Rh are loaded at the grain boundary and the surface of the cerium-zirconium composite oxide and the alumina of the honeycomb noble metal catalyst. The samples were subjected to catalytic performance testing, the sample preparation procedure and catalytic testing conditions were the same as in comparative example 2, and the test results were a light-off temperature of CO of 281 ℃, a light-off temperature of NO of 294 ℃, and a light-off temperature of HC of 287 ℃.
As can be seen from the above comparative examples and examples, with the catalyst and the method for preparing a honeycomb-type noble metal catalyst, which are provided in the examples of the present invention, the catalyst and the honeycomb-type noble metal catalyst, which are provided with noble metals on the grain boundaries and the surfaces, can be aged at 1000℃for 4 hours against CO, NO by controlling the atmosphere, temperature and time of the heat treatment and the calcination step X The light-off temperature of HC is obviously lower than that of the catalyst prepared by the conventional method of the comparative example, and the catalyst has good high-temperature stability and catalytic activity. The embodiment of the invention is realized by diffusing noble metal into cerium-zirconium composite oxide or cerium-zirconium-containing composite oxide and oxidizingThe migration, agglomeration and growth of noble metal particles are avoided at the grain boundary and surface of the active coating of aluminum, so that the catalytic activity of the noble metal catalyst is well maintained, the high-temperature stability is improved, and the consumption of noble metal is reduced.
In summary, the invention relates to a catalyst with noble metal supported on grain boundaries and surfaces, a honeycomb noble metal catalyst, and a preparation method and application thereof. The noble metal is dispersed at the grain boundary and surface of the alumina and/or cerium-zirconium composite oxide. According to the invention, the noble metal is loaded and diffused to the grain boundary and the surface of the catalyst, and the grain boundary and the surface are provided with abundant defect sites, so that the activity of the noble metal can be improved, the anchoring effect of the noble metal is realized, the migration, agglomeration and growth of noble metal particles are avoided, the catalytic activity and high-temperature stability of the noble metal catalyst are maintained, and the consumption of the noble metal is reduced.
It is to be understood that the above-described embodiments of the present invention are merely illustrative of or explanation of the principles of the present invention and are in no way limiting of the invention. Accordingly, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present invention should be included in the scope of the present invention. Furthermore, the appended claims are intended to cover all such changes and modifications that fall within the scope and boundary of the appended claims, or equivalents of such scope and boundary.

Claims (17)

1. A catalyst having noble metal supported on grain boundary and surface, characterized in that the catalyst comprises noble metal G, alumina and/or cerium-zirconium composite oxide, the noble metal G being dispersed at the grain boundary and surface of the alumina and/or cerium-zirconium composite oxide, the cerium-zirconium composite oxide having the chemical formula G/Ce x Zr y M z O 2-α D δ The method comprises the steps of carrying out a first treatment on the surface of the Wherein,,
m is a cation doping element, and D is an anion doping element;
x is more than or equal to 0 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 1, z is more than or equal to 0 and less than 0.5, and x, y and z meet x+y+z=1;
0≤α≤0.1；0≤δ≤0.1。
2. a honeycomb noble metal catalyst is characterized by comprising a honeycomb carrier, noble metal G and an active coating, wherein the active coating contains alumina and/or cerium-zirconium composite oxide Ce x Zr y M z O 2-α D δ The method comprises the steps of carrying out a first treatment on the surface of the The noble metal G is dispersed at the grain boundary and the surface of the active coating; wherein,,
m is a cation doping element, and D is an anion doping element;
x is more than or equal to 0 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 1, z is more than or equal to 0 and less than 0.5, and x, y and z meet x+y+z=1; alpha is more than or equal to 0 and less than or equal to 0.1; delta is more than or equal to 0 and less than or equal to 0.1.
3. Catalyst according to claim 2, characterized in that the cerium zirconium composite oxide represents 0 to 100%, preferably 30 to 70% of the total mass of the active coating.
4. A catalyst according to any one of claims 1 to 3, wherein the noble metal G at the grain boundaries and surfaces is in a metallic state, or in a metallic state and in an oxidized state.
5. The catalyst according to any one of claims 1 to 4, characterized in that the noble metal G comprises one or more combinations of Pt, pd, rh, ir, os, ru, au and Ag, preferably one or more combinations of Pt, pd, rh and Ru.
6. The catalyst according to any one of claims 1 to 5, wherein the doping element M comprises one or more combinations of Mg, ca, sr, ba, al, ga, si, ti, mn, sc, fe, co, ni, bi, cu, zn, nb, sn, hf, W, mo and non-cerium rare earth elements, preferably one or more combinations of Sr, ba, al, si, ti, mn, fe, ni, cu, nb, sn, la, pr, nd, sm, eu, gd, er, tm, yb and Y; the doping element D includes one or a combination of more than one of anions N, F and P.
7. The honeycomb carrier catalyst according to claim 2, wherein the honeycomb carrier is made of porous ceramics or metal.
8. The catalyst of claim 1, wherein the noble metal G is supported on the grain boundaries and surfaces in a mass fraction of 0.01% to 3%, preferably 0.1% to 2%.
9. The honeycomb carrier catalyst according to claim 2, characterized in that the loading of noble metal G in the catalyst is 0.01-2.8G/L, preferably 0.1-2G/L.
10. A method for preparing the catalyst of claim 1, 4, 5, 6 or 8, wherein the catalyst comprises the following steps:
s1, uniformly mixing cerium-zirconium composite oxide and/or activated alumina with liquid salt of noble metal G;
s2, carrying out heat treatment on the product obtained in the step S1 once or twice;
s3, carrying out one-time or two-time reduction roasting on the product obtained in the step S2 in air or a reducing atmosphere to obtain the cerium-zirconium composite oxide and/or the active alumina grain boundary and the catalyst with the surface loaded with noble metal.
11. A method for preparing the honeycomb type noble metal catalyst according to claim 2, 3, 4, 5, 6, 7 or 9, wherein the honeycomb type noble metal catalyst is coated with one or more coating materials in steps, the coating materials being one or two of cerium-zirconium composite oxide, aluminum oxide, grain boundary and surface noble metal-supported cerium-zirconium composite oxide, grain boundary and surface noble metal-supported aluminum oxide, grain boundary and surface noble metal-supported cerium-zirconium composite oxide and aluminum oxide mixture, comprising the steps of:
B1, uniformly mixing the coating material, an adhesive, an acidity regulator and water in one step or multiple steps to prepare coating slurry;
b2, coating the coating slurry obtained in the step B1 on a honeycomb carrier in one step or multiple steps, or coating the coating slurry on the honeycomb carrier in a zoning or layering manner, and drying;
and B3, carrying out heat treatment or/and roasting on the product obtained in the step B2 in air or reducing atmosphere to obtain the noble metal honeycomb catalyst.
12. A process for preparing a honeycomb noble metal catalyst according to claim 2, 3, 4, 5, 6, 7 or 9,
uniformly mixing cerium-zirconium composite oxide or aluminum oxide or cerium-zirconium composite oxide with aluminum oxide, noble metal, acidity regulator, adhesive and water in one step or multiple steps to prepare coating slurry;
coating the obtained product on a honeycomb carrier through one or more steps, or coating the product on the honeycomb carrier in a zoning or layering manner, and drying;
and carrying out heat treatment or/and reduction roasting on the dried honeycomb carrier in a reducing atmosphere to obtain the honeycomb noble metal catalyst.
13. The method according to any one of claims 10 to 12, wherein the heat treatment temperature is 200 to 800 ℃ and the heat treatment time is 0.5 to 24 hours; the heat treatment temperature is preferably 400-700 ℃, and the heat treatment time is preferably 1-12h.
14. The method according to claims 10-12, wherein the firing temperature is 400-700 ℃ for a time of 0.5-24 hours; preferably the calcination temperature is 450-600 ℃, preferably the calcination time is 1-12 h.
15. The method according to claims 10-12, characterized in that the reducing atmosphere comprises CO and H 2 One or more than one of the following.
16. The method according to any one of claims 10 to 12, wherein the liquid salt of noble metal G comprises one or more of a molten salt or an aqueous solution of chloride, nitrate and acetate.
17. Use of the catalyst according to any one of claims 1-9 in the fields of automotive exhaust gas purification, industrial organic waste gas treatment, catalytic combustion of natural gas, petrochemical industry, hydrogen energy and batteries.
CN202210135425.8A 2022-02-14 2022-02-14 Catalyst with noble metal loaded on grain boundary and surface, and preparation method and application thereof Pending CN116618044A (en)

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