A non-uniform particle type combustion catalyst and a method for preparing the same

Abstract

The application relates to the technical field of catalysts, and discloses a non-uniform particle type combustion catalyst and a preparation method thereof, which comprises a carrier, an active component and an additive; the active component and the additive are distributed in a radial non-uniform state in the carrier; the active component comprises noble metal or an oxide thereof and transition metal or an oxide thereof; the additive metal comprises rare earth and / or alkali metal; the noble metal or the oxide thereof is distributed in a shell layer, the additive metal or the oxide thereof is distributed in the shell layer and a transition layer, and the transition metal or the oxide thereof is distributed in a core layer and the transition layer. The application is a noble metal-non-noble metal multi-component non-uniform distribution catalyst prepared by a multi-step impregnation and surface rolling coating method of the carrier, and has the advantages of high total active component loading, low noble metal consumption and high utilization rate; meanwhile, the noble metal is not wrapped by the high loading non-noble metal, so that the catalyst shows better catalytic activity and high-temperature stability at a lower raw material cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of catalyst technology, in particular, to a non-uniform particle type combustion catalyst and a preparation method thereof. BACKGROUND

[0002] Atmospheric environmental protection is related to the survival and fundamental interests of human beings. In recent years, with the continuous consumption of fossil energy and the emission of a large amount of harmful gases in the industrial production process, the atmospheric pollution situation has become increasingly serious, and volatile organic compounds (VOCs) are one of the main sources of atmospheric pollution. The control of VOCs is a challenging world problem.

[0003] Catalytic combustion technology has the advantages of low energy consumption, high treatment efficiency and no secondary pollution, and can treat VOCs on a large scale, which can effectively alleviate the environmental pollution caused by VOCs. However, the core of catalytic combustion is the design and optimization of catalysts, and noble metal catalysts are considered to be the most effective active components for treating VOCs.

[0004] However, the total reserves of noble metals are low, which causes the prices of noble metal catalysts such as Pt, Pd and Rh to rise continuously, making the cost of VOCs treatment catalysts too high, and the control of catalyst cost also becomes a problem that cannot be ignored. The existing catalysts have high noble metal loading, and the actual utilization rate of noble metals is low. Therefore, it is of great significance to develop non-uniform noble metal catalysts to make the noble metals in the catalysts play the maximum effect from the aspects of environmental protection and economy.

[0005] Patent No. CN101116820A discloses a main preparation method of a non-uniform catalyst product. The method mainly prepares the catalyst by immersing an alumina carrier in a mixed solution of active components through co-impregnation competitive adsorption, precipitation, pre-impregnation competitive adsorption and colloid method. The noble metals in the catalyst prepared by this method cannot only be distributed in the shell, and it is difficult to form obvious non-uniform distribution. In addition, the noble metals and non-noble metals are cross-distributed, the loading of non-noble metals is large, and the active sites of noble metals are easily covered, which reduces the actual utilization rate of noble metals.

[0006] Patent No. CN1923360A discloses an axial non-uniform monolithic catalyst, which uses cordierite as a matrix and adopts a special process to make the noble metal active components of the catalyst axially non-uniform, and is mainly used for nuclear reactor hydrogen-oxygen composite devices.

[0007] Patent with publication number CN1227140A discloses a nitric acid tail gas combustion temperature active non-uniform catalyst, and a noble metal component is prepared in a shell layer radial non-uniform catalyst by pre-impregnation of an organic oxygen-containing compound. However, the catalyst is mainly used in a high-temperature reaction system of 500-750 DEG C, and the low-temperature activity of the conventional volatile organic compounds needs to be further improved.

[0008] In summary, the noble metal catalyst is considered to be the most effective catalyst for treating VOCs, but the high price of the noble metal limits its application. On the one hand, the existing patent reduces the amount of noble metal and improves the utilization rate of noble metal through the noble metal non-uniform technology, but the amount of noble metal is still large and the price is high in order to achieve the necessary activity. On the other hand, the total loading amount of the active component of the noble metal non-uniform technology is low, and the catalytic activity is slightly insufficient, so that the long-term stability and the service life of the catalyst are affected. SUMMARY

[0009] <Technical problems solved by the present application>

[0010] To solve the problems of high noble metal loading, low actual utilization rate, high cost, poor non-noble metal activity and the like in the existing catalytic combustion catalyst.

[0011] <Technical solutions adopted by the present application>

[0012] In view of the above technical problems, the purpose of the present application is to provide a non-uniform particle type combustion catalyst and a preparation method thereof.

[0013] The specific content is as follows:

[0014] Firstly, the present application provides a non-uniform particle type combustion catalyst, which comprises:

[0015] a carrier, an active component and an additive;

[0016] The active component and the additive are distributed in the carrier in a radial non-uniform state; the active component comprises a noble metal or an oxide thereof and a transition metal or an oxide thereof; the additive metal comprises a rare earth metal and / or an alkali metal; the noble metal or the oxide thereof is distributed in a shell layer, the additive metal or the oxide thereof is distributed in the shell layer and a transition layer, and the transition metal or the oxide thereof is distributed in a core layer and the transition layer.

[0017] Secondly, the present application provides a preparation method of the aforementioned non-uniform particle type combustion catalyst, which comprises the following steps:

[0018] S1 impregnating the carrier 1 in a transition metal precursor, taking out, drying and calcining to obtain a precursor a;

[0019] S2 impregnating the precursor a in a transition metal precursor containing an additive metal precursor, taking out, drying and calcining to obtain a precursor b;

[0020] S3 impregnate the carrier 2 in the mixed system of noble metal precursor and auxiliary metal precursor, and after drying, blend with the binder to prepare c; S4 add the precursor b to c, and roll ball coating to make c uniformly wrapped on the surface of the precursor b to obtain the precursor d, and the precursor d is calcined to obtain the finished product.

[0021] <Advantages achieved by the present application>

[0022] (1) In the catalyst provided by the present application, the active component and the auxiliary agent are radially non-uniformly distributed: the noble metal is highly dispersed on the surface shell layer of the catalyst, and under working condition, the VOCs gas is preferentially adsorbed on the surface of the catalyst and contacts with the noble metal dispersed on the surface shell layer, which is beneficial to the light-off of VOCs gas and improves the utilization rate of noble metal, so that the amount of noble metal is significantly reduced.

[0023] (2) In the catalyst provided by the present application, the active component and the auxiliary agent are radially non-uniformly distributed: the auxiliary metal (rare earth and alkali metal) is mainly distributed in the shell layer and the transition layer, which is beneficial to improve the oxygen storage capacity of noble metal, reduce the activity shock and the carbon deposition resistance of the catalyst.

[0024] (3) In the catalyst provided by the present application, the active component and the auxiliary agent are non-uniformly distributed: the transition metal is mainly distributed in the core layer, which does not cross contact with the noble metal, reduces the coverage of the non-noble metal on the active site of the noble metal, and can form a synergistic effect with the noble metal through the transition layer to improve the activity and stability of the catalyst.

[0025] (4) In summary, the noble metal-non-noble metal multi-component non-uniformly distributed catalyst prepared by the carrier through the multi-step impregnation and surface rolling coating method has the advantages of high total loading amount of active component, low amount of noble metal, and high utilization rate. At the same time, the noble metal is not wrapped by the high loading amount of non-noble metal, so that the catalyst shows better catalytic activity and high temperature stability at lower raw material cost. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be clearly and completely described below. If the specific conditions are not specified in the embodiments, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be purchased on the market.

[0027] <TECHNICAL SCHEME>

[0028] Now the terms mentioned in the present application are stated as follows:

[0029] g is the unit of mass gram; ml is the unit of volume milliliter; ℃ is the unit of temperature Celsius; mol / L is the unit of concentration mole / liter; vol% is the unit of volume percentage; ml / min is the unit of gas flow rate milliliter / minute.

[0030] Specifically,

[0031] Firstly, the present application provides a non-uniform particle type combustion catalyst, comprising:

[0032] a carrier, an active component, an auxiliary agent;

[0033] The active component and the auxiliary agent are radially distributed in the carrier in a non-uniform state; the active component comprises a noble metal or an oxide thereof, and a transition metal or an oxide thereof; the auxiliary agent metal comprises a rare earth metal and / or an alkali metal; the noble metal or the oxide thereof is distributed in a shell layer, the auxiliary agent metal or the oxide thereof is distributed in the shell layer and a transition layer, and the transition metal or the oxide thereof is distributed in a core layer and the transition layer.

[0034] In the present application, the carrier is γ-Al2O3-TiO2, and the purchasing manufacturer is Taizhou Tianping Purification Material Co., Ltd.

[0035] In the present application, the transition metal comprises at least one of copper, manganese, iron and cobalt; and / or, the transition metal precursor is selected from nitrate.

[0036] The auxiliary agent metal comprises at least one of cerium, lanthanum and sodium; and / or, the auxiliary agent metal precursor is selected from at least one of nitrate, carbonate and bicarbonate.

[0037] The noble metal comprises at least one of palladium and platinum; and / or, the noble metal precursor comprises at least one of nitrate and chlorate.

[0038] In the present application, each component of the combustion catalyst comprises at least one of features (1) to (4):

[0039] (1) the total loading amount of the noble metal or the oxide thereof is 0.01-0.5wt%;

[0040] (2) the total loading amount of the transition metal or the oxide thereof is 5-25wt%;

[0041] (3) the total loading amount of the auxiliary agent metal or the oxide thereof is 0.5-2wt%;

[0042] (4) the balance is the carrier, or the carrier and a binder; the binder is pseudo-boehmite.

[0043] Secondly, the present application provides a preparation method of the aforementioned non-uniform particle type combustion catalyst, comprising the following steps:

[0044] S1 impregnate carrier 1 (2-4mm γ-Al2O3-TiO2) in transition metal precursor, take out, dry, calcine to obtain precursor a;

[0045] S2 impregnate precursor a in a mixture containing assistant metal precursor, take out, dry, calcine to obtain precursor b;

[0046] S3 impregnate carrier 2 (γ-Al2O3-TiO2 powder) in a mixture of noble metal precursor and assistant metal precursor, dry, and mix with the assistant to obtain c;

[0047] S4 mix precursors b and c, coat, so that c is coated on the surface of precursor b to obtain precursor d, and calcine the precursor d to obtain the finished product.

[0048] In the present application, the binder accounts for 5-15wt% of the total weight of wet material c.

[0049] In the present application, c accounts for 6-20wt% of the total weight of precursor d.

[0050] In detail, the preparation method is as follows:

[0051] (1) Impregnate 2-4mm diameter γ-Al2O3-TiO2 spherical carrier particles in a transition metal precursor solution by excess impregnation method, impregnate for 1h, take out, dry at 120℃, and calcine at 550℃ to obtain precursor a;

[0052] (2) Preparation of catalyst precursor b: impregnate a rare earth and alkali metal-containing precursor solution on precursor a by equal volume impregnation method, dry at 120℃, and calcine at 550℃ to obtain precursor b;

[0053] (3) Preparation of shell material c: impregnate a noble metal and assistant metal precursor solution on γ-Al2O3-TiO2 powder by equal volume impregnation, dry at 120℃, take out, and add a certain amount of pseudoboehmite to mix uniformly, spray a small amount of moisture to make the mixed powder have a certain humidity, and mark as c;

[0054] (4) Rolling ball coating: add particle precursor b to c, and roll the ball by a rolling ball machine to coat, so that c uniformly coats on the surface of precursor b, and calcine at 550℃ for 3h to obtain a non-uniform particle type combustion catalyst.

[0055] <Embodiment>

[0056] Example 1

[0057] A preparation method of a non-uniform particle type combustion catalyst, comprising the following steps:

[0058] (1) Copper nitrate was dissolved in water to form a 3.0 mol / L copper nitrate solution, 200 ml of the solution was taken, 100 g of 2-4 mm γ-Al2O3-TiO2 spherical carrier particles were placed in the solution for excessive impregnation for 6 hours, then dried at 120°C for 2 hours, and then calcined at 550°C for 4 hours to obtain precursor a;

[0059] (2) 8.0 g of sodium carbonate and 12.0 g of cerium nitrate hexahydrate were dissolved in 100 ml of deionized water, 56 g of the above solution was taken and impregnated on the precursor a in an equal volume, dried at 120°C, and calcined at 550°C to obtain precursor b;

[0060] (3) 2.8 g of palladium nitrate solution with a concentration of 14.6 wt% and 8.0 g of sodium carbonate were added to deionized water to make up to 60 ml, 100 g of γ-Al2O3-TiO2 powder was impregnated in an equal volume, dried at 120°C, 10 g of pseudo-boehmite was added and mixed uniformly, a small amount of water was sprayed to make the mixed powder have a certain humidity, and shell material c was obtained;

[0061] (4) 100 g of particle precursor b was added to c, and the ball rolling machine was used to roll and coat, so that c was uniformly wrapped on the precursor b, the shell material was coated with 10 g of loading, dried at 120°C, and calcined at 550°C for 3 hours to obtain a non-uniform particle type catalytic combustion catalyst.

[0062] Example 2

[0063] A preparation method of a non-uniform particle type combustion catalyst, comprising the following steps:

[0064] (1) 60 g of copper nitrate trihydrate and 120 g of 50% manganese nitrate solution were added to deionized water to make up to 200 ml to form a Cu-Mn precursor mixed solution, 100 g of 2-4 mm γ-Al2O3-TiO2 spherical carrier particles were placed in the solution for excessive impregnation for 6 hours, then dried at 120°C for 2 hours, and then calcined at 550°C for 4 hours to obtain precursor a;

[0065] (2) 8.0 g of sodium carbonate and 12.0 g of cerium nitrate hexahydrate were dissolved in 100 ml of deionized water, 56 g of the above solution was taken and impregnated on the precursor a in an equal volume, dried at 120°C, and calcined at 550°C to obtain precursor b;

[0066] (3) 2.8 g of palladium nitrate solution with a concentration of 14.6 wt% and 8.0 g of sodium carbonate were added to deionized water to make up to 60 ml, 100 g of γ-Al2O3-TiO2 powder was impregnated in an equal volume, dried at 120°C, 10 g of pseudo-boehmite was added and mixed uniformly, a small amount of water was sprayed to make the mixed powder have a certain humidity, and shell material c was obtained;

[0067] (4) 100 g of the granular precursor b is added to c, and the rolling ball machine is used for rolling ball coating, so that c is uniformly wrapped on the precursor b, the shell material is coated with 10 g of the coating, dried at 120°C, and calcined at 550°C for 3 h to obtain the non-uniform granular combustion catalyst.

[0068] Example 3

[0069] A preparation method of a non-uniform granular combustion catalyst, comprising the following steps:

[0070] (1) 60 g of copper nitrate trihydrate and 120 g of 50% manganese nitrate solution are added to deionized water to make up to 200 ml to form a Cu-Mn precursor mixed solution, 100 g of 2-4 mm γ-Al2O3-TiO2 spherical carrier particles are placed in the solution for excessive impregnation for 6 hr, then dried at 120°C for 2 hr, and calcined at 550°C for 4 hr to obtain a precursor a;

[0071] (2) 8.0 g of sodium carbonate and 12.0 g of cerium nitrate hexahydrate are dissolved in 100 ml of deionized water, 56 g of the above solution is taken for equal-volume impregnation on the precursor a, dried at 120°C, and calcined at 550°C to obtain a precursor b;

[0072] (3) 1.8 g of a palladium nitrate solution with a concentration of 14.6 wt% is uniformly mixed with 1.0 g of a chloroplatinic acid solution with a concentration of 12.5 wt%, 12.0 g of sodium carbonate is added to deionized water to make up to 60 ml, 100 g of γ-Al2O3-TiO2 powder is taken for equal-volume impregnation, dried at 120°C, 15 g of pseudo-boehmite is uniformly mixed, a small amount of water is sprayed to make the mixed powder have a certain humidity, and a shell material c is obtained;

[0073] (4) 100 g of the granular precursor b is added to c, and the rolling ball machine is used for rolling ball coating, so that c is uniformly wrapped on the precursor b, the shell material is coated with 10 g of the coating, dried at 120°C, and calcined at 550°C for 3 h to obtain the non-uniform granular combustion catalyst;

[0074] Example 4

[0075] A preparation method of a non-uniform granular combustion catalyst, comprising the following steps:

[0076] (1) 60 g of copper nitrate trihydrate and 120 g of 50% manganese nitrate solution are added to deionized water to make up to 200 ml to form a Cu-Mn precursor mixed solution, 100 g of 2-4 mm γ-Al2O3-TiO2 spherical carrier particles are placed in the solution for excessive impregnation for 6 hr, then dried at 120°C for 2 hr, and calcined at 550°C for 4 hr to obtain a precursor a;

[0077] (2) 6.0 g of sodium bicarbonate and 12.0 g of cerium nitrate hexahydrate were dissolved in 100 ml of deionized water, 56 g of the above solution was taken and impregnated on precursor a in an equal volume, dried at 120°C, and calcined at 550°C to obtain precursor b;

[0078] (3) 1.8 g of palladium nitrate solution with a concentration of 14.6 wt% was uniformly mixed with 1.0 g of platinum nitrate solution with a concentration of 14.9 wt%, 12.0 g of sodium carbonate was added to deionized water to make 60 ml, 100 g of γ-Al2O3-TiO2 powder was taken and impregnated in an equal volume, dried at 120°C, 15 g of pseudo-boehmite was mixed uniformly, a small amount of water was sprayed to make the mixed powder have a certain humidity, and shell material c was obtained;

[0079] (4) 100 g of granular precursor b was added to c, and the ball rolling machine was used for ball rolling coating, so that c was uniformly wrapped on precursor b, the shell material was loaded and coated by 10 g, dried at 120°C, and calcined at 550°C for 3 h to obtain a non-uniform granular combustion catalyst.

[0080] Example 5

[0081] A preparation method of a non-uniform granular combustion catalyst, comprising the following steps:

[0082] (1) 60 g of copper nitrate trihydrate and 120 g of 50% manganese nitrate solution were added to deionized water to make 200 ml, forming a Cu-Mn precursor mixed solution, 100 g of 2-4 mm γ-Al2O3-TiO2 spherical carrier particles were placed in it and impregnated for 6 hr, then dried at 120°C for 2 hr, and calcined at 550°C for 4 hr to obtain precursor a;

[0083] (2) 6.0 g of sodium bicarbonate and 12.0 g of cerium nitrate hexahydrate were dissolved in 100 ml of deionized water, 56 g of the above solution was taken and impregnated on precursor a in an equal volume, dried at 120°C, and calcined at 550°C to obtain precursor b;

[0084] (3) 1.8 g of palladium nitrate solution with a concentration of 14.6 wt% was uniformly mixed with 1.0 g of platinum nitrate solution with a concentration of 14.9 wt%, 8.0 g of sodium bicarbonate was added to deionized water to make 60 ml, 100 g of γ-Al2O3-TiO2 powder was taken and impregnated in an equal volume, dried at 120°C, 15 g of pseudo-boehmite was mixed uniformly, a small amount of water was sprayed to make the mixed powder have a certain humidity, and shell material c was obtained;

[0085] (4) 100 g of granular precursor b was added to c, and the ball rolling machine was used for ball rolling coating, so that c was uniformly wrapped on precursor b, the shell material was loaded and coated by 10 g, dried at 120°C, and calcined at 550°C for 3 h to obtain a non-uniform granular combustion catalyst.

[0086] Example 6

[0087] A preparation method of a non-uniform particle type combustion catalyst, comprising the following steps:

[0088] (1) 60 g of copper nitrate trihydrate, 120 g of 50% manganese nitrate solution, and deionized water are added to make up to 200 ml to form a Cu-Mn precursor mixed solution, 100 g of 2-4 mm γ-Al2O3-TiO2 spherical carrier particles are placed in it for excessive impregnation for 6 hours, then dried at 120°C for 2 hours, and then calcined at 550°C for 4 hours to obtain a precursor a;

[0089] (2) 8.0 g of sodium carbonate and 12.0 g of lanthanum nitrate hexahydrate are dissolved in 100 ml of deionized water, and 56 g of the above solution is taken for equal volume impregnation on the precursor a, dried at 120°C, and calcined at 550°C to obtain a precursor b;

[0090] (3) 1.8 g of a palladium nitrate solution with a concentration of 14.6 wt% is uniformly mixed with 1.0 g of a platinum nitrate solution with a concentration of 14.9 wt%, 12.0 g of sodium carbonate is added to deionized water to make up to 60 ml, 100 g of γ-Al2O3-TiO2 powder is taken for equal volume impregnation, dried at 120°C, and uniformly mixed with 15 g of pseudo-boehmite, a small amount of water is sprayed to make the mixed powder have a certain humidity, to obtain a shell material c;

[0091] (4) 100 g of the particle precursor b is added to c, and the ball rolling machine is used to roll and coat, so that c is uniformly wrapped on the precursor b, the shell material is loaded and coated with 10 g, dried at 120°C, and calcined at 550°C for 3 h to obtain a non-uniform particle type combustion catalyst.

[0092] Example 7

[0093] (1) 60 g of copper nitrate trihydrate, 120 g of 50% manganese nitrate solution, and deionized water are added to make up to 200 ml to form a Cu-Mn precursor mixed solution, 100 g of 2-4 mm γ-Al2O3-TiO2 spherical carrier particles are placed in it for excessive impregnation for 6 hours, then dried at 120°C for 2 hours, and then calcined at 550°C for 4 hours to obtain a precursor a;

[0094] (2) 8.0 g of sodium carbonate and 12.0 g of lanthanum nitrate hexahydrate are dissolved in 100 ml of deionized water, and 56 g of the above solution is taken for equal volume impregnation on the precursor a, dried at 120°C, and calcined at 550°C to obtain a precursor b;

[0095] (3) 1.8 g of a palladium nitrate solution with a concentration of 14.6 wt% was uniformly mixed with 1.0 g of a platinum nitrate solution with a concentration of 14.9 wt%, 12.0 g of sodium carbonate was added to deionized water to make 60 ml, 100 g of γ-Al2O3-TiO2 powder was taken and impregnated in equal volume, dried at 120°C, 15 g of pseudo-boehmite was added and uniformly mixed, a small amount of water was sprayed to make the mixed powder have a certain humidity, and a shell material c was obtained;

[0096] (4) 100 g of the granular precursor b was added to c, and the balling machine was used for balling coating, so that c was uniformly coated on the precursor b, the loading amount of the shell material was 15 g, and the non-uniformly distributed granular combustion catalyst was prepared by drying at 120°C and calcining at 550°C for 3 h.

[0097] <Comparative Example>

[0098] Comparative Example 1

[0099] Compared with Example 1, the active components and the loading amount of the auxiliary agent were the same, and the difference between Comparative Example 1 and Example 1 was that the active components of the catalyst of Comparative Example 1 were prepared by co-impregnation, and the active components were uniformly distributed without obvious stratification.

[0100] Comparative Example 2

[0101] Compared with Example 1, the difference between Comparative Example 1 and Example 1 was that the active components of the catalyst of Comparative Example 1 were prepared by co-impregnation, and the active components were uniformly distributed without obvious stratification, and the loading amount of the noble metal was increased by 20%, and the content of the remaining active components was unchanged.

[0102] <Test Example>

[0103] The catalyst activity evaluation was carried out on a fixed bed reactor using propane as a probe molecule, the catalyst dosage was 0.6 g, the propane concentration was 0.3 vol%, the rest was air, and the gas flow rate was 200 mL / min. The reaction tail gas was detected and analyzed by gas chromatography, and the catalytic activity was represented by the operating temperature at which the conversion rate of toluene was 10% and 90%. The catalysts obtained from Examples 1-7 and Comparative Examples 1-2 were used as samples, and the evaluation results are shown in Table 1.

[0104] Table 1

[0105] Sample T 50 (°C) T 90 (°C) Comparative Example 1 257 321 Comparative Example 2 226 309 Example 1 218 280 Example 2 210 270 Example 3 197 282 Example 4 173 263 Example 5 176 270 Example 6 182 274 Example 7 166 242

[0106] As can be seen from the data in Table 1, the non-uniform distribution of noble metals and transition metals is beneficial to improving the catalyst activity, can effectively improve the utilization rate of noble metals, and reduce the cost of the catalyst.

[0107] The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A non-uniformly distributed particulate combustion catalyst, characterized in that, include: Carrier, active ingredient, and auxiliaries; The active components and additives are radially heterogeneously distributed within the carrier; the active components include noble metals or their oxides, transition metals or their oxides; the additive metals include rare earth and / or alkali metals; the noble metals or their oxides are distributed in the shell layer, the additive metals or their oxides are distributed in the shell layer and the transition layer, and the transition metals or their oxides are distributed in the core layer and the transition layer. The support is γ-Al2O3-TiO2; The transition metal includes at least one of copper, manganese, iron, and cobalt; and / or, the transition metal precursor is selected from nitrates; The preparation method of the non-uniformly distributed particulate combustion catalyst includes the following steps: S1 Carrier 1 is immersed in a transition metal precursor, then removed, dried, and calcined to obtain precursor a; S2. Precursor a is immersed in a metal precursor containing additives, then removed, dried, and calcined to obtain precursor b. S3 The carrier 2 is impregnated in a mixed system of noble metal precursor and auxiliary metal precursor, dried and then blended with an adhesive to form c; S4 adds precursor b to c and rolls it to coat it so that c is evenly wrapped on the surface of precursor b, thus obtaining precursor d. Precursor d is then calcined to obtain the finished product.

2. The non-uniformly distributed particulate combustion catalyst according to claim 1, characterized in that, The additive metal includes at least one of cerium, lanthanum, and sodium; and / or, the additive metal precursor is selected from at least one of nitrate, carbonate, and bicarbonate.

3. The non-uniformly distributed particulate combustion catalyst according to claim 1, characterized in that, The precious metal includes at least one of palladium and platinum; and / or, the precious metal precursor includes at least one of nitrate and chlorate.

4. The non-uniformly distributed particulate combustion catalyst according to any one of claims 1 to 3, characterized in that, The components of the propellant include at least one of features (1) to (4): (1) The total loading of precious metals or their oxides is 0.01-0.5 wt%; (2) The total loading of transition metals or their oxides is 5-25 wt%; (3) The total loading of the additive metal or its oxide is 0.5-2 wt%; (4) The remainder is a carrier, or a carrier and an adhesive; the adhesive is boehmite.

5. A method for preparing a non-uniformly distributed particulate combustion catalyst as described in any one of claims 1 to 4, characterized in that, Includes the following steps: S1 Carrier 1 is immersed in a transition metal precursor, then removed, dried, and calcined to obtain precursor a; S2. Precursor a is immersed in a metal precursor containing additives, then removed, dried, and calcined to obtain precursor b. S3 The carrier 2 is impregnated in a mixed system of noble metal precursor and auxiliary metal precursor, dried and then blended with an adhesive to form c; S4 adds precursor b to c and rolls it to coat it so that c is evenly wrapped on the surface of precursor b, thus obtaining precursor d. Precursor d is then calcined to obtain the finished product.

6. The method for preparing the non-uniformly distributed particulate combustion catalyst according to claim 5, characterized in that, The preparation method includes at least one of features (1) to (3): (1) In S1, the impregnation method is the over-impregnation method; (2) In S2, the impregnation method is the same volume impregnation method; (3) In S3, the impregnation method is the equal volume impregnation method.

7. The method for preparing the non-uniformly distributed particulate combustion catalyst according to claim 5 or 6, characterized in that, The adhesive accounts for 5-15 wt% of the total weight of c.

8. The method for preparing the non-uniformly distributed particulate combustion catalyst according to claim 5 or 6, characterized in that, c accounts for 6-20 wt% of the total weight of precursor d.