Recyclable catalyst for purification of co-rich exhaust gas and method for its preparation

Abstract

This invention discloses a recyclable catalyst for purifying CO-rich waste gas and its preparation method, belonging to the field of catalyst preparation technology. It addresses the technical problem that the mechanical and regeneration performance of existing CO waste gas purification catalysts needs further improvement. This invention involves preparing a rare-earth manganese-zirconium composite oxygen storage body, a phosphorus-boron-aluminum-silicon composite, and a manganese-iron-titanium-phosphorus composite oxide, and then combining them to construct a recyclable catalyst. The rare-earth manganese-zirconium composite oxygen storage body provides an oxygen storage and release framework, the phosphorus-boron-aluminum-silicon composite constructs an inorganic connection network, and the manganese-iron-titanium-phosphorus composite oxide plays a role in interface transition and structural coordination. The three components work synergistically to improve the catalyst's structural integrity, interfacial bonding stability, and operational stability during the recycling process.

Description

Technical Field

[0001] This invention relates to the field of catalyst preparation technology, specifically to a recyclable catalyst for purifying CO-rich waste gas and its preparation method. Background Technology

[0002] Recyclable catalysts used for CO-rich waste gas purification typically consist of active components, oxygen storage aids, and supports or inorganic linking components. Preparation processes often employ methods such as co-precipitation, impregnation, sol-gel, hydrothermal synthesis, and calcination. In these systems, one or more elements such as cerium, zirconium, manganese, iron, titanium, phosphorus, aluminum, silicon, and boron are often introduced to form metal oxides, composite oxides, or inorganic network structures. These catalysts are used for the oxidation and conversion of CO under CO-rich waste gas conditions and for structural restoration during regeneration. Such catalysts usually require long-term use under alternating reaction and regeneration atmospheres, thus demanding high requirements for material compositional stability, oxygen regulation capabilities, and structural retention.

[0003] Currently, in recyclable catalysts used for CO-rich waste gas purification, oxygen storage-related components mostly exist in the form of single oxides or simple composites. The dispersion uniformity of different metal components during precursor formation and high-temperature treatment is insufficient, which easily leads to local segregation and phase boundary separation. This causes discontinuity in the oxygen migration channels inside the catalyst, resulting in an uncoordinated oxygen supply and replenishment process required for CO oxidation under CO-rich atmospheres. Furthermore, during repeated switching between reaction and regeneration, different regions respond differently to changes in oxygen partial pressure, which can easily trigger local structural rearrangement and affect the continuous stability of the catalyst's working state during CO purification.

[0004] In addition, there is often a lack of composite structures that combine particle connection and interface transition between different functional phases. The oxygen storage component, active component and inorganic framework are mostly in direct contact or simply bonded. In the process of CO-rich waste gas purification and regeneration, the catalyst needs to undergo continuous oxygen release, oxygen replenishment and thermal stress changes. If the interface bonding is insufficient and the framework coordination is weak, problems such as loose particle boundaries, local peeling and pore connection disorder are likely to occur. Especially after multiple cycles, the overall structural integrity and interface stability of the material are difficult to maintain, which is not conducive to the long-term cyclic regeneration and use of the catalyst under CO-rich waste gas purification conditions.

[0005] To address this technical deficiency, a solution is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a recyclable catalyst for the purification of CO-rich waste gas and its preparation method, thereby solving the technical problem that the mechanical properties and regeneration performance of catalysts used for CO waste gas purification in the prior art need to be further improved.

[0007] The objective of this invention can be achieved through the following technical solution: a method for preparing a recyclable catalyst for purifying CO-rich waste gas, comprising the following steps:

[0008] S1. The rare earth manganese zirconium dual-phase oxygen-fixing framework is loaded into a tube furnace, mixed gas is introduced and the temperature is raised to 350-400℃, and the heat treatment is carried out for 1-2 hours. After the heat treatment is completed, it is cooled to room temperature and sealed for storage to obtain rare earth manganese zirconium composite oxygen storage body.

[0009] S2. Add rare earth manganese zirconium composite oxygen storage body, phosphorus boron aluminum silicon composite body and manganese iron titanium phosphorus composite oxide into the reaction vessel and stir. After mixing evenly, add the molding agent and stir for 10-15 minutes. Then, perform post-treatment to obtain the molded composite carrier.

[0010] S3. Add copper nitrate trihydrate, palladium chloride and deionized water to the reactor and stir. After mixing evenly, add 8-12 wt% dilute nitric acid aqueous solution, 12-18 wt% ammonia and urea. After stirring evenly, add the molded composite carrier. Heat the reactor to 88-92℃ and keep it at that temperature for 3-4 hours. The post-treatment yields a recyclable catalyst.

[0011] Furthermore, in step S1, the heating rate of the tube furnace is 2-3℃ / min, and the mixed gas is obtained by mixing air, carbon dioxide and water vapor in a volume ratio of 18-21:2-3:2-3.

[0012] Further, in step S2, the ratio of the rare earth manganese zirconium composite oxygen storage body, phosphorus boron aluminum silicon composite body, manganese iron titanium phosphorus composite oxide and molding agent is 32-38g:12-15g:7-9g:36-45mL. The molding agent is obtained by mixing anhydrous ethanol, deionized water and 10-14wt% phosphoric acid aqueous solution in a ratio of 20-30mL:8-12mL:4-6mL. The post-treatment includes: after stirring, transferring to a kneading device and kneading until the strip diameter is 2-3mm and the length is 6-8mm, then aging at 55-65℃ for 1.5-2.5h, and drying after aging to obtain the molded composite carrier.

[0013] Further, in step S3, the ratio of copper nitrate trihydrate, palladium chloride, deionized water, 8-12wt% dilute nitric acid aqueous solution, 12-18wt% ammonia, urea, and the molded composite carrier is 2.4-3.2g:0.08-0.12g:160mL:3-5mL:2-4mL:2.0-2.8g:24-30g. The post-treatment includes: after stirring, the mixture is allowed to stand for 4-6 hours, washed with deionized water until the filtrate is close to neutral, then dried in a drying oven at 105-115℃ for 5-7 hours, and then treated at 300-320℃ in air for 1.5-2.5 hours to obtain a recyclable catalyst.

[0014] Furthermore, the rare-earth manganese-zirconium dual-phase oxygen-fixing framework is prepared by the following method:

[0015] A1. Cerium nitrate hexahydrate, lanthanum nitrate hexahydrate, praseodymium nitrate hexahydrate, zirconium nitrate oxyhydrate, manganese nitrate tetrahydrate and deionized water are added to a reaction vessel and stirred. After mixing evenly, urea is added, the reaction vessel is heated to 85-95℃, and stirred for 3-5 hours. The rare earth manganese zirconium hydroxy carbonate precursor is obtained by post-treatment.

[0016] A2. Rare earth manganese zirconium hydroxy carbonate precursor, sodium chloride and potassium chloride are added to a crucible, mixed evenly, and then placed in a muffle furnace. The temperature is increased to 730-820℃ at 4-6℃ / min and held for 2.5-3.5h. The post-treatment yields a rare earth manganese zirconium biphase oxygen-fixing framework.

[0017] Further, in step A1, the ratio of the amounts of cerium nitrate hexahydrate, lanthanum nitrate hexahydrate, praseodymium nitrate hexahydrate, zirconium nitrate hydrate, manganese nitrate tetrahydrate, deionized water, and urea is 18-24g:5-7g:2.5-3.5g:4-6g:3.5-4.5g:180-220mL:22-28g. The post-treatment includes: after stirring, allowing the mixture to stand and mature for 0.5-1.0h, filtering to collect the filter cake, washing and drying it to obtain the rare earth manganese zirconium hydroxycarbonate precursor.

[0018] Furthermore, in step A2, the ratio of the rare earth manganese zirconium hydroxy carbonate precursor, sodium chloride, and potassium chloride is 3-4g:9-12g:9-12g. The post-treatment includes: after the heat preservation is completed, the material is taken out after the muffle furnace is cooled to room temperature, the material is washed with 80℃ deionized water 3-5 times and dried to obtain a rare earth manganese zirconium biphase oxygen-fixing framework.

[0019] Furthermore, the preparation method of the manganese-iron-titanium-phosphorus composite oxide is as follows: deionized water, 80-85wt% phosphoric acid aqueous solution, ferric nitrate nonahydrate, manganese acetate tetrahydrate and urea are added to a reaction vessel and stirred. After mixing evenly, tetrabutyl titanate is added, stirred evenly, and then transferred to a hydrothermal reaction vessel. The mixture is kept at 180-205℃ for 10-14h, and then post-processed to obtain the manganese-iron-titanium-phosphorus composite oxide.

[0020] Furthermore, the ratio of deionized water, 80-85wt% phosphoric acid aqueous solution, ferric nitrate nonahydrate, manganese acetate tetrahydrate, urea, and tetrabutyl titanate is 160mL:8-12mL:6-8g:7-9g:5-7g:18-24mL. The post-treatment includes: after the reaction is completed, after the hydrothermal reactor is cooled to room temperature, the filter cake is collected by suction filtration, washed, and dried to obtain manganese-iron-titanium-phosphorus composite oxide.

[0021] Furthermore, the phosphorus-boron-aluminum-silicon composite is prepared by the following method:

[0022] B1. Add tetraethyl orthosilicate, aluminum isopropoxide, triethyl borate and triethyl phosphate to a reaction vessel and stir. After mixing evenly, heat the reaction vessel to 125-140℃ and keep it at that temperature for 5-7 hours to obtain the phosphorus boron aluminum silicon precursor.

[0023] B2. Place the phosphorus-boron-aluminum-silicon precursor in a tube furnace, introduce ammonia gas, and heat the tube furnace to 500-540℃ at a heating rate of 1.5-2.5℃ / min. Hold the temperature for 1.5-2.5h, then continue heating to 600-650℃ and hold for 0.5-1.5h. Post-processing yields the phosphorus-boron-aluminum-silicon composite.

[0024] Furthermore, in step B1, the ratio of tetraethyl orthosilicate, aluminum isopropoxide, triethyl borate, and triethyl phosphate is 28-34 mL: 5.5-7.0 g: 6.5-8.0 mL: 7.5-9.5 mL;

[0025] Furthermore, in step B2, the post-processing includes: after the reaction is completed, ammonia gas is introduced and the tube furnace is allowed to cool naturally to room temperature. The material is then removed, milled through a 100-mesh sieve, and the phosphorus-boron-aluminum-silicon composite is obtained.

[0026] Additionally, the present invention also discloses a recyclable catalyst for purifying CO-rich waste gas, which is prepared using the above-described method for preparing a recyclable catalyst for purifying CO-rich waste gas.

[0027] Furthermore, the regeneration method of the recyclable catalyst is as follows: the deactivated recyclable catalyst is loaded into a fixed bed reactor, a mixed regeneration gas consisting of oxygen, carbon dioxide, nitrogen and water vapor in a volume ratio of 1:6-10:8-10:79-85 is introduced, the temperature is raised to 300-340℃ at 1-2℃ / min, held at the temperature for 45-70min, and then the atmosphere is maintained and the temperature is lowered to 180℃ to obtain the regenerated catalyst.

[0028] The principle of regeneration is:

[0029] Under elevated temperatures, the regeneration atmosphere composed of oxygen, carbon dioxide, water vapor, and nitrogen promotes the oxidative cracking, vaporization desorption, and chemical equilibrium reforming of adsorbed residues, carbon deposits, and partially covered oxygen-containing intermediates on the surface of the deactivated catalyst. Oxygen participates in the re-oxidation process of surface metal species and the near-surface layer of the support, water vapor affects the surface hydroxylation state and oxygen exchange environment, and carbon dioxide participates in the reforming of carbonate / bicarbonate coordination states and the removal of carbon deposits. At the same time, the interfacial oxygen bonding relationships and local coordination structures between copper and palladium species and rare earth manganese zirconium composite oxygen storage bodies, phosphorus boron aluminum silicon composites, and manganese iron titanium phosphorus composite oxides are readjusted under the medium- and low-temperature oxidation atmosphere, so that the surface composition, oxygen species distribution, and defect chemical state tend to stabilize again, ultimately forming a regenerated catalyst.

[0030] Furthermore, the criteria for determining deactivation are as follows: under standard operating conditions, when the outlet carbon monoxide concentration increases to more than 1.3 times the initial stable value, or the carbon monoxide conversion rate decreases by more than 8%, or the pressure drop of the catalyst bed increases by more than 15%, the catalyst is deemed to have deactivated.

[0031] The present invention has the following beneficial effects:

[0032] 1. In the structural configuration of the recyclable catalyst, the phosphorus-boron-aluminum-silicon composite forms a continuous inorganic network with Si-O-Al, Si-OB, Si-OP, and some Al-OP and BOP connections. During extrusion kneading and aging, it first establishes surface contact and point connections between particles. The rare earth manganese-zirconium composite oxygen storage body, with its high structural strength, forms a relatively stable framework support, making the stress distribution of each component more uniform during the molding process. Simultaneously, manganese-iron-titanium-phosphorus composite oxides are dispersed between the two, playing a filling and coordinating role in the particle interface and pore transition region, and enhancing the continuity of the bond between different phases. The resulting composite carrier does not simply rely on external bonding, but forms a continuous structure between inorganic network connections, framework support, and interface transitions. After entering the rolling wear condition, the stress release path at the edge of the strip is relatively complete, and surface peeling and particle detachment are less likely to occur in a concentrated manner. The shape of the molded body and the internal pore state can be balanced within the same structural framework.

[0033] 2. In the process of waste gas purification, the oxygen storage-release framework formed by the rare earth manganese zirconium composite oxygen storage body prepared by this invention first participates in the oxygen species regulation under atmospheric fluctuations, so that the catalyst surface and near-surface layers maintain a relatively stable oxygen supply rhythm under the conditions of heating and continuous ventilation. On this basis, the multi-metal oxide interface and phosphorus coordination environment provided by the manganese iron titanium phosphorus composite oxide further connect the surface adsorption, oxygen exchange and intermediate species conversion processes, so that CO and C3H6 can obtain smoother continuous oxidation conditions in the same reaction path. At the same time, the constraint effect of the phosphorus boron aluminum silicon composite on the pore structure and dispersion state makes the aforementioned two types of functional phases maintain a more suitable contact scale inside the support, and are not easily weakened by local enrichment or isolation. Therefore, the catalyst exhibits a more coordinated reaction response under the condition of coexistence of two types of pollutants.

[0034] 3. Under alternating deactivation-regeneration conditions, the manganese-iron-titanium-phosphorus composite oxide focuses more on maintaining interfacial order during the cycle. When it is distributed adjacent to the rare earth manganese-zirconium composite oxygen storage body, the reintroduction of oxygen in the regeneration atmosphere and the removal of surface coverings can continue along the interfacial region. The active-related structures after deactivation do not need to rely on a single high-temperature reconstruction to recover to a state more suitable for reaction. At the same time, the inorganic network composed of phosphorus-boron-aluminum-silicon composite provides external constraints for the above-mentioned interfaces during multiple heating, cooling and atmosphere switching, reducing microcracks, loosening and active phase migration caused by inconsistent particle shrinkage. Thus, the structure maintenance, oxygen migration channel continuation and surface reaction environment recovery during the cycle can be connected in the same system, and the regenerated operating state is more likely to continue to the subsequent cycle. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 SEM image of the rare earth manganese zirconium composite oxygen storage body prepared in Example 3;

[0037] Figure 2 SEM image of the phosphorus boron aluminum silicon composite prepared in Example 6;

[0038] Figure 3 The image shows a SEM image of the manganese-iron-titanium-phosphorus composite oxide prepared in Example 9. Detailed Implementation

[0039] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1

[0041] This embodiment provides a method for preparing a rare earth manganese-zirconium composite oxygen storage material, including the following steps:

[0042] Step I: Preparation of rare earth manganese zirconium hydroxycarbonate precursor

[0043] Weigh out 36.0 g of cerium nitrate hexahydrate, 10.0 g of lanthanum nitrate hexahydrate, 5.0 g of praseodymium nitrate hexahydrate, 8.0 g of zirconium nitrate hydrate, 7.0 g of manganese nitrate tetrahydrate, and 360.0 mL of deionized water and add them to the reaction vessel. Stir and mix thoroughly. Then add 44.0 g of urea. Heat the reaction vessel to 85°C and keep it at that temperature with stirring for 3 hours. After stirring, let it stand for 0.5 hours to mature. Filter, collect the filter cake, wash and dry it to obtain the rare earth manganese zirconium hydroxy carbonate precursor.

[0044] Step II: Preparation of rare earth manganese zirconium dual-phase oxygen-fixing framework

[0045] Weigh out 45.0g of rare earth manganese zirconium hydroxy carbonate precursor, 135.0g of sodium chloride and 135.0g of potassium chloride, add them to a crucible and mix well. Place the crucible in a muffle furnace and heat it to 730℃ at 4℃ / min. Hold the temperature for 2.5h. After the holding time is completed, wait for the muffle furnace to cool to room temperature and then take out the material. Wash the material three times with 80℃ deionized water and dry it to obtain a rare earth manganese zirconium biphase oxygen-fixing framework.

[0046] Step III: Preparation of rare earth manganese-zirconium composite oxygen storage

[0047] Weigh out 45.0g of rare earth manganese zirconium biphase oxygen-fixing framework and load it into a tube furnace. Introduce air, carbon dioxide and water vapor in a volume ratio of 9:1:1 to obtain a mixed gas. Heat the mixture to 350℃ at a heating rate of 2℃ / min and hold it at that temperature for 1h. After the holding time is over, cool it to room temperature and seal it for storage to obtain rare earth manganese zirconium composite oxygen storage body.

[0048] The reaction principle for preparing rare earth manganese zirconium composite oxygen storage is as follows:

[0049] Urea gradually decomposes and releases OH under heating conditions. - With CO3 2- The process involves the synergistic hydrolysis and co-deposition of cerium, lanthanum, praseodymium, zirconium, and manganese species in solution to form a hydroxycarbonate precursor with a relatively uniform composition. After heat treatment in a sodium chloride-potassium chloride molten salt environment, the coordinating components such as hydroxyl, carbonate, and nitrate in the precursor are removed, the metal-oxygen bond network is reconstructed, and the cerium-zirconium related oxide phase and the manganese-based oxide phase complete crystallization and interface rearrangement. Subsequently, in an atmosphere where air, carbon dioxide, and water vapor coexist, the oxygen species, hydroxyl / carbonate coordination state, and local defect distribution on the surface and near-surface of the material further reach a new chemical equilibrium, ultimately forming a rare earth manganese-zirconium composite oxygen storage body with a specific composition and structural state.

[0050] The mechanism of rare earth manganese zirconium composite oxygen storage in recyclable catalysts is as follows:

[0051] This process constitutes a structural evolution of rare earth manganese-zirconium composite oxygen storage bodies, formed step-by-step from "uniform introduction - framework reconstruction - surface integration". Step I involves the uniform release of carbonate ions from urea, leading to the synergistic hydrolysis and co-deposition of Ce, La, Pr, Zr, and Mn species, laying the foundation for the uniform distribution and interfacial contact of subsequent multi-metal components. Step II utilizes a NaCl-KCl molten salt environment to promote the removal of coordinating groups in the precursor, the reconstruction of the metal-oxygen network, and the rearrangement of the biphase interface, thereby forming a rare earth manganese-zirconium biphase oxygen-solidifying framework with both structural stability and oxygen transport capacity. Step III further rebalances the oxygen species, hydroxyl / carbonate coordination state, and defect distribution on the surface and near-surface of the material under an atmosphere where air, carbon dioxide, and water vapor coexist. This allows the resulting composite oxygen storage body to enter the final catalyst system with a more coordinated interfacial state and a more stable surface chemical environment. As a result, the product, intermediates, and processing components obtained in this step collectively affect the oxygen migration continuity, phase boundary matching, framework integrity, and structural retention capacity during cycling of the final recyclable catalyst. This is further manifested in the synergistic changes in wear control, initial activity, and cycle stability.

[0052] Example 2

[0053] This embodiment provides a method for preparing a rare earth manganese-zirconium composite oxygen storage material, including the following steps:

[0054] Step I: Preparation of rare earth manganese zirconium hydroxycarbonate precursor

[0055] Weigh out 48.0g of cerium nitrate hexahydrate, 14.0g of lanthanum nitrate hexahydrate, 7.0g of praseodymium nitrate hexahydrate, 12.0g of zirconium nitrate hydrate, 8.0g of manganese nitrate tetrahydrate, and 440.0mL of deionized water and add them to the reaction vessel. Stir and mix thoroughly. Then add 56.0g of urea. Heat the reaction vessel to 95℃ and keep it at that temperature for 5 hours. After stirring, let it stand for 1 hour to mature. Filter, collect the filter cake, wash and dry it to obtain the rare earth manganese zirconium hydroxycarbonate precursor.

[0056] Step II: Preparation of rare earth manganese zirconium dual-phase oxygen-fixing framework

[0057] Weigh out 60.0g of rare earth manganese zirconium hydroxy carbonate precursor, 180.0g of sodium chloride and 180.0g of potassium chloride, add them to a crucible and mix well. Place the crucible in a muffle furnace and heat it to 820℃ at 6℃ / min. Hold the temperature for 3.5h. After the holding time is completed, wait for the muffle furnace to cool to room temperature and then take out the material. Wash the material 5 times with 80℃ deionized water and dry it to obtain a rare earth manganese zirconium biphase oxygen-fixing framework.

[0058] Step III: Preparation of rare earth manganese-zirconium composite oxygen storage

[0059] Weigh out 45.0g of rare earth manganese zirconium biphase oxygen-fixing framework and load it into a tube furnace. Introduce air, carbon dioxide and water vapor in a volume ratio of 7:1:1 to obtain a mixed gas. Heat the mixture to 400℃ at a heating rate of 3℃ / min and hold it at that temperature for 2 hours. After the holding period, cool it to room temperature and seal it for storage to obtain rare earth manganese zirconium composite oxygen storage body.

[0060] Example 3

[0061] This embodiment provides a method for preparing a rare earth manganese-zirconium composite oxygen storage material, including the following steps:

[0062] Step I: Preparation of rare earth manganese zirconium hydroxycarbonate precursor

[0063] Weigh out 42.0g of cerium nitrate hexahydrate, 12.0g of lanthanum nitrate hexahydrate, 6.0g of praseodymium nitrate hexahydrate, 10.0g of zirconium nitrate hydrate, 7.5g of manganese nitrate tetrahydrate, and 400.0mL of deionized water and add them to the reaction vessel. Stir and mix thoroughly. Then add 50.0g of urea. Heat the reaction vessel to 90℃ and keep it at that temperature for 4 hours. After stirring, let it stand for 0.8 hours to mature. Filter, collect the filter cake, wash and dry it to obtain the rare earth manganese zirconium hydroxycarbonate precursor.

[0064] Step II: Preparation of rare earth manganese zirconium dual-phase oxygen-fixing framework

[0065] Weigh out 54.0g of rare earth manganese zirconium hydroxy carbonate precursor, 150.0g of sodium chloride and 150.0g of potassium chloride, add them to a crucible and mix well. Place the crucible in a muffle furnace and heat it to 770℃ at 5℃ / min. Hold the temperature for 3.0h. After the holding time is completed, wait for the muffle furnace to cool to room temperature and then take out the material. Wash the material four times with 80℃ deionized water and dry it to obtain a rare earth manganese zirconium biphase oxygen-fixing framework.

[0066] Step III: Preparation of rare earth manganese-zirconium composite oxygen storage

[0067] Weigh out 45.0g of rare earth manganese zirconium biphase oxygen-fixing framework and load it into a tube furnace. Introduce air, carbon dioxide and water vapor in a volume ratio of 10:1:1 to obtain a mixed gas. Heat the mixture to 380℃ at a heating rate of 3℃ / min and hold it at that temperature for 2 hours. After the holding period, cool it to room temperature and seal it for storage to obtain rare earth manganese zirconium composite oxygen storage body.

[0068] Example 4

[0069] This embodiment provides a method for preparing a phosphorus boron aluminum silicon composite, including the following steps:

[0070] Step ①: Preparation of phosphorus boron aluminum silicon precursor

[0071] Weigh out 28.0 mL of tetraethyl orthosilicate, 5.5 g of aluminum isopropoxide, 6.5 mL of triethyl borate and 7.5 mL of triethyl phosphate and add them to the reaction vessel. Stir and mix thoroughly. Then heat the reaction vessel to 125 °C and keep it at that temperature for 5 h to obtain the phosphorus boron aluminum silicon precursor.

[0072] Step 2: Preparation of phosphorus-boron-aluminum-silicon composite

[0073] Weigh 24.0g of phosphorus boron aluminum silicon precursor and place it in a tube furnace. Introduce ammonia gas and heat the tube furnace to 500℃ at a heating rate of 1.5℃ / min. Hold the temperature for 1.5h, then continue heating to 600℃ and hold for 0.5h. After the reaction is complete, continue to introduce ammonia gas and allow the tube furnace to cool naturally to room temperature. Remove the material and grind it through a 100-mesh sieve to obtain the phosphorus boron aluminum silicon composite.

[0074] The reaction principle for preparing phosphorus-boron-aluminum-silicon composites is as follows:

[0075] Tetraethyl orthosilicate, aluminum isopropoxide, triethyl borate, and triethyl phosphate undergo alcoholysis, transesterification, and polycondensation reactions under heating conditions, gradually forming a multi-component inorganic precursor network centered on Si, Al, B, and P. Subsequently, heat treatment is carried out under an ammonia atmosphere, during which organic coordination groups such as ethoxy and isopropoxy in the precursors are continuously cracked and removed, small molecule byproducts escape, and the structural units of silicon-oxygen, aluminum-oxygen, boron-oxygen, and phosphorus-oxygen further condense and rearrange. The internal structure of the material changes from a dispersed organometallic-oxygen coordination state to an inorganic composite network characterized by Si-O-Al, Si-OB, Si-OP, and some Al-OP and BOP connections, forming a phosphorus-boron-aluminum-silicon composite with mutually coupled composition.

[0076] The mechanism of action of phosphorus-boron-aluminum-silicon composites in recyclable catalysts is as follows:

[0077] This process involves the gradual formation of a multi-element interconnected phase through "molecular-level precursor network construction—inorganic rearrangement under an ammonia atmosphere." Tetraethyl orthosilicate, aluminum isopropoxide, triethyl borate, and triethyl phosphate undergo alcoholysis, transesterification, and condensation reactions under heating conditions to first establish a precursor network of Si, Al, B, and P elements interwoven at the molecular scale, providing a foundation for the uniform coupling of subsequent structural units. Subsequently, heat treatment under an ammonia atmosphere leads to the continuous cleavage and removal of organic coordinating groups, further condensing and rearranging Si-O-Al, Si-OB, Si-OP, and some Al-OP and BOP connections to form a continuous... The phosphorus-boron-aluminum-silicon composite with inorganic connectivity features plays a crucial role in particle bonding, interfacial transition, and framework stabilization after entering the final recyclable catalyst system. On the one hand, it provides a more continuous inorganic network and a more flexible interfacial connection between different functional phases, reducing the local mismatch caused by direct hard contact between components. On the other hand, its multi-element oxygen bridge connection structure helps maintain the integrity of particle packing and the coordination of pore connection, making the final catalyst less prone to structural loosening, edge peeling, and local instability during heat treatment and regeneration. This further manifests as a synergistic improvement in wear control, activity retention, and cycle stability.

[0078] Example 5

[0079] This embodiment provides a method for preparing a phosphorus boron aluminum silicon composite, including the following steps:

[0080] Step ①: Preparation of phosphorus boron aluminum silicon precursor

[0081] Weigh out 34.0 mL of tetraethyl orthosilicate, 7.0 g of aluminum isopropoxide, 8.0 mL of triethyl borate and 9.5 mL of triethyl phosphate and add them to the reaction vessel. Stir and mix thoroughly. Then heat the reaction vessel to 140 °C and keep it at that temperature for 7 h to obtain the phosphorus boron aluminum silicon precursor.

[0082] Step 2: Preparation of phosphorus-boron-aluminum-silicon composite

[0083] Weigh 24.0g of phosphorus boron aluminum silicon precursor and place it in a tube furnace. Introduce ammonia gas and heat the tube furnace to 540℃ at a heating rate of 2.5℃ / min. Hold the temperature for 2.5h, then continue heating to 650℃ and hold for 1.5h. After the reaction is complete, continue to introduce ammonia gas and allow the tube furnace to cool naturally to room temperature. Remove the material and grind it through a 100-mesh sieve to obtain the phosphorus boron aluminum silicon composite.

[0084] Example 6

[0085] This embodiment provides a method for preparing a phosphorus boron aluminum silicon composite, including the following steps:

[0086] Step ①: Preparation of phosphorus boron aluminum silicon precursor

[0087] Weigh out 32.0 mL of tetraethyl orthosilicate, 6.4 g of aluminum isopropoxide, 7.2 mL of triethyl borate and 8.5 mL of triethyl phosphate and add them to the reaction vessel. Stir and mix thoroughly. Then heat the reaction vessel to 130 °C and keep it at that temperature for 6 h to obtain the phosphorus boron aluminum silicon precursor.

[0088] Step 2: Preparation of phosphorus-boron-aluminum-silicon composite

[0089] Weigh 24.0g of phosphorus boron aluminum silicon precursor and place it in a tube furnace. Introduce ammonia gas and heat the tube furnace to 520℃ at a heating rate of 2.0℃ / min. Hold the temperature for 2.0h, then continue heating to 640℃ and hold for 1.0h. After the reaction is complete, continue to introduce ammonia gas and allow the tube furnace to cool naturally to room temperature. Remove the material and grind it through a 100-mesh sieve to obtain the phosphorus boron aluminum silicon composite.

[0090] Example 7

[0091] This embodiment provides a method for preparing a recyclable catalyst, including the following steps:

[0092] Step 1: Preparation of manganese-iron-titanium-phosphorus composite oxides

[0093] Weigh out 160.0 mL of deionized water, 8.0 mL of 80 wt% phosphoric acid aqueous solution, 6.0 g of ferric nitrate nonahydrate, 7.0 g of manganese acetate tetrahydrate, and 5.0 g of urea and add them to the reaction vessel. Stir and mix well. Then add 18.0 mL of tetrabutyl titanate and stir well. Transfer the mixture to a hydrothermal reaction vessel and keep it at 180 °C for 10 h. After the reaction is complete, wait for the hydrothermal reaction vessel to cool to room temperature, filter and collect the filter cake. After washing and drying, manganese-iron-titanium-phosphorus composite oxide is obtained.

[0094] The reaction principle for preparing manganese-iron-titanium-phosphorus composite oxides is as follows:

[0095] In deionized water, phosphate, iron, manganese, and titanium precursors undergo hydrolysis and partial coordination reactions under the action of urea-released hydroxide ions, forming metal hydroxyl and phosphate coordination intermediates. Under high-temperature hydrothermal conditions, metal ions and phosphate units gradually form a composite oxide network structure of Mn, Fe, Ti, and P elements through condensation, coordination, and crystallization-driven rearrangement. During the process, organic ligands and soluble byproducts are removed, and local chemical reconstruction occurs at the interface between metal oxide units, ultimately forming a homogeneous and structurally coupled manganese-iron-titanium-phosphorus composite oxide.

[0096] The mechanism of action of manganese-iron-titanium-phosphorus composite oxides in recyclable catalysts is as follows:

[0097] This process involves the gradual formation of a multi-metal transitional phase through "slow-release hydrolysis - hydrothermal rearrangement - interfacial coupling": Phosphoric acid, ferric nitrate, manganese acetate, tetrabutyl titanate, and urea first establish a synergistic hydrolysis and coordination basis for Mn, Fe, Ti, and P species in an aqueous medium. The alkaline components released by urea allow for the relatively uniform generation of metal hydroxyl and phosphate coordination intermediates, providing a short-range mixing source for the subsequent formation of the composite oxide network. Subsequently, under hydrothermal conditions at 180℃, the metal-oxygen units and phosphate structural units undergo continuous rearrangement driven by condensation, coordination, and crystallization, gradually forming a manganese-iron-titanium-phosphorus composite oxide with a relatively uniform composition and interfacial coupling. After entering the final recyclable catalyst system, the composite oxide mainly plays the roles of transition connection, interface buffer and local structural coordination: on the one hand, it can provide a more continuous chemical connection and a softer interface transition between the oxygen storage component and the inorganic network component, reducing the local stress concentration and bonding mismatch caused by direct contact between different functional phases; on the other hand, the coupling of Mn, Fe, Ti multi-metal oxide units with phosphorus-oxygen structures is also conducive to stabilizing the local oxygen exchange environment and the bonding state between particles, so that the final catalyst is less prone to interface loosening, local instability and asynchronous performance response during the reaction-regeneration cycle, and is further reflected in the coordinated changes of activity, wear control and cycle retention.

[0098] Step 2: Preparation of the molded composite carrier

[0099] Weigh out 20.0 mL of anhydrous ethanol, 8.0 mL of deionized water and 4.0 mL of 10 wt% phosphoric acid aqueous solution and mix them to obtain the molding agent;

[0100] Weigh out 32.0g of the rare earth manganese zirconium composite oxygen storage body prepared in Example 1, 12.0g of the phosphorus boron aluminum silicon composite body prepared in Example 4, and 7.0g of manganese iron titanium phosphorus composite oxide. Add them to the reaction vessel and stir. After mixing evenly, add 36.0mL of molding agent and stir for 10min. After stirring, transfer the mixture to a kneading device and knead until the strip diameter is 2mm and the length is 6mm. Then age it at 55℃ for 1.5h. After aging, dry it to obtain the molded composite carrier.

[0101] Step 3: Preparation of recyclable catalyst

[0102] Weigh out 2.4 g of copper nitrate trihydrate, 0.08 g of palladium chloride, and 160.0 mL of deionized water and add them to the reactor. Stir and mix thoroughly. Then add 3.0 mL of 8 wt% dilute nitric acid solution, 2.0 mL of 12 wt% ammonia solution, and 2.0 g of urea. Stir thoroughly and then add 24.0 g of molded composite support. Heat the reactor to 88°C and keep it at that temperature for 3 hours. After stirring, let it stand for 4 hours. Wash with deionized water until the filtrate is close to neutral. Then dry it in a drying oven at 105°C for 5 hours. Finally, treat it at 300°C in air for 1.5 hours to obtain a recyclable catalyst.

[0103] The reaction principle for preparing recyclable catalysts is as follows:

[0104] The molding system composed of anhydrous ethanol, deionized water, and phosphoric acid provides wetting, dispersion, and acidic condensation between particles, enabling rare earth manganese zirconium composite oxygen storage bodies, phosphorus boron aluminum silicon composites, and manganese iron titanium phosphorus composite oxides to form composite carrier structures characterized by particle stacking, surface hydroxyl interactions, and phosphate bonding during the kneading process. On this basis, copper and palladium salts in the aqueous phase undergo local hydrolysis, coordination, and deposition triggered by acid-base regulation and urea slow-release decomposition, gradually interacting with hydroxyl groups, oxygen bridge sites, and phosphorus-containing sites on the carrier surface to form a dispersed metal precursor bonded state. After drying and heat treatment in an air atmosphere, residual ligands and volatile components are removed, and the metal species are transformed into a stable loading structure coupled with the surface of the composite carrier.

[0105] Example 8

[0106] This embodiment provides a method for preparing a recyclable catalyst, including the following steps:

[0107] Step 1: Preparation of manganese-iron-titanium-phosphorus composite oxides

[0108] Weigh out 160.0 mL of deionized water, 12.0 mL of 85 wt% phosphoric acid aqueous solution, 8.0 g of ferric nitrate nonahydrate, 9.0 g of manganese acetate tetrahydrate, and 7.0 g of urea and add them to the reaction vessel. Stir and mix well. Then add 24.0 mL of tetrabutyl titanate and stir well. Transfer the mixture to a hydrothermal reaction vessel and keep it at 205 °C for 14 h. After the reaction is complete, wait for the hydrothermal reaction vessel to cool to room temperature, filter and collect the filter cake. After washing and drying, manganese-iron-titanium-phosphorus composite oxide is obtained.

[0109] Step 2: Preparation of the molded composite carrier

[0110] Weigh out 30.0 mL of anhydrous ethanol, 12.0 mL of deionized water, and 6.0 mL of 14 wt% phosphoric acid aqueous solution and mix them to obtain the molding agent;

[0111] Weigh out 38.0g of the rare earth manganese zirconium composite oxygen storage body prepared in Example 2, 15.0g of the phosphorus boron aluminum silicon composite body prepared in Example 5, and 9.0g of manganese iron titanium phosphorus composite oxide. Add them to the reaction vessel and stir. After mixing evenly, add 45.0mL of molding agent and stir for 12min. After stirring, transfer the mixture to a kneading device and knead until the strip diameter is 3mm and the length is 8mm. Then age it at 65℃ for 2.5h. After aging, dry it to obtain the molded composite carrier.

[0112] Step 3: Preparation of recyclable catalyst

[0113] Weigh out 3.2g of copper nitrate trihydrate, 0.12g of palladium chloride, and 160.0mL of deionized water and add them to the reactor. Stir and mix thoroughly. Then add 5.0mL of 12wt% dilute nitric acid solution, 4.0mL of 18wt% ammonia solution, and 2.8g of urea. Stir thoroughly and then add 30.0g of molded composite support. Heat the reactor to 92℃ and keep it at that temperature for 4 hours. After stirring, let it stand for 6 hours. Wash with deionized water until the filtrate is close to neutral. Then dry it in a drying oven at 115℃ for 7 hours. Finally, treat it at 320℃ in air for 2.5 hours to obtain a recyclable catalyst.

[0114] Example 9

[0115] This embodiment provides a method for preparing a recyclable catalyst, including the following steps:

[0116] Step 1: Preparation of manganese-iron-titanium-phosphorus composite oxides

[0117] Weigh out 160.0 mL of deionized water, 10.0 mL of 82 wt% phosphoric acid aqueous solution, 7.0 g of ferric nitrate nonahydrate, 8.0 g of manganese acetate tetrahydrate, and 6.0 g of urea and add them to the reaction vessel. Stir and mix well. Then add 21.0 mL of tetrabutyl titanate and stir well. Transfer the mixture to a hydrothermal reaction vessel and keep it at 190 °C for 12 h. After the reaction is complete, wait for the hydrothermal reaction vessel to cool to room temperature, filter and collect the filter cake. After washing and drying, manganese-iron-titanium-phosphorus composite oxide is obtained.

[0118] Step 2: Preparation of the molded composite carrier

[0119] Weigh out 25.0 mL of anhydrous ethanol, 10.0 mL of deionized water and 5.0 mL of 12 wt% phosphoric acid aqueous solution and mix them to obtain the molding agent;

[0120] Weigh out 36.0g of the rare earth manganese zirconium composite oxygen storage body prepared in Example 3, 13.0g of the phosphorus boron aluminum silicon composite body prepared in Example 6, and 8.0g of manganese iron titanium phosphorus composite oxide. Add them to the reaction vessel and stir. After mixing evenly, add 40.0mL of molding agent and stir for 12min. After stirring, transfer the mixture to a kneading device and knead until the strip diameter is 3mm and the length is 6mm. Then age it at 60℃ for 2.0h. After aging, dry it to obtain the molded composite carrier.

[0121] Step 3: Preparation of recyclable catalyst

[0122] Weigh out 2.7g of copper nitrate trihydrate, 0.10g of palladium chloride, and 160.0mL of deionized water and add them to the reactor. Stir and mix thoroughly. Then add 4.0mL of 10wt% dilute nitric acid solution, 3.0mL of 15wt% ammonia solution, and 2.4g of urea. Stir thoroughly and then add 27.0g of molded composite support. Heat the reactor to 90℃ and keep it at that temperature for 4 hours. After stirring, let it stand for 5 hours. Wash with deionized water until the filtrate is close to neutral. Then dry it in a drying oven at 110℃ for 6 hours. Finally, treat it at 310℃ in air for 2.0 hours to obtain a recyclable catalyst.

[0123] Comparative Example 1

[0124] The difference between this comparative example and Example 9 is that step III is omitted in the preparation process of the rare earth manganese zirconium composite oxygen storage body used in step II, and the rare earth manganese zirconium biphase oxygen-fixing framework obtained in step II is used to replace the rare earth manganese zirconium composite oxygen storage body in an equal amount in step II.

[0125] Comparative Example 2

[0126] The difference between this comparative example and Example 9 is that, in step 2, air is used instead of ammonia in the preparation process of the phosphorus boron aluminum silicon composite.

[0127] Comparative Example 3

[0128] The difference between this comparative example and Example 9 is that the manganese-iron-titanium-phosphorus composite oxide was omitted in step two, and an equal amount of rare earth manganese-zirconium composite oxygen storage body was used to replace the manganese-iron-titanium-phosphorus composite oxide.

[0129] Performance testing:

[0130] The recyclable catalysts prepared in Examples 7-9 and Comparative Examples 1-3 were placed in a drum-type abrasion test device and continuously rolled at 25 rpm for 30 min. After the test, all samples were removed and sieved through a 0.5 mm sieve. The mass of the powder passing through the sieve was weighed, and the catalyst abrasion amount was expressed as the percentage of the mass of the powder passing through the sieve relative to the initial sample mass. The abrasion amount was calculated according to this formula: Where A is the wear rate, m0 is the initial mass, and m1 is the mass of powder passing through the sieve;

[0131] The recyclable catalysts prepared in Examples 7-9 and Comparative Examples 1-3 were loaded into a reactor. The two ends of the bed were fixed with quartz wool. After loading, air was first introduced, and the temperature was raised to 300°C at 5°C / min and held for 1 hour. Then, the temperature was lowered to 100°C, and a mixed gas consisting of 0.50 vol% CO, 0.10 vol% C3H6, 8.0 vol% O2, 8.0 vol% CO2, 8.0 vol% H2O, and 75.40 vol% N2 was introduced, and the gas hourly space velocity was controlled to be 30,000 h⁻¹. -1 The test started at 100℃ and increased to 450℃ at a rate of 2℃ / min. The concentrations of CO and C3H6 in the reactor outlet gas were continuously measured and analyzed according to the formula: and Calculate the conversion rates of CO and C3H6 separately, where, CO conversion rate, For C3H6 conversion rate, and These represent the inlet concentration and stable outlet concentration of CO, respectively. and The inlet and stable outlet concentrations of C3H6 were set as follows: When the stable outlet concentration of carbon monoxide increased to 1.3 of the initial stable value, the recyclable catalyst was removed and loaded into a fixed-bed reactor. A mixed regeneration gas consisting of oxygen, carbon dioxide, nitrogen, and water vapor in a volume ratio of 1:8:9:81 was introduced, and the temperature was increased to 340℃ at a rate of 2℃ / min and held for 60min. Then, the temperature was maintained and the temperature was lowered to 180℃ to obtain the regenerated catalyst. The regenerated catalyst was then loaded into the reactor again, and the CO and C3H6 reactions were repeated. 6的转化率 During the test, the conversion rates of CO and C3H6 were measured after 5, 10, and 20 cycles, and recorded as follows: , , , , and Specific data are shown in Table 1;

[0132] Table 1 - Performance Test Data for Each Sample

[0133] Data Analysis:

[0134] A comparative analysis of the data in Table 1 reveals that the wear rate of the recyclable catalyst prepared in this invention is 2.33%. 96.5% 93.3%, 95.9%, 94.9%, 93.6%, 92.3%, It is 91.2% and The figure was 89.7%, and all data points were better than the comparative figure. This indicates that:

[0135] In Comparative Example 1, after step III was removed from the rare earth manganese zirconium system, the further integration and stabilization effect on the particle surface, phase boundary contact state and outer transition structure during the subsequent atmosphere control process was lost. As a result, when this component is combined with phosphorus boron aluminum silicon composite and manganese iron titanium phosphorus composite oxide, it is difficult to form a more coordinated interface matching relationship and continuous material transfer channel. As a result, the degree of synergistic response between different phases inside the molded composite carrier decreases. Local areas are more prone to asynchronous transfer and uneven stress release under heat treatment and cyclic conditions, which in turn damages the uniformity of the internal structure of the strip and loosens the bonding state between particles. Ultimately, this leads to a decrease in the overall composite performance of the sample during the cyclic use process.

[0136] In Comparative Example 2, after replacing ammonia with air in step ②, the phosphorus boron aluminum silicon system lost the directional regulation effect on the internal connection mode, network degree, and surface active site configuration under the original process conditions. This resulted in the difficulty of establishing a continuous and stable inorganic connection network in the composite carrier. Due to the weakening of this network constraint effect, the interfacial bonding between components changed from continuous transition to local contact. Consequently, the force transmission between particles and the connection of the pore structure became uneven, and the stability of the internal skeleton formed during the molding process was also weakened. Furthermore, under drying, calcination, and subsequent use conditions, local areas were more prone to structural loosening, edge peeling, and microcrack propagation, causing a simultaneous decline in the overall structural integrity and composite performance of the sample.

[0137] In Comparative Example 3, after the removal of the manganese-iron-titanium-phosphorus composite oxide, the system lost the original interfacial transition units and connecting buffer layers between the multiple components. This led to an increase in the proportion of direct contact between the rare earth manganese-zirconium composite oxygen storage body and the phosphorus-boron-aluminum-silicon composite body. The structural transition between different phases changed from gradual connection to relatively abrupt connection. This change made it more difficult to maintain a uniform particle packing state inside the composite support, and the coexistence of local dense and loose regions became more obvious. Consequently, stress transmission paths were interrupted, interfacial bonding continuity decreased, and local stability was insufficient. Under subsequent thermal shock, atmosphere switching, and mechanical disturbance conditions, this non-uniform structure was more likely to induce particle detachment and local instability, ultimately resulting in a decrease in the overall composite performance of the sample.

[0138] In conclusion, the rare earth manganese-zirconium composite oxygen storage body, phosphorus-boron-aluminum-silicon composite body, and manganese-iron-titanium-phosphorus composite oxide in this application system are not isolated parallel entities, but rather participate in the structural construction at different levels, such as framework stabilization, interface transition, and particle connection, during the preparation process. When any of the aforementioned links is replaced, weakened, or missing, the phase boundary continuity, stress transfer balance, and heat / mass transfer coordination within the composite system all change accordingly. This makes it easier for local areas to experience bonding mismatch, structural loosening, or asynchronous response. Therefore, the operating state of this system depends more on the overall synergistic structure formed under specific material configuration and preparation path, rather than simply attributing the resulting performance to the independent action of a single component or step.

[0139] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A process for the preparation of a recyclable catalyst for the purification of CO-rich exhaust gases, characterized in that, Includes the following steps: S1. The rare earth manganese zirconium dual-phase oxygen-fixing framework is loaded into a tube furnace, mixed gas is introduced and the temperature is raised to 350-400℃, and the heat treatment is carried out for 1-2 hours. After the heat treatment is completed, it is cooled to room temperature and sealed for storage to obtain rare earth manganese zirconium composite oxygen storage body. S2. Add rare earth manganese zirconium composite oxygen storage body, phosphorus boron aluminum silicon composite body and manganese iron titanium phosphorus composite oxide into the reaction vessel and stir. After mixing evenly, add the molding agent and stir for 10-15 minutes. Then, perform post-treatment to obtain the molded composite carrier. S3. Add copper nitrate trihydrate, palladium chloride and deionized water to the reactor and stir. After mixing evenly, add 8-12 wt% dilute nitric acid aqueous solution, 12-18 wt% ammonia and urea. After stirring evenly, add the molded composite carrier. Heat the reactor to 88-92℃ and keep it at that temperature for 3-4 hours. The post-treatment yields a recyclable catalyst.

2. The method for producing a recyclable catalyst for purification of CO-rich exhaust gas according to claim 1, characterized by, In step S1, the heating rate of the tube furnace is 2-3℃ / min, and the mixed gas is obtained by mixing air, carbon dioxide and water vapor in a volume ratio of 18-21:2-3:2-3. In step S2, the ratio of the rare earth manganese zirconium composite oxygen storage body, phosphorus boron aluminum silicon composite body and manganese iron titanium phosphorus composite oxide and the molding agent is 32-38g:12-15g:7-9g:36-45mL, wherein the molding agent is obtained by mixing anhydrous ethanol, deionized water and 10-14wt% phosphoric acid aqueous solution in a volume ratio of 20-30mL:8-12mL:4-6mL.

3. The method for producing a recyclable catalyst for purification of CO-rich exhaust gas according to claim 1, characterized by, In step S3, the ratio of copper nitrate trihydrate, palladium chloride, deionized water, 8-12wt% dilute nitric acid aqueous solution, 12-18wt% ammonia water, urea and the molded composite carrier is 2.4-3.2g:0.08-0.12g:160mL:3-5mL:2-4mL:2.0-2.8g:24-30g.

4. The method for producing a recyclable catalyst for purification of CO-rich exhaust gas according to claim 1, characterized by, The rare-earth manganese-zirconium dual-phase oxygen-fixing framework was prepared by the following method: A1. Cerium nitrate hexahydrate, lanthanum nitrate hexahydrate, praseodymium nitrate hexahydrate, zirconium nitrate oxyhydrate, manganese nitrate tetrahydrate and deionized water are added to a reaction vessel and stirred. After mixing evenly, urea is added, the reaction vessel is heated to 85-95℃, and stirred for 3-5 hours. The rare earth manganese zirconium hydroxy carbonate precursor is obtained by post-treatment. A2. Rare earth manganese zirconium hydroxy carbonate precursor, sodium chloride and potassium chloride are added to a crucible, mixed evenly, and then placed in a muffle furnace. The temperature is increased to 730-820℃ at 4-6℃ / min and held for 2.5-3.5h. The post-treatment yields a rare earth manganese zirconium biphase oxygen-fixing framework.

5. The method for producing a recyclable catalyst for purification of CO-rich exhaust gas according to claim 3, characterized by, In step A1, the ratio of the amounts of cerium nitrate hexahydrate, lanthanum nitrate hexahydrate, praseodymium nitrate hexahydrate, zirconium nitrate hydrate, manganese nitrate tetrahydrate, deionized water, and urea is 18-24g:5-7g:2.5-3.5g:4-6g:3.5-4.5g:180-220mL:22-28g; in step A2, the ratio of the amounts of the rare earth manganese zirconium hydroxycarbonate precursor, sodium chloride, and potassium chloride is 3-4g:9-12g:9-12g.

6. The method for producing a recyclable catalyst for purification of CO-rich exhaust gas according to claim 1, characterized by, The preparation method of the manganese-iron-titanium-phosphorus composite oxide is as follows: deionized water, 80-85wt% phosphoric acid aqueous solution, ferric nitrate nonahydrate, manganese acetate tetrahydrate and urea are added to a reaction vessel and stirred. After mixing evenly, tetrabutyl titanate is added and stirred evenly. The mixture is then transferred to a hydrothermal reaction vessel and kept at 180-205℃ for 10-14h. The manganese-iron-titanium-phosphorus composite oxide is obtained after post-treatment. The ratio of the amount of deionized water, 80-85wt% phosphoric acid aqueous solution, ferric nitrate nonahydrate, manganese acetate tetrahydrate, urea and tetrabutyl titanate is 160mL:8-12mL:6-8g:7-9g:5-7g:18-24mL.

7. The method for producing a recyclable catalyst for purification of CO-rich exhaust gas according to claim 1, characterized by, The phosphorus-boron-aluminum-silicon composite was prepared by the following method: B1. Add tetraethyl orthosilicate, aluminum isopropoxide, triethyl borate and triethyl phosphate to a reaction vessel and stir. After mixing evenly, heat the reaction vessel to 125-140℃ and keep it at that temperature for 5-7 hours to obtain the phosphorus boron aluminum silicon precursor. B2. Place the phosphorus-boron-aluminum-silicon precursor in a tube furnace, introduce ammonia gas, and heat the tube furnace to 500-540℃ at a heating rate of 1.5-2.5℃ / min. Hold the temperature for 1.5-2.5h, then continue heating to 600-650℃ and hold for 0.5-1.5h. Post-processing yields the phosphorus-boron-aluminum-silicon composite.

8. The method for producing a recyclable catalyst for purification of CO-rich exhaust gas according to claim 7, characterized by, In step B1, the ratio of tetraethyl orthosilicate, aluminum isopropoxide, triethyl borate, and triethyl phosphate is 28-34 mL: 5.5-7.0 g: 6.5-8.0 mL: 7.5-9.5 mL.

9. A recyclable catalyst for purifying CO-rich waste gas, characterized in that, The recyclable catalyst is prepared using the method for preparing a recyclable catalyst for purifying CO-rich waste gas as described in any one of claims 1-8.

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