A method and system for detecting the content of platinum, palladium and rhodium in an automobile exhaust purification catalyst, and application thereof

Abstract

This invention provides a method, system, and application for detecting platinum, palladium, and rhodium content in automotive exhaust purification catalysts, relating to the field of automotive exhaust purification technology. The method includes the following steps: pulverizing, grinding, and sieving the catalyst sample; microwave acid hydrolysis; neutralization, washing, and drying to obtain a dry filter residue; adding a collector and flux to the dry filter residue; heating at a constant temperature under an inert gas atmosphere; and then cooling and shaping to obtain an alloy clip; blowing the alloy clip with soot; then adding a mixed acid; heating in a 95°C water bath for 25-35 minutes to obtain a solution; subsequently adding a masking agent to the solution and shaking to obtain the test solution; and filtering, adjusting the volume, and detecting the test solution. This method can achieve accurate quantification of trace platinum, palladium, and rhodium in complex matrix catalysts with a high recovery rate; it also avoids the use of polluting elements, making it green and efficient, and more in line with the concept of green chemistry.

Description

Technical Field

[0001] This invention relates to the field of automotive exhaust purification technology, and in particular to a method, system, and application for detecting the platinum, palladium, and rhodium content in automotive exhaust purification catalysts. Background Technology

[0002] There are two main types of catalyst supports for automotive exhaust: cordierite and metallic. Currently used catalysts are mostly cordierite-type supports coated with platinum group metals. Because cordierite supports are extremely stable and insoluble in acids and alkalis, and due to the transformation of Al2O3 crystal form in the high-temperature exhaust gas, the platinum group metals are encapsulated, making them difficult to separate and accumulate. This poses a significant challenge to the direct detection of platinum group metals in waste automotive exhaust catalysts.

[0003] Current traditional detection methods have significant limitations: while fire assays can enrich precious metals, the recovery rate of rhodium is low, and lead contamination is severe; wet acid dissolution treatment is prone to incomplete dissolution due to the corrosion resistance of the catalyst support (such as alumina and cordierite), affecting the accuracy of detection. In addition, problems such as interference from coexisting metals and cumbersome procedures further restrict the detection efficiency.

[0004] To address the aforementioned shortcomings, there is an urgent need to develop a detection method with high recovery rate, low pollution, and wide applicability to achieve accurate quantification of trace platinum, palladium, and rhodium in complex matrix catalysts, providing the industry with a reliable analytical tool.

[0005] Therefore, this invention is proposed. Summary of the Invention

[0006] To address the aforementioned technical problems, the primary objective of this invention is to provide a method for detecting the platinum, palladium, and rhodium content in automotive exhaust purification catalysts. This method enables precise quantification of trace amounts of platinum, palladium, and rhodium in complex matrix catalysts, achieving a high recovery rate. Simultaneously, it avoids the use of polluting elements, making it green, efficient, and more in line with the principles of green chemistry.

[0007] The second objective of this invention is to provide a detection system for the platinum, palladium, and rhodium content in the aforementioned automotive exhaust purification catalyst. This system is matched with the detection method and can accurately quantify complex matrices, further enabling intelligent detection.

[0008] The third objective of this invention is to provide an application of the above-mentioned method for detecting the platinum, palladium, and rhodium content in automotive exhaust purification catalysts in the detection of the platinum, palladium, and rhodium content in catalysts.

[0009] To achieve the objective of this invention, a method for detecting the platinum, palladium, and rhodium content in automotive exhaust purification catalysts is provided, comprising the following steps:

[0010] S1. The catalyst sample is crushed, ground, and passed through a 200-mesh sieve. It is then subjected to microwave acid hydrolysis, neutralized and washed with 3wt%-7wt% H3BO3 until pH=7.0, and then dried at 100℃-120℃ for 2h-3h to obtain dry filter residue.

[0011] S2. Add a collector and a flux to the dry filter residue, heat it at a constant temperature of 890℃-910℃ under an inert gas for 25min-35min, and then quench it in water at 300℃ for 2s-5s to form the alloy buckle.

[0012] S3. Blow the alloy ash, then add mixed acid to it, heat in a 95℃ water bath for 25min-35min to obtain a solution, then add a masking agent to the solution and shake to obtain the test solution;

[0013] S4. Filter, dilute to volume, and test the test solution;

[0014] The trapping agent is a ternary alloy trapping agent of bismuth, tin and copper;

[0015] The trapping agent is prepared by mixing bismuth, tin and copper in a mass ratio of (50-70):(20-30):(10-20).

[0016] Furthermore, in step S2, the temperature of the isothermal heating under inert gas is 900°C, and the heating time is 30 min; the flow rate of the inert gas is 2 L / min.

[0017] Furthermore, in step S3, the temperature of the ash blowing is 950±5℃, and the blowing time is 30min-40min.

[0018] Furthermore, in step S3, the temperature of the ash blowing is 950°C, and the blowing time is 35 minutes.

[0019] Furthermore, the flux is prepared by mixing sodium tetraborate and silicon dioxide in a mass ratio of (1-3):1.

[0020] Furthermore, the trapping agent is prepared by mixing bismuth, tin, and copper in a mass ratio of 65:25:15;

[0021] The flux is prepared by mixing sodium tetraborate and silicon dioxide in a mass ratio of 2:1.

[0022] Furthermore, the mixed acid is formed by mixing mixture 1 and mixture 2 at a volume ratio of 30:1;

[0023] Mixture 1 is a mixture of 37wt% HCl and 65wt% nitric acid in a volume ratio of 3:1;

[0024] Mixture 2 contains 0.5 wt% HF.

[0025] Furthermore, the masking agent is a 1 wt% thiourea solution.

[0026] Furthermore, the acid used in the microwave acidolysis is a mixture of 40wt% HF and 65wt% HNO3 in a volume ratio of 1:3.

[0027] Furthermore, the reagent used in the neutralization and washing step is 5 wt% H3BO3.

[0028] Furthermore, it was dried at 110°C for 2 hours.

[0029] Furthermore, the mass ratio of dry filter residue to precipitant is 1:10.

[0030] The present invention also provides a system for detecting the platinum, palladium and rhodium content in exhaust gas purification catalysts, comprising: a sample pretreatment module, wherein the sample pretreatment module is sequentially connected to a microwave acidolysis module, a solid-liquid separation and filter residue treatment module, a smelting and enrichment module, a ash blowing module, a dissolution and volume adjustment module and an ICP-AES detection module.

[0031] The present invention also provides a method for detecting the platinum, palladium, and rhodium content in vehicle exhaust purification catalysts, and its application in detecting the platinum, palladium, and rhodium content in catalysts.

[0032] The present invention has the following technical effects:

[0033] This invention achieves highly efficient extraction of platinum, palladium, and rhodium from catalysts through microwave acidolysis combined with ternary bismuth-tin-copper scavenging and enrichment, increasing rhodium recovery to over 95%. The ash blowing-mixed acid dissolution process eliminates carrier interference, achieving a detection limit of 0.1 μg / g. The masking agent and optimized acid system synergistically suppress interference from coexisting ions, with a relative standard deviation of <3%. The entire process is lead-free, shortens the detection cycle by 30%, and is suitable for complex catalyst systems such as alumina / cordierite-based catalysts. Simultaneously, it significantly simplifies the detection steps and reduces the detection temperature, providing a precise, green, and efficient solution for precious metal resource recovery and product quality control. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0035] Firstly, a method for detecting platinum, palladium, and rhodium content in automotive exhaust purification catalysts is provided. This method can achieve accurate quantification of trace amounts of platinum, palladium, and rhodium in complex matrix catalysts with a high recovery rate. At the same time, it avoids the use of polluting elements, is green and efficient, and is more in line with the concept of green chemistry.

[0036] Includes the following steps:

[0037] S1. The catalyst sample is crushed, ground, and passed through a 200-mesh sieve. It is then subjected to microwave acid hydrolysis, neutralized and washed with 3wt%-7wt% H3BO3 until pH=7.0, and then dried at 100℃-120℃ for 2h-3h to obtain dry filter residue.

[0038] S2. Add a collector and a flux to the dry filter residue, heat it at a constant temperature of 890℃-910℃ under an inert gas for 25min-35min, and then quench it in water at 300℃ for 2s-5s to form the alloy buckle.

[0039] S3. Blow the alloy ash, then add mixed acid to it, heat in a 95℃ water bath for 25min-35min to obtain a solution, then add a masking agent to the solution and shake to obtain the test solution;

[0040] S4. Filter, dilute to volume, and test the test solution;

[0041] The trapping agent is a ternary alloy trapping agent of bismuth, tin and copper;

[0042] The trapping agent is prepared by mixing bismuth, tin and copper in a mass ratio of (50-70):(20-30):(10-20).

[0043] This invention utilizes microwave acidolysis. Microwave energy effectively accelerates the destruction of the cordierite or Al2O3 support structure by mixed acid, completely breaking down the cordierite encapsulation, eliminating support interference, and releasing platinum group elements. Simultaneously, a ternary alloy of bismuth, tin, and copper is used as a collector. This alloy of three elements can efficiently collect platinum, palladium, and rhodium in the molten state, forming easily separable alloy phases. The ternary alloy's rhodium collection efficiency is >95%, effectively solving the problem of low rhodium recovery in traditional fire assay methods and further improving the recovery rate. Furthermore, bismuth is used to replace lead, significantly reducing lead pollution. A flux lowers the melting point and promotes phase separation; an inert gas prevents oxidation loss. High-temperature ash blowing removes base metals from the alloy and enriches precious metals. The addition of mixed acid completely dissolves the precious metal-enriched phase and breaks down residual oxide encapsulation. Finally, a masking agent is added to complex Cu. 2+ Interfering ions are eliminated to avoid detection interference.

[0044] The formulation of the precipitant was optimized. Bismuth, as the main precipitant, has a low melting point, which can significantly reduce the melting point of the entire alloy system and improve the fluidity of the molten state. This allows the precipitant to fully contact the sample melt and efficiently "capture" dispersed platinum group metal (PGM) particles. The noble metal alloy formed after melting has a high density, which is easy to separate from the slag phase (molten slag) with a lower density, thus improving the recovery rate. Bismuth has similar chemical properties to lead, which can meet the basic requirements for being a precipitant, but it is non-toxic and environmentally friendly, achieving the goal of "green chemistry" and avoiding the harm of lead to the environment and operators.

[0045] Tin can regulate the melting point, further enhance the fluidity of the alloy, and increase its affinity for rhodium. Rhodium readily forms stable intermetallic compounds with tin (such as RhSn2). In the molten state, tin can effectively "pull" rhodium into the alloy phase, significantly solving the problem of low rhodium recovery (usually <85%) in the traditional lead assay method.

[0046] Copper enhances the mechanical strength of alloys, as bismuth and tin alloy buckles are typically soft and brittle. The addition of copper (melting point 1083°C) creates a stronger metallic network structure, resulting in alloy buckles with high mechanical strength and resistance to breakage, facilitating subsequent soot blowing and forming processes. Simultaneously, copper optimizes the surface tension of the molten alloy, improving its wettability and trapping efficiency for PGMs. Copper itself also possesses some trapping ability for platinum and palladium, creating a synergistic effect with Bi and Sn. By optimizing the proportions of these three metals, the molten surface tension is increased, thereby enhancing the trapping ability of precious metals and effectively improving their trapping efficiency.

[0047] In this invention, the contents of the three metals are simultaneously limited to ensure that bismuth remains within this range. This ensures that the alloy is still based on bismuth and maintains a low eutectic melting point (the melting point of the Bi-Sn-Cu ternary alloy can be below 300°C), resulting in excellent fluidity at a heating temperature of 900°C. At the same time, the high bismuth content ensures that the alloy has sufficient density to separate from the slag. If the content is too high, the alloy becomes too soft, lacks mechanical strength, and is prone to collapse during ash blowing. The effective component in the total amount of the collector is relatively reduced, which may affect the collection efficiency of Rh; if the content is too low, the alloy melting point increases, the fluidity deteriorates, and the collection effect decreases; the density decreases, which may lead to incomplete slag-metal separation.

[0048] The amount of tin used optimizes rhodium capture. This ratio provides sufficient tin to react fully with trace amounts of rhodium to form stable compounds, which is crucial for achieving a rhodium recovery rate >95%. Simultaneously, this ratio forms good eutectic compounds with Bi and Cu without significantly increasing the alloy's melting point. Excessive tin increases the alloy's oxidation tendency, potentially forming more tin oxides during ash blowing. These oxides can coat PGMs, causing losses and making the alloy brittle. Conversely, insufficient tin content fails to effectively capture all rhodium, leading to a decrease in rhodium recovery and failing to address the core issue.

[0049] The optimal copper content achieves the best mechanical properties. This proportion is sufficient to form a robust mesh structure, significantly improving the hardness and flatness of the alloy buckle, enabling it to withstand the physical stress of subsequent high-temperature dust blowing without cracking. Simultaneously, this copper proportion has minimal negative impact on melting point and fluidity; excessive copper significantly increases the overall melting point of the alloy, potentially leading to poor fluidity at the set temperature and affecting collection efficiency. Too much copper will also introduce more Cu after dissolution. 2+ Ions increase the burden on the masking agent and create potential interference. When the amount used is insufficient, the alloy buckle is not strong enough, is brittle, and is easily damaged during transfer and dust blowing, resulting in physical loss of PGMs.

[0050] In this invention, the three metals have distinct roles and work synergistically to achieve a 1+1+1>3 effect, which not only significantly simplifies the detection steps and reduces the reaction temperature, but also effectively improves the detection accuracy.

[0051] In some embodiments, in step S2, the temperature of the isothermal heating under inert gas is 900±10℃, and the heating time is 25min-30min; the flow rate of the inert gas is 2L / min.

[0052] In step S2, heating conditions are controlled to ensure the fluidity of the alloy, allowing the ternary alloy to melt completely and efficiently capture platinum, palladium, and rhodium. At the same time, the flow rate of inert gas is controlled to balance oxidation and volatilization of precious metals, ensuring the stability of the reaction, fully capturing platinum, palladium, and rhodium, ensuring the capture effect, and avoiding the loss of precious metals.

[0053] In some embodiments, in step S3, the temperature of the ash blowing is 950±5℃, and the blowing time is 30min-40min.

[0054] At around 950℃, it can oxidize base metals while retaining precious metals. This prevents base metal residue due to insufficient time or precious metal loss due to excessive time, improves enrichment purity, and reduces subsequent acid consumption and interference.

[0055] In some embodiments, the trapping agent is prepared by mixing bismuth, tin, and copper in a mass ratio of (50-70):(20-30):(10-20);

[0056] The flux is prepared by mixing sodium tetraborate and silicon dioxide in a mass ratio of (1-3):1.

[0057] In some embodiments, the trapping agent is prepared by mixing bismuth, tin, and copper in a mass ratio of 65:25:15;

[0058] The flux is prepared by mixing sodium tetraborate and silicon dioxide in a mass ratio of 2:1.

[0059] Sodium tetraborate and silicon dioxide are mixed in a 2:1 mass ratio to form a eutectic, which promotes slag-metal separation.

[0060] In some embodiments, the mixed acid is formed by mixing mixture 1 and mixture 2 at a volume ratio of 30:1;

[0061] Mixture 1 is a mixture of 37wt% HCl and 65wt% nitric acid in a volume ratio of 3:1;

[0062] Mixture 2 contains 0.5 wt% HF.

[0063] The mixed acid consists of aqua regia mixed with a low concentration of hydrofluoric acid. On the one hand, aqua regia can dissolve platinum, palladium, and rhodium, while the hydrofluoric acid can further clean the remaining SiO2 or cordierite residue after ash blowing. On the other hand, the low concentration of hydrofluoric acid can reduce equipment corrosion and avoid excessive fluorine interfering with detection.

[0064] In some embodiments, the masking agent is a 1 wt% thiourea solution.

[0065] Thiourea and Cu 2+ A stable complex [Cu(SCN2H4)4] is formed. 2+ This eliminates the spectral interference of Cu on ICP-AES detection, thereby improving the accuracy of platinum, palladium, and rhodium detection.

[0066] In some embodiments, the acid in the microwave acidolysis is a mixture of 40wt% HF and 65wt% HNO3 in a volume ratio of 1:3;

[0067] The reagent used in the neutralization and washing step is 5 wt% H3BO3.

[0068] Hydrofluoric acid can destroy aluminosilicate carriers, nitric acid can oxidize organic matter, and boric acid can generate stable fluoroborate, neutralize residual HF, and prevent equipment corrosion.

[0069] In some embodiments, the drying step in step S1 specifically involves drying at 110℃-120℃ for 2-3 hours.

[0070] Furthermore, it was dried at 110°C for 2 hours.

[0071] In some embodiments, the specific step of cooling and forming in step S2 is to pour the molten material into a mold preheated to 300°C and quench it in water for 1s ≤ water quenching time ≤ 5s.

[0072] The following is a detailed explanation using specific embodiments:

[0073] Example 1

[0074] A. Microwave acidolysis pretreatment

[0075] The sample was crushed to 200 mesh using a vibratory sample preparation machine. 10g of sample was weighed and mixed with HF (40wt%) and HNO3 (65wt%) in a ratio of 1:3 to maintain the total acid volume at 50mL. The sample was then filtered to obtain the filter residue. The filter residue was rinsed with 200mL of 5wt% H3BO3 solution to bring the pH of the filter residue to 7.0.

[0076] The filter residue was then placed in an oven and dried at 110°C for 2 hours to obtain dry filter residue.

[0077] B. Ternary alloy smelting and enrichment

[0078] Preparation of ternary alloy: Mix bismuth powder, tin powder and copper powder in a mass ratio of 6g:2.5g:1.5g;

[0079] Simultaneously, prepare the flux: mix sodium tetraborate and silicon dioxide at a mass ratio of 3g:1.5g.

[0080] Preheat the magnesia crucible to 900℃, take 1g of dry filter residue, and simultaneously load the ternary alloy and flux into the magnesia crucible. Then, pass argon gas through the crucible at a flow rate of 2L / min and heat it at a constant temperature for 30min until the material is in a molten state. Then, pour the molten material into a mold that has been preheated to 300℃, and then quench it in water for 5s to obtain the alloy buckle.

[0081] C. Combined treatment of ash blowing and dissolution

[0082] Prepare a mixed acid solution: HCl (37wt%): HNO3 (65wt%) in a volume ratio of 3:1, prepare 30mL of the solution to obtain aqua regia; add 1mL of 0.5wt% HF to the aqua regia.

[0083] The alloy buckle was ash blown at 950℃ for 35 minutes, and then heated with mixed acid in a water bath at 95℃ for 30 minutes to obtain a solution; then 10 mL of 1 wt% thiourea solution was added to the solution and shaken for 5 minutes.

[0084] The mixture was then filtered through a 0.22 μm glass fiber membrane, brought to a final volume of 50 mL, and then analyzed by ICP-AES.

[0085] Example 2

[0086] The specific implementation method is consistent with Example 1, in which bismuth powder, tin powder and copper powder are mixed in a mass ratio of 7g: 2g: 1g.

[0087] Example 3

[0088] The specific implementation method is consistent with Example 1, and bismuth powder: tin powder: copper powder is mixed in a mass ratio of 5g: 3g: 2g.

[0089] Example 4

[0090] The specific implementation method is consistent with Example 1, with sodium tetraborate and silicon dioxide in a mass ratio of 1.5g:1.5g.

[0091] Example 5

[0092] The specific implementation method is consistent with Example 1, with sodium tetraborate and silicon dioxide in a mass ratio of 4.5g:1.5g.

[0093] Comparative Example 1: Traditional Lead Assay

[0094] Take 10g of catalyst powder and mix it with 150g of flux (PbO:Na2CO3:borax = 2:1:0.5), add 15g of silver foil as a protective agent, and put it into a magnesium abrasive crucible;

[0095] Melt at 980℃ for 40 minutes to form a lead alloy buckle;

[0096] When the lead buckle is placed in a 950℃ ash blowing furnace, the lead oxide is absorbed by the urn, leaving behind silver alloy particles containing PGMs.

[0097] The silver alloy granules were dissolved in 10 mL of hot nitric acid, filtered, and then diluted to 50 mL.

[0098] Analyze the PGM content in the filtrate.

[0099] Comparative Example 2: Copper-Nickel Matte Identification Method

[0100] The sample was desulfurized by calcination at 650℃ for 2 hours;

[0101] Mix with 30g nickel sulfide, 20g copper sulfide, and 10g sodium carbonate, and smelt at 1150℃ for 1 hour to produce copper-nickel matte;

[0102] After the matte block was crushed, the base metals were leached with 10wt% sulfuric acid, leaving residue rich in PGMs.

[0103] The residue was dissolved in 40 mL of aqua regia (HCl:HNO3 = 3:1) at 95°C for 1 hour;

[0104] The solution was enriched with PGMs by passing it through an activated carbon column, and after ashing, it was dissolved and diluted with hydrochloric acid to a final volume.

[0105] Determined by atomic absorption spectrometry.

[0106] Comparative Example 3: Tin Collection-Fumigation Method

[0107] Mix 10g of sample with 200g of tin granules and 20g of borax, and melt at 900℃ for 30min;

[0108] The tin ingots are placed in a ash blowing furnace and heated to 1000°C at a rate of 20°C / min, and kept at a constant temperature until the tin is completely oxidized and volatilized.

[0109] The residual PGMs granules were dissolved in 30 mL of aqua regia (HCl:HNO3=3:1) at 30 °C.

[0110] Add 5 mL of hydrobromic acid to remove the antimony-tin oxide precipitate;

[0111] The filtrate was brought to a final volume of 25 mL and analyzed by ICP-AES.

[0112] Experimental Example 1: Comparison of Recovery Rates

[0113] Preparation of standards: Cordierite carriers were loaded with known amounts of platinum, palladium, and rhodium (50 μg / g each);

[0114] The standard samples were processed using the detection methods of the examples and comparative examples, respectively, and the PGMs content was detected by ICP-AES.

[0115] Calculate the recovery rate: Recovery rate = Detected value / Nominal value × 100%.

[0116] The experimental results are shown in Table 1.

[0117] Table 1: Recovery rates of platinum, palladium, and rhodium in the examples and comparative examples

[0118]

[0119] Experiment Example 2: Precision and Residual Pollutants Verification

[0120] Take the same spiked sample (Pt / Pd / Rh=50 / 30 / 10 μg / g), and process it in parallel 6 times using the above detection method. Calculate the relative standard deviation (RSD) of the 6 detection results. The RSD should be <3%.

[0121] Simultaneously, the residual pollutants in the examples and comparative examples were tested, and the experimental results are shown in Table 2.

[0122] Table 2: Precision and Residual Pollutants in Examples and Comparative Examples

[0123]

[0124] In this application, the detection limit of Example 1 can reach 0.1 μg / g, which shows that the detection method of the present invention has high sensitivity and can provide an accurate data basis for the recycling of precious metal resources.

[0125] The experimental comparison between Example 1 and Comparative Examples 1-3 shows that the detection method of this application can not only achieve efficient recovery of platinum, palladium and rhodium; at the same time, the detection method has high precision, effectively improving the accuracy of detection; in addition, it can effectively reduce the residue of polluting elements, providing a precise, green and efficient solution for precious metal resource recovery and product quality control.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting the platinum, palladium, and rhodium content in automotive exhaust purification catalysts, characterized in that, Includes the following steps: S1. The catalyst sample is crushed, ground, and passed through a 200-mesh sieve. It is then subjected to microwave acid hydrolysis, neutralized and washed with 3wt%-7wt% H3BO3 until pH=7.0, and then dried at 100℃-120℃ for 2h-3h to obtain dry filter residue. S2. Add a collector and a flux to the dry filter residue, heat it at a constant temperature of 890℃-910℃ under an inert gas for 25min-35min, and then quench it in water at 300℃ for 2s-5s to form the alloy buckle. S3. Blow the alloy ash, then add mixed acid to it, heat in a 95℃ water bath for 25min-35min to obtain a solution, then add a masking agent to the solution and shake to obtain the test solution; S4. Filter, dilute to volume, and test the test solution; The trapping agent is a ternary alloy trapping agent of bismuth, tin and copper; The trapping agent is prepared by mixing bismuth, tin, and copper in a mass ratio of (50-70):(20-30):(10-20); The flux is prepared by mixing sodium tetraborate and silicon dioxide in a mass ratio of (1-3):1; The masking agent is a 1 wt% thiourea solution.

2. The method for detecting the platinum, palladium, and rhodium content in an automotive exhaust purification catalyst according to claim 1, characterized in that, In step S2, the temperature for isothermal heating under inert gas is 900℃, and the heating time is 30 minutes; the flow rate of the inert gas is 2 L / min.

3. The method for detecting the platinum, palladium, and rhodium content in an automotive exhaust purification catalyst according to claim 1, characterized in that, In step S3, the temperature of the ash blowing is 950±5℃, and the blowing time is 30min-40min.

4. The method for detecting the platinum, palladium, and rhodium content in an automotive exhaust purification catalyst according to claim 1, characterized in that, The trapping agent is prepared by mixing bismuth, tin and copper in a mass ratio of 65:25:15; The flux is prepared by mixing sodium tetraborate and silicon dioxide in a mass ratio of 2:

1.

5. The method for detecting the platinum, palladium, and rhodium content in the vehicle exhaust purification catalyst according to claim 1, characterized in that, The mixed acid is formed by mixing mixture 1 and mixture 2 at a volume ratio of 30:1; Mixture 1 is a mixture of 37wt% HCl and 65wt% nitric acid in a volume ratio of 3:1; Mixture 2 contains 0.5 wt% HF.

6. The method for detecting the platinum, palladium, and rhodium content in the vehicle exhaust purification catalyst according to claim 1, characterized in that, The acid used in the microwave acidolysis is a mixture of 40wt% HF and 65wt% HNO3 in a volume ratio of 1:

3. The reagent used in the neutralization and washing step is 5 wt% H3BO3.

7. A system used in the method for detecting the platinum, palladium, and rhodium content in an automotive exhaust purification catalyst as described in any one of claims 1-6, characterized in that, include: The sample pretreatment module is sequentially connected to the microwave acid hydrolysis module, the solid-liquid separation and filter residue treatment module, the smelting and enrichment module, the ash blowing module, the dissolution and volume adjustment module, and the ICP-AES detection module.

8. The application of the method for detecting the platinum, palladium, and rhodium content in an automotive exhaust purification catalyst as described in any one of claims 1-6 in the detection of the platinum, palladium, and rhodium content in the catalyst.

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