Method for enhancing catalytic degradation of VOCs (Volatile Organic Compounds) by constructing carrier defects through chelating agent

Abstract

The invention discloses a method for enhancing catalytic degradation of VOCs (Volatile Organic Compounds) by constructing a carrier defect through a chelating agent, and belongs to the technical field of VOCs treatment. Comprising the following steps: pretreating zeolite, treating with a DTPA solution, centrifugally separating the mixed solution, washing with water to be neutral, and drying in a hot air drying oven at 80 DEG C to obtain zeolite; the preparation method comprises the following steps: dipping zeolite in a Pt source solution, drying after ultrasonic constant-temperature treatment, and calcining at 450 DEG C to obtain a Pt / zeolite catalyst; the catalytic oxidation performance of the catalyst to 420 ppm toluene is tested through a fixed bed reactor, and the relationship between the structure and the performance of the catalyst is analyzed by combining multiple characterization means. The zeolite catalyst with high-dispersion Pt active sites is prepared, that is, more Pt is anchored by defect sites.

Description

Technical Field

[0001] This invention relates to a method for enhancing the catalytic degradation of VOCs by constructing carrier defects with chelating agents, and more particularly to a method for enhancing the catalytic degradation of VOCs by constructing carrier defects with chelating agents, belonging to the field of VOCs treatment technology. Background Technology

[0002] Volatile organic compounds (VOCs) are a class of typical air pollutants originating from industrial flue gas and vehicle emissions, with aromatic hydrocarbons (such as xylene and toluene) accounting for a significant proportion. These compounds not only possess strong toxicity and carcinogenic potential, but can also promote the formation of ozone and secondary particulate matter through photochemical reactions, posing a serious threat to air quality and public health. Therefore, the efficient treatment of VOCs has become a crucial and widely concerned issue in the field of environmental chemistry.

[0003] Among existing technologies, the combination of adsorption and catalytic oxidation is widely considered one of the most effective treatment methods. Adsorption alone primarily utilizes adsorbents (such as activated carbon and zeolite) to capture VOCs molecules, but these adsorbents require periodic replacement or regeneration. Catalytic oxidation, or catalytic combustion, consumes heat, but its actual production process is complex, and substances such as paint mist, dust, and heavy metals in the flue gas environment can directly enter the catalytic bed, leading to catalyst poisoning and rapid deactivation. However, the combined adsorption and catalytic oxidation process effectively alleviates these drawbacks. First, porous adsorbents are used to capture volatile organic compounds in the flue gas environment. Then, the regenerated concentrated VOCs are catalytically oxidized using precious metals or metal oxides as catalysts, within a temperature range of 200 to 350°C. This completely solves the problem of efficient purification of high-concentration waste gas after adsorption, converting it into non-toxic products, namely carbon dioxide and water.

[0004] Against this backdrop, zeolites, due to their regular pores and stable structure, are promising candidates as VOCs adsorbents and catalyst supports. Their high specific surface area not only effectively captures VOCs but also promotes the uniform distribution of active metals such as Pt and Pd. To enhance the adsorption selectivity of zeolites for VOCs in humid environments, post-treatment methods such as acid treatment are often used to strengthen their aluminum removal, but these methods generally suffer from insufficient controllability. Disordered or excessive aluminum removal leads to the formation of large-sized vacancy clusters, microporous channel collapse, and a significant reduction in specific surface area. These structural degradations hinder the diffusion of volatile organic compounds (VOCs), limit the number of accessible active sites, and ultimately reduce both adsorption and catalytic performance. Previous studies have shown that post-treatment of FAU molecular sieves with bulky organic chelating agents such as ethylenediaminetetraacetic acid (EDTA) allows the aluminum removal process to proceed gently within a more confined space due to the steric hindrance effect of the chelating molecules and the confinement effect of the zeolite micropores. This improves hydrophobicity while maintaining the integrity of the framework structure to some extent. More importantly, the skeletal defects (especially silanol nests) generated during dealumination can serve as anchoring sites for metal cations (such as Pt2+), thereby promoting high dispersion of metal ions and preventing their aggregation. Loading highly dispersed (even at the single-atom level) platinum onto zeolites is expected to exhibit enhanced dispersibility and excellent catalytic oxidation activity towards toluene at lower temperatures. Summary of the Invention

[0005] This study aims to achieve moderately controllable dealumination using the organic chelating agent diethylenetriaminepentaacetic acid (DTPA), with different degrees of dealumination achieved by adjusting the DTPA concentration. Defect structures such as silanol nests are introduced to anchor Pt species, resulting in a zeolite catalyst with highly dispersed Pt active sites, enabling efficient catalytic oxidation of VOCs such as toluene at low temperatures (e.g., 150°C).

[0006] The technical solution of this invention is a method for enhancing the catalytic degradation of VOCs by constructing carrier defects using chelating agents, comprising the following steps:

[0007] Step 1) Zeolite pretreatment: Select FAU or BEA zeolite raw powder with a medium to low silica-alumina ratio, process it in a hot air drying oven and set it aside for later use; the medium to low silica-alumina ratio is 1-15;

[0008] Step 2) DTPA solution treatment: Disperse the zeolite in aqueous solutions of organic chelating agent acid, i.e., DTPA, at different concentrations (0.01 M to 0.2 M), react for 15 minutes under constant temperature conditions (80-120°C) and continue stirring to obtain a well mixed solution;

[0009] Step 3) Washing and drying: Centrifuge the mixed solution, wash with water until neutral, and dry in a hot air drying oven at 80°C to obtain zeolite;

[0010] Step 4) Loading Pt: The zeolite obtained in step 3 is immersed in a Pt source solution, ultrasonically isothermal treated for 4 hours, and then dried.

[0011] Step 5) and calcined at 450°C for 1 hour to obtain the Pt / zeolite catalyst;

[0012] Step 6) Performance testing: The catalytic oxidation performance of the catalyst for 420 ppm toluene (20% oxygen) was tested using a fixed-bed reactor, and the relationship between its structure and performance was analyzed using various characterization methods (XPS, DRIFTS, H2-TPR, etc.).

[0013] Compared to existing technologies, due to the pore size limitations of Y-type and BETA-type zeolites, the dealumination etching of the zeolite framework by DTPA molecules can only proceed from the outside in. The reaction rate of dealumination of molecular sieves at a low concentration of 0.01 M DTPA is slow, while increasing the concentration to 0.1 M accelerates dealumination, resulting in more Si-OH defects after etching. The silanol nests, composed of multiple adjacent Si–OH groups, are formed after the Al loss in the framework following dealumination. Multiple adjacent Si–OH groups can simultaneously react with Pt species. This leads to the preparation of a zeolite catalyst with highly dispersed Pt active sites, meaning more Pt is anchored by defect sites. Attached Figure Description

[0014] Figure 1 This is the adsorption isotherm of the sample in Example 1.

[0015] Figure 2 This is the XRD pattern of the sample from Example 1.

[0016] Figure 3 This is the dynamic adsorption curve of toluene (420 ppm) on the sample of Example 1.

[0017] Figure 4 This is a high-resolution XPS Pt 4f spectrum of the sample from Example 1 with pt loading.

[0018] Figure 5 This is the adsorption isotherm of the sample in Example 2.

[0019] Figure 6 This is the XRD pattern of the sample from Example 2.

[0020] Figure 7 This is the dynamic adsorption curve of toluene (420 ppm) on the sample of Example 2.

[0021] Figure 8This is a high-resolution XPS Pt 4f spectrum of the sample from Example 2 loaded with Pt.

[0022] Figure 9 This is the adsorption isotherm of the sample in Comparative Example 1.

[0023] Figure 10 This is the XRD pattern of the sample from Comparative Example 1.

[0024] Figure 11 The image shows the dynamic adsorption curve of toluene (420 ppm) on the sample of Comparative Example 1.

[0025] Figure 12 This is a high-resolution XPS Pt 4f spectrum of the comparative example 1 sample with pt loading.

[0026] Figure 13 This is the adsorption isotherm of the sample in Example 3.

[0027] Figure 14 This is the XRD pattern of the sample from Example 3.

[0028] Figure 15 This is the dynamic adsorption curve of toluene (420 ppm) on the sample of Example 3.

[0029] Figure 16 This is a high-resolution XPS Pt 4f spectrum of the sample from Example 3 loaded with Pt.

[0030] Figure 17 The image shows the H2-TPR curve of the sample from Example 3 with a load of pt.

[0031] Figure 18 This is the adsorption isotherm of the sample in Example 4.

[0032] Figure 19 This is the XRD pattern of the sample from Example 4.

[0033] Figure 20 This is the dynamic adsorption curve of toluene (420 ppm) on the sample of Example 4.

[0034] Figure 21 This is a high-resolution XPS Pt 4f spectrum of the sample from Example 4 loaded with Pt.

[0035] Figure 22 This is the H2-TPR curve of sample 4 of Example 4 with pt loading.

[0036] Figure 23 This is the adsorption isotherm of the sample in Comparative Example 2.

[0037] Figure 24 The XRD pattern of sample from Comparative Example 2 is shown.

[0038] Figure 25 This is the dynamic adsorption curve of toluene (420 ppm) on the sample of Comparative Example 2.

[0039] Figure 26 This is a high-resolution XPS Pt 4f spectrum of the comparative example 2 sample with pt loading.

[0040] Figure 27 The H2-TPR curve of the comparative example 2 with load pt is shown.

[0041] Figure 28 This is the dynamic adsorption curve of toluene (420 ppm) on the unloaded sample of Comparative Example 2.

[0042] Figure 29 This is a high-resolution XPS Pt 4f spectrum of the sample from Comparative Example 2.

[0043] Figure 30 This is the H2-TPR curve of sample 2 in Comparative Example 2. Detailed Implementation

[0044] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0045] Example 1:

[0046] The following steps were taken to prepare Beta-type zeolite molecular sieves treated with low concentrations of DTPA:

[0047] Step 1) Zeolite pretreatment: Select 2 grams of Beta-type zeolite, dry it, and set it aside for later use;

[0048] Step 2) DTPA solution treatment: Disperse the zeolite in 30 ml of 0.01 M DTPA aqueous solution and react at 100°C for 15 minutes;

[0049] Step 3) Washing and drying: After centrifuging the mixed solution, wash it with deionized water until neutral, and dry it at 80°C overnight;

[0050] Step 4) Pt loading: The dried zeolite was impregnated in chloroplatinic acid solution, sonicated for 4 hours, dried, and calcined at 450°C for 1 hour to obtain the Pt / zeolite catalyst;

[0051] Step 5) Performance testing: The catalytic oxidation performance of the catalyst for toluene was tested using a fixed-bed reactor, and the relationship between its structure and performance was analyzed using various characterization methods (XPS, DRIFTS, etc.).

[0052] The obtained catalyst has the following properties and effects:

[0053] The pore structure is as follows:

[0054]

[0055] Figure 1 The N2 adsorption-desorption isotherm for sample 1 (Beta-DTPA-0.01) is shown as a type I isotherm. However, the N2 adsorption amount is significantly reduced at the relative pressure (P / P0 < 0.01), indicating a loss of microporosity. This is because the extra-aluminum species generated during the DTPA chelation process cause partial damage to the framework or blockage of micropores.

[0056] Figure 2 The XRD pattern of the sample from Example 1 shows that the diffraction peak positions are consistent with the parent Beta zeolite, indicating that the BEA-type framework is retained, but the peak intensity is reduced and the relative crystallinity drops from 100% to 80% of the parent, confirming the removal of framework aluminum.

[0057] Figure 3 The image shows the dynamic adsorption curve of toluene (420 ppm) on the sample of Example 1. The toluene adsorption capacity was 106 mg / g, which was lower than that of the parent Beta zeolite (120 mg / g), indicating that the porosity loss caused by DTPA treatment had a negative impact on the toluene capture performance.

[0058] Figure 4 High-resolution XPS Pt 4f spectrum of Example 1 sample (β-DTPA-0.01-Pt) loaded with Pt, Pt content 0.21 at%, Pt 0 / Pt 2+ The ratio of 0.50 indicates that the Pt species exist in a moderately dispersed form.

[0059] The catalytic oxidation performance of the catalyst for toluene was tested using a fixed-bed reactor. At 150°C, the toluene conversion efficiency was 15%, and the CO2 selectivity reached 99% above 200°C. This indicates that the catalyst has lower activity at low temperatures but can completely oxidize toluene at high temperatures.

[0060] Example 2:

[0061] High-concentration DTPA-treated Y-type zeolite molecular sieves were prepared using the following steps:

[0062] Step 1) Zeolite pretreatment: Select Y-type zeolite, dry it, and set it aside for later use;

[0063] Step 2) DTPA solution treatment: Disperse the zeolite in 30 ml of 0.1 M DTPA aqueous solution and react at 100°C for 15 minutes;

[0064] Step 3) Washing and drying: After centrifuging the mixed solution, wash it with deionized water until neutral, and dry it at 80°C overnight;

[0065] Step 4) Pt loading: The dried zeolite was impregnated in chloroplatinic acid solution, sonicated for 4 hours, dried, and calcined at 450°C for 1 hour to obtain the Pt / zeolite catalyst;

[0066] Step 5) Performance testing: The catalytic oxidation performance of the catalyst for toluene was tested using a fixed-bed reactor, and the relationship between its structure and performance was analyzed using various characterization methods (XPS, DRIFTS, etc.).

[0067] The obtained catalyst has the following properties and effects:

[0068] The pore structure is as follows:

[0069]

[0070] Figure 5 The N2 adsorption-desorption isotherm for the sample in Example 2 shows further loss of microporosity, with the BET surface area decreasing to 496 m². 2 / g.

[0071] Figure 6 The XRD pattern of the sample in Example 2 shows that the relative crystallinity decreased to 62%, indicating that the high concentration of DTPA treatment led to more severe skeleton degradation.

[0072] Figure 7 The image shows the dynamic adsorption curve of toluene (420 ppm) on the sample of Example 2. The toluene adsorption capacity is 78 mg / g, further confirming the negative impact of pore loss on adsorption performance.

[0073] Figure 8 High-resolution XPS 4f spectrum of Pt 4f spectrum for the Pt-loaded sample of Example 2, with a Pt content of 0.13 at%, Pt 0 / Pt 2+ The ratio is 1.14, indicating that the Pt species are predominantly metallic Pt. 0 The main form is clusters.

[0074] Tests conducted in a fixed-bed reactor showed that the toluene conversion efficiency of this catalyst at 150°C was lower than that in Example 1. 90 The value was higher than that in Example 1, indicating that high-concentration DTPA treatment reduced catalytic activity.

[0075] Comparative Example 1:

[0076] Y-type zeolite molecular sieves were prepared as a control group using the following steps:

[0077] Step 1) Zeolite pretreatment: Select Y-type zeolite, dry it, and set it aside for later use;

[0078] Step 2) Solution treatment: Disperse the zeolite in 30 ml of deionized water and react at 100°C for 15 minutes;

[0079] Step 3) Washing and drying: After centrifuging the mixed solution, wash it with deionized water until neutral, and dry it at 80°C overnight;

[0080] Step 4) Pt loading: The dried zeolite was impregnated in chloroplatinic acid solution, sonicated for 4 hours, dried, and calcined at 450°C for 1 hour to obtain the Pt / zeolite catalyst;

[0081] Step 5) Performance testing: The catalytic oxidation performance of the catalyst for toluene was tested using a fixed-bed reactor, and the relationship between its structure and performance was analyzed using various characterization methods (XPS, DRIFTS, etc.).

[0082] The obtained catalyst has the following properties and effects:

[0083] The pore structure is as follows:

[0084]

[0085] Figure 9 The N2 adsorption-desorption isotherm of the sample in Comparative Example 1 shows a typical Type I isotherm with good microporosity.

[0086] Figure 10 For comparison, the XRD pattern of the sample in Example 1 shows a relative crystallinity of 100% and a complete skeletal structure.

[0087] Figure 11 The image shows the dynamic adsorption curve of toluene (420 ppm) on the sample of Comparative Example 1. The toluene adsorption capacity is 120 mg / g, and the adsorption kinetics follow a pseudo-first-order model (K1=0.0122, R0). 2 =0.997).

[0088] Figure 12 High-resolution XPS 4f spectrum of Pt 4f spectrum for Comparative Example 1 sample loaded with Pt, Pt content is 0.18 at%, Pt 0 / Pt 2+ The ratio is 0.47.

[0089] Tests conducted in a fixed-bed reactor revealed that the catalyst exhibited low toluene conversion efficiency at 150°C. 90 The values ​​of the samples treated with DTPA are higher than those of the unmodified Beta zeolite, indicating that the catalytic performance of the unmodified Beta zeolite is poor.

[0090] Example 3:

[0091] The following steps were used to prepare Y-type zeolite molecular sieves treated with low concentrations of DTPA:

[0092] Step 1) Zeolite pretreatment: Select Y-type zeolite, dry it, and set it aside for later use;

[0093] Step 2) DTPA solution treatment: Disperse the zeolite in 30 ml of 0.01 M DTPA aqueous solution and react at 100°C for 15 minutes;

[0094] Step 3) Washing and drying: After centrifuging the mixed solution, wash it with deionized water until neutral, and dry it at 80°C overnight;

[0095] Step 4) Pt loading: The dried zeolite was impregnated in chloroplatinic acid solution, sonicated for 4 hours, dried, and calcined at 450°C for 1 hour to obtain the Pt / zeolite catalyst;

[0096] Step 5) Performance testing: The catalytic oxidation performance of the catalyst for toluene was tested using a fixed-bed reactor, and the relationship between its structure and performance was analyzed using a variety of characterization methods (XPS, DRIFTS, H2-TPR, etc.).

[0097] The obtained catalyst has the following properties and effects:

[0098] The pore structure is as follows:

[0099]

[0100] Figure 13 The N2 adsorption-desorption isotherm of the sample in Example 3 shows that microporosity is dominant, and the BET surface area is slightly increased (827m²). 2 / g), indicating that mild chelation may help remove pore-blocking EFA species.

[0101] Figure 14 The XRD pattern of the sample in Example 3 shows that the relative crystallinity remains above 90% and the skeletal structure is well preserved.

[0102] Figure 15 The image shows the dynamic adsorption curve of toluene (420 ppm) on the sample of Example 3. The toluene adsorption capacity was 82 mg / g, which was higher than that of comparative Example 2 (59 mg / g). The adsorption kinetics followed a pseudo-first-order model (K1=0.0081, R0). 2 =0.998).

[0103] Figure 16 High-resolution XPS 4f spectrum of Pt 4f spectrum of Pt-loaded sample from Example 3, with a Pt content of 0.72 at%, Pt 0 / Pt 2+ The ratio of 0.70 indicates that the Pt species are highly dispersed.

[0104] Figure 17The H2-TPR curve of the Pt-loaded sample from Example 3 shows almost no H2 consumption peak, indicating the absence of reducible PtO species. 2+ It interacts strongly with silanol defects.

[0105] Tests conducted in a fixed-bed reactor showed that the catalyst achieved a toluene conversion efficiency of 90% at 150°C, a CO2 selectivity of over 90%, and complete oxidation at temperatures above 200°C, demonstrating optimal performance.

[0106] Example 4:

[0107] High-concentration DTPA-treated Y-type zeolite molecular sieves were prepared using the following steps:

[0108] Step 1) Zeolite pretreatment: Select Y-type zeolite, dry it, and set it aside for later use;

[0109] Step 2) DTPA solution treatment: Disperse the zeolite in 30 ml of 0.1 M DTPA aqueous solution and react at 100°C for 15 minutes;

[0110] Step 3) Washing and drying: After centrifuging the mixed solution, wash it with deionized water until neutral, and dry it at 80°C overnight;

[0111] Step 4) Pt loading: The dried zeolite was impregnated in chloroplatinic acid solution, sonicated for 4 hours, dried, and calcined at 450°C for 1 hour to obtain the Pt / zeolite catalyst;

[0112] Step 5) Performance testing: The catalytic oxidation performance of the catalyst for toluene was tested using a fixed-bed reactor, and the relationship between its structure and performance was analyzed using a variety of characterization methods (XPS, DRIFTS, H2-TPR, etc.).

[0113] The obtained catalyst has the following properties and effects:

[0114] The pore structure is as follows:

[0115]

[0116] Figure 18 The N2 adsorption-desorption isotherm of the sample in Example 4 shows a significant reduction in BET surface area and micropore volume.

[0117] Figure 19 The XRD pattern of the sample in Example 4 shows that the relative crystallinity dropped to 55%, indicating that severe dealumination led to skeleton degradation.

[0118] Figure 20 The image shows the dynamic adsorption curve of toluene (420 ppm) on the sample of Example 4. The toluene adsorption capacity is 110 mg / g, which is higher than that of the parent Y zeolite, but the adsorption kinetics are slower due to pore loss.

[0119] Figure 21 High-resolution XPS 4f spectrum of Pt-loaded sample from Example 4, with a Pt content of 0.34 at%, Pt 0 / Pt 2+ A ratio of 0.98 indicates that Pt 0 The proportion of clusters is relatively high.

[0120] Figure 22 The H2-TPR curve of the Pt-loaded sample from Example 4 shows a weak H2 consumption signal, indicating the presence of a small amount of PtO species.

[0121] Tests conducted in a fixed-bed reactor showed that the catalyst exhibited lower toluene conversion efficiency and CO2 selectivity at 150°C compared to Example 3, indicating that severe dealumination reduced catalytic performance.

[0122] Comparative Example 2:

[0123] Y-type zeolite molecular sieves were prepared as a control group using the following steps:

[0124] Step 1) Zeolite pretreatment: Select Y-type zeolite, dry it, and set it aside for later use;

[0125] Step 2) Solution treatment: Disperse the zeolite in 30 ml of deionized water and react at 100°C for 15 minutes;

[0126] Step 3) Washing and drying: After centrifuging the mixed solution, wash it with deionized water until neutral, and dry it at 80°C overnight;

[0127] Step 4) Pt loading: The dried zeolite was impregnated in chloroplatinic acid solution, sonicated for 4 hours, dried, and calcined at 450°C for 1 hour to obtain Pt / Beta zeolite catalyst;

[0128] Step 5) Performance testing: The catalytic oxidation performance of the catalyst for toluene was tested using a fixed-bed reactor, and the relationship between its structure and performance was analyzed using a variety of characterization methods (XPS, DRIFTS, H2-TPR, etc.).

[0129] The obtained catalyst has the following properties and effects:

[0130] The pore structure is as follows:

[0131]

[0132] Figure 23 The N2 adsorption-desorption isotherm of the sample in Comparative Example 2 shows a typical Type I isotherm with good microporosity.

[0133] Figure 24For comparison, the XRD pattern of the sample in Example 2 shows a relative crystallinity of 100% and an intact skeletal structure.

[0134] Figure 25 The image shows the dynamic adsorption curve of toluene (420 ppm) on the sample of Comparative Example 2. The toluene adsorption capacity was 59 mg / g, and the adsorption kinetics followed a pseudo-first-order model (K1 = 0.0074, R0). 2 =0.998).

[0135] Figure 26 High-resolution XPS 4f spectrum of Pt 4f spectrum of Comparative Example 2 sample (Y-parent-Pt) loaded with Pt, Pt content is 0.63 at%, Pt 0 / Pt 2+ The ratio is 0.69.

[0136] Figure 27 The H2-TPR curve of the Pt-loaded Comparative Example 2 sample shows an H2 consumption peak at 400°C, indicating the presence of PtO species.

[0137] Tests conducted in a fixed-bed reactor revealed that the catalyst exhibited lower toluene conversion efficiency at 150°C and lower CO2 selectivity compared to the DTPA-treated sample, indicating that the unmodified Y zeolite has limited catalytic performance.

[0138] The various embodiments of the present invention have now been described in detail. To avoid obscuring the concept of the invention, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions of this invention based on the above description.

[0139] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. The above drawings and specific embodiments are for illustrative purposes only, and this invention is not limited thereto. Minor modifications to this invention within the inventive spirit and scope defined by the claims of this invention all fall within the protection scope of this invention.

Claims

1. A method for enhancing the catalytic degradation of VOCs by constructing carrier defects using chelating agents, characterized in that: Includes the following steps: Step 1) Zeolite pretreatment: Select FAU or BEA zeolite raw powder with a medium to low silica-alumina ratio, process it in a hot air drying oven and set it aside for later use. Step 2) DTPA solution treatment: The zeolite is dispersed in aqueous solutions of organic chelating agent acid, i.e., DTPA, at different concentrations, and reacted under constant temperature conditions while continuously stirring to obtain a well mixed solution; Step 3) Washing and drying: Centrifuge the mixed solution, wash with water until neutral, and dry in a hot air drying oven to obtain zeolite; Step 4) Loading Pt: The zeolite obtained in step 3 is impregnated in a Pt source solution, ultrasonically isothermal treated, and then dried; Step 5) Calcination for 1 hour yields Pt / zeolite catalyst; Step 6) Performance testing: The catalytic oxidation performance of the catalyst at 420 ppm toluene was tested using a fixed-bed reactor, and the relationship between its structure and performance was analyzed using a variety of characterization methods.

2. The method for enhancing the catalytic degradation of VOCs by constructing carrier defects using chelating agents according to claim 1, characterized in that: In step 1), the silicon-to-aluminum ratio is 1-15.

3. The method for enhancing the catalytic degradation of VOCs by constructing carrier defects using chelating agents according to claim 1, characterized in that: In step 2), the different concentrations range from 0.01 M to 0.2 M.

4. The method for enhancing the catalytic degradation of VOCs by constructing carrier defects using chelating agents according to claim 1, characterized in that: In step 2), the constant temperature range is 80-120°C.

5. The method for enhancing the catalytic degradation of VOCs by constructing carrier defects using chelating agents according to claim 1, characterized in that: In step 5), the calcination temperature is 450°C.

6. The method for enhancing the catalytic degradation of VOCs by constructing carrier defects using chelating agents according to claim 1, characterized in that: In step 6), the characterization methods are XPS, DRIFTS, and H2-TPR.

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