Method for degrading toluene at low temperature by using noble metal-based catalyst under assistance of external electric field

Abstract

The invention discloses a method for low-temperature toluene degradation by an external electric field assisted noble metal-based catalyst, and relates to the field of environmental catalysis. The carrier is graphite carbon nitride (C3N4-rGO) with good conductivity and accounts for 99%-99.95% of the total mass of the catalyst; the noble metal accounts for 0.05-1% of the total mass of the catalyst, and the noble metal element is one or more of platinum, palladium, ruthenium and rhodium; the noble metal is loaded on the carrier. And toluene is efficiently catalytically degraded at low temperature under the auxiliary condition of an external electric field. According to the catalyst, a conductive carrier is synthesized in situ by using a nitrogen source and graphene oxide, a low-load noble metal is used as an active component, and methylbenzene in a room can be completely degraded at the reaction temperature of 160 DEG C.

Description

Technical Field

[0001] The present application relates to the field of environmental catalysis, and particularly relates to a noble metal-based catalyst with a low loading amount for low-temperature degradation of indoor toluene under the assistance of an external electric field. Background Art

[0002] Toluene is a volatile organic compound (VOC) that is known to be harmful to human health and the environment. Toluene naturally exists in oil trees and crude oil. It is produced in some human activities, such as the manufacturing processes of fuels and coke. It is commonly used in the production processes of paints, adhesives, nail polishes, rubbers, and lacquers. It is also used in the production of benzene, plastics, nylon, and polyurethane, as well as in the synthesis reactions of toluene diisocyanate, benzoic acid, trinitrotoluene (TNT), and benzoyl chloride. Therefore, in the past few decades, it has played a crucial role in human daily life and industrial development. However, due to its toxicity and volatility, toluene has been recorded in the Pollutant Release and Transfer Register (PRTR) in many countries.

[0003] 43% of the total indoor VOCs pollution mainly includes ethyl acetate, formaldehyde, and toluene. Toluene is one of the pollutants that harm the environment and human health and has been listed as a key pollutant.

[0004] The catalytic oxidation method refers to the strong oxidation reaction between active oxygen species and VOCs molecules under the action of a catalyst, converting low-concentration VOCs into CO2 and H2O at a lower temperature. The catalytic oxidation method is applicable to the treatment of various types of VOCs, including benzene compounds, aldehydes, ketones, etc., and has a wide application range. However, the catalyst may be deactivated due to poisoning, sintering, or coking during use, and the product selectivity is not good. Therefore, developing new, efficient, and stable catalysts has important application value.

[0005] Patent CN202410774778 discloses a carambola-shaped CeCoO x composite material with relatively high thermal catalytic performance. Under the conditions of an airspeed of 40000 ml·g -1 ·h -1 , and a toluene concentration of 1000 ppm, the temperature at which degradation is complete is 246 °C. Compared with the conventional Co3O4 catalyst (T 100 is 265 °C), the catalytic temperature is reduced, but the temperature is still relatively high, which is not conducive to the purification of indoor toluene.

[0006] Noble metals show excellent low-temperature activity in the field of toluene catalytic combustion.

[0007] Patent CN202410018808 discloses a 0.81 wt% Pt / SiWO catalyst. Under the condition of 1000 ppm toluene, the T of this catalyst50 (Temperature at 50% toluene conversion) and T 90 (Temperature at 90% toluene conversion) were 170 °C and 180 °C respectively, achieving low-temperature catalytic degradation of toluene. For the Pd / TiO₂ catalyst prepared in Patent CN202111531174, the loading of Pd element was 1 wt%, and at 230 °C, the conversion of 1000 ppm toluene was close to 100%, and the CO₂ selectivity reached 100%. However, the high loading of precious metals led to expensive catalyst costs and was not conducive to commercial promotion. Patent CN202410542050 reported a carbon fiber-precious metal nanoparticle composite material with a Pt loading of 0.48%. At a toluene concentration of 1000 ppm and a space velocity of 30000 ml·g -1 ·h -1 , T 50 was 182 °C, and T 90 was 203 °C. Compared with the above-mentioned precious metal catalysts, the loading of precious metals was reduced, but the temperature for complete conversion of toluene was relatively high.

[0008] Patent CN202311754434 disclosed a PtCu / SiO₂ alloy catalyst with a Pt loading of 0.7 wt%, and under the conditions of 500 ppm toluene and 38700 mL·g -1 ·h -1 , it was able to achieve the effect of low-temperature oxidation of toluene. The T 50 of the catalyst was 158 °C, and T 90 was 169 °C. Patent CN202410762299 disclosed that the conversion rate of a single-atom alloy Au-Pt / UiO-66 catalyst was 90% at 164 °C and 100% for toluene conversion at 180 °C. The solutions proposed in these patents reduced the reaction temperature by doping a second metal, but the loading of precious metals was still relatively high and was not conducive to commercial promotion.

[0009] Currently, there are two major problems with catalysts for degrading indoor pollutant toluene: (1) The reaction temperature of cheap transition metal-based catalysts is relatively high, making it difficult to apply them to degrade toluene under indoor environmental conditions; (2) The reaction temperature of precious metal-based catalysts is relatively low, but the amount of precious metals used is relatively large, resulting in expensive catalysts and being not conducive to commercial promotion. Therefore, there is an urgent need to develop a catalyst and catalytic technology with a low reaction temperature and less precious metal consumption for indoor toluene purification.

[0010] Electric field synergistic catalysis technology has been studied and applied to various reaction systems, including electrocatalysis, wet catalytic oxidation, and methane steam catalytic reforming, due to its advantages such as simple process operation conditions, effective reduction of experimental harshness, significant increase in reaction rate, and enhanced selectivity for target products. Therefore, applying electric field synergistic catalysis technology to indoor toluene purification is a highly promising technical solution. Summary of the Invention

[0011] In order to solve the problems existing in the prior art, further reduce the loading of precious metals, and achieve low-temperature catalytic degradation at the same time, the present invention provides a method for low-temperature degradation of toluene using precious metal-based catalysts assisted by an external electric field. Under the catalysis assisted by an external electric field, the relatively low-cost, low-load precious metal-based catalyst can completely degrade indoor toluene under low-temperature conditions.

[0012] The present invention provides a conductive precious metal-based catalyst for the low-temperature catalytic degradation of toluene. The catalyst comprises a highly conductive graphite carbon nitride (C3N4-rGO) carrier, which accounts for 99% to 99.95% of the total catalyst mass. The precious metal accounts for 0.05% to 1% of the total catalyst mass. The precious metal element is one or more of platinum (Pt), palladium (Pd), ruthenium (Ru), and rhodium (Rh). The precious metal is supported on the carrier.

[0013] The present invention provides a conductive noble metal-based catalyst for catalytic degradation of toluene at low temperature, and the preparation method comprises the following steps:

[0014] (1) Graphene oxide is mixed with a nitrogen source, and an appropriate amount of water is added to obtain a mixed solution. The mixed solution is stirred at a certain temperature for a period of time, and then placed in a vacuum oven to dry; the dried sample is calcined in a tubular furnace filled with inert gas for a period of time, and cooled in the furnace to obtain a conductive carrier graphite carbon nitride (C3N4-rGO);

[0015] (2) adding a suitable amount of water and polyvinyl pyrrolidone to the noble metal salt and stirring until the solution becomes clear to form a noble metal complex solution;

[0016] (3) adding the conductive carrier obtained in step (1) to the noble metal complex solution obtained in step (2), and adding a certain amount of ethylene glycol, and stirring thoroughly to obtain a catalyst synthesis mother liquor, which is transferred to an autoclave and crystallized at a certain temperature. The solid sample obtained is filtered, washed with deionized water and ethanol respectively, and dried in a vacuum oven.

[0017] The nitrogen source in step (1) is a mixture of one or more of melamine, urea, and 2,4,6-triaminopyrimidine (TAP);

[0018] The mass ratio of the mixed solution in step (1) is nitrogen source: graphene oxide: water = 1-2:1-2:1000.

[0019] The stirring temperature described in step (1) is 80-90 °C, and the stirring time is 1-4 hours;

[0020] The inert gas described in step (1) is one or more of nitrogen, argon, and helium;

[0021] The calcination temperature described in step (1) is 550-650 °C, the heating rate is 10 °C / min, and the calcination time is 1-4 hours.

[0022] The noble metal element described in step (2) is one or more mixtures of platinum (Pt), palladium (Pd), ruthenium (Ru), and rhodium (Rh);

[0023] The noble metal salt described in step (2) is one or more mixtures of chloride salts, nitrate salts, and acetate salts;

[0024] In the noble metal complex solution described in step (2), the mass ratio of the noble metal element, water, and polyvinylpyrrolidone is: noble metal element: polyvinylpyrrolidone: water = 0.05-1: 6-10: 40.

[0025] In the catalyst synthesis mother liquor described in step (3), the mass ratio of each component is: C3N4-rGO: noble metal element: ethylene glycol = 0.1-0.4: 0.1×10 -5 ~5×10 -4 : 40-80; the crystallization temperature is 160-200 °C, and the crystallization time is 4-10 hours.

[0026] The drying temperature described in step (3) is 50-80 °C; the drying time is 12-36 h.

[0027] The present invention provides a method for low-temperature degradation of toluene by an externally applied electric field-assisted catalytic conductive noble metal-based catalyst. As shown in the appendix Figure 1 On both sides of the conductive catalyst, parallel conductor interlayers are tightly fixed. The electrodes are directly in contact with the conductor interlayers respectively. The electrodes are electrically connected to the power supply to provide an externally applied electric field to the conductive catalyst in the form of an externally applied power supply. The current direction is the same as the toluene flow direction (for the catalyst, the electrode on the side where the toluene gas enters the catalyst corresponds to the positive electrode, and the electrode on the side where the gas leaves the catalyst corresponds to the negative electrode); when heating and energizing, the electrodes are hollow electrodes, and a thermocouple is inserted into the hollow electrodes to measure the internal temperature of the catalyst in real time.

[0028] The externally applied power supply is one of a DC power supply and an AC power supply.

[0029] The current provided by the externally applied electric field to the catalyst is 0-1 A, preferably 200-500 mA, more preferably 300 mA, and a constant current is preferred.

[0030] The electrode material is one of copper, iron, nickel, silver, and gold electrodes.

[0031] The conductor interlayer material is one of copper, iron, and nickel;

[0032] The interlayer structure is one of copper foam, copper mesh, nickel foam, and iron foam.

[0033] The temperature for further catalytic reaction, that is, the internal temperature of the catalyst, is 150°C - 200°C to achieve the complete conversion of toluene into CO2 and H2O.

[0034] The beneficial effects of the present invention are as follows: The low-loading conductive noble metal-based catalyst can achieve the complete degradation of indoor toluene at a lower temperature with the assistance of an external electric field. For example, in Example 1 (0.1Pt / C3N4-rGO), under the condition of providing a 300 mA microcurrent by the external electric field, 1000 ppm toluene can be completely converted into CO2 and H2O at 160°C. The preparation method of the low-loading conductive noble metal-based catalyst provided by the present invention is simple and has a low cost. Under the assistance of an external electric field, it can efficiently purify indoor toluene at low temperature and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a diagram of the experimental device;

[0036] In the figure: 1 - power supply; 2 - wire; 3 - electrode; 4 - toluene raw gas; 5 - catalyst; 6 - conductive interlayer.

[0037] Figure 2 It is the XRD diagram of the 0.1Pt-C3N4 / rGO catalyst synthesized in Example 1;

[0038] Figure 3 It is the TEM diagram of the 0.1Pt-C3N4 / rGO catalyst synthesized in Example 1; DETAILED DESCRIPTION OF THE INVENTION

[0039] The following are specific examples of the present invention, and the technical solutions of the present invention are further elaborated in combination with the examples. These examples shall in no way limit the scope of the present invention.

[0040] The reagents, methods, and equipment used in the present invention are all conventional reagents, methods, and equipment in the technical field, unless otherwise specified.

[0041] Catalyst performance test method:

[0042] After granulating 30 mg of the catalyst, it was loaded into a quartz reaction tube with an inner diameter of 6 mm. The two sides of the catalyst were fixed by parallel conductor interlayers. The hollow electrodes (outer diameter 4 mm) were directly in contact with the conductor interlayers respectively. The electrodes were electrically connected to the power supply to provide an external electric field for the conductive catalyst in the form of an external power supply, and the current direction was the same as the toluene flow direction. Indoor toluene pollutants were simulated by 1000 ppm toluene, 20 vol% O2 and balance gas N2. The volumetric space velocity of the mixed gas was 30000 ml·g -1 ·h -1 . In the reaction temperature range of 40 - 230 °C, sampling detection and analysis were carried out every 40 °C by Fourier transform infrared spectroscopy.

[0043] The toluene conversion rate was calculated by the following formula:

[0044]

[0045] In the formula: C C7H8(in) is the toluene inlet concentration; C C7H8(out) is the toluene outlet concentration; α C7H8 is the toluene conversion rate.

[0046] Example 1

[0047] 0.177 g of H2PtCl6 was dissolved in 40 g of H2O, and then 8 g of polyvinylpyrrolidone was added (Pt: polyvinylpyrrolidone: H2O = 0.0664: 8: 40). The mixture was stirred until the solution became clear to obtain a noble metal complex solution containing Pt. 0.2 g of melamine and 0.1 g of graphene oxide were mixed (melamine: graphene oxide = 2: 1) and added to water. The reaction mixture was stirred at 80 °C for 2 hours, dried in an oven for 12 hours, then placed in a tube furnace and heated to 650 °C at a rate of 10 °C / min under a N2 atmosphere and calcined at this temperature for 2 hours. The sample conductive support C3N4-rGO was obtained. 0.2 g of the conductive support was weighed, and then 67 g of ethylene glycol and 0.04 g of the noble metal complex solution were added in turn to form a catalyst synthesis mother liquor (graphene oxide: ethylene glycol: Pt = 0.2: 67: 5.5×10 -5 ). After stirring thoroughly at room temperature for 6 hours, it was transferred to an autoclave and crystallized at 200 °C for 2 hours. The obtained sample was washed 5 times with deionized water and ethanol respectively. Then it was transferred to a 50 °C vacuum oven and dried overnight to obtain a dry sample of 0.1Pt / C3N4-rGO catalyst. Foam copper was used as the conductive interlayer to fix the catalyst and connected by an external copper rod electrode. Finally, an external current of 300 mA was provided by a DC power supply for auxiliary catalysis.

[0048] Example 2

[0049] Prepare the 0.1Pt / C3N4-rGO catalyst as in Example 1, and carry out the catalysis using the traditional heating method without the assistance of an external electric field.

[0050] Example 3

[0051] Dissolve 0.177 g of H2PtCl6 in 40 g of H2O, then add polyvinylpyrrolidone (Pt: polyvinylpyrrolidone: H2O = 0.0664: 8: 40), and stir until the solution becomes clear to obtain a noble metal complex solution containing Pt. Mix 0.2 g of melamine and 0.1 g of graphene oxide (melamine: graphene oxide = 2: 1), heat the reaction mixture at 80 °C and stir for 2 hours, then place it in an oven overnight, and then place it in a tube furnace and heat it to 650 °C at a rate of 10 °C / min under N2 conditions and hold at this temperature for 2 hours. Obtain the sample C3N4-rGO. Weigh 0.2 g of C3N4-rGO, and then successively add 67 g of ethylene glycol and 0.8 g of the noble metal complex solution (graphene oxide: ethylene glycol: Pt = 0.2: 67: 1.1×10 -4 ). After stirring well at room temperature for 6 hours, add the noble metal complex solution to obtain the catalyst synthesis mother liquor, transfer it to an autoclave, and crystallize it at 200 °C for 2 hours. The obtained samples are washed 5 times with deionized water and ethanol respectively. Then transfer it to a vacuum oven at 50 °C and dry it for 12 hours to obtain the dried sample and obtain the Pt / C3N4-rGO catalyst of Example 2. And carry out the catalysis using the traditional heating method without the assistance of an external electric field.

[0052] Example 4

[0053] Dissolve 0.2 g of PdCl2 in 40 g of H2O, then add polyvinylpyrrolidone (Pd: polyvinylpyrrolidone: H2O = 0.12: 8: 40), and stir until the solution becomes clear to obtain a noble metal complex solution containing Pd. Mix 0.2 g of melamine and 0.1 g of graphene oxide (melamine: graphene oxide = 2: 1), heat the reaction mixture at 8 °C and stir for 2 hours, then place it in an oven overnight, and then place it in a tube furnace and heat it to 650 °C at a rate of 10 °C / min under N2 conditions and hold at this temperature for 2 hours. Obtain the sample C3N4-rGO. Weigh 0.2 g of C3N4-rGO, and then successively add 67 g of ethylene glycol and 0.0221 g of the noble metal complex solution to form the catalyst synthesis mother liquor (graphene oxide: ethylene glycol: Pd = 0.2: 67: 5.5×10 -5) After stirring well at room temperature for 6 hours, it was transferred to an autoclave and crystallized at 200 °C for 2 hours. The obtained sample was washed 5 times with deionized water and ethanol respectively. Then it was transferred to a vacuum oven at 50 °C and dried overnight to obtain the dried sample of 0.1Pd / C3N4-rGO catalyst. The same external electric field-assisted catalysis as in Example 1 was adopted.

[0054] Comparative Example 1

[0055] Weigh 5 g of melamine and place it in a muffle furnace. Set the heating rate to 10 °C / min to 650 °C and hold for 2 hours to obtain carbon nitride (C3N4).

[0056] 0.177 g of H2PtCl6 was dissolved in 40 g of H2O, and then 8 g of polyvinylpyrrolidone (Pt: polyvinylpyrrolidone: H2O = 0.0664: 8: 40) was added. Stir until the solution became clear to obtain a noble metal complex solution containing Pt. 0.1 g of C3N4 and 0.1 g of graphene oxide were respectively added successively to 67 g of ethylene glycol and 0.04 g of the noble metal complex solution (C3N4 + graphene oxide: ethylene glycol: Pt = 0.2: 67: 5.5×10 -5 ) After stirring well at room temperature for 6 hours, the noble metal complex solution was added to obtain the catalyst synthesis mother liquor, which was transferred to an autoclave and crystallized at 200 °C for 2 hours. The obtained sample was washed 5 times with deionized water and ethanol respectively. Then it was transferred to an oven at 50 °C and dried for 12 hours to obtain the dried sample. And it was ground and mixed to obtain the catalyst of Example 0.1Pt / (C3N4+rGO) (mixed). The same external electric field-assisted catalysis as in Example 1 was adopted.

[0057] Comparative Example 2

[0058] 0.177 g of H2PtCl6 was dissolved in 40 g of H2O, and then polyvinylpyrrolidone (Pt: polyvinylpyrrolidone: H2O = 0.0664: 8: 40) was added. Stir until the solution became clear to obtain a noble metal complex solution containing Pt. 0.2 g of graphene oxide was then added successively to 67 mL of ethylene glycol and 0.04 g of the noble metal complex solution (graphene oxide: ethylene glycol: Pt = 0.2: 67: 5.5×10 -2 ) After stirring well at room temperature for 6 hours, the noble metal complex solution was added to obtain the catalyst synthesis mother liquor, which was transferred to an autoclave and crystallized at 200 °C for 2 hours. The obtained sample was washed 5 times with deionized water and ethanol respectively. Then it was transferred to an oven at 50 °C and dried for 12 hours to obtain the dried sample. The catalyst of Example 0.1Pt / rGO was obtained. The same external electric field-assisted catalysis as in Example 1 was adopted.

[0059] Experimental results

[0060] Table 1 Toluene→CO2 conversion data of Example 1 and Comparative Examples

[0061]

[0062]

[0063] Table 2 Toluene→CO2 conversion data of Examples 1-3

[0064]

[0065] As shown in Table 1, from the data of Example 1 and Comparative Examples 1 and 2, it can be seen that under the same external electric field assistance conditions, the conductive noble metal-based catalyst prepared with the in-situ synthesized conductive support (Example 1) has a better effect on catalytic degradation of toluene than the catalyst with the mechanically mixed conductive support (Comparative Example 1) and the single conductive support (Comparative Example 2). Toluene is completely converted to CO2 only at 160 °C, which is attributed to the fact that the in-situ synthesized conductive support not only has excellent electron transport ability, but also the in-situ growth of carbon nitride makes it easier for Pt to be anchored on the conductive support, promoting the dispersion of Pt and improving the utilization rate of noble metals.

[0066] As shown in Table 2, by comparing the data of Example 1 and Example 2, the temperature for the complete degradation of toluene by the conductive noble metal-based catalyst is significantly reduced under the assistance of an external electric field. Both Example 1 and Example 3 basically achieved complete degradation of toluene at 160 °C, but under the assistance of an external electric field, the noble metal Pt loading of the catalyst in Example 1 is only 0.1%, which is 1 / 20 of the noble metal loading of the catalyst in Example 3, greatly reducing the cost of the catalyst.

[0067] By comparing the data of Example 1 and Example 4, under the assistance of an external electric field, the conductive noble metal-based catalyst has the activity of efficiently degrading toluene at low temperature. Among them, the Pt-based catalyst has more excellent performance than the Pd-based catalyst.

[0068] In summary, the method provided by the present invention for catalytic degradation of toluene at low temperature by an external electric field-assisted conductive noble metal-based catalyst can further reduce the temperature for complete degradation of toluene and the noble metal loading.

[0069] The above has made a detailed description in combination with the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made without departing from the gist of the present invention within the knowledge scope of those of ordinary skill in the art to which the present invention pertains.

[0070] Matters not described in the present invention are applicable to the prior art.

Claims

1. A conductive noble metal-based catalyst for low-temperature catalytic degradation of toluene, characterized in that, The carrier is graphite carbon nitride (C3N4-rGO) with good conductivity, accounting for 99% to 99.95% of the total mass of the catalyst; the precious metal accounts for 0.05% to 1% of the total mass of the catalyst, and the precious metal element is one or more of platinum (Pt), palladium (Pd), ruthenium (Ru), and rhodium (Rh); the precious metal is loaded on the carrier.

2. The preparation method of a conductive noble metal-based catalyst for catalytic degradation of toluene at low temperature according to claim 1, characterized in that, The following steps are involved: (1) Graphene oxide is mixed with a nitrogen source, and an appropriate amount of water is added to obtain a mixed solution. The mixed solution is stirred at a certain temperature for a period of time, and then placed in a vacuum oven to dry; the dried sample is calcined in a tubular furnace filled with inert gas for a period of time, and cooled in the furnace to obtain a conductive carrier graphite carbon nitride (C3N4-rGO); (2) adding a suitable amount of water and polyvinyl pyrrolidone to the noble metal salt and stirring until the solution becomes clear to form a noble metal complex solution; (3) adding the conductive carrier obtained in step (1) to the noble metal complex solution obtained in step (2), and adding a certain amount of ethylene glycol, and stirring thoroughly to obtain a catalyst synthesis mother liquor, which is transferred to an autoclave and crystallized at a certain temperature. The solid sample obtained is filtered, washed with deionized water and ethanol respectively, and dried in a vacuum oven.

3. The preparation method according to claim 2, wherein, The nitrogen source in step (1) is a mixture of one or more of melamine, urea, and 2,4,6-triaminopyrimidine (TAP); the mass ratio in the mixed solution is nitrogen source: graphene oxide: water = 1-2:1-2:1000; the stirring temperature of the mixed solution is 80-90° C., and the stirring time is 1-4 hours; the inert gas in the calcination environment is one or more of nitrogen, argon, and helium; the calcination temperature is 550-650° C., and the calcination time is 1-4 hours.

4. The preparation method according to claim 2, characterized in that, The precious metal in step (2) is a mixture of one or more of platinum (Pt), palladium (Pd), ruthenium (Ru), and rhodium (Rh); the precious metal salt in step (2) is a mixture of one or more of chloride, nitrate, and acetate; the mass ratio of the precious metal element, water, and polyvinyl pyrrolidone in the precious metal complex solution in step (2) is precious metal element: polyvinyl pyrrolidone: water = 0.05-1:6-10:

40.

5. The preparation method according to claim 2, characterized in that, In step (3), the mass ratio of each component in the catalyst synthesis mother liquor is C3N4-rGO: noble metal element: ethylene glycol = 0.1 - 0.4: 0.1×10 -5 ~5×10 -4 : 40 - 80; the crystallization temperature is 160 - 200 °C, the crystallization time is 4 - 10 hours; the drying temperature is 50 - 80 °C; the drying time is 12 - 36 h.

6. Use of the conductive noble metal-based catalyst for low-temperature catalytic degradation of toluene as claimed in claim 1 for catalytic degradation of toluene.

7. The application according to claim 6, wherein The electrocatalyst is fixed by a conductor interlayer, the electrode is in direct contact with the conductor interlayer, and an external power supply is used to provide an external electric field; the direction of the current is the same as the flow direction of toluene; the current provided to the catalyst by the external electric field is 0 to 1A.

8. The application according to claim 7, wherein The external power supply is one of a DC power supply and an AC power supply; the electrode material is one of copper, iron, nickel, silver, and gold electrodes; the conductor interlayer material is one of copper, iron, and nickel; and the interlayer structure is one of foam copper, copper mesh, foam nickel, and foam iron.

9. The application according to claim 7, wherein The external electric field provides a current of 200-500 mA to the catalyst, more preferably 300 mA, preferably a constant current.

10. The application according to claim 7, characterized in that The temperature of the catalytic reaction, that is, the temperature inside the catalyst, is 150°C-200°C to achieve complete conversion of toluene into CO2 and H2O, thereby completely degrading toluene.

Images