Method for low-temperature catalytic combustion of chlorinated hydrocarbon through cooperation of electrostatic field and tungsten-cerium catalyst

Abstract

The invention belongs to the technical field of catalytic oxidation of VOCs (Volatile Organic Compounds), and particularly relates to a method for low-temperature catalytic combustion of chlorinated hydrocarbon by an electrostatic field in cooperation with a tungsten-cerium catalyst. According to the method, the electrostatic field in a non-Faraday mode and the tungsten-cerium catalyst (W / CeO2) are innovatively combined, the catalytic combustion conversion rate of chlorinated hydrocarbon (such as dichloroethane) is remarkably increased and the conversion temperature is reduced through the synergistic effect of the electrostatic field and the tungsten-cerium catalyst, 90% degradation can be achieved at the temperature of 200 DEG C or below, COx selectivity is high, generation of polychlorinated by-products is avoided, and the chlorine poisoning phenomenon is avoided. In addition, under the condition of an electric field, introduction of 1-5 vol% of water vapor can promote the conversion activity of DCE. The invention provides a novel method for efficient and low-temperature catalytic combustion of DCE, and the method has a good application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of catalytic oxidation of VOCs, and specifically relates to a method for low-temperature catalytic combustion of chlorinated hydrocarbons using an electrostatic field in conjunction with a tungsten-cerium catalyst. Background Art

[0002] Chlorinated volatile organic compounds (CVOCs) pose significant risks to the environment and health due to their difficulty in degradation and carcinogenicity. Catalytic combustion (oxidation) is a key method for CVOCs purification, which relies on efficient and stable catalysts. Cerium oxide (CeO2) has a favorable Ce 3+ / Ce 4+ CeO2 is widely used in the oxidation of CVOCs due to its redox cycle, abundant oxygen vacancies, and the auxiliary role of its 4f orbital in CVOCs adsorption and C–Cl bond activation. However, CeO2 still faces some challenges, such as deactivation due to chlorine (Cl) adsorption, weak oxygen (O2) activation ability under low temperature conditions, and competitive adsorption of water (H2O). Previous studies have shown that the use of noble metal loading such as platinum (Pt) can enhance the activity of CeO2 at low temperatures, but noble metals are prone to chlorine poisoning. The introduction of molecular sieves, such as HZSM–5, can improve chlorine resistance, but will cover the redox sites of CeO2. Modification with non-metallic elements such as phosphorus (P) can reduce the amount of water adsorption, but cannot completely prevent deactivation due to competitive water adsorption. Therefore, in order to further improve the comprehensive performance of low-temperature catalytic combustion CVOCs, Ce-based catalyst technology still needs to be improved.

[0003] In addition to modifying the catalyst material itself, in recent years, external field assistance (photothermal coupling, electric field / magnetic field / plasma synergy, etc.) and strengthening the performance of nanocatalysts have become a research hotspot in the field of heterogeneous catalysis. These methods have improved the catalytic purification efficiency of volatile organic compounds (VOCs), but still face some challenges, such as effective use of photon energy and minimization of ozone and nitrogen oxides produced by plasma. At present, electric field-assisted catalysis has attracted attention due to its simple operating conditions, mild reaction, significant reaction rate improvement and improved selectivity, and has been applied to fields such as electrocatalysis, wet oxidation and methane reforming. In the electric field, charge migration changes the electron density and valence state distribution on the catalyst surface, thereby affecting the interaction between the adsorbate and the catalyst surface. Therefore, changes in adsorption characteristics under the electric field will affect the activation energy and reaction path of the reaction, thereby changing the macroscopic reaction performance. These effects are particularly significant in polar reaction systems, such as methanol synthesis, reactions containing water or polar aromatic hydrocarbons, and metal / metal oxide catalyst systems. Studies have shown that in the catalytic oxidation of non-polar VOCs (such as benzene), the electric field can change the reaction path and significantly enhance low-temperature activity. However, currently, research on electric field-assisted low-temperature catalytic oxidation of chlorinated hydrocarbons (CVOCs) is still relatively scarce. Summary of the invention

[0004] The present invention addresses the shortcomings of existing cerium-based catalyst catalytic combustion CVOCs technology, including deactivation caused by chlorine (Cl) adsorption, weak oxygen activation ability under low temperature conditions, and competitive adsorption of water (H2O). A method for the low-temperature catalytic combustion of chlorinated hydrocarbons using an efficient cerium-based catalyst is proposed, with ethylene dichloride as a typical pollutant of chlorinated hydrocarbons. The selected catalyst is a monolayer dispersed tungsten oxide nanocluster catalyst supported by cerium oxide, and an electrostatic field of non-Faraday effect is introduced into this catalyst system. The efficiency of catalytic oxidation of ethylene dichloride (including under humid conditions) is enhanced through the synergistic effect of the electrostatic field and the cerium-based catalyst. Under lower DC current conditions (1 to 7.5 mA), a higher degradation efficiency can be achieved. Under optimal electric field conditions, compared with traditional thermal catalysis, the degradation efficiency of ethylene dichloride is 1.2 times that of tungsten oxide nanocluster catalyst. 90 The temperature can be lower than 200℃, and no polychlorinated byproducts are produced. x The selectivity is over 95%. In addition, under water vapor conditions (1% to 5% volume fraction of H2O), the electric field can activate the adsorbed water, reduce competitive adsorption, and further improve the degradation rate of ethylene dichloride.

[0005] The method for low-temperature catalytic combustion of ethylene dichloride by using an electrostatic field in coordination with a tungsten-cerium catalyst adopts a synergistic system of a non-Faraday mode electrostatic field and a cerium oxide-supported tungsten oxide catalyst.

[0006] Specifically, a tungsten-cerium catalyst (W / CeO2) is loaded into a reactor capable of generating an electrostatic field, a mixed gas containing chlorinated hydrocarbon gas (ethylene dichloride is used as a typical chlorinated hydrocarbon) is introduced, and catalytic combustion is performed in an electrostatic field of ≤200°C.

[0007] Furthermore, the current of the electrostatic field is 1-7.5 mA, and the voltage is 0.2-1.2 kV; the current is a direct current.

[0008] Preferably, the electrostatic field has a current of 1-5 mA and a voltage of 0.2-0.7 kV.

[0009] Preferably, the current of the electrostatic field is 2.5-7.5 mA, and the voltage is 0.8-1.2 kV.

[0010] The voltage value depends on the current and the catalyst bed height (ie resistance value).

[0011] Furthermore, the reactor includes a quartz tube, a high-voltage electrode rod, a constant-current power generator, and a thermocouple; two pieces of nickel foam are installed in the quartz tube, and a catalyst is filled between the two pieces of nickel foam as a bed layer; the two pieces of nickel foam are connected to high-voltage electrode rods on both sides; the high-voltage electrode rod is connected to the constant-current power generator; and the thermocouple extends into the catalyst.

[0012] Furthermore, the high voltage electrode rod is a tungsten electrode rod.

[0013] Furthermore, in the mixed gas, the concentration of chlorinated hydrocarbon gas is 1000-4000 mg m -3 , O2 content is 5~20vol%, and N2 is used as the balance gas.

[0014] Furthermore, in the mixed gas, the concentration of chlorinated hydrocarbon gas is 1000-4000 mg m -3 , O2 content is 5-20vol%, H2O content is 1-5vol% (preferably 1vol%), and N2 is used as the balance gas.

[0015] Furthermore, the chlorinated hydrocarbon gas is ethylene dichloride.

[0016] Furthermore, the tungsten-cerium catalyst is a tungsten oxide nanocluster in a monolayer dispersed form supported on the surface of a cerium oxide carrier.

[0017] In ethylene dichloride, 1000 mg m -3 When the current is low (1-2.5 mA), T can be achieved on 10W / CeO2. 90 Catalytic combustion of ethylene dichloride below 200°C; under high voltage conditions (0.8-1.2 kV), T 90 It can even be lower than 100°C. Under the conditions of low current (1-2.5 mA) and high voltage (0.8-1.2 kV), CO x The selectivity can reach more than 95% even at a temperature below 100°C, and no polychlorinated byproducts are produced, and no chlorine poisoning occurs. Other conditions are: catalyst dosage 200 mg; air atmosphere (i.e. 20 vol% O2, 80 vol% N2).

[0018] Under low current conditions (1-5 mA), T can be achieved in either oxygen-poor or oxygen-rich (5-20 vol% O2) atmospheres. 90 Catalytic combustion of ethylene dichloride below 200°C. When the current is 5 mA and the O2 volume fraction is 10 vol%, T 90 The temperature can even be lower than 145° C. Other conditions are: 200 mg of catalyst and air atmosphere (i.e. 20 vol% O2, 80 vol% N2).

[0019] Even under different water vapor conditions (1-5 vol% H2O), the current is kept low (1-5 mA), T 90 Still below 200℃. Under 1vol% water vapor condition, when the current value is 5mA, T 90 The value can even be reduced to 140℃, and CO xThe selectivity is higher than 95% in the whole temperature range (90-380°C). Other conditions are: catalyst dosage 200mg; ethylene dichloride concentration 1000mgm -3 , air atmosphere (i.e. 20 vol% O2, 80 vol% N2).

[0020] Furthermore, the preparation method of the cerium tungsten catalyst is:

[0021] S1. Dissolve Ce(NO3)3·6H2O in ethylene glycol and stir thoroughly until completely dissolved;

[0022] S2, transferring the above solution into a polytetrafluoroethylene-lined autoclave, placing it in an oven at 180°C for 24 hours, filtering, washing, drying, and calcining it in a muffle furnace at 450°C for 2 hours to obtain a CeO2 carrier;

[0023] S3. Load ammonium metatungstate onto the above-mentioned CeO2 carrier by an equal volume impregnation method, with the ratio of tungsten mass to CeO2 mass being 3-15wt% (preferably, the ratio of tungsten mass to CeO2 mass is 10%). The obtained slurry is dried at 80°C for 6h, and then placed in a muffle furnace and calcined at 450°C for 2h to obtain a tungsten-cerium catalyst.

[0024] The beneficial effects of the present invention are:

[0025] 1. The present invention adopts a synergistic system of non-Faraday mode electrostatic field and tungsten-cerium catalyst to achieve efficient degradation of dichloroethane under low temperature conditions (≤200°C) and low DC current (1-7.5mA) electrostatic field conditions, especially when the current is 2.5mA, T 90 (90% conversion temperature) is only 168°C. When the voltage is 0.68kV and the current is 2.5mA, T 90 (90% conversion temperature) is even only 90°C. x The selectivity is higher than 95%, no polychlorinated byproducts are produced, and no chlorine poisoning occurs. Under the same conditions, the thermal catalytic T 90 The value reaches 236℃, CO x Selectivities above 95% require temperatures above 300°C.

[0026] 2. The present invention further introduces water vapor into the synergistic system of the electrostatic field in the non-Faraday mode and the tungsten-cerium catalyst. The present invention changes the adsorption-activation process of water vapor through the electrostatic field, eliminating the decrease in catalytic oxidation performance caused by the accumulation of water on the catalyst surface. The introduction of a small amount of water vapor (1-5 vol%) can increase the conversion rate of dichloroethane, reduce the reaction temperature and increase CO xFor example, in the present embodiment, in an electrostatic field with a current of 5 mA, 1 vol% water vapor is introduced, and the T 90 The value can be reduced to 140℃ and CO x The selectivity is higher than 95%. Even if the water vapor concentration increases to 3-5 vol%, T 90 The value is still below 200℃. Under the same conditions, the introduction of water vapor during the thermal catalytic process increases the conversion rate of ethylene dichloride and CO x The selectivity will be greatly reduced. 3vol% water vapor is introduced into the thermal catalytic system, T 90 Increased to 307°C, and CO x Even at 380°, selectivity is difficult to reach 95%. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention can be further illustrated by the non-limiting examples given in the accompanying drawings;

[0028] Figure 1 This is a schematic diagram of the reactor structure of an embodiment of a method for low-temperature catalytic combustion of ethylene dichloride using an electrostatic field in coordination with a tungsten-cerium catalyst according to the present invention;

[0029] Figure 2 The activity diagram of thermal catalytic oxidation of ethylene dichloride by tungsten-cerium catalyst with different W loadings. Reaction conditions: 1000 mg m -3 DCE, 20 vol% O2 (N2 as balance gas);

[0030] Figure 3 The activity of 10W / CeO2 catalyst under traditional thermal catalysis and different current conditions, CO x Comparison of selectivity (a) and polychlorinated byproduct concentration-temperature distribution (b), reaction conditions: 1000 mg m -3 DCE, 20 vol% O2 (N2 as balance gas);

[0031] Figure 4 The activity of 10W / CeO2 catalyst under traditional thermal catalysis and different voltage conditions, CO x Comparison of selectivity (a) and polychlorinated byproduct concentration-temperature distribution (b), reaction conditions: 1000 mg m -3 DCE, 20 vol% O2 (N2 as balance gas);

[0032] Figure 5 Comparison of the activity of 10W / CeO2 catalyst under different oxygen contents (5-30 vol%), conventional thermal catalysis and electric field conditions. Reaction conditions: 1000 mg m -3 DCE, 20 vol% O2 (N2 as balance gas), current 5 mA;

[0033] Figure 6 The activity and CO of 10W / CeO2 catalyst under different water vapor content (1-5 vol%) conditions under traditional thermal catalysis and electric field conditions x Comparison of selectivity, reaction conditions: 1000 mg m -3 DCE, 20 vol% O2 (N2 as balance gas), current 5 mA.

[0034] Figure 7 Comparison of the stability of 10W / CeO2 catalyst under traditional thermal catalysis and electric field conditions. Reaction conditions: 1000 mg m -3 DCE, 3 vol% H2O, 20 vol% O2 (N2 as balance gas), current 5 mA; Figure (a) shows the stability under anhydrous conditions, and Figure (b) shows the stability of repeated "H2O on / off" cycles.

[0035] Figure 8 The scanning transmission electron microscopy (STEM) spectrum of the 10W / CeO2 catalyst and the X-ray powder diffraction (XRD) spectrum before and after the reaction. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0037] Example

[0038] A method for low-temperature catalytic combustion of ethylene dichloride using an electrostatic field in coordination with a tungsten-cerium catalyst of the present invention comprises the following steps:

[0039] S1. Preparation of reactor (such as Figure 1 shown);

[0040] The reactor of the electric field synergistic catalyst includes a quartz tube (inner diameter 5mm), two pieces of nickel foam (thickness 3mm) are installed in the quartz tube, the catalyst is filled between the two pieces of nickel foam as a bed, and a tungsten material high-voltage electrode rod (diameter 2mm) is connected to each side of the two pieces of nickel foam, and a thermocouple extending into the catalyst is installed in the quartz tube. In this implementation case, two high-voltage electrodes are fixed at both ends of the reactor, and both ends of the high-voltage electrodes are connected to a constant current power generator. A piece of nickel foam is placed between the electrode and the catalyst bed, which is used to fix the catalyst and reduce the contact resistance.

[0041] In this embodiment, the high voltage electrode material is a tungsten rod. The tungsten electrode has strong corrosion resistance and can withstand the acidic gases (HCl and Cl2 gases) generated during the catalytic combustion of ethylene dichloride.

[0042] S2, preparing the catalyst by step-by-step synthesis using a solvothermal method and an impregnation method;

[0043] S2.1. Dissolve Ce(NO3)3·6H2O in 50 mL of ethylene glycol and stir thoroughly until completely dissolved;

[0044] S2.2, the above solution was transferred to a polytetrafluoroethylene-lined autoclave, placed in an oven at 180°C for 24 hours, filtered, washed, dried, and calcined in a muffle furnace at 450°C for 2 hours to obtain a CeO2 carrier;

[0045] S2.3, load ammonium metatungstate onto the above CeO2 carrier (0.5g) by equal volume impregnation method, with the ratio of tungsten mass to CeO2 mass being 3-15wt% for loading. Specifically (taking the loading amount of W as 3wt% as an example), weigh 0.0201g of ammonium metatungstate and dissolve it in deionized water. The volume of water (0.15mL) should be equal to the pore volume of 0.5g CeO2. Put 0.5g CeO2 carrier into a clean watch glass. Slowly add the prepared ammonium metatungstate solution to CeO2 to ensure that the solution completely infiltrates the carrier. Let it stand for 1-2 hours to allow the solution to be evenly distributed and fully absorbed. The obtained slurry is dried at 80℃ for 6h, and then placed in a muffle furnace and calcined at 450℃ for 2h to obtain tungsten-cerium catalysts with different W loading amounts, recorded as 3W / CeO2 catalyst, 10W / CeO2 catalyst, and 15W / CeO2 catalyst.

[0046] S3. Evaluation of catalytic combustion performance of catalyst;

[0047] The catalyst was loaded into the reactor obtained in S1, and a mixed gas containing DCE was introduced. The difference in the degradation performance of dichloroethane between traditional catalysis and electrostatic field synergistic catalysis was compared, and the effect of different reaction conditions on the performance of the catalyst in the electric field was explored. The catalyst and the electric field have a good synergistic effect and can obtain higher activity. The main control conditions include current, voltage and water vapor concentration. The specific comparison results are as follows:

[0048] S3.1 Effect of different W loadings on thermal catalysis ( Figure 2 ); reaction conditions: 1000mg m -3 DCE, 20 vol% O2 (N2 as balance gas, total gas flow rate is 100 mL min -1 );from Figure 2 It can be seen that when the W loading is too high (>10wt%) or too low (<10wt%), the thermal catalytic oxidation activity of ethylene dichloride decreases. 10wt% is the optimal loading, with the lowest T 90 10wt% loading reached WO xThe maximum threshold of monolayer dispersion on the surface of ceria can provide more WO x / CeO2 interface as the active site for catalytic oxidation of ethylene dichloride. Since 10wt% W loading (10W / CeO2) showed the best activity in thermal catalysis, 10W / CeO2 was selected for further electric field synergy experiments.

[0049] S3.2, the influence of current ( Figure 3 a, b); reaction conditions: 1000 mg m -3 DCE, 20 vol% O2 (N2 as balance gas, total gas flow rate is 100 mL min -1 ), the voltage is 0.2-0.7 kV; under the synergistic effect of the 10W / CeO2 catalyst and the electrostatic field under low current conditions (1-5 mA), T 90 It catalyzes the combustion of ethylene dichloride below 200°C. It exhibits better activity at lower currents (1.25-2.5 mA), with the best current being 2.5 mA. 90 168℃ (see Figure 3 a), 68℃ earlier than thermal catalysis, CO x The selectivity was maintained above 95% at all temperatures, and no polychlorinated byproducts were produced. In an electrostatic field of >5 mA, especially in an electrostatic field of 10 mA, the degradation ability of DCE on 10W / CeO2 was worse than that without an electrostatic field. In addition, a high current (5-10 mA) electrostatic field promoted the grain growth of the CeO2 support, which reduced the WO x / CeO2 interface, which increases the surface exposure of CeO2, making it more likely to be poisoned by chlorine under stronger currents. x The selectivity was affected by chlorine poisoning and showed a downward trend.

[0050] S3.3、Influence of voltage ( Figure 4 a, b); reaction conditions: 1000 mg m -3 DCE, 20 vol% O2 (N2 as balance gas, total gas flow rate is 100 mL min -1 ), the voltage was 0.3-1.2 kV; adjusting the inner diameter of the reaction tube changed the height of the catalyst bed, thereby changing the reaction voltage. On 10W / CeO2, DCE conversion showed great sensitivity to voltage. Under high voltage conditions, at 0.8 kV (7.5 mA) and 1.2 kV (2.5 mA), DCE was almost completely converted at 100 °C, and CO x The selectivity is over 95%. The active sites on 10W / CeO2 include unsaturated W 6+(Lewis acid) and W–OH (Brønsted acid), these sites are more easily polarized at high voltage, thus enhancing the activation effect of DCE. At the same time, with the change of voltage, polychlorinated byproducts still do not appear, indicating the excellent chlorine resistance of 10W / CeO2.

[0051] S3.4 Effect of oxygen concentration ( Figure 5 ); Reaction conditions: 1000 mg m -3 DCE, 5-30 vol% O2 (N2 as balance gas, total gas flow rate is 100 mL min -1 ), current 5mA, voltage 0.3~0.6kV; under the electric field condition, the conversion rate of DCE does not increase with the addition of oxygen, and the optimal O2 concentration is 5~10vol%, at which time T 90 Below 145°C. Because under the electric field condition, O2 and ethylene dichloride can produce strong competitive adsorption, and excessive O2 occupies the sites for ethylene dichloride adsorption activation.

[0052] S3.5 Effect of water vapor concentration ( Figure 6 ); Reaction conditions: 1000 mg m -3 DCE, 20 vol% O2 (N2 as balance gas, total gas flow rate is 100 mL min -1 ), current 5mA, voltage 0.3~0.6kV; in thermal catalysis, the activity of 10W / CeO2 and CO x The selectivity is more obviously inhibited by water vapor. After the introduction of 3 vol% water vapor, T 90 In general, H2O easily occupies Lewis acid sites and competes with O2 for adsorption, which greatly reduces the activation-oxidation reaction of DCE. After the introduction of the electrostatic field, a small amount of H2O (1 vol%) further improved the DCE conversion rate and CO x Selectivity, T 90 Compared with thermal catalysis, it is 167 °C earlier. Higher H2O content (3-5 vol%) slightly reduces the performance of 10W / CeO2 in the electric field, but compared with thermal catalysis, the performance in the wet electric field is still outstanding, indicating that the competitive adsorption of water in the electric field is weaker than that in traditional thermal catalysis.

[0053] S4. Stability of catalyst ( Figure 7 a,b):

[0054] The 10W / CeO2 catalyst showed more stable activity under electric field conditions, especially after 9 h (reaction conditions: 1000 mg m -3 DCE, 3 vol% H2O, 20 vol% O2 (N2 as balance gas, total gas flow rate is 100 mL min -1), current 5 mA, temperature 196 ° C, initial voltage 0.54 kV. ), this is because the electric field reduces the strength of Lewis acid and increases the concentration of Bronsted acid, thus promoting the chlorine in WO x / CeO2 interface. In the absence of an electric field, the CO x The selectivity gradually decreases (see Figure 7 a), which may be due to the accumulation of water on the catalyst surface, which enhances the competitive adsorption between H2O and O2. However, under the electric field condition, repeated “H2O on / off” cycles have a significant effect on the CO adsorption of 10W / CeO2. x The selectivity and DCE conversion caused almost no final changes (see Figure 7 b) These results suggest that the electric field alters the adsorption-activation process of water vapor, possibly providing more active species, such as protons and oxygen species, to participate in the reaction.

[0055] S5. Structure of the catalyst;

[0056] STEM images (see Figure 8 a) shows that WO on 10W / CeO2 x It is mainly highly dispersed on the surface of CeO2 carrier in the form of nanoclusters (size < 2nm) (monolayer dispersion). Importantly, the XRD patterns of 10W / CeO2 before and after the reaction ( Figure 8 b) No clear WO appears x peak, which means WO x After long-term electric field treatment, it is still highly dispersed. These phenomena may be due to the fact that WO x The strong interaction between the species and the CeO2 support leads to its high stability.

[0057] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A method for low-temperature catalytic combustion of chlorinated hydrocarbons using an electrostatic field in coordination with a tungsten-cerium catalyst, characterized in that: The method adopts a synergistic system of a non-Faraday mode electrostatic field and a tungsten-cerium catalyst.

2. The method for low-temperature catalytic combustion of chlorinated hydrocarbons using an electrostatic field-coordinated cerium-tungsten catalyst according to claim 1 is characterized in that: The method comprises the following steps: loading a tungsten-cerium catalyst into a reactor capable of generating an electrostatic field, introducing a mixed gas containing chlorinated hydrocarbon gas, and performing catalytic combustion in an electrostatic field at ≤200°C.

3. The method for low-temperature catalytic combustion of chlorinated hydrocarbons using an electrostatic field-coordinated cerium-tungsten catalyst according to claim 2 is characterized in that: The current of the electrostatic field is 1-7.5 mA, and the voltage is 0.2-1.2 kV; the current is a direct current.

4. The method for low-temperature catalytic combustion of chlorinated hydrocarbons using an electrostatic field in coordination with a tungsten-cerium catalyst according to claim 3 is characterized in that: The electrostatic field has a current of 1-5 mA and a voltage of 0.2-0.7 kV.

5. The method for low-temperature catalytic combustion of chlorinated hydrocarbons using an electrostatic field in coordination with a tungsten-cerium catalyst according to claim 3 is characterized in that: The current of the electrostatic field is 2.5-7.5 mA, and the voltage is 0.8-1.2 kV.

6. The method for low-temperature catalytic combustion of chlorinated hydrocarbons using an electrostatic field in coordination with a tungsten-cerium catalyst according to claim 2, characterized in that: The concentration of chlorinated hydrocarbon gas in the mixed gas is 1000-4000 mg m -3 , O2 content is 5~20vol%, and N2 is used as the balance gas.

7. The method for low-temperature catalytic combustion of chlorinated hydrocarbons using an electrostatic field in coordination with a tungsten-cerium catalyst according to claim 2, characterized in that: The concentration of chlorinated hydrocarbon gas in the mixed gas is 1000-4000 mg m -3 , O2 content is 5~20vol%, H2O content is 1~5vol%, and N2 is used as the balance gas.

8. The method for low-temperature catalytic combustion of chlorinated hydrocarbons using an electrostatic field in coordination with a tungsten-cerium catalyst according to claim 1 or 2, characterized in that: The tungsten-cerium catalyst is a tungsten oxide nanocluster in a monolayer dispersed form supported on the surface of a cerium oxide carrier; the ratio of the mass of tungsten to the mass of CeO2 is 3-15wt%.

9. The method for low-temperature catalytic combustion of chlorinated hydrocarbons using an electrostatic field in coordination with a tungsten-cerium catalyst according to claim 8, characterized in that: The preparation method of the cerium tungsten catalyst comprises the following steps: S1. Dissolve Ce(NO3)3·6H2O in ethylene glycol and stir thoroughly until completely dissolved; S2, transferring the above solution into a polytetrafluoroethylene-lined autoclave, placing it in an oven at 180°C for 24 hours, filtering, washing, drying, and calcining it in a muffle furnace at 450°C for 2 hours to obtain a CeO2 carrier; S3. Load ammonium metatungstate onto the CeO2 carrier by an equal volume impregnation method. The obtained slurry is dried at 80° C. for 6 h, and then calcined at 450° C. for 2 h in a muffle furnace to obtain a tungsten-cerium catalyst.

10. The method for low-temperature catalytic combustion of chlorinated hydrocarbons using an electrostatic field in coordination with a tungsten-cerium catalyst according to claim 2, characterized in that: The reactor comprises a quartz tube, a high-voltage electrode rod, a constant-current power generator, and a thermocouple; two pieces of nickel foam are installed in the quartz tube, and a catalyst is filled between the two pieces of nickel foam as a bed layer; the two sides of the two pieces of nickel foam are respectively connected to the high-voltage electrode rod; the high-voltage electrode rod is connected to the constant-current power generator; and the thermocouple extends into the catalyst.

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