A catalyst for the synergistic catalysis of co and no x and a method for its preparation

Abstract

The present application relates to the technical field of catalyst, in particular to a catalyst for synergistically catalyzing CO and NO and a preparation method thereof. x The catalyst is prepared by the method. The method comprises adding ammonium metavanadate into ethanolamine, stirring and dissolving to obtain a first mixed solution; uniformly mixing and dissolving 1,3,5-benzene tricarboxylic acid, water and an iron salt to obtain a second mixed solution; uniformly mixing the second mixed solution and the first mixed solution to form a mixture; performing a first reaction treatment on the mixture under a closed condition to obtain a carbon three-dimensional network structure loaded with iron and vanadium; performing a first drying treatment and a first calcination treatment under an inert atmosphere on the carbon three-dimensional network structure to obtain a cage-shaped porous carbon structure loaded with iron and vanadium; adding the cage-shaped porous carbon structure and a copper salt into water, performing a heating and stirring treatment, and then performing a second drying treatment and a second calcination treatment to obtain a porous catalyst loaded with copper, iron and vanadium. The present application can prepare a porous catalyst for synergistically catalyzing the removal of CO and NO. x ​

Description

Technical Field

[0001] The present invention relates to the field of catalyst technology, and in particular to a method for synergistically catalyzing the reaction of CO and NO x Catalyst and preparation method thereof. Background Art

[0002] Nitrogen oxides (NO) x (such as NO and NO2) and carbon monoxide CO are common pollutants in exhaust gases emitted by power plants, steel mills and automobiles. x It is extremely harmful to the environment. It is one of the main substances that form acid rain and an important substance that forms photochemical smog in the atmosphere. It also consumes O3 and destroys the ozone layer. CO is toxic. After entering the human body, it will combine with hemoglobin in the blood to produce carboxyhemoglobin, which in turn prevents hemoglobin from combining with oxygen, causing hypoxia in the body tissues and leading to death by suffocation. How to reduce NO? x The emission concentration of CO is extremely important for waste gas treatment.

[0003] In traditional governance, NO x It is usually treated separately by NH3-SCR (Selective Catalytic Reduction) technology, which mainly uses ammonia to reduce NO x Under the action of SCR catalyst, nitrogen and water are generated. x To achieve the desired treatment, excessive ammonia water is usually added, which can easily cause ammonia to escape, leading to environmental pollution, equipment corrosion, and safety hazards. CO is mainly oxidized by oxygen under the action of a catalyst to produce CO2. However, in the actual exhaust gas, NO x It is often produced together with CO (such as steel sintering flue gas). If it is treated separately, two independent catalytic systems are required, which will lead to problems such as complex equipment, high cost and large space occupation.

[0004] In summary, it is necessary to develop a synergistic catalytic reaction between CO and NO x Catalyst and preparation method thereof to solve the problems of CO and NO in the prior art x Separate catalysis requires two independent catalytic systems, which leads to problems of complex equipment, high cost and large space occupation. Summary of the Invention

[0005] The present invention aims to provide a synergistic catalytic reaction between CO and NO x The catalyst and preparation method thereof, the specific technical scheme is as follows:

[0006] In the first aspect, the present invention provides a synergistic catalytic reaction of CO and NO x The preparation method of the catalyst comprises:

[0007] Step S1, preparing a first mixed solution; specifically, adding 0.82 to 0.87 parts by mass of ammonium metavanadate to 1 part by mass of ethanolamine, stirring and dissolving, to obtain a first mixed solution;

[0008] Prepare a second mixed solution; specifically, mix and dissolve 1 to 3 parts by mass of 1, 3, 5-benzenetricarboxylic acid, 20 to 60 parts by mass of water and an iron salt to obtain a second mixed solution; wherein the mass ratio of the iron salt to the ammonium metavanadate is 85 to 95:15 to 5; the iron salt is a trivalent iron salt;

[0009] mixing the second mixed liquid and the first mixed liquid to form a mixture;

[0010] Step S2, subjecting the mixture to a first reaction treatment under closed conditions to obtain a carbon three-dimensional network structure loaded with iron and vanadium;

[0011] Step S3, subjecting the carbon three-dimensional network structure to a first drying treatment and a first calcination treatment under an inert atmosphere to obtain a cage-like porous carbon structure loaded with iron and vanadium;

[0012] Step S4: adding 1 part by mass of the cage-like porous carbon structure and 0.4-1 part by mass of copper salt to 2-4 parts by mass of water, heating and stirring until the water is evaporated, and then performing a second drying process and a second calcination process to obtain a porous catalyst loaded with copper, iron and vanadium for synergistic catalysis of CO and NO x .

[0013] Optionally, the iron salt includes any one of ferric nitrate nonahydrate and ferric chloride hexahydrate.

[0014] Optionally, the copper salt comprises copper nitrate trihydrate.

[0015] Optionally, the first reaction treatment adopts a reaction temperature of 150-200° C. and a reaction time of 8-36 h.

[0016] Optionally, before the first drying treatment, the carbon three-dimensional network structure is subjected to washing treatment and filtering treatment in sequence.

[0017] Optionally, the drying temperature used in the first drying treatment is 100~140°C, and the drying time is 3~5 hours; the calcination temperature used in the first calcination treatment is 450~550°C, and the calcination time is 2~4 hours; the inert atmosphere includes a nitrogen atmosphere.

[0018] Optionally, the second drying treatment adopts a drying temperature of 100-140°C and a drying time of 3-5 hours; the second calcination treatment adopts a calcination temperature of 250-350°C and a calcination time of 2-4 hours, and the calcination atmosphere is air atmosphere.

[0019] Optionally, the heating temperature used in the heating and stirring treatment is 80-95° C., and the stirring speed used is 80-120 rpm.

[0020] In a second aspect, the present invention provides a synergistic catalytic reaction of CO and NO x The catalyst adopts the synergistic catalysis of CO and NO x The catalyst is prepared by the method for preparing the catalyst.

[0021] Optionally, the catalyst has a high catalytic activity against CO and NO at a catalytic temperature of 220°C. x The synergistic catalytic removal rate reached more than 90%.

[0022] The application of the technical solution of the present invention has at least the following beneficial effects:

[0023] The present invention provides a synergistic catalytic reaction between CO and NO x The preparation method of the catalyst can prepare the catalyst for CO and NO x The porous catalyst for synergistic catalytic removal achieves waste treatment, high efficiency and low cost for CO and NO x Synergistic catalytic removal. Specific:

[0024] In terms of the preparation method, the present invention adopts a combination of steps S1 to S3 to obtain a cage-like porous carbon structure loaded with iron and vanadium; wherein 1, 3, 5-benzenetricarboxylic acid is a ligand, and ammonium metavanadate forms hydrolyzable VO2 (HOCH2CH2NH2) under the action of ethanolamine, and VO2 (HOCH2CH2NH2) dissociates into VO2 after hydrolysis. + In the first reaction, the VO2 + As the central ion, the d orbital of V is an empty orbital, which can accept the lone pair of electrons provided by the oxygen atom in the carboxyl group of the ligand to form a coordination bond, and then combine with the oxygen bridge between V and V to form a primary carbon network structure loaded with vanadium; as the coordination effect on VO2 + The consumption of VO2(HOCH2CH2NH2) promotes the forward movement of the hydrolysis reaction of VO2(HOCH2CH2NH2), which in turn promotes the formation of all hydrolyzable VO2(HOCH2CH2NH2) by ammonium metavanadate under the action of ethanolamine, and then achieves the full coordination of vanadium through coordination; the iron salt dissolves in water to form Fe 3+ In the first reaction process, Fe 3+As a central ion, its d orbital is an empty orbital, which can accept the lone pair of electrons provided by the oxygen atom in the carboxyl group of the ligand to form a coordination bond, and then combine with the oxygen bridge between Fe and Fe to form a primary carbon network structure loaded with iron; the remaining carboxyl groups of the ligands in each primary carbon network structure are further coordinated with the remaining carboxyl groups of the ligands in other primary carbon network structures, and then gradually expand to form a carbon three-dimensional network structure loaded with iron and vanadium, greatly improving the loading stability of iron and vanadium; the carbon three-dimensional network structure is sequentially subjected to a first drying treatment and a first calcination treatment under an inert atmosphere, so that hydrogen and oxygen in the carbon three-dimensional network structure are removed, thereby obtaining a cage-like porous carbon structure loaded with iron and vanadium and having a large mass transfer contact area;

[0025] The present invention adopts step S4 to obtain a porous catalyst loaded with copper, iron and vanadium; wherein, the present invention adopts the stirring effect in the heating and stirring treatment to make the cage-like porous carbon structure uniformly dispersed with the stirring effect, and the copper component in the solvent water is gradually and evenly diffused and loaded on the surface and pores of the cage-like porous carbon structure with the stirring effect, and further, the heating effect is used to promote the solvent water to assist the copper component to quickly and evenly diffuse and load on the surface and pores of the cage-like porous carbon structure, and the heating effect can promote the gradual evaporation of the solvent water, thereby avoiding the retention of the solvent water and affecting the stability of the copper component after loading, and can also avoid the problem of the pores of the cage-like porous carbon structure being blocked or insufficiently loaded due to the surface tension of the solvent caused by conventional static impregnation; the second drying treatment can remove the solvent in the pores of the cage-like porous carbon structure, leaving only the solute copper salt; the second roasting treatment can decompose the copper salt into copper oxide by heat, thereby obtaining a porous catalyst loaded with copper, iron and vanadium;

[0026] In terms of catalytic principle, the porous catalyst uses a cage-like porous carbon structure as a carrier. It has a porous structure with a large specific surface area. Copper, iron and vanadium are evenly loaded on the carrier surface and the inner wall of the pores as active components. It can synergistically catalyze CO and NO through the process of adsorption-activation-reaction-desorption. x , realizing waste treatment with waste, efficient and low-cost treatment of CO and NO x Synergistic catalytic removal. Specific:

[0027] (A) Regarding the active ingredients copper and iron:

[0028] In terms of adsorption and activation, NO x Diffusion to the surface and pores of the carrier forms chemical bonds with the active components copper and iron through lone pair electrons, thereby achieving NO x CO diffuses to the surface and pores of the carrier, and forms chemical bonds with the active components copper and iron through lone pairs of electrons, thereby achieving CO adsorption and activation of CO bonds.

[0029] In terms of reaction and desorption, CO is a reducing agent, and the activated CO bond converts the active component copper from Cu 2+ Reduction to Cu + , the active component iron is Fe 3+ Reduction to Fe 2+ , CO is oxidized to CO2 and desorbed, releasing the active sites where the active components are located; NO x As an oxidant, the activated NO bond converts the active component copper from Cu + Oxidation to Cu 2+ , the active component iron is Fe 2+ Oxidized to Fe 3+ , NO x It is reduced to N2 and desorbed, releasing the active sites where the active components are located; the redox reaction of the active component copper to Cu + / Cu 2+ and the redox reaction of Fe 2+ / Fe 3+ Can be recycled in the catalytic process;

[0030] When NO x When the content in the exhaust gas is insufficient, the CO in the exhaust gas can react with the oxygen in the exhaust gas after being adsorbed and activated by the active components to generate CO2 and desorb, releasing the active sites where the active components are located; under the oxidation provided by the oxygen in the exhaust gas, the Cu reduced by CO + Then oxidized to Cu 2+ , Fe reduced by CO 2+ Then oxidized to Fe 3+ , so that the redox pair of active components copper and iron can be recycled; in addition, the adsorbed and activated CO can also react with the lattice oxygen or dissociated oxygen free radicals on the active site to generate CO2 and desorb, releasing the active site where the active component is located;

[0031] (B) Regarding the active component vanadium:

[0032] The active component vanadium loaded on the carrier cage-like porous carbon structure of the present invention is VO with variable valence 2+ and VO2 + , which can promote the mutual conversion of NO and NO2, that is, when NO is excessive, it promotes the conversion of NO to NO2 (see reaction formula 1) ~ 4)); when NO2 is excessive, it promotes the conversion of NO2 to NO (see reaction formula 5) ~ 8)); Therefore, the variable valence VO 2+ and VO2 + It can make the molar amount of NO and NO2 equal, so that the same molar amount of NO and NO2 can react with the molar amount of CO equal to the sum of the molar amounts of NO and NO2 to generate CO2 and N2 (see reaction formula 9)), achieving the goal of CO and NO xThe reaction rate of synergistic catalytic removal reaches the fastest;

[0033] NO+VO2 + =NO2 - +VO 2+ Reaction formula 1);

[0034] NO2 - =NO2+e - Reaction formula 2);

[0035] VO 2+ +1 / 2O2+e - =VO2 + Reaction 3);

[0036] From reaction equations 1) to 3), we can see that NO + 1 / 2O2 = NO2 (reaction equation 4);

[0037] NO2+VO 2+ =NO + +VO2 + Reaction formula 5);

[0038] NO + +e - =NO (Reaction formula 6);

[0039] VO2 + -e - =VO 2+ Reaction 7);

[0040] From reaction equations 5) to 7), we can see that NO2=NO+1 / 2O2 (reaction equation 8);

[0041] 2CO+NO+NO2=2CO2+N2 (Reaction Equation 9);

[0042] Therefore, the porous catalyst loaded with copper, iron and vanadium can achieve the waste treatment, high efficiency and low cost of CO and NO x Synergistic catalytic removal, at the same time, the combination of active component vanadium with active components copper and iron can make the molar amount of NO and NO2 equal, achieving the best catalytic effect of treating waste with waste.

[0043] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0045] Figure 1 is a SEM image of the catalyst prepared in Example 1. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention are within the scope of protection of the present invention.

[0047] Example 1:

[0048] A synergistic catalytic reaction of CO and NO x The preparation method of the catalyst comprises:

[0049] Step S1, preparing a first mixed solution; specifically, adding 0.82 to 0.87 parts (specifically 0.85 parts) of ammonium metavanadate to 1 part by mass of ethanolamine, stirring and dissolving, to obtain a first mixed solution;

[0050] Prepare a second mixed solution; specifically, mix and dissolve 1 to 3 parts (specifically 2 parts) of 1,3,5-benzenetricarboxylic acid, 20 to 60 parts (specifically 40 parts) of water, and an iron salt to obtain a second mixed solution; wherein the mass ratio of the iron salt to the ammonium metavanadate is 85 to 95:15 to 5 (specifically 90:10); the iron salt is a trivalent iron salt;

[0051] mixing the second mixed liquid and the first mixed liquid to form a mixture;

[0052] Step S2, subjecting the mixture to a first reaction treatment under closed conditions to obtain a carbon three-dimensional network structure loaded with iron and vanadium;

[0053] Step S3, subjecting the carbon three-dimensional network structure to a first drying treatment and a first calcination treatment under an inert atmosphere, so that hydrogen and oxygen in the carbon three-dimensional network structure are removed, thereby obtaining a cage-like porous carbon structure loaded with iron and vanadium and having a large mass transfer contact area;

[0054] Step S4, adding 1 part by mass of the cage-shaped porous carbon structure and 0.4-1 parts by mass (specifically 0.6 parts) of copper salt to 2-4 parts by mass (specifically 3 parts) of water, heating and stirring until the water is evaporated, and then performing a second drying treatment and a second calcination treatment to obtain a porous catalyst loaded with copper, iron and vanadium for synergistic catalysis of CO and NOx.

[0055] The iron salt includes any one of ferric nitrate nonahydrate and ferric chloride hexahydrate, and is specifically ferric nitrate nonahydrate.

[0056] The copper salt is copper nitrate trihydrate.

[0057] The reaction temperature used in the first reaction treatment is 150-200° C. (specifically 180° C.), and the reaction time is 8-36 h (specifically 24 h).

[0058] Before the first drying process, the carbon three-dimensional network structure is subjected to washing and filtering processes in sequence.

[0059] The drying temperature used in the first drying treatment is 120° C. and the drying time is 4 hours; the baking temperature used in the first calcination treatment is 500° C. and the baking time is 3 hours; the inert atmosphere includes a nitrogen atmosphere.

[0060] The second drying treatment uses a drying temperature of 120°C and a drying time of 4 hours. The second drying treatment can remove the solvent in the pores of the cage-like porous carbon structure, leaving only the solute copper salt; the second calcination treatment uses a calcination temperature of 300°C and a calcination time of 3 hours, which is used to thermally decompose the copper salt to obtain copper oxide, and the calcination atmosphere is an air atmosphere.

[0061] The heating and stirring treatment is performed at a heating temperature of 80-95° C. (specifically 90° C.) and a stirring speed of 100 rpm.

[0062] The catalyst prepared in Example 1 was sampled and tested by scanning electron microscopy. Figure 1 .Depend on Figure 1 It is known that the catalyst prepared in Example 1 of the present invention has a porous structure.

[0063] Example 2:

[0064] The difference from Example 1 is that the mass fraction of 1,3,5-benzenetricarboxylic acid in step S1 is adjusted to 1 part.

[0065] Example 3:

[0066] Different from Example 1, the mass ratio of the iron salt to the ammonium metavanadate in step S1 is adjusted to 85:15.

[0067] Example 4:

[0068] The difference from Example 1 is that the mass fraction of copper salt in step S4 is adjusted to 0.4 parts.

[0069] Example 5:

[0070] The difference from Example 1 is that the mass fraction of 1,3,5-benzenetricarboxylic acid in step S1 is adjusted to 3 parts.

[0071] Example 6:

[0072] Different from Example 1, the mass ratio of the iron salt to the ammonium metavanadate in step S1 is adjusted to 95:5.

[0073] Example 7:

[0074] The difference from Example 1 is that the mass fraction of the copper salt in step S4 is adjusted to 1 part.

[0075] Comparative Example 1:

[0076] The difference from Example 1 is that the mass fraction of 1,3,5-benzenetricarboxylic acid in step S1 is adjusted to 0.5 parts.

[0077] Comparative Example 2:

[0078] The difference from Example 1 is that the mass ratio of the iron salt to the ammonium metavanadate in step S1 is adjusted to 80:20.

[0079] Comparative Example 3:

[0080] The difference from Example 1 is that the mass fraction of copper salt in step S4 is adjusted to 0.3 parts.

[0081] Comparative Example 4:

[0082] The difference from Example 1 is that the mass fraction of 1,3,5-benzenetricarboxylic acid in step S1 is adjusted to 4 parts.

[0083] Comparative Example 5:

[0084] Different from Example 1, the mass ratio of the iron salt to the ammonium metavanadate in step S1 is adjusted to 96:4.

[0085] Comparative Example 6:

[0086] The difference from Example 1 is that the mass fraction of copper salt in step S4 is adjusted to 1.1 parts.

[0087] The catalysts prepared in Examples 1 to 7 and Comparative Examples 1 to 6 were sampled and subjected to the first test atmosphere to measure the CO and NO x The test results are shown in Table 1, where "a" represents NO x The conversion rate is calculated as follows: NO xConversion rate = (1-total content of NO and NO2 at the outlet / total content of NO and NO2 at the inlet) × 100%; "b" represents the calculation formula for CO conversion rate, specifically: CO conversion rate = (1-total content of CO at the outlet / total content of CO at the inlet) × 100%. The gas composition used in the first test atmosphere was: 500ppm NO, 500ppm NO2, 1500ppm CO, 5% O2 by volume, and the remainder N2. Other test conditions were: catalyst loading of 0.2g; intake flow rate of 200mL / min; intake temperature of 220°C; and the analyzer was a Testo 340 handheld CO and NO analyzer. x Concentration analyzer.

[0088] Table 1 Test results under the first test atmosphere

[0089]

[0090] From the data in Table 1, we know that:

[0091] Compared with Comparative Examples 1 to 6, the present invention can prepare synergistic NO x The porous catalyst with high CO conversion rate realizes waste treatment, high efficiency and low cost for the conversion of CO and NO x Synergistic catalytic removal.

[0092] The porous catalyst prepared in Comparative Example 1 can synergistically x The CO conversion rate was close to that of Example 1, but the yield was low. This is because the ligand 1,3,5-benzenetricarboxylic acid was used in an excessively low dosage in Comparative Example 1. Although this did not affect its coordination with iron and vanadium to form a carbon three-dimensional network structure, nor did it affect the final porous catalyst formation, the use of an excessively low dosage of the ligand resulted in a low yield of the carbon three-dimensional network structure, resulting in a low yield of the prepared porous catalyst, making it difficult to scale up production.

[0093] The porous catalyst prepared in Comparative Example 2 synergistically x The conversion rate of CO is significantly lower than that of Example 1. This is because in Comparative Example 2, an excessively high amount of ammonium metavanadate is used. The main function of vanadium is to adjust the molar ratio of NO to NO2 to be close to 1:1. Since the ppm ratio of NO to NO2 in the first test atmosphere is 1:1, the adjustment effect of vanadium is not required. However, the excessively high amount of ammonium metavanadate reduces the iron and copper contents relatively, and the main catalytic activity is provided by iron and copper, which leads to a decrease in catalytic activity and a synergistic effect on NO. x The conversion rate of CO is significantly lower than that of Example 1.

[0094] The porous catalyst prepared in Comparative Example 3 synergistically xThe conversion rate of CO is significantly lower than that of Example 1. This is because the amount of copper salt used in Comparative Example 3 is too low, which makes the redox reaction of Cu + / Cu 2+ The decrease in content leads to a decrease in catalytic activity and a synergistic effect on NO x The conversion rate of CO is significantly lower than that of Example 1.

[0095] The porous catalyst prepared in Comparative Example 4 synergistically x The conversion rate of CO is significantly lower than that of Example 1. This is because in Comparative Example 4, an excessively high amount of 1,3,5-benzenetricarboxylic acid is used, which cannot be completely dissolved in water, resulting in 1,3,5-benzenetricarboxylic acid in the carbon three-dimensional network structure. In the first and second calcination treatments, excess carbon particles are generated. These carbon particles are distributed in the porous catalyst, which not only reduces the effective content of the porous catalyst, but also causes the pores of the porous catalyst to be clogged and carbon deposited, thereby resulting in a decrease in catalytic activity and a synergistic reaction to NO. x The conversion rate of CO is significantly lower than that of Example 1.

[0096] The porous catalyst prepared in Comparative Example 5 synergistically x The conversion rate of CO is close to that of Example 1. This is because in Comparative Example 5, too low a dosage of ammonium metavanadate is used, and the main function of vanadium is to adjust the molar ratio of NO to NO2 to be close to 1:1. Since the ppm ratio of NO to NO2 in the first test atmosphere is 1:1, the adjustment effect of vanadium is not required, which makes the catalytic activity change little, and the synergistic effect on NO is not significant. x The conversion rate of CO is close to that of Example 1.

[0097] The porous catalyst prepared in Comparative Example 6 synergistically x The conversion rate of CO is significantly lower than that of Example 1. This is because the excessive amount of copper salt used in Comparative Example 6 easily causes clogging of the porous catalyst channels, resulting in a decrease in adsorption performance and catalytic efficiency, and the synergistic effect on NO x The conversion rate of CO is significantly lower than that of Example 1.

[0098] The catalysts prepared in Example 1, Comparative Example 2 and 5 were sampled and subjected to the second test atmosphere to the reaction of CO and NO. x The test results are shown in Table 2, where "a" and "b" have the same meanings as in Table 1. The second test atmosphere used a gas composition of 100 ppm NO, 900 ppm NO₂, 1500 ppm CO, 5% by volume O₂, and the remainder N₂. Other test conditions were the same as those in the first test atmosphere.

[0099] Table 2 Test results under the second test atmosphere

[0100]

[0101] From the data in Table 2, we know that:

[0102] Compared with Comparative Examples 2 and 5, the present invention can prepare a synergistic NO x Porous catalysts with high CO conversion rates.

[0103] The porous catalyst prepared in Comparative Example 2 synergistically x The conversion rate of CO is significantly lower than that of Example 1. This is because in Comparative Example 2, an excessively high amount of ammonium metavanadate is used. The main function of vanadium is to adjust the molar ratio of NO to NO2 in the second test atmosphere to be close to 1:1. Although this helps to accelerate the conversion of CO to NO, the conversion rate of ammonium metavanadate to NO2 is significantly lower than that of Example 1. x However, the use of excessively high amounts of ammonium metavanadate reduces the iron and copper contents, and the main catalytic activity is provided by iron and copper, which leads to a decrease in catalytic activity and a synergistic effect on NO. x The conversion rate of CO is significantly lower than that of Example 1.

[0104] The porous catalyst prepared in Comparative Example 5 synergistically x The conversion rate of CO is lower than that of Example 1. This is because in Comparative Example 5, too low an amount of ammonium metavanadate is used. The main function of vanadium is to adjust the molar ratio of NO to NO2 in the second test atmosphere to be close to 1:1. Although this helps to accelerate the conversion of CO to NO, the conversion rate of ammonium metavanadate to NO2 is lower than that of Example 1. x However, the dosage of ammonium metavanadate is too low to effectively adjust the molar ratio of NO to NO2 to be close to 1:1, resulting in a decrease in catalytic efficiency and a synergistic removal of NO. x The conversion rate of CO is lower than that of Example 1.

[0105] The catalysts prepared in Example 1, Comparative Example 2 and 5 were sampled and subjected to the third test atmosphere for the reaction of CO and NO. x The test results are shown in Table 3, where "a" and "b" have the same meanings as in Table 1. The third test atmosphere used a gas composition of 900 ppm NO, 100 ppm NO₂, 1500 ppm CO, 5% by volume O₂, and the remainder N₂. Other test conditions were the same as those in the first test atmosphere.

[0106] Table 3 Test results under the third test atmosphere

[0107]

[0108] From the data in Table 3, we know that:

[0109] Compared with Comparative Examples 2 and 5, the present invention can prepare a synergistic NO x The porous catalyst has a high CO conversion rate. The specific reasons are analyzed in Table 2.

[0110] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A synergistic catalytic removal of CO and NO x The method for preparing a catalyst is characterized in that include: Step S1, preparing a first mixed solution; specifically, adding 0.82 to 0.87 parts by mass of ammonium metavanadate to 1 part by mass of ethanolamine, stirring and dissolving, to obtain a first mixed solution; Preparing a second mixed solution; specifically, mixing and dissolving 1 to 3 parts by mass of 1, 3, 5-benzenetricarboxylic acid, 20 to 60 parts by mass of water and an iron salt to obtain a second mixed solution; in ； The mass ratio of the iron salt to the ammonium metavanadate is 85-95:15-5; the iron salt is a trivalent iron salt; mixing the second mixed liquid and the first mixed liquid to form a mixture; Step S2, subjecting the mixture to a first reaction treatment under closed conditions to obtain a carbon three-dimensional network structure loaded with iron and vanadium; Step S3, subjecting the carbon three-dimensional network structure to a first drying treatment and a first calcination treatment under an inert atmosphere to obtain a cage-like porous carbon structure loaded with iron and vanadium; Step S4: adding 1 part by mass of the cage-like porous carbon structure and 0.4-1 part by mass of copper salt to 2-4 parts by mass of water, heating and stirring until the water is evaporated, and then performing a second drying treatment and a second calcination treatment to obtain a porous catalyst loaded with copper, iron and vanadium for synergistic catalytic removal of CO and NO x .

2. The synergistic catalytic removal of CO and NO according to claim 1 x The method for preparing a catalyst is characterized in that The iron salt includes any one of ferric nitrate nonahydrate and ferric chloride hexahydrate.

3. The synergistic catalytic removal of CO and NO according to claim 1 x The method for preparing a catalyst is characterized in that The copper salt includes copper nitrate trihydrate.

4. The synergistic catalytic removal of CO and NO according to claim 1 x The method for preparing a catalyst is characterized in that The reaction temperature used in the first reaction treatment is 150-200° C., and the reaction time is 8-36 hours.

5. The synergistic catalytic removal of CO and NO according to claim 1 x The method for preparing a catalyst is characterized in that Before the first drying process, the carbon three-dimensional network structure is subjected to washing and filtering processes in sequence.

6. The synergistic catalytic removal of CO and NO according to claim 1 x The method for preparing a catalyst is characterized in that The drying temperature used in the first drying treatment is 100-140° C., and the drying time is 3-5 hours; the baking temperature used in the first calcination treatment is 450-550° C., and the baking time is 2-4 hours; the inert atmosphere includes a nitrogen atmosphere.

7. The synergistic catalytic removal of CO and NO according to claim 1 x The method for preparing a catalyst is characterized in that The second drying treatment adopts a drying temperature of 100-140° C. and a drying time of 3-5 hours; the second calcination treatment adopts a calcination temperature of 250-350° C. and a calcination time of 2-4 hours, and the calcination atmosphere is air atmosphere.

8. The synergistic catalytic removal of CO and NO according to claim 1 x The method for preparing a catalyst is characterized in that The heating temperature used in the heating and stirring treatment is 80-95° C., and the stirring speed used is 80-120 rpm.

9. A synergistic catalytic removal of CO and NO x The catalyst is characterized in that The synergistic catalytic removal of CO and NO by any one of claims 1 to 8 x The catalyst is prepared by the method for preparing the catalyst.

10. The synergistic catalytic removal of CO and NO according to claim 9 x The use of a catalyst, characterized in that The catalyst has a catalytic temperature of 220°C and a x The synergistic catalytic removal rate reached more than 90%.

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