CN113813956A - Anti-poisoning modified layered catalyst and preparation method thereof - Google Patents

Anti-poisoning modified layered catalyst and preparation method thereof Download PDF

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CN113813956A
CN113813956A CN202111269372.0A CN202111269372A CN113813956A CN 113813956 A CN113813956 A CN 113813956A CN 202111269372 A CN202111269372 A CN 202111269372A CN 113813956 A CN113813956 A CN 113813956A
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vocs
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丁龙
龙红明
钱立新
徐辉
顾明言
魏进超
陈萍
王光应
杨本涛
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Anhui University of Technology AHUT
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Abstract

The invention discloses an anti-poisoning modified layered catalyst and a preparation method thereof, and relates to the technical field of catalysts2、H2O, alkali metal poisoning property.

Description

Anti-poisoning modified layered catalyst and preparation method thereof
Technical Field
The invention belongs to the technical field of catalysts, and particularly relates to an anti-poisoning modified layered catalyst and a preparation method thereof.
Background
The perovskite type composite oxide is a catalyst type with excellent treatment effect on flue gas containing organic pollutants (VOCs), dioxin (PCDD/Fs) and CO, the pollutants have certain reducibility, and the perovskite type composite oxide can be efficiently catalyzed, combusted and degraded. But the general flue gas contains a large amount of SO2、H2O and alkali metals (potassium, sodium) and the like, and the perovskite type composite oxide is easily affected by the substances to cause poisoning, thereby losing the degradation activity. How to improve the water resistance, sulfur resistance and alkali metal resistance of the perovskite type composite oxide becomes a limiting factor of the application of the perovskite type catalyst.
At present, aiming at the anti-poisoning research of the catalyst, the method mainly aims at adjusting the adding proportion of each element in the catalyst in the preparation process of the catalyst, changing the preparation method and adding Sr, Zr and other elements to improve the anti-poisoning performance of the catalyst. Although the modes can improve the anti-poisoning performance of the catalyst, the active site of the prepared catalyst is still exposed in smoke, and the anti-poisoning performance can hardly meet the requirement of actual production.
The applicant prepares the perovskite type metal oxide catalyst by adopting lanthanum nitrate, strontium nitrate and manganese nitrate according to a preparation method of a sulfur-resistant perovskite type catalyst proposed by Shenliuqian (research on activity, toxicity resistance and stability of the perovskite type catalyst for catalyzing and burning VOCs), and respectively takes toluene (VOCs substitute), chlorobenzene (PCDD/Fs substitute) and CO as pollutants (toluene concentration is 500 mg/m)3Chlorobenzene concentration 500mg/m3CO concentration 1000mg/m3) The total air flow is 280ml/min, and the air speed ratio is 42000h-1，O2Content 16%, N2The degradation efficiency of the catalyst on VOCs, PCDD/Fs and CO is respectively tested under the laboratory condition of balance gas, and the catalyst is also tested when the catalyst is loaded with 1% of mass fraction K2The degradation characteristics of the O-containing catalyst on the pollutants are tested, and the sulfur resistance (SO in mixed gas) of the 300 ℃ catalyst is also tested2The concentration is 100mg/m3) Water-resistant (H in mixed gas)2O volume fraction 10%) performance. The results of the experiment are shown in table 1. (mode of Activity parameter detection in the following description of the embodiments)
TABLE 1
Figure BDA0003327586420000011
Figure BDA0003327586420000021
From the above results, it is clear that the catalysts known in the literature are specific to poisoning substances such as SO2Resistant to SO2The activity of the product is still more than 80% after 4.5H, but other toxic substances such as H2O、K2O, etc., and the resistance is poor, and the catalyst activity is seriously lowered under the influence of these poisoning substances. The method of only adopting simple element addition can improve a certain anti-poisoning performance of the catalyst, but has great disadvantages. Therefore, it is necessary to prepare a catalyst with high poisoning resistance by other means on the basis of ensuring the activity of the catalyst.
The applicant has tried to coat the active component in the catalyst, but found that the coating improves the anti-toxicity performance, but limits the contact between the catalytically active component and the pollutant to some extent, and limits the catalytic effect.
Disclosure of Invention
Aiming at the technical problem that the catalytic effect of the prepared coated catalyst is limited, the layered perovskite catalyst compounding method and the composite catalyst are provided, and the technical problem is favorably improved by setting oxygen storage components in the coating layer.
In order to solve the problems, the technical scheme adopted by the invention is as follows:
the anti-poisoning modified layered catalyst comprises a catalyst core and a coating layer, wherein the coating layer is coated outside the catalyst core, the catalyst core comprises a catalytic active component, the coating layer contains an oxygen storage component, and the oxygen storage component is used for being combined with oxygen; the catalyst and O are mixed by the oxygen storage component with good oxygen storage and carrying capacity2The contact position of the O capture, the wrapping layer and the core can be connected through oxygen storage components, and the captured O of the wrapping layer can be transferred through the oxygen storage components, SO that sufficient O is provided for catalytic oxidation reaction on the catalyst core, oxidation is promoted, the phenomenon that the O cannot be timely supplemented due to limited gas diffusion of the particle core is avoided, and good SO resistance is achieved2、H2O, alkali metal poisoning property.
Preferably, the element of the oxygen storage component comprises Ce, the coating layer and the core can be connected through a Ce-O-Ce structure, and O captured by the coating layer can be transferred through the Ce-O-Ce structure, so that the coating layer is CeMnO3The catalytic oxidation reaction can provide sufficient O to promote oxidation, and avoid the phenomenon that the O can not be supplemented in time due to limited gas diffusion of the particle core.
Preferably, pores are formed in the coating layer, through which catalytically active components in the catalyst core are communicated to the outside of the catalyst particles.
Preferably, the oxygen storage component is distributed in the pores, and during the use of the catalyst, pollutants in the flue gas need to pass through the coating layer with the pores on the outer layer before reaching the catalyst core with the catalytically active component, and in the pores, such as SO2、H2Substances such as O, alkali metals and the like which easily cause the catalyst to be poisoned and deactivated can be absorbed, and the contact of the catalytic active ingredients and the smoke is facilitated.
Preferably, the coating layer comprises titanium-containing oxide and silicon-containing oxide, and the pores are formed between titanium-containing oxide grains and silicon-containing oxide grains;by using TiO2With SiO2Phase transition law, TiO at 620 deg.C2Crystal shrinkage and SiO2The crystal expands, gaps appear among the composite metal oxide crystal grains, and a large number of gaps are communicated to form complex reticular pores.
Preferably, Ce of the oxygen storage component is embedded in TiO2、SiO2Forming solid solutions in the crystal lattice; or is directly connected with Ti and Si atoms, Ce is uniformly dispersed in the coating layer and can be better contacted with reaction gas, and the good oxygen storage and carrying capacity of Ce is utilized, so that the catalyst and O are mixed2O capture of contact location.
Preferably, the outer surface layer of the catalyst core contains a graphene oxide component; the chemical structure of graphene oxide is six-membered ring structure (-C)6H6) Carboxyl (-COOH), hydroxyl (-OH), other oxygen-containing groups and the like, and the structures can form pi-pi bonds, hydrogen bonds and other acting forces with VOCs and dioxins, so that the adsorption effect of the core particles on pollutants is enhanced.
The layered catalyst is prepared to obtain a catalyst core containing a catalytic active component, then the catalyst core is placed in a system containing an oxygen storage component for roasting, and the catalyst core is dried and ground to obtain the layered granular catalyst.
Preferably, dissolving ethyl orthosilicate and tetrabutyl titanate in absolute ethyl alcohol to obtain a solution A, and adding the catalyst core into the solution A and uniformly stirring; dissolving cerium nitrate in an acetic acid solution to obtain a solution B, then dripping the solution B into the solution A containing the catalyst core, stirring while dripping, standing to form gel after dripping, drying in an oven, grinding, and roasting the ground powder to obtain the layered catalyst.
Preferably, after the catalyst core is prepared, the catalyst core is mixed with graphene oxide powder and milled.
Drawings
FIG. 1 is a schematic view of the structure of an anti-poisoning modified layered catalyst according to the present invention.
Fig. 2 is a schematic structural diagram of the poisoning-resistant modified layered catalyst containing graphene oxide.
Description of reference numerals:
100. catalyst particles; 110. a catalyst core; 111. a catalytically active component; 112. graphene oxide;
120. a coating layer; 121. an oxygen storage component; 122. a pore; 123. a titanium-containing oxide; 124. a silicon-containing oxide.
Detailed Description
For a further understanding of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings and examples.
The structure, proportion, size and the like shown in the drawings are only used for matching with the content disclosed in the specification, so that the person skilled in the art can understand and read the description, and the description is not used for limiting the limit condition of the implementation of the invention, so the method has no technical essence, and any structural modification, proportion relation change or size adjustment still falls within the scope of the technical content disclosed by the invention without affecting the effect and the achievable purpose of the invention. Meanwhile, the terms such as "upper", "lower", "left", "right" and "middle" used in the present specification are for clarity of description only, and are not used to limit the implementable scope, and the relative relationship changes or adjustments may be considered to be within the implementable scope of the present invention without substantial technical changes; in addition, the embodiments of the present invention are not independent of each other, but may be combined.
The poisoning-resistant modified layered catalyst comprises a catalyst core 110 and a coating layer 120, wherein the coating layer 120 is coated outside the catalyst core 110, the catalyst core 110 comprises a catalytic active component 111, the coating layer 120 contains an oxygen storage component 121, and the oxygen storage component 121 is used for being combined with oxygen. The element of the oxygen storage component 121 may include Ce, the cladding and the core may be connected by a Ce-O-Ce structure, and O captured by the cladding may be transferred by the Ce-O-Ce structure, thereby being cefno3The catalytic oxidation reaction can provide sufficient O to promote oxidation, and avoid the phenomenon that the O can not be supplemented in time due to limited gas diffusion of the particle core.
In addition, pores 122 are formed in the coating layer 120, and the catalytically active components 111 in the catalyst core 110 are communicated to the outside of the catalyst particle 100 through the pores 122. The oxygen storage elements 121 may be distributed in the pores 122 to facilitate contact of the catalytically active elements 111 with the flue gas. Specifically, the pores 122 are formed between the titanium-containing oxide 123 and the silicon-containing oxide 124 grains; by using TiO2With SiO2Phase transition law, TiO at 620 deg.C2Crystal shrinkage and SiO2The crystal expands, gaps appear among the composite metal oxide crystal grains, and a large number of gaps are communicated to form complex reticular pores.
The Ce of the oxygen storage component 121 may be intercalated into TiO2、SiO2Forming solid solutions in the crystal lattice; or is directly connected with Ti and Si atoms, Ce is uniformly dispersed in the coating layer and can be better contacted with reaction gas, and the good oxygen storage and carrying capacity of Ce is utilized, so that the catalyst and O are mixed2O capture of contact location.
In addition, the outer surface layer of the catalyst core 110 contains a graphene oxide component; the chemical structure of graphene oxide is six-membered ring structure (-C)6H6) Carboxyl (-COOH), hydroxyl (-OH), other oxygen-containing groups and the like, and the structures can form pi-pi bonds, hydrogen bonds and other acting forces with VOCs and dioxins, so that the adsorption effect of the core particles on pollutants is enhanced.
The layered catalyst is the layered catalyst, the catalyst core 110 containing the catalytic active component 111 is prepared, then the catalyst core 110 is placed in a system containing the oxygen storage component 121 to be roasted, dried and ground to prepare the layered granular catalyst.
In the specific steps, tetraethoxysilane and tetrabutyl titanate are dissolved in absolute ethyl alcohol to obtain a solution A, and the catalyst core 110 is added into the solution A and stirred uniformly; dissolving cerium nitrate in an acetic acid solution to obtain a solution B, then dripping the solution B into the solution A containing the catalyst core 110, stirring while dripping, standing to form a gel after dripping, drying in an oven, grinding, and roasting the ground powder to obtain the layered catalyst.
After preparing the catalyst core 110, the catalyst core 110 is mixed with graphene oxide powder and ground.
For the specific preparation process, the preparation process comprises the following steps:
(1) preparation of perovskite-type composite oxide catalyst core 110
Dissolving cerium-containing salt, manganese-containing salt and citric acid in water, stirring after dissolving, using the dissolved citric acid as a complexing agent to react with metal ions to generate a soluble complex, continuously losing water in the stirring process, converting the soluble complex solution into colloid, stirring into colloid, drying, grinding, and roasting to obtain the perovskite type composite oxide catalyst core 110.
In addition, the cerium-containing salt and the manganese-containing salt are respectively cerium nitrate and manganese acetate; the molar ratio of Ce to Mn in the added cerium nitrate and manganese acetate is 1 (0.9-1.1); the mole number of the citric acid is 1.5-2 times of that of the metal salt, wherein the mole number of the cerium nitrate and the manganese acetate refers to the total mole number of cerium atoms and manganese atoms, the citric acid is a complexing agent of metal ions, if the amount of the citric acid is too small, the metal salt is precipitated, the metal ions cannot be uniformly dispersed, and the uniformity of the catalyst is influenced; if the citric acid is too much, the xerogel is excessive, and the crystal growth of the metal oxide is not facilitated.
In addition, the mass of the deionized water can be 10-15 times of the total amount of the solid, and the solid comprises cerium-containing salt, manganese-containing salt and citric acid; the particle size of the catalyst core 110 obtained by grinding is not more than 400 meshes, when roasting is carried out, the roasting atmosphere is air, the temperature rising speed is 10 ℃/min in the process of from room temperature to 300 +/-10 ℃, after the temperature of 300 +/-10 ℃ is preserved for 0.8 h-1.2 h, the temperature is raised to 1000 +/-20 ℃ at the temperature rising speed of 2 ℃/min, the temperature is preserved for 1.8 h-2.2 h, and furnace cooling is carried out after the temperature preservation is finished;
the obtained powder was mixed with graphene oxide powder, and then ground to modify the powder.
(2) Preparation of the coating layer 120
Dissolving ethyl orthosilicate and tetrabutyl titanate in an organic solvent to form a coating layer 120 mixed solution, adding the catalyst core 110 prepared in the step (1) into the coating layer 120 mixed solution, stirring, and standing to form a gel state to form a catalyst precursor; preparing ethyl orthosilicate and tetrabutyl titanate according to a molar ratio of 1 (8-10); and/or the organic solvent is absolute ethyl alcohol, and the added mass of the absolute ethyl alcohol is 0.8-1.2 times of the sum of the volumes of the ethyl orthosilicate and the tetrabutyl titanate; and/or acetic acid is 0.1-0.15 times of the volume of the absolute ethyl alcohol; adding acetic acid in the process of dissolving ethyl orthosilicate and tetrabutyl titanate in an organic solvent; and/or the volume of the acetic acid is 0.1-0.15 times of that of the organic solvent.
(3) Preparation of the composite catalyst
And (3) drying the catalyst precursor in the step (2), grinding the dried catalyst precursor into powder, and roasting the powder to prepare the composite catalyst, wherein in the roasting process, the temperature is increased at the temperature rise speed of 10 ℃/min, the roasting temperature is 620-650 ℃, and the roasting time is 2-2.5 h.
Example 1
The specific parameters of the poisoning-resistant modified layered catalyst of the embodiment are embodied in the preparation process, and the preparation process is as follows:
step one, preparing perovskite type composite oxide powder.
(1) Preparing a powder precursor: weighing 0.1mol of cerium nitrate, 0.1mol of manganese acetate and 0.15mol of citric acid, dissolving in 1000ml of deionized water, stirring at the speed of 250r/min at 90 ℃ after completely dissolving, stirring for 4 hours to obtain a mixture which is a ready-made colloid, drying in a drying oven at 105 ℃ for 24 hours to obtain a dried precursor, and grinding the dried precursor powder to obtain precursor powder below 400 meshes;
(2) precursor roasting: roasting the precursor powder in a muffle furnace, heating to 300 ℃ at a heating rate of 10 ℃/min under the air atmosphere, preserving heat for 1h, then heating to 1000 ℃ at a heating rate of 2 ℃/min, preserving heat for 2h, and cooling a sample to room temperature along with the furnace after heat preservation is finished;
(3) powder preparation: grinding the powder obtained by roasting to obtain particles (400 meshes) with the size of less than 37 microns;
(4) powder modification: mixing the obtained powder with graphene oxide powder according to a mass ratio of 100: 1, mixing and grinding for 2 hours;
and step two, preparing the layered spherical particle perovskite type catalyst.
(1) Preparing a mixed solution A: dissolving 0.1mol of ethyl orthosilicate and 0.8mol of tetrabutyl titanate in 100ml of absolute ethyl alcohol, adding 15ml of acetic acid to inhibit hydrolysis, adding 55g of the modified powder prepared in the step one into the solution A, and uniformly stirring the components of the solution A by adopting 100HZ ultrasonic oscillation and 250r/min electromagnetic stirring, wherein the treatment time is 30 min;
(2) preparing a mixed solution B: dissolving 55g of cerium nitrate in 25g of acetic acid solution with the concentration of 0.05mol/L to obtain solution B;
(3) preparing a catalyst precursor: adding the solution B into the solution A containing the catalyst core (110) at a dropping speed of 10ml/min, stirring at a stirring speed of 100r/min while dropping, standing for 10h after dropping to obtain colloidal liquid, drying in an oven at 60 ℃ for 12h, and grinding the dried colloid to obtain 250-425-micron catalyst precursor particles;
(4) roasting the catalyst: roasting the dried catalyst precursor in a nitrogen protective atmosphere at the heating rate of 10 ℃/min, the roasting temperature of 620 ℃ and the roasting time of 2h to finally obtain the layered spherical particle perovskite catalyst;
step three: catalyst activity detection
A plurality of gas paths are adopted to prepare mixed gas, and the pollutant degradation performance of the catalyst is tested in a temperature programmed furnace. The main process is as follows: the catalyst is placed in a quartz tube with the inner diameter of 5mm, the quartz tube filled with the catalyst is placed in a temperature programmed heating furnace, mixed gas is introduced into the quartz tube, and gas components are detected at a gas inlet and a gas outlet of the quartz tube respectively. The CO content is detected by an ECOM electrochemical flue gas analyzer, and the contents of toluene (VOCs substitute) and chlorobenzene (PCDD/Fs substitute) are detected by hydrogen ion flame chromatography.
Catalyst catalyzed CO activity detectionWhen the gas distribution component is CO, 1000mg/m3，O216% of balance gas N2. The catalyst loading is 0.5g, the gas flow rate is 280ml/min, and the air speed ratio is 42000h-1。
When the catalyst is used for catalyzing the activity detection of toluene (VOCs substitutes), the gas distribution component is toluene which is 500mg/m3，O216% of balance gas N2. The catalyst loading is 0.5g, the gas flow rate is 280ml/min, and the air speed ratio is 42000h-1。
When the catalyst is used for catalyzing the activity detection of chlorobenzene (PCDD/Fs substitute), the gas distribution component is toluene which is 500mg/m3，O216% of balance gas N2. The catalyst loading is 0.5g, the gas flow rate is 280ml/min, and the air speed ratio is 42000h-1。
The catalyst activity test temperature is controlled by adopting temperature programming. The temperature range is 100-300 ℃, the temperature difference of the stages is 25 ℃, the heating rate is 10 ℃/min, and after the temperature reaction of each stage is stable for 15min, the tail gas components are detected. The catalyst activity calculation formula is calculated as follows:
Figure BDA0003327586420000071
wherein [ pollutant ]]oUtIndicates the concentration of the pollutant in the mixed gas after the reaction, [ pollutant ]]inIndicating the mixed gas contaminant concentration prior to reaction.
Step four: catalyst sulfur poisoning resistance detection
When the sulfur resistance of the catalyst is tested, 100mg/m of active detection gas is added3SO of (A)2And controlling the reaction temperature at 200 ℃, detecting the gas components once every 0.5h, continuously testing for 4.5h, and carrying out the catalyst activity calculation method in the same step three.
Step five: catalyst anti-water poisoning detection
When the catalyst is used for water resistance test, H with the volume fraction of 10 percent is added into activity detection gas2O, controlling the reaction temperature at 200 ℃, detecting the gas components once every 0.5h, continuously testing for 4.5h, and obtaining the catalystThe activity calculation method is the same as the third step.
Step six: catalyst anti-alkalosis detection
During the test of the catalyst for resisting alkali poisoning, potassium nitrate is dissolved in deionized water, the potassium nitrate is converted into potassium oxide, and the mass ratio of the potassium oxide to the catalyst is 1: 100, adding the catalyst into the solution, heating and stirring the catalyst at 80 ℃, and roasting the potassium nitrate-loaded catalyst for 4 hours at 400 ℃ in air after the liquid is stirred to be dry to obtain the potassium poisoning catalyst. And (5) detecting the activity of the poisoned catalyst in the same way as the third step. The results are reported in table 2.
TABLE 2
Figure BDA0003327586420000072
Figure BDA0003327586420000081
Comparative example 1
This comparative example is used as a reference experiment, and the experimental procedure of this comparative example is the same as that of example 1 except that: the powder modification (4) in step one was not used, and all the steps of step two were not used. The results are reported in Table 3 as the basis for the later experiments.
TABLE 3
Figure BDA0003327586420000082
Figure BDA0003327586420000091
Comparative example 2
The experimental procedure of this comparative example was the same as example 1 except that: the powder modification of the step (4) in the step one is not adopted, and cerium nitrate is not added in the preparation of the mixed solution B of the step (2) in the step two. The results are reported in table 4.
TABLE 4
Figure BDA0003327586420000092
Comparative example 3
The experimental procedure of this comparative example was the same as example 1 except that: the modified powder prepared in the first step is not adopted, and the modified powder is not added in the preparation of the mixed solution A in the second step (1). The results are reported in table 5.
TABLE 5
Figure BDA0003327586420000093
Figure BDA0003327586420000101
Comparative example 4
The experimental procedure of this comparative example was the same as example 1 except that: in step one, the powder is not modified. The results are reported in table 6.
TABLE 6
Figure BDA0003327586420000102
Figure BDA0003327586420000111
Comparative example 5
The experimental procedure of this comparative example was the same as example 1 except that: and in the second step, cerium nitrate is not added for modification during preparation of the mixed solution B in the step (2). The results are reported in table 7.
TABLE 7
Figure BDA0003327586420000112
Comparative example 6
The experimental procedure of this comparative example was the same as example 1 except that: in the step two, when the mixed solution A is prepared in the step (1), tetrabutyl titanate is replaced by equal amount of ethyl orthosilicate. The results are reported in Table 8.
TABLE 8
Figure BDA0003327586420000113
Figure BDA0003327586420000121
Comparative example 7
The experimental procedure of this comparative example was the same as example 1 except that: in the step two, when the mixed solution A is prepared in the step (1), the ethyl orthosilicate is replaced by tetrabutyl titanate with the same quantity. The results are reported in Table 9.
TABLE 9
Figure BDA0003327586420000122
Figure BDA0003327586420000131
By performing comparative analysis on the experimental data, the following conclusions can be obtained:
(1) through the experiments of the example 1 and the comparative example 1, the basic activities of VOCs, PCDD/Fs and CO of the example 1 are all 100% at 175 ℃, and the basic activities of VOCs, PCDD/Fs and CO of the comparative example 1 are all 100% at 175 ℃; catalyst in K2After O poisoning, the degradation activities of VOCs, PCDD/Fs and CO at 175 ℃ in example 1 are 95%, 95% and 100%, while the degradation activities of VOCs, PCDD/Fs and CO in comparative example 1 are 50%, 42% and 65%; in a water-resistant experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 95, 99 and 100 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in comparative example 1 is 62, 63 and 72 percent; in the sulfur resistance test, in example 1, at 4.5h, the VOCs and the PCDD-The Fs and CO activities are 98, 96 and 96 percent, while the corresponding activities of the VOCs, PCDD/Fs and CO in the comparative example 1 are 45 percent, 38 percent and 45 percent; it can thus be seen that the core particles prepared by the present invention have good activity but poor resistance to poisoning.
(2) Through experiments of example 1 and comparative example 2, it can be found that basic activities of VOCs, PCDD/Fs and CO of example 1 are all 100% at 175 ℃, and basic activities of VOCs, PCDD/Fs and CO of comparative example 2 are 85%, 86% and 100% at 175 ℃; catalyst in K2After O poisoning, the VOCs, PCDD/Fs and CO degrading activities of example 1 at 175 ℃ are 95%, 95% and 100%, while the VOCs, PCDD/Fs and CO degrading activities of comparative example 2 are 80%, 85% and 100%; in a water-resistant experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 95, 99 and 100 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in comparative example 2 is 95, 91 and 100 percent; in the sulfur resistance experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 98, 96 and 96 percent at 4.5h, while the activity of VOCs, PCDD/Fs and CO in comparative example 2 is 85 percent, 85 percent and 100 percent; therefore, no graphene oxide exists on the surface of the core particles of the catalyst, and no CeO exists in the wrapping layer2The activity of the catalyst towards contaminants is reduced.
(3) Through experiments of example 1 and comparative example 3, it can be found that basic activities of VOCs, PCDD/Fs and CO of example 1 are all 100% at 175 ℃, and basic activities of VOCs, PCDD/Fs and CO of comparative example 3 are 25%, 15% and 30% at 175 ℃; catalyst in K2After O poisoning, the degradation activities of VOCs, PCDD/Fs and CO at 175 ℃ in example 1 are 95%, 95% and 100%, while the degradation activities of VOCs, PCDD/Fs and CO in comparative example 3 are 20%, 18% and 28%; in a water-resistant experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 95, 99 and 100 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in comparative example 3 is 50, 35 and 48 percent; in the sulfur resistance test, the activity of VOCs, PCDD/Fs and CO in example 1 is 98, 96 and 96 percent at 4.5h, while the activity of VOCs, PCDD/Fs and CO in comparative example 3 is 40, 30 and 43 percent; therefore, the catalyst does not contain core particles and graphene oxide, and the activity of the catalyst is obviously reduced.
(4) Through the experiments of example 1 and comparative example 4, it can be found that the basic activities of VOCs, PCDD/Fs and CO of example 1 are respectively 80%, 85% and 100% at 150 ℃, and the basic activities of VOCs, PCDD/Fs and CO of comparative example 4 are respectively 78%, 80% and 100% at 150 ℃; catalyst in K2After O poisoning, the VOCs, PCDD/Fs and CO degrading activities of example 1 at 150 ℃ are 80%, 82% and 95%, while the VOCs, PCDD/Fs and CO degrading activities of comparative example 4 are 76%, 78% and 100%; in a water-resistant experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 98%, 96% and 96% at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in comparative example 4 is 95%, 91% and 100%; in the sulfur resistance experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 98, 96 and 96 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in comparative example 4 is 92, 90 and 100 percent; therefore, graphene oxide is not contained in the catalyst, and the basic activity of the catalyst on VOCs and PCDD/Fs is reduced.
(5) Through experiments of example 1 and comparative example 5, the basic activities of VOCs, PCDD/Fs and CO of example 1 are all 100% at 175 ℃, and the basic activities of VOCs, PCDD/Fs and CO of comparative example 5 are 85%, 86% and 90% at 175 ℃; catalyst in K2After O poisoning, the VOCs, PCDD/Fs and CO degrading activities of example 1 at 175 ℃ are 95%, 95% and 100%, while the VOCs, PCDD/Fs and CO degrading activities of comparative example 5 are 82%, 83% and 90%; in a water-resistant experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 95, 99 and 100 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in comparative example 5 is 96 percent, 96 percent and 96 percent; in the sulfur resistance experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 98, 96 and 96 percent at 4.5h, while the activity of VOCs, PCDD/Fs and CO in comparative example 5 is 98, 98 and 100 percent; it can be seen that no CeO is added to the catalyst coating2The basic activity of the catalyst is greatly reduced.
(6) It can be found through experiments of example 1 and comparative example 6 that at 175 deg.C, the basic activities of VOCs, PCDD/Fs and CO of example 1 are all 100%, and at 175 deg.C, the basic activities of VOCs, PCDD/Fs and CO of comparative example 6 are all 100%Respectively 95%, 96% and 100%; catalyst in K2After O poisoning, the VOCs, PCDD/Fs and CO degrading activities of example 1 at 175 ℃ were 95%, 95% and 100%, while those of comparative example 6 were 95%, 95% and 100%; in a water-resistant experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 95, 99 and 100 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in comparative example 6 is 84, 84 and 84 percent; in the sulfur resistance experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 98, 96 and 96 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in comparative example 6 is 95, 91 and 100 percent; it can be seen that no TiO is added to the catalyst coating2The anti-activity is reduced, and the water resistance is obviously reduced.
(7) Through experiments of example 1 and comparative example 7, it can be found that at 175 ℃, the basic activities of VOCs, PCDD/Fs and CO of example 1 are all 100%, and at 175 ℃, the basic activities of VOCs, PCDD/Fs and CO of comparative example 7 are all 100%; catalyst in K2After O poisoning, the VOCs, PCDD/Fs and CO degrading activities of example 1 at 175 ℃ were 95%, 95% and 100%, while the VOCs, PCDD/Fs and CO degrading activities of comparative example 7 were 55%, 60% and 80%; in a water-resistant experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 95, 99 and 100 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in comparative example 7 is 96, 96 and 100 percent; in the sulfur resistance experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 98, 96 and 96 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in comparative example 7 is 95, 95 and 100 percent; it can be seen that SiO was not added to the catalyst2The anti-alkali poisoning performance of the catalyst is greatly reduced.
The invention is prepared by mixing perovskite CeMnO3The composite oxide particles are used as the catalyst core, and the anti-poisoning substance is coated on the outer layer of the core, thereby avoiding CeMnO3Composite oxide and SO2、H2O、K2And due to direct contact of toxic substances such as O and the like, the prepared catalyst has good resistance to various toxic substances.
The invention leads the SiO coated outside to be coated by changing the thermodynamic condition2With TiO2A crystal transition takes place fromAnd a reticular structure is generated on the catalyst wrapping layer, so that pollutants in the flue gas have better contact with anti-poisoning substances, the pollutants are prevented from entering the inner core of the catalyst, and the anti-poisoning performance of the catalyst is improved. By thermodynamic calculation, externally wrapped SiO2At 573 ℃, a phase transition of beta quartz → alpha quartz occurs, and the process is SiO2Volume expansion occurs with an expansion rate of about 0.82%, while the outer coating of TiO2At 600 ℃ an anatase → rutile phase transition occurs, a process which TiO2The density of the crystal form is increased, the volume is shrunk, the two phase changes can occur simultaneously at the temperature adopted by the invention, and a complex reticular pore canal can be formed on the wrapping layer, which is beneficial to the contact of poisoning substances and anti-poisoning substances.
The invention passes through SiO in the wrapping layer2With TiO2Realize water resistance, sulfur resistance and alkali poisoning resistance. TiO 22With SiO2Hydroxylation easily occurs in the presence of water, and the Ti-O structure is converted into Ti-OH, the Si-O structure is converted into Si-OH, and in addition, TiO2The specific surface area is large, and the coating layer is easy to combine with water in gas, so that the coating layer structure has good water resistance, and-H in Ti-OH and Si-OH is easy to replace alkali metal, so that the Ti-OH and the Si-OH are converted into Ti-O-K and Si-O-K, wherein the Si-OH structure has strong capability of replacing alkali metal elements, and good alkali metal resistance can be realized. SiO22Belongs to acidic oxides, which are used for SO in mixed gas2Having a repulsive action, SO2Poor adsorption in the coating, H2O in the product during the catalytic reaction, hydroxylates Ti-O and Si-O with SO2Adsorption process, competitive relationship, repulsion at SiO2 and H2Under the competition effect of O, SO2 is difficult to enter the catalyst core and has better sulfur resistance on the macroscopic scale.
The invention enhances pollutant adsorption by enhancing chemical adsorption and physical adsorption. Perovskite type CeMnO3The composite oxide has small specific surface area and poor pollutant adsorption, and is prepared by perovskite CeMnO3Grinding the composite oxide particle core and the graphene oxide to ensure that the graphene oxide is tightly connected with the particle coreIn combination, the graphene oxide distributed on the surface of the particle core has large pi bonds, so that the chemical adsorption effect of the composite oxide core on organic pollutants VOCs and PCDD/Fs can be enhanced, and TiO is wrapped on the outer layer of the core2So that the specific surface area of the catalyst is greatly increased, and the pollutant adsorption is further improved.
The invention enhances the oxidation performance of the catalyst to pollutants through a surface active oxygen transfer channel. Catalytic oxidation of pollutants is a non-closed cyclic process requiring constant consumption of oxygen, CeMnO3The composite oxide can oxidize pollutants by consuming oxygen in crystal lattices or absorbing oxygen on the surfaces of the consumed crystals, but the gaseous oxygen in the gas flow is difficult to supplement the consumed oxygen for the composite oxide due to a certain wrapping effect on particle cores. In the invention through CeO2And an oxygen transfer channel is constructed, and the oxygen supply of the composite oxide is enhanced. CeO in the wrapping layer2And CeMnO3CeO in composite oxides2Can be connected with the O in the gas through a Ce-O-Ce structure2Can be fully contacted with O2Converted into surface adsorbed oxygen (O) with high activity2 2-、O-、O2-) Oxygen ions passing through CeO2The crystal lattice can be transferred to the CeMnO3 composite oxide core from the outside to participate in catalytic reaction, and oxygen ions introduced through the oxygen transfer channels have stronger reactivity.
Example 2
The experimental procedure of this comparative example was the same as example 1 except that: and (4) roasting the catalyst in the second step at the roasting temperature of 550 ℃. The results are reported in Table 10.
Watch 10
Figure BDA0003327586420000161
Example 3
The experimental procedure of this comparative example was the same as example 1 except that: and in the second step (4), when the catalyst is roasted, the roasting temperature is 590 ℃. The results are reported in Table 11.
TABLE 11
Figure BDA0003327586420000171
Example 4
The experimental procedure of this comparative example was the same as example 1 except that: and (4) roasting the catalyst in the second step at 800 ℃. The results are reported in table 12.
TABLE 12
Figure BDA0003327586420000172
Figure BDA0003327586420000181
Example 5
The experimental procedure of this comparative example was the same as example 1 except that: and in the step two, when the catalyst in the step (4) is roasted, the roasting time is 4 hours. The results are reported in Table 13.
Watch 13
Figure BDA0003327586420000182
Figure BDA0003327586420000191
Example 6
The experimental procedure of this example is the same as example 1, except that: in the second step (1), when the mixed solution A was prepared, the mass of the added modified powder was 25g, and the results of the experiment are shown in Table 14.
TABLE 14
Figure BDA0003327586420000192
Example 7
The experimental procedure of this example is the same as example 1, except that: in the second step (1), when the mixed solution A was prepared, the mass of the added modified powder was 100g, and the results of the experiment are shown in Table 15.
Watch 15
Figure BDA0003327586420000193
Figure BDA0003327586420000201
Example 8
The experimental procedure of this example is the same as example 1, except that: when the powder is prepared in the step (3), the powder particles are 200-300 meshes, and the experimental results are recorded in the table 16.
TABLE 16
Figure BDA0003327586420000202
Figure BDA0003327586420000211
(1) Through experiments of example 1 and example 2, it can be found that the basic activities of VOCs, PCDD/Fs and CO of example 1 are all 100% at 175 ℃, and the basic activities of VOCs, PCDD/Fs and CO of comparative example 7 are 84%, 85% and 88% at 175 ℃; catalyst in K2After O poisoning, the VOCs, PCDD/Fs and CO degrading activities of example 1 at 175 ℃ are 95%, 95% and 100%, while the VOCs, PCDD/Fs and CO degrading activities of comparative example 7 are 83%, 83% and 86%; in a water-resistant experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 95, 99 and 100 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in comparative example 7 is 92, 98 and 100 percent; in the sulfur resistance test, the activity of VOCs, PCDD/Fs and CO in example 1 was 92, 96 and 100% at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in comparative example 7 was 90% and 93%93%; it can be seen that the firing temperature is lower than SiO2With TiO2Crystal transformation temperature, SiO2Not expanded, TiO2The shrinkage is not generated, which is not beneficial to the formation of the pore channels of the wrapping layer and leads to the reduction of the activity of the catalyst.
(2) Through the experiments of example 1 and example 3, the basic activities of VOCs, PCDD/Fs and CO of example 1 are all 100% at 175 ℃, and the basic activities of VOCs, PCDD/Fs and CO of example 3 are respectively 88%, 88% and 89% at 175 ℃; catalyst in K2After O poisoning, the degradation activities of VOCs, PCDD/Fs and CO in example 1 are 95%, 95% and 100% at 175 ℃, while the degradation activities of VOCs, PCDD/Fs and CO in example 3 are 85%, 86% and 88%; in a water-resistant experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 95, 99 and 100 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in example 3 is 91, 90 and 95 percent; in the sulfur resistance experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 98, 96 and 96 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in example 3 is 90, 93 and 99 percent; it can be seen that the firing temperature is higher than SiO2Phase transition temperature lower than TiO2The phase transition temperature and the incomplete formation of the pore canal of the wrapping layer lead to the reduction of the activity of the catalyst.
(3) Through the experiments of example 1 and example 4, the basic activities of VOCs, PCDD/Fs and CO of example 1 are all 100% at 175 ℃, and the basic activities of VOCs, PCDD/Fs and CO of example 4 are all 100% at 175 ℃; catalyst in K2After O poisoning, the degradation activities of VOCs, PCDD/Fs and CO in example 1 are 95%, 95% and 100% at 175 ℃, while the degradation activities of VOCs, PCDD/Fs and CO in example 4 are 88%, 95% and 98%; in a water-resistant experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 95, 99 and 100 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in example 4 is 94, 93 and 95 percent; in the sulfur resistance experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 98, 96 and 96 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in example 4 is 85, 85 and 95 percent; it can be seen that the firing temperature exceeds SiO2Phase transition temperature and TiO2Phase transition temperature of about 200And C, the pore canal size of the coating layer is too large, so that the catalytic poisoning resistance is reduced.
(4) Through the experiments of example 1 and example 5, the basic activities of VOCs, PCDD/Fs and CO of example 1 are all 100% at 175 ℃, and the basic activities of VOCs, PCDD/Fs and CO of example 5 are all 100% at 175 ℃; catalyst in K2After O poisoning, the degrading activities of VOCs, PCDD/Fs and CO of example 1 at 175 ℃ are 95%, 95% and 100%, while the degrading activities of VOCs, PCDD/Fs and CO of example 5 are 95%, 96% and 96%; in a water-resistant experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 95, 99 and 100 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in example 5 is 92, 91 and 92 percent; in the sulfur resistance experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 98, 96 and 96 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in example 5 is 92, 91 and 92 percent; it can be seen that the calcination time is twice that of example 1, the crystal growth time of the wrapping layer is sufficient, and the sizes of the crystal pore channels are too large, so that the catalytic poisoning resistance is reduced.
(5) Through the experiments of example 1 and example 6, the basic activities of VOCs, PCDD/Fs and CO of example 1 are all 100% at 175 ℃, and the basic activities of VOCs, PCDD/Fs and CO of example 6 are 95%, 98% and 100% at 175 ℃; catalyst in K2After O poisoning, the degradation activities of VOCs, PCDD/Fs and CO in example 1 are 95%, 95% and 100% at 175 ℃, while the degradation activities of VOCs, PCDD/Fs and CO in example 6 are 93%, 96% and 100%; in a water-resistant experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 95, 99 and 100 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in example 6 is 95, 100 and 100 percent; in the sulfur resistance experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 98, 96 and 96 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in example 6 is 90, 90 and 95 percent; from this, it can be seen that when the amount of the core particles added was 50% of that of example 1, the catalyst activity was lowered.
(6) Through the experiments of example 1 and example 7, it can be found that the basic activities of VOCs, PCDD/Fs and CO of example 1 are all 100% at 175 ℃, and thatAt 175 ℃, the basic activities of VOCs, PCDD/Fs and CO in example 7 are all 100%; catalyst in K2After O poisoning, the degradation activities of VOCs, PCDD/Fs and CO in example 1 are 95%, 95% and 100% at 175 ℃, while the degradation activities of VOCs, PCDD/Fs and CO in example 7 are 89%, 92% and 98%; in a water-resistant experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 95, 99 and 100 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in example 7 is 89, 89 and 96 percent; in the sulfur resistance experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 98, 96 and 96 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in example 7 is 84, 85 and 91 percent; it can be seen that when the amount of the core particles added is 200% of that of example 1, the coating layer is thinner than the core particles, and the catalyst poisoning resistance is remarkably lowered.
(7) Through the experiments of example 1 and example 8, the basic activities of VOCs, PCDD/Fs and CO of example 1 are all 100% at 175 ℃, and the basic activities of VOCs, PCDD/Fs and CO of example 7 are all 100% at 175 ℃; catalyst in K2After O poisoning, the degradation activities of VOCs, PCDD/Fs and CO in example 1 are 95%, 95% and 100% at 175 ℃, while the degradation activities of VOCs, PCDD/Fs and CO in example 7 are 88%, 90% and 98%; in a water-resistant experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 95, 99 and 100 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in example 7 is 86, 86 and 96 percent; in the sulfur resistance experiment, the activity of VOCs, PCDD/Fs and CO in example 1 is 98, 96 and 96 percent at 4.5h, while the corresponding activity of VOCs, PCDD/Fs and CO in example 7 is 84, 85 and 91 percent; it can be seen that, when the size of the added amount of the core particles is between 200 and 300 meshes, the particle size is larger than that of the example 1, the coating layer is thinner than the core particles, and the anti-poisoning performance of the catalyst is obviously reduced.
More specifically, although exemplary embodiments of the invention have been described herein, the invention is not limited to these embodiments, but includes any and all embodiments modified, omitted, combined, e.g., between various embodiments, adapted and/or substituted, as would be recognized by those skilled in the art from the foregoing detailed description. The limitations in the claims are to be interpreted broadly based the language employed in the claims and not limited to examples described in the foregoing detailed description or during the prosecution of the application, which examples are to be construed as non-exclusive. Any steps recited in any method or process claims may be executed in any order and are not limited to the order presented in the claims. The scope of the invention should, therefore, be determined only by the appended claims and their legal equivalents, rather than by the descriptions and examples given above.

Claims (10)

1. An anti-poisoning modified layered catalyst is characterized by comprising a catalyst core (110) and a coating layer (120), wherein the coating layer (120) is coated outside the catalyst core (110), the catalyst core (110) comprises a catalytic active component (111), the coating layer (120) comprises an oxygen storage component (121), and the oxygen storage component (121) is used for combining with oxygen.
2. The poison-resistant modified layered catalyst as recited in claim 1 wherein the element of the oxygen storage component (121) includes Ce.
3. The poisoning-resistant modified layered catalyst according to claim 2, wherein pores (122) are formed in the coating layer (120), and the catalytically active component (111) in the catalyst core (110) is communicated to the outside of the catalyst particle (100) through the pores (122).
4. The poison-resistant modified layered catalyst of claim 3 wherein the oxygen storage component (121) is distributed at the pores (122).
5. The poisoning-resistant modified layered catalyst of claim 4, wherein the cladding layer (120) comprises a titanium-containing oxide (123) and a silicon-containing oxide (124), and the pores (122) are formed between grains of the titanium-containing oxide (123) and the silicon-containing oxide (124).
6. The poison-resistant modified layered catalyst as claimed in claim 5, wherein Ce of the oxygen storage component (121) is embedded in TiO2、SiO2Forming solid solutions in the crystal lattice; or directly connected with Ti and Si atoms.
7. The poison-resistant modified layered catalyst of claim 1 wherein the outer surface layer of the catalyst core (110) contains graphene oxide components.
8. A preparation method of an anti-poisoning modified layered catalyst is characterized in that the layered catalyst is the layered catalyst as claimed in any one of claims 1 to 7, a catalyst core (110) containing a catalytic active component (111) is prepared, then the catalyst core (110) is placed in a system containing an oxygen storage component (121) for roasting, and the layered granular catalyst is prepared after drying and grinding.
9. The method for preparing the poisoning-resistant modified layered catalyst as claimed in claim 8, wherein solution A is obtained by dissolving ethyl orthosilicate and tetrabutyl titanate in absolute ethyl alcohol, and the catalyst core (110) is added into solution A and stirred uniformly; dissolving cerium nitrate in an acetic acid solution to obtain a solution B, then dripping the solution B into the solution A containing the catalyst core (110), stirring while dripping, standing to form gel after dripping, drying in an oven, grinding, and roasting the ground powder to obtain the layered catalyst.
10. The method of claim 8, wherein the catalyst core (110) is prepared by mixing and grinding the catalyst core (110) with graphene oxide powder.
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104190409A (en) * 2014-08-19 2014-12-10 南京师范大学 Graphene-loaded titanium-based core-shell-structured low-temperature SCR sulfur-resisting catalyst and preparation method thereof
CN106824208A (en) * 2017-03-22 2017-06-13 中国人民大学 A kind of catalyst with core-casing structure for denitration demercuration decarburization simultaneously and preparation method thereof
CN106902823A (en) * 2017-03-22 2017-06-30 中国人民大学 A kind of core shell structure denitrating catalyst of the resistance to sulfur poisoning of chlorine-resistant and preparation method thereof
CN106964360A (en) * 2017-04-27 2017-07-21 山西大学 Low-temperature catalyzed decomposition N in one kind2O catalyst and preparation method and application
CN108212146A (en) * 2018-01-09 2018-06-29 上海大学 Nucleocapsid denitrating catalyst of metallic monoliths and preparation method thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104190409A (en) * 2014-08-19 2014-12-10 南京师范大学 Graphene-loaded titanium-based core-shell-structured low-temperature SCR sulfur-resisting catalyst and preparation method thereof
CN106824208A (en) * 2017-03-22 2017-06-13 中国人民大学 A kind of catalyst with core-casing structure for denitration demercuration decarburization simultaneously and preparation method thereof
CN106902823A (en) * 2017-03-22 2017-06-30 中国人民大学 A kind of core shell structure denitrating catalyst of the resistance to sulfur poisoning of chlorine-resistant and preparation method thereof
CN106964360A (en) * 2017-04-27 2017-07-21 山西大学 Low-temperature catalyzed decomposition N in one kind2O catalyst and preparation method and application
CN108212146A (en) * 2018-01-09 2018-06-29 上海大学 Nucleocapsid denitrating catalyst of metallic monoliths and preparation method thereof

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