CN114797841B - Mn (Mn) 4+ And Ce (Ce) 3+ Preparation method of enhanced Mn-M-Ti-O ultralow temperature denitration catalyst - Google Patents
Mn (Mn) 4+ And Ce (Ce) 3+ Preparation method of enhanced Mn-M-Ti-O ultralow temperature denitration catalyst Download PDFInfo
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- 239000003054 catalyst Substances 0.000 title claims abstract description 156
- 229910003077 Ti−O Inorganic materials 0.000 title claims abstract description 18
- 238000002360 preparation method Methods 0.000 title claims abstract description 15
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims abstract description 57
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 claims abstract description 35
- 230000009467 reduction Effects 0.000 claims abstract description 24
- 229910052684 Cerium Inorganic materials 0.000 claims abstract description 17
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 17
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 17
- 239000001301 oxygen Substances 0.000 claims abstract description 17
- 229910052688 Gadolinium Inorganic materials 0.000 claims abstract description 8
- 239000011148 porous material Substances 0.000 claims abstract description 7
- 239000012752 auxiliary agent Substances 0.000 claims abstract description 5
- 239000004480 active ingredient Substances 0.000 claims abstract description 4
- 239000002245 particle Substances 0.000 claims abstract description 4
- 229910010413 TiO 2 Inorganic materials 0.000 claims abstract description 3
- 239000011572 manganese Substances 0.000 claims description 51
- 239000000725 suspension Substances 0.000 claims description 44
- 238000003756 stirring Methods 0.000 claims description 43
- 239000007921 spray Substances 0.000 claims description 33
- 239000002002 slurry Substances 0.000 claims description 31
- 238000001354 calcination Methods 0.000 claims description 30
- 239000000243 solution Substances 0.000 claims description 30
- 230000003647 oxidation Effects 0.000 claims description 29
- 238000007254 oxidation reaction Methods 0.000 claims description 29
- 238000001035 drying Methods 0.000 claims description 25
- 239000007787 solid Substances 0.000 claims description 23
- MIVBAHRSNUNMPP-UHFFFAOYSA-N manganese(2+);dinitrate Chemical compound [Mn+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MIVBAHRSNUNMPP-UHFFFAOYSA-N 0.000 claims description 21
- 239000000463 material Substances 0.000 claims description 20
- 239000011259 mixed solution Substances 0.000 claims description 19
- 239000011268 mixed slurry Substances 0.000 claims description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 14
- 238000009423 ventilation Methods 0.000 claims description 12
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 claims description 11
- 239000012153 distilled water Substances 0.000 claims description 11
- 238000001704 evaporation Methods 0.000 claims description 11
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 10
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 10
- 238000010438 heat treatment Methods 0.000 claims description 10
- 229910052761 rare earth metal Inorganic materials 0.000 claims description 10
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 9
- 229910052748 manganese Inorganic materials 0.000 claims description 9
- 150000002910 rare earth metals Chemical class 0.000 claims description 9
- 230000001105 regulatory effect Effects 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 7
- 230000003197 catalytic effect Effects 0.000 claims description 6
- 230000001276 controlling effect Effects 0.000 claims description 4
- UIWYJDYFSGRHKR-UHFFFAOYSA-N gadolinium atom Chemical compound [Gd] UIWYJDYFSGRHKR-UHFFFAOYSA-N 0.000 claims description 4
- 229910052746 lanthanum Inorganic materials 0.000 claims description 4
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 claims description 4
- 238000005406 washing Methods 0.000 claims description 4
- 238000001914 filtration Methods 0.000 claims description 3
- 239000000843 powder Substances 0.000 claims description 3
- 238000011049 filling Methods 0.000 claims description 2
- 238000000227 grinding Methods 0.000 claims description 2
- 239000000203 mixture Substances 0.000 claims description 2
- 229910052723 transition metal Inorganic materials 0.000 claims description 2
- 230000001590 oxidative effect Effects 0.000 abstract description 2
- 238000009776 industrial production Methods 0.000 abstract 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 28
- HSJPMRKMPBAUAU-UHFFFAOYSA-N cerium(3+);trinitrate Chemical compound [Ce+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O HSJPMRKMPBAUAU-UHFFFAOYSA-N 0.000 description 24
- 238000006243 chemical reaction Methods 0.000 description 24
- 230000000694 effects Effects 0.000 description 19
- 150000002500 ions Chemical class 0.000 description 14
- 239000004408 titanium dioxide Substances 0.000 description 14
- 230000000052 comparative effect Effects 0.000 description 12
- HTBAHYGLEFPCLK-UHFFFAOYSA-N [Ti].[Ce].[Mn] Chemical compound [Ti].[Ce].[Mn] HTBAHYGLEFPCLK-UHFFFAOYSA-N 0.000 description 10
- 238000000498 ball milling Methods 0.000 description 8
- 230000000630 rising effect Effects 0.000 description 8
- 238000012512 characterization method Methods 0.000 description 7
- 238000005507 spraying Methods 0.000 description 7
- 230000009286 beneficial effect Effects 0.000 description 5
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 4
- 239000002028 Biomass Substances 0.000 description 3
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 229910001882 dioxygen Inorganic materials 0.000 description 3
- 230000001965 increasing effect Effects 0.000 description 3
- 230000033116 oxidation-reduction process Effects 0.000 description 3
- 238000005086 pumping Methods 0.000 description 3
- 238000001179 sorption measurement Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 230000002708 enhancing effect Effects 0.000 description 2
- MWFSXYMZCVAQCC-UHFFFAOYSA-N gadolinium(iii) nitrate Chemical compound [Gd+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O MWFSXYMZCVAQCC-UHFFFAOYSA-N 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- AMWRITDGCCNYAT-UHFFFAOYSA-L hydroxy(oxo)manganese;manganese Chemical compound [Mn].O[Mn]=O.O[Mn]=O AMWRITDGCCNYAT-UHFFFAOYSA-L 0.000 description 2
- -1 manganese gadolinium titanium Chemical compound 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 231100000572 poisoning Toxicity 0.000 description 2
- 230000000607 poisoning effect Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 206010021143 Hypoxia Diseases 0.000 description 1
- 239000002841 Lewis acid Substances 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 238000005273 aeration Methods 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000003546 flue gas Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000002779 inactivation Effects 0.000 description 1
- FYDKNKUEBJQCCN-UHFFFAOYSA-N lanthanum(3+);trinitrate Chemical compound [La+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O FYDKNKUEBJQCCN-UHFFFAOYSA-N 0.000 description 1
- 150000007517 lewis acids Chemical class 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 239000002574 poison Substances 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 238000010248 power generation Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000027756 respiratory electron transport chain Effects 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 229910000314 transition metal oxide Inorganic materials 0.000 description 1
- 238000004056 waste incineration Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/002—Mixed oxides other than spinels, e.g. perovskite
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/8621—Removing nitrogen compounds
- B01D53/8625—Nitrogen oxides
- B01D53/8628—Processes characterised by a specific catalyst
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
- B01J23/32—Manganese, technetium or rhenium
- B01J23/34—Manganese
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- B01J35/00—Catalysts, in general, characterised by their form or physical properties
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- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
- B01J35/61—Surface area
- B01J35/613—10-100 m2/g
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
- B01J35/64—Pore diameter
- B01J35/647—2-50 nm
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- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
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- B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
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Abstract
Mn (Mn) 4+ And Ce (Ce) 3+ Preparation method of enhanced Mn-M-Ti-O ultralow temperature denitration catalyst, wherein the Mn-M-Ti-O (M=Ce, la and Gd) ultralow temperature denitration catalyst is prepared from TiO 2 Loading denitration active ingredient and auxiliary agent on carrier and oxidizing Mn by ozone x+ Reduction of Ce by hydrogen peroxide 4+ Obtained. The catalyst obtained by the invention has proper specific surface area (70-90 m 2 /g), particle size uniformity (1-5 μm), surface Mn 4+ High ratio (47-50%), surface Ce 3+ The ratio is high (19-25%), the number of surface active oxygen species is large (45-50%), the average pore diameter is small (less than 13 nm), the hydrothermal stability is high, the low-temperature active temperature window is wide (125-400 ℃), the denitration performance is good, and the like, meets the requirements of the high-efficiency denitration SCR catalyst, and has the advantages of controllable product components, simple operation flow, low cost, good stability and easy realization of large-scale industrial production.
Description
Technical Field
The invention belongs to the technical field of environmental protection, in particular to Mn 4+ And Ce (Ce) 3+ A preparation method of an enhanced Mn-M-Ti-O ultralow temperature denitration catalyst.
Background
Coal-electric power units accounting for 60-70% of the total power generation amount nowadays are planned to be completely withdrawn in 2060, and solar energy, wind energy and biomass energy are dominant. The industries such as waste incineration, biomass energy and the like are the way of changing waste into valuables in the whole environment-friendly industry, but the generated flue gas has the characteristics of acid substances, low temperature and the like, the current domestic catalyst is difficult to meet the temperature requirement of ultralow temperature, the tail gas is required to be subjected to temperature rising treatment, so that the greenhouse effect is severe, various ultralow temperature catalysts are monopoly all the time by foreign countries, and therefore, the development of an ultralow temperature denitration catalyst with high efficiency and strong poisoning resistance is urgently needed.
In recent years it has been demonstrated in various studies that transition metal oxides are active for SCR reactions, in particular Mn-based oxide catalysts are widely investigated for low temperature NH due to their excellent catalytic properties 3 -SCR reaction. The method has the specific advantages that: the stability is outstanding, and the specific surface area is large. Manganese oxide easily forms an oxidation-reduction cycle, thus exhibiting good low-temperature SCR denitration performance. Mn has MnO and Mn 2 O 3 、Mn 3 O 4 、Mn 5 O 8 、 MnO 2 Five common valence states, mnO 2 The oxygen transfer capacity of (a) is better than that of the other (a), and the (b) has the best catalytic efficiency. But single MnO x Catalyst presence N 2 Poor selectivity, easy inactivation and the like. Therefore, the catalyst needs to be modified by doping other metal oxides so as to have higher redox capacity and acid sites, thereby having better SCR performance.
The rare earth metal elements (m=ce, la, gd) in the denitration catalyst mainly exist in the form of a cocatalyst, and mainly play the following roles: causing the surface electron unbalance of the catalyst, forming unsaturated chemical bonds and oxygen vacancies, increasing the concentration of oxygen adsorbed on the surface and improving the oxidation capability of the catalyst; in addition, more NH can be provided 3 Adsorption sites to increase the activity of the catalyst; at the same time, the heat stability of the sulfate can be reduced, and the decomposition of the sulfate can be promoted, thereby improvingHigh sulfur poisoning resistance of the catalyst. Mn and rare earth element are cooperated with Ce as an example:
1. at Ce 4+ With Ce 3+ Is subjected to redox displacement, thereby enhancing MnO x Low temperature activity of Ce 4+ /Ce 3+ The higher the ratio is, ce 4+ With Ce 3+ The stronger the oxygen storage and release in between, the higher the SCR activity.
2. Providing more NH 3 Adsorption sites Mn-Ce samples have higher reducibility and can provide more ammonia adsorption sites on Lewis acid sites.
3. Ce improves the stability of the Mn-based catalyst structure, so that the Mn-based catalyst has larger specific surface area.
To further increase Mn 4+ Thereby improving the oxidation-reduction performance of the catalyst, and the Mn-Ce catalyst adopts hydrogen peroxide to improve the catalyst surface Ce by adding an oxidant 3+ /(Ce 3+ +Ce 4+ ) Indicating that the concentration of surface oxygen vacancies can be increased after hydrogen peroxide modification. Meanwhile, the Ce species on the surface of the catalyst modified by the hydrogen peroxide is dispersed and enhanced, which is helpful for improving NH thereof 3 -SCR activity.
Therefore, the invention adopts the synergistic effect of rare earth metal and Mn base and modifies the catalyst in a novel oxidation-reduction form, develops the ultralow-temperature Mn base denitration catalyst, is expected to solve the problems of large specific surface area, narrow temperature window, few active oxygen species and the like, and realizes the ultralow emission in the field of garbage incineration and biomass energy.
Disclosure of Invention
The invention aims to synthesize Mn 4+ And Ce (Ce) 3+ Enhanced Mn-M-Ti-O (M=Ce, la, gd) ultra-low temperature denitration catalyst.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
mn (Mn) 4+ And Ce (Ce) 3+ Preparation method of enhanced Mn-M-Ti-O ultralow temperature denitration catalyst, wherein the denitration catalyst is prepared from TiO 2 Is used as a carrier to load denitration active ingredients and rare earth metal element auxiliary agents, and is subjected to ozone oxidation and hydrogen peroxide solutionRaw materials and calcination. Surface Mn of oxidized active component 4+ The proportion is improved, and the catalytic oxidation performance is enhanced; the reduction of hydrogen peroxide can promote Ce 4+ Reduction to Ce 3+ Increase the surface Ce of the active ingredient 3+ The proportion and the number of surface active oxygen species increase oxygen deficiency sites and promote electron transfer.
The active component is transition metal element manganese; the auxiliary agent is one of rare earth metal elements cerium, lanthanum and gadolinium, and is preferably cerium.
The specific surface area of the denitration catalyst is 70-90m 2 Per gram, particle size of 1-5 μm, surface Mn 4+ The proportion is 47-50%, the surface Ce 3+ The proportion is 19-25%, the number of surface active oxygen species is 45-50%, and the average pore diameter is less than 13nm; the denitration efficiency reaches more than 97 percent, and the catalytic activity temperature window is 125-400 ℃.
The method specifically comprises the following steps:
(1) Manganese nitrate solution and M (NO) 3 ) x Adding the solid into distilled water, stirring and dissolving to obtain a mixed solution; wherein M is Ce, la or Gd;
(2) TiO catalyst carrier 2 Adding the mixture into the mixed solution, and uniformly stirring to obtain mixed slurry;
(3) Regulating the pH value of the mixed slurry, and continuing stirring at normal temperature to obtain a suspension;
(4) Introducing ozone into the suspension while stirring by adopting a pneumatic stirrer to fully oxidize the suspension;
(5) After the filling is finished, dropwise adding hydrogen peroxide into the slurry after ozone oxidation;
(6) After stirring for a period of time, centrifugally washing for a plurality of times;
(7) Drying the catalyst after washing;
(8) Calcining the dried product at a programmed temperature;
(9) Grinding the calcined product into powder to obtain the material meeting the requirements.
The concentration of the manganese nitrate solution was 50wt%, manganese nitrate solution, M (NO 3 ) x Distilled water, tiO 2 The mass ratio of (5.94-6.31): (6.04-7.64): 100:3.53。
In the step (3), ammonia water with the concentration of 20-30wt% is adopted to adjust the pH value to 8-10.
In the step (4), the specific method of ozone oxidation is as follows: a pneumatic stirrer with a convex or concave propeller is adopted, a vent hole is arranged on a propeller shaft, the suspension is placed in the pneumatic stirrer, and ozone is introduced into the suspension through the vent hole while stirring; the rotating speed of the propeller is 10-15r/min, and the ozone ventilation is 500mL/min.
In the step (5), the specific method for dropwise adding hydrogen peroxide is as follows: the dropper is stretched into the bottom of the slurry, dioxygen water is added dropwise, and the dropping speed is controlled at 10 seconds/drop.
In the step (7), the drying method is a negative pressure drying method or a spray evaporation method: the negative pressure drying method is to form a negative pressure state by a vacuum pump, and dry the materials by a drying furnace, a heating chamber, stirring, driving, steam, filtering, condensing and other devices; the spray evaporation method is to pump the catalyst into a spray dryer, atomize the catalyst by a spray head and spray the catalyst from the bottom of the spray dryer.
In the step (8), the temperature programming rate is 10 ℃/min, the calcining temperature is 500-550 ℃, and the calcining time is 4 hours.
The beneficial effects of the invention are as follows:
the invention adopts Mn (NO 3 ) 2 And M (NO) 3 ) x( M=ce, la, gd), adjusting the pH value of the solution by ammonia water to obtain a mixed solution, carrying out ozone oxidation and hydrogen peroxide reduction, drying the solution by negative pressure drying or spray evaporation, and calcining and ball milling to obtain the material meeting the required granularity. The preparation method has the advantages of simple operation, simple and convenient equipment requirement and the like.
Mn prepared by the invention 4+ And Ce (Ce) 3+ In the enhanced Mn-M-Ti-O (M=Ce, la, gd) ultra-low Wen Tuoxiao catalyst, the mass fraction adjustment range of the manganese nitrate solution is 20-30%, and the mass fraction adjustment range of the cerium nitrate (lanthanum, gadolinium) is 20-30%. The composite powder has moderate specific surface area (70-90 m) 2 /g), particle size uniformity (1-5 μm), surface Mn 4+ High ratio (47-5)0%), surface Ce 3+ The ratio is high (19-25%), the number of surface active oxygen species is large (45-50%), the average pore diameter is small (less than 13 nm), the hydrothermal stability is high, the low-temperature active temperature window is wide (125-400 ℃), the denitration performance is good, and the like, thereby meeting the requirements of SCR catalyst carriers.
A great number of researches show that the rare earth metal elements such as cerium and the like can provide an acid site to ensure the catalytic activity of SCR, reduce the stability of sulfate, promote the decomposition of sulfate and promote the SO resistance of the catalyst 2 Ability to poison. In addition, rare earth metal elements such as cerium and the like can bring a large amount of lattice oxygen defects, and play a role in improving the oxygen storage capacity and enhancing the reducibility of the catalyst. Therefore, the addition of rare earth metal elements such as cerium can improve the stability of the catalyst structure, so that the catalyst has larger specific surface area and provides a large number of active centers for SCR reaction.
Detailed Description
The invention will be further illustrated by the following examples (in which the reagents used are chemically pure), it being noted that the following examples are given by way of illustration only and the invention is not limited thereto.
Example 1: preparing the MnCeTi-O ultralow-temperature denitration catalyst with the manganese content of 24 weight percent and the cerium content of 24 weight percent.
Step 1: 6.31g of a manganese nitrate solution and 7.64g of cerium nitrate solid were dissolved in 100g of distilled water, and stirred for 30 minutes to obtain a mixed solution.
Step 2: 3.53g of titanium dioxide serving as a catalyst carrier is added into the mixed solution obtained in the step 1, and stirring is continued for 1 hour, so as to obtain mixed slurry of manganese nitrate, cerium nitrate and titanium dioxide.
Step 3: and (3) slowly dropwise adding an ammonia water solution (with the concentration of 20-30 wt%) into the mixed slurry in the step (2), regulating the pH value of the solution to 10, and continuously stirring at normal temperature for half an hour to obtain the manganese-cerium-titanium suspension.
Step 4: a pneumatic stirrer with a convex or concave propeller is adopted, and a vent hole is arranged on the propeller; and (3) placing the stirred manganese-cerium-titanium suspension in a pneumatic stirrer, fully stirring the suspension by a screw, and simultaneously introducing ozone into the suspension through a vent hole to fully oxidize the suspension, wherein the rotating speed of the screw is 10-15r/min, and the ventilation volume is 500mL/min.
Step 5: and (3) dropwise adding hydrogen peroxide into the oxidized slurry, wherein the dropwise adding mode is to extend a dropper into the bottom of the slurry, and the dropwise adding speed is controlled at 10 seconds/drop.
Step 6: after stirring for a period of time, the slurry after oxidation and reduction is centrifugally washed for a plurality of times to obtain a more moist catalyst solid.
Step 7: and the obtained catalyst solid is subjected to a spray evaporation method (namely, the catalyst is pumped into a spray dryer and sprayed out from the bottom of the spray dryer after being atomized by a spray nozzle), the granularity of the introduced slurry is 10-20 mu m, the spraying temperature is controlled at 250-300 ℃, and the drying time is effectively reduced.
Step 8: and placing the obtained dry material into a muffle furnace for programmed heating and calcining. The calcination temperature is 550 ℃, the temperature rising speed is 10 ℃/min, and the calcination time is 4 hours.
Step 9: and (3) putting the calcined material into a ball mill for ball milling to obtain the MnCeTi-O ultralow-temperature denitration catalyst with the granularity of 1-5 mu m.
Comparative example 1
MnCeTi denitration catalyst was prepared as in example 1, except that the ozone oxidation and hydrogen peroxide reduction steps were omitted.
NH of MnCeTi-O ultralow temperature denitration catalyst 3 The SCR reaction activity is shown in Table 1, the denitration conversion rate of the catalyst is kept at 100% in the temperature range of 125-350 ℃, and the denitration conversion rate is always kept above 98% below 400 ℃, so that the catalyst has good denitration performance.
TABLE 1 characterization of Activity of MnCeTi-O ultra-low temperature denitration catalyst
The XPS ion species analogy of the denitration catalyst prepared in example 1 and comparative example 1 is shown in Table 2, and it is clear that Mn is reduced by ozone oxidation and hydrogen peroxide 4+ 、Ce 3+ Significant proportion of active oxygen speciesThe lifting is beneficial to low-temperature reduction.
TABLE 2 XPS ion species ratio of denitration catalyst
Programmed temperature reduction (H) of MnCeTi-O ultra-low temperature denitration catalyst 2 TPR) hydrogen consumption is shown in Table 3, it can be seen that the catalyst reduced by ozone oxidation and hydrogen peroxide gives MnO 2 CeO on surface 2 The increase in the area of the low-temperature reduction peak indicates that the oxidation of ozone leads to Mn 4+ Increase, hydrogen peroxide solution reduces to make Ce 3+ The increase is beneficial to low-temperature reduction.
TABLE 3 temperature programmed reduction (H) of MnCeTi-O ultra low temperature denitration catalyst 2 -TPR) hydrogen consumption
Example 2: preparing the MnCeTi-O ultralow-temperature denitration catalyst with the manganese content of 24 weight percent and the cerium content of 24 weight percent.
Step 1: 6.31g of a manganese nitrate solution and 7.64g of cerium nitrate solid were dissolved in 100g of distilled water, and stirred for 30 minutes to obtain a mixed solution.
Step 2: 3.53g of titanium dioxide serving as a catalyst carrier is added into the mixed solution obtained in the step 1, and stirring is continued for 1 hour, so as to obtain mixed slurry of manganese nitrate, cerium nitrate and titanium dioxide.
Step 3: and (3) slowly dropwise adding an ammonia water solution (with the concentration of 20-30 wt%) into the mixed slurry in the step (2), regulating the pH value of the solution to 8, and continuously stirring at normal temperature for half an hour to obtain the manganese-cerium-titanium suspension.
Step 4: a pneumatic stirrer with a convex or concave propeller is adopted, and a vent hole is arranged on the propeller; and (3) placing the stirred manganese-cerium-titanium suspension in a pneumatic stirrer, fully stirring the suspension by a screw, and simultaneously introducing ozone into the suspension through a vent hole to fully oxidize the suspension, wherein the rotating speed of the screw is 10-15r/min, and the ventilation volume is 500mL/min.
Step 5: and (3) dropwise adding hydrogen peroxide into the oxidized slurry, wherein the dropwise adding mode is to extend a dropper into the bottom of the slurry, and the dropwise adding speed is controlled at 10 seconds/drop.
Step 6: after stirring for a period of time, the slurry after oxidation and reduction is centrifugally washed for a plurality of times to obtain a more moist catalyst solid.
Step 7: and the obtained catalyst solid is dried by adopting a spray evaporation method, the granularity of the introduced slurry is 10-20 mu m, the spray temperature is controlled at 250-300 ℃, and the drying time is effectively reduced.
Step 8: and placing the obtained dry material into a muffle furnace for programmed heating and calcining. The calcination temperature is 550 ℃, the temperature rising speed is 10 ℃/min, and the calcination time is 4 hours.
Step 9: and (3) putting the calcined material into a ball mill for ball milling to obtain the MnCeTi-O ultralow-temperature denitration catalyst with the granularity of 1-5 mu m.
NH of MnCeTi-O ultralow temperature denitration catalyst 3 The SCR reaction activity is shown in Table 4, the denitration conversion rate of the catalyst is kept at 100% in the temperature range of 125-275 ℃, and the denitration conversion rate is always kept at more than 97% below 400 ℃, so that the catalyst has good denitration performance.
Table 4 MnCeTi-O ultralow temperature denitration catalyst characterization Activity
The XPS ion species analogy of the MnCeTi-O ultra-low temperature denitration catalyst is shown in Table 5, and comparative examples 1 and 1 show Mn after ozone oxidation and hydrogen peroxide reduction 4+ 、Ce 3+ An increased proportion of active oxygen species, and compared to ph=10The catalyst prepared was low, indicating that ph=10 is the optimum pH.
TABLE 5 XPS ion species and active oxygen species quantitative ratio of MnCeTi-O ultra-low temperature denitration catalyst
Example 3: preparing the MnCeTi-O ultralow-temperature denitration catalyst with the manganese content of 24 weight percent and the cerium content of 24 weight percent.
Step 1: 6.31g of a manganese nitrate solution and 7.64g of cerium nitrate solid were dissolved in 100g of distilled water, and stirred for 30 minutes to obtain a mixed solution.
Step 2: 3.53g of titanium dioxide serving as a catalyst carrier is added into the mixed solution obtained in the step 1, and stirring is continued for 1 hour, so as to obtain mixed slurry of manganese nitrate, cerium nitrate and titanium dioxide.
Step 3: and (3) slowly dropwise adding an ammonia water solution (with the concentration of 20-30 wt%) into the mixed slurry in the step (2), regulating the pH value of the solution to 10, and continuously stirring at normal temperature for half an hour to obtain the manganese-cerium-titanium suspension.
Step 4: a pneumatic stirrer with a convex or concave propeller is adopted, and a vent hole is arranged on the propeller; placing the stirred manganese-cerium-titanium suspension in a pneumatic stirrer, fully stirring the suspension by a screw, and simultaneously introducing ozone into the suspension through a vent hole to fully oxidize the suspension, wherein the rotating speed of the screw is 10-15r/min, and the ventilation amount is 300mL/min; the solution color was found not to darken rapidly during oxidation, probably due to Mn at lower aeration rates 2+ Cannot be rapidly and completely oxidized into Mn 4+ Thus, the ventilation time needs to be properly prolonged.
Step 5: and (3) dropwise adding hydrogen peroxide into the oxidized slurry, wherein the dropwise adding mode is to extend a dropper into the bottom of the slurry, and the dropwise adding speed is controlled at 10 seconds/drop.
Step 6: after stirring for a period of time, the slurry after oxidation and reduction is centrifugally washed for a plurality of times to obtain a more moist catalyst solid.
Step 7: and drying the obtained catalyst solid by adopting a spray evaporation method (namely pumping the catalyst into a spray dryer, spraying the catalyst from the bottom of the spray dryer after atomizing the catalyst by a spray nozzle), introducing slurry with the granularity of 10-20 mu m, controlling the spraying temperature to be 250-300 ℃, and effectively reducing the drying time.
Step 8: and placing the obtained dry material into a muffle furnace for programmed heating and calcining. The calcination temperature is 550 ℃, the temperature rising speed is 10 ℃/min, and the calcination time is 4 hours.
Step 9: and (3) putting the calcined material into a ball mill for ball milling to obtain the MnCeTi-O ultralow-temperature denitration catalyst with the granularity of 1-5 mu m.
NH of MnCeTi-O ultralow temperature denitration catalyst 3 The SCR reaction activity is shown in Table 6, the denitration conversion rate of the catalyst is kept at 100% in the temperature range of 125-275 ℃, and the denitration conversion rate is always kept at more than 96% below 400 ℃, so that the catalyst has good denitration performance.
Table 6 MnCeTi-O ultralow temperature denitration catalyst characterization Activity
The XPS ion species analogy of the MnCeTi-O ultra-low temperature denitration catalyst is shown in Table 7, and comparison of comparative example 1 and example 1 shows that Mn is reduced by ozone oxidation and hydrogen peroxide 4+ 、Ce 3+ The proportion of active oxygen species is improved, and compared with the ozone ventilation of 500mL/min, the ozone ventilation is reduced.
TABLE 7 XPS ion species proportion of MnCeTi-O ultra-low temperature denitration catalyst
Example 4: preparing the MnCeTi-O ultralow-temperature denitration catalyst with the manganese content of 24 weight percent and the cerium content of 24 weight percent.
Step 1: 6.31g of a manganese nitrate solution and 7.64g of cerium nitrate solid were dissolved in 100g of distilled water, and stirred for 30 minutes to obtain a mixed solution.
Step 2: 3.53g of titanium dioxide serving as a catalyst carrier is added into the mixed solution obtained in the step 1, and stirring is continued for 1 hour, so as to obtain mixed slurry of manganese nitrate, cerium nitrate and titanium dioxide.
Step 3: and (3) slowly dropwise adding an ammonia water solution (with the concentration of 20-30 wt%) into the mixed slurry in the step (2), regulating the pH value of the solution to 10, and continuously stirring at normal temperature for half an hour to obtain the manganese-cerium-titanium suspension.
Step 4: a pneumatic stirrer with a convex or concave propeller is adopted, and a vent hole is arranged on the propeller; and (3) placing the stirred manganese-cerium-titanium suspension in a pneumatic stirrer, fully stirring the suspension by a screw, and simultaneously introducing ozone into the suspension through a vent hole to fully oxidize the suspension, wherein the rotating speed of the screw is 10-15r/min, and the ventilation volume is 500mL/min.
Step 5: and (3) dropwise adding hydrogen peroxide into the oxidized slurry, wherein the dropwise adding mode is to extend a dropper into the bottom of the slurry, and the dropwise adding speed is controlled at 10 seconds/drop.
Step 6: after stirring for a period of time, the slurry after oxidation and reduction is centrifugally washed for a plurality of times to obtain a more moist catalyst solid.
Step 7: and drying the obtained catalyst solid by adopting a negative pressure drying method (namely, forming a negative pressure state by a vacuum pump, drying by using a drying furnace, a heating chamber, stirring, driving, steam, filtering, condensing and other devices), wherein the internal temperature in the negative pressure is controlled within the range of 160-180 ℃.
Step 8: and placing the obtained dry material into a muffle furnace for programmed heating and calcining. The calcination temperature is 550 ℃, the temperature rising speed is 10 ℃/min, and the calcination time is 4 hours.
Step 9: and (3) putting the calcined material into a ball mill for ball milling to obtain the MnCeTi-O ultralow-temperature denitration catalyst with the granularity of 1-5 mu m.
NH of MnCeTi-O ultralow temperature denitration catalyst 3 The SCR reaction activity is shown in Table 8, the denitration conversion rate of the catalyst is kept at 100% in the temperature range of 125-350 ℃, and the denitration conversion rate is always kept at more than 96% below 400 ℃, so that the catalyst has good denitration performance.
Table 8 characterization of Activity of MnCeTi-O ultra-low temperature denitration catalyst
As can be seen from comparative example 1, the XPS ion species of the MnCeTi-O ultra-low temperature denitration catalyst are shown in Table 9, and Mn is reduced by ozone oxidation and hydrogen peroxide 4+ 、Ce 3+ The ratio is improved, and the low-temperature reduction is facilitated.
TABLE 9 XPS ion species proportion of MnCeTi-O ultra-low temperature denitration catalyst
Example 5: preparing the MnCeTi-O ultralow-temperature denitration catalyst with the manganese content of 24 weight percent and the cerium content of 24 weight percent.
Step 1: 6.31g of a manganese nitrate solution and 7.64g of cerium nitrate solid were dissolved in 100g of distilled water, and stirred for 30 minutes to obtain a mixed solution.
Step 2: 3.53g of titanium dioxide serving as a catalyst carrier is added into the mixed solution obtained in the step 1, and stirring is continued for 1 hour, so as to obtain mixed slurry of manganese nitrate, cerium nitrate and titanium dioxide.
Step 3: and (3) slowly dropwise adding an ammonia water solution (with the concentration of 20-30 wt%) into the mixed slurry in the step (2), regulating the pH value of the solution to 10, and continuously stirring at normal temperature for half an hour to obtain the manganese-cerium-titanium suspension.
Step 4: a pneumatic stirrer with a convex or concave propeller is adopted, and a vent hole is arranged on the propeller; and (3) placing the stirred manganese-cerium-titanium suspension in a pneumatic stirrer, fully stirring the suspension by a screw, and simultaneously introducing ozone into the suspension through a vent hole to fully oxidize the suspension, wherein the rotating speed of the screw is 10-15r/min, and the ventilation volume is 500mL/min.
Step 5: and (3) dropwise adding hydrogen peroxide into the oxidized slurry, wherein the dropwise adding mode is to extend a dropper into the bottom of the slurry, and the dropwise adding speed is controlled at 10 seconds/drop.
Step 6: after stirring for a period of time, the slurry after oxidation and reduction is centrifugally washed for a plurality of times to obtain a more moist catalyst solid.
Step 7: and the obtained catalyst solid is subjected to a spray evaporation method, slurry granularity is 10-20 mu m, the spray temperature is controlled at 250-300 ℃, and the drying time is effectively reduced.
Step 8: and placing the obtained dry material into a muffle furnace for programmed heating and calcining. The calcination temperature is 500 ℃, the temperature rising speed is 10 ℃/min, and the calcination time is 4 hours.
Step 9: and (3) putting the calcined material into a ball mill for ball milling to obtain the MnCeTi-O ultralow-temperature denitration catalyst with the granularity of 1-5 mu m.
NH of MnCeTi-O ultralow temperature denitration catalyst 3 The SCR reaction activity is shown in Table 10, the denitration conversion rate of the catalyst is kept at 100% in the temperature range of 125-275 ℃, and the denitration conversion rate is always kept at more than 95% below 400 ℃, so that the catalyst has good denitration performance.
Table 10 MnCeTi-O ultralow temperature denitration catalyst characterization Activity
The XPS ion species ratio of the MnCeTi-O ultra-low temperature denitration catalyst is shown in Table 11, and comparative examples 1 and 1 show that Mn is reduced by ozone oxidation and hydrogen peroxide 4+ 、Ce 3+ The ratio is improved, and compared with the catalyst prepared at 550 ℃, the catalyst has a reduced temperature, which shows that the temperature has an influence on the denitration performance of the catalyst.
TABLE 11 XPS ion species proportion of MnCeTi-O ultra-low temperature denitration catalyst
Example 6: preparing the MnLaTi-O ultralow-temperature denitration catalyst with the manganese content of 24wt% and the lanthanum content of 24 wt%.
Step 1: 5.94g of a manganese nitrate solution and 7.62g of cerium nitrate solid were dissolved in 100g of distilled water, and stirred for 30 minutes to obtain a mixed solution.
Step 2: 3.53g of titanium dioxide serving as a catalyst carrier is added into the mixed solution obtained in the step 1, and stirring is continued for 1 hour, so as to obtain mixed slurry of manganese nitrate, lanthanum nitrate and titanium dioxide.
Step 3: and (3) slowly dropwise adding an ammonia water solution (with the concentration of 20-30 wt%) into the mixed slurry in the step (2), regulating the pH value of the solution to 10, and continuously stirring at normal temperature for half an hour to obtain the Mn-La-Ti suspension.
Step 4: a pneumatic stirrer with a convex or concave propeller is adopted, and a vent hole is arranged on the propeller; and (3) placing the stirred Mn-La-Ti suspension in a pneumatic stirrer, fully stirring by a screw, and simultaneously introducing ozone into the suspension through a vent hole to fully oxidize the suspension, wherein the rotating speed of the screw is 10-15r/min, and the ventilation amount is 500mL/min.
Step 5: and (3) dropwise adding hydrogen peroxide into the oxidized slurry, wherein the dropwise adding mode is to extend a dropper into the bottom of the slurry, and the dropwise adding speed is controlled at 10 seconds/drop.
Step 6: after stirring for a period of time, the slurry after oxidation and reduction is centrifugally washed for a plurality of times to obtain a more moist catalyst solid.
Step 7: and drying the obtained catalyst solid by adopting a spray evaporation method (namely pumping the catalyst into a spray dryer, spraying the catalyst from the bottom of the spray dryer after atomizing the catalyst by a spray nozzle), introducing slurry with the granularity of 10-20 mu m, controlling the spraying temperature to be 250-300 ℃, and effectively reducing the drying time.
Step 8: and placing the obtained dry material into a muffle furnace for programmed heating and calcining. The calcination temperature is 550 ℃, the temperature rising speed is 10 ℃/min, and the calcination time is 4 hours.
Step 9: and (3) putting the calcined material into a ball mill for ball milling to obtain the MnLaTi-O ultra-low temperature denitration catalyst with the granularity of 1-5 mu m.
Comparative example 2
A denitration catalyst was produced by the method of example 6, except that the steps of ozone oxidation and dioxygen water reduction were omitted.
MnLaTi-O superNH of low-temperature denitration catalyst 3 The SCR reaction activity is shown in Table 12, the denitration conversion rate of the catalyst is kept at 100% in the temperature range of 100-350 ℃, and the denitration conversion rate is always kept at more than 97% below 400 ℃, so that the catalyst has good denitration performance.
Table 12 MnLaTi-O ultralow temperature denitration catalyst characterization Activity
The XPS ion species analogy of the denitration catalyst prepared in comparative example 6 and comparative example 1 is shown in Table 13, and it is clear that Mn is reduced by ozone oxidation and hydrogen peroxide 4+ 、La 3+ The ratio is improved, which is beneficial to low-temperature reduction.
TABLE 13 XPS ion species ratio of 1MnLaTi-O ultra low temperature denitration catalyst
Example 7: preparing the MnGdTi-O ultralow-temperature denitration catalyst with the manganese content of 24wt% and the gadolinium content of 24 wt%.
Step 1: 5.94g of manganese nitrate and 6.04g of gadolinium nitrate solid were dissolved in 100g of distilled water and stirred for 30 minutes to obtain a mixed solution.
Step 2: 3.53g of titanium dioxide serving as a catalyst carrier is added into the mixed solution obtained in the step 1, and stirring is continued for 1 hour to obtain mixed slurry of manganese nitrate, gadolinium nitrate and titanium dioxide.
Step 3: and (3) slowly dropwise adding an ammonia water solution (with the concentration of 20-30 wt%) into the mixed slurry in the step (2), regulating the pH value of the solution to 10, and continuously stirring at normal temperature for half an hour to obtain the manganese gadolinium titanium suspension.
Step 4: a pneumatic stirrer with a convex or concave propeller is adopted, and a vent hole is arranged on the propeller; and (3) placing the stirred manganese gadolinium titanium suspension in a pneumatic stirrer, fully stirring the suspension by a screw, and simultaneously introducing ozone into the suspension through a vent hole to fully oxidize the suspension, wherein the rotating speed of the screw is 10-15r/min, and the ventilation volume is 500mL/min.
Step 5: and (3) dropwise adding hydrogen peroxide into the oxidized slurry, wherein the dropwise adding mode is to extend a dropper into the bottom of the slurry, and the dropwise adding speed is controlled at 10 seconds/drop.
Step 6: after stirring for a period of time, the slurry after oxidation and reduction is centrifugally washed for a plurality of times to obtain a more moist catalyst solid.
Step 7: and drying the obtained catalyst solid by adopting a spray evaporation method (namely pumping the catalyst into a spray dryer, spraying the catalyst from the bottom of the spray dryer after atomizing the catalyst by a spray nozzle), introducing slurry with the granularity of 10-20 mu m, controlling the spraying temperature to be 250-300 ℃, and effectively reducing the drying time.
Step 8: and placing the obtained dry material into a muffle furnace for programmed heating and calcining. The calcination temperature is 550 ℃, the temperature rising speed is 10 ℃/min, and the calcination time is 4 hours.
Step 9: and (3) putting the calcined material into a ball mill for ball milling to obtain the MnGdTi-O ultra-low temperature denitration catalyst with the granularity of 1-5 mu m.
Comparative example 3
A denitration catalyst was produced by the method of example 7, except that the steps of ozone oxidation and dioxygen water reduction were omitted.
NH (NH) of MnGdTi-O ultralow-temperature denitration catalyst 3 The SCR reaction activity is shown in Table 14, the denitration conversion rate of the catalyst is kept at 100% in the temperature range of 100-350 ℃, and the denitration conversion rate is always kept at more than 97% below 400 ℃, so that the catalyst has good denitration performance.
Table 14 characterization of Activity of MnGdTi-O ultra low temperature denitration catalyst
The XPS ion species analogy of the denitration catalyst prepared in comparative example 6 and comparative example 1 is shown in Table 15, and it is clear that Mn is reduced by ozone oxidation and hydrogen peroxide 4+ 、Gd 3+ The ratio is improved, which is beneficial to low-temperature reduction.
TABLE 15 XPS ion species proportion of MnCeTi-O ultra-low temperature denitration catalyst
The specific surface area and pore size of the MGdTi-O ultra low temperature denitration catalyst prepared in examples 1 to 7 are shown in Table 16.
TABLE 16 specific surface area and pore size of MGdTi-O ultra low temperature denitration catalyst
| Example 1 | Example 2 | Example 3 | Example 4 | Example 5 | Example 6 | Example 7 | |
| Specific surface area | 88 | 80 | 79 | 85 | 75 | 83 | 80 |
| Pore diameter | 11.43 | 12.2 | 10.6 | 12.32 | 12.94 | 12.14 | 12.08 |
The foregoing description of the preferred embodiments of the invention is not intended to limit the invention, but rather to enable any modification, equivalent replacement, improvement or the like to be included within the spirit and principles of the invention.
Claims (9)
1. Mn (Mn) 4+ And Ce (Ce) 3+ Or La (La) 3+ Or Gd 3+ The preparation method of the enhanced Mn-M-Ti-O ultralow temperature denitration catalyst is characterized in that the denitration catalyst is prepared by TiO 2 Is used as a carrier, is loaded with a denitration active ingredient and a rare earth metal element auxiliary agent, and is prepared by ozone oxidation, hydrogen peroxide reduction and calcination; the active component is transition metal element manganese; the auxiliary agent is one of rare earth metal elements cerium, lanthanum and gadolinium; m in Mn-M-Ti-O represents Ce, la or Gd.
2. A Mn according to claim 1 4+ And Ce (Ce) 3+ Or La (La) 3+ Or Gd 3+ The preparation method of the enhanced Mn-M-Ti-O ultralow temperature denitration catalyst is characterized in that the specific surface area of the denitration catalyst is 70-90M 2 Per gram, particle size of 1-5 μm, surface Mn 4+ The proportion is 47-50%, the surface Ce 3+ The proportion is 19-25%, the number of surface active oxygen species is 45-50%, and the average pore diameter is less than 13nm; the denitration efficiency reaches more than 97 percent, and the catalytic activity temperature window is 125-400 ℃.
3. A Mn according to any one of claims 1 to 2 4+ And Ce (Ce) 3+ Or La (La) 3+ Or Gd 3+ The preparation method of the enhanced Mn-M-Ti-O ultralow temperature denitration catalyst is characterized by comprising the following steps of:
(1) Manganese nitrate solution and M (NO) 3 ) x Adding the solid into distilled water, stirring and dissolving to obtain a mixed solution; wherein M is Ce, la or Gd;
(2) TiO catalyst carrier 2 Adding the mixture into the mixed solution, and uniformly stirring to obtain mixed slurry;
(3) Regulating the pH value of the mixed slurry, and continuing stirring at normal temperature to obtain a suspension;
(4) Introducing ozone into the suspension while stirring by adopting a pneumatic stirrer to fully oxidize the suspension;
(5) After the filling is finished, dropwise adding hydrogen peroxide into the slurry after ozone oxidation;
(6) After stirring for a period of time, centrifugally washing for a plurality of times;
(7) Drying the catalyst after washing;
(8) Calcining the dried product at a programmed temperature;
(9) Grinding the calcined product into powder to obtain the material meeting the requirements.
4. A Mn according to claim 3 4+ And Ce (Ce) 3+ Or La (La) 3+ Or Gd 3+ The preparation method of the enhanced Mn-M-Ti-O ultralow temperature denitration catalyst is characterized by comprising 50wt% of manganese nitrate solution, and 50wt% of manganese nitrate solution and M (NO 3 ) x Distilled water, tiO 2 The mass ratio of (5.94-6.31): (6.04-7.64): 100:3.53.
5. a Mn according to claim 3 4+ And Ce (Ce) 3+ Or La (La) 3+ Or Gd 3+ The preparation method of the enhanced Mn-M-Ti-O ultralow temperature denitration catalyst is characterized in that in the step (3), ammonia water with the concentration of 20-30wt% is adopted to adjust the pH value to 8-10.
6. A Mn according to claim 3 4+ And Ce (Ce) 3+ Or La (La) 3+ Or Gd 3+ The preparation method of the enhanced Mn-M-Ti-O ultralow temperature denitration catalyst is characterized in that in the step (4), the specific method of ozone oxidation is as follows: a pneumatic stirrer with a convex or concave propeller is adopted, a vent hole is arranged on a propeller shaft, the suspension is placed in the pneumatic stirrer, and ozone is introduced into the suspension through the vent hole while stirring; the rotating speed of the propeller is 10-15r/min, and the ozone ventilation is 500mL/min.
7. A Mn according to claim 3 4+ And Ce (Ce) 3+ Or La (La) 3+ Or Gd 3+ The preparation method of the enhanced Mn-M-Ti-O ultralow temperature denitration catalyst is characterized by comprising the following specific steps of: and (3) extending a dropper into the bottom of the slurry, dropwise adding hydrogen peroxide, and controlling the dropping speed to be 10 seconds/drop.
8. A Mn according to claim 3 4+ And Ce (Ce) 3+ Or La (La) 3+ Or Gd 3+ The preparation method of the enhanced Mn-M-Ti-O ultralow temperature denitration catalyst is characterized in that in the step (7), the drying method is a negative pressure drying or spray evaporation method: the negative pressure drying method is to form a negative pressure state by a vacuum pump, and dry the materials by a drying furnace, a heating chamber, stirring, driving, steam, filtering and condensing devices; the spray evaporation method is to pump the catalyst into a spray dryer, atomize the catalyst by a spray head and spray the catalyst from the bottom of the spray dryer.
9. A Mn according to claim 3 4+ And Ce (Ce) 3+ Or La (La) 3+ Or Gd 3+ The preparation method of the enhanced Mn-M-Ti-O ultralow temperature denitration catalyst is characterized in that in the step (8), the temperature programming rate is 10 ℃/min, the calcination temperature is 500-550 ℃, and the calcination time is 4 hours.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103055848A (en) * | 2012-12-25 | 2013-04-24 | 浙江海亮环境材料有限公司 | Rare-earth doped low-temperature denitration catalyst and preparation method thereof |
| CN106238040A (en) * | 2016-07-29 | 2016-12-21 | 西安科技大学 | The preparation method of modified fly ash loading Mn Ce bimetallic denitration catalyst |
| KR20180064350A (en) * | 2018-05-30 | 2018-06-14 | 주식회사 에코프로 | Manganese-Ceria-Tungsten-titania catalyst for removing NOx and preparing method of thereof |
| CN108452796A (en) * | 2018-03-12 | 2018-08-28 | 北京科技大学 | A kind of preparation method of the modified montmorillonite used base SCR denitration of Supported Manganese and cerium |
| CN110339832A (en) * | 2019-06-28 | 2019-10-18 | 华中科技大学 | A kind of sheet Detitanium-ore-type TiO2For the manganese cerium compound of carrier and preparation and application |
| CN112642421A (en) * | 2019-10-10 | 2021-04-13 | 中国石油天然气集团有限公司 | MnCeOXMetal oxide and method for producing same |
| CN113578333A (en) * | 2021-07-30 | 2021-11-02 | 西安交通大学 | Low-temperature denitration catalyst and preparation method and application thereof |
-
2022
- 2022-03-24 CN CN202210295908.4A patent/CN114797841B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103055848A (en) * | 2012-12-25 | 2013-04-24 | 浙江海亮环境材料有限公司 | Rare-earth doped low-temperature denitration catalyst and preparation method thereof |
| CN106238040A (en) * | 2016-07-29 | 2016-12-21 | 西安科技大学 | The preparation method of modified fly ash loading Mn Ce bimetallic denitration catalyst |
| CN108452796A (en) * | 2018-03-12 | 2018-08-28 | 北京科技大学 | A kind of preparation method of the modified montmorillonite used base SCR denitration of Supported Manganese and cerium |
| KR20180064350A (en) * | 2018-05-30 | 2018-06-14 | 주식회사 에코프로 | Manganese-Ceria-Tungsten-titania catalyst for removing NOx and preparing method of thereof |
| CN110339832A (en) * | 2019-06-28 | 2019-10-18 | 华中科技大学 | A kind of sheet Detitanium-ore-type TiO2For the manganese cerium compound of carrier and preparation and application |
| CN112642421A (en) * | 2019-10-10 | 2021-04-13 | 中国石油天然气集团有限公司 | MnCeOXMetal oxide and method for producing same |
| CN113578333A (en) * | 2021-07-30 | 2021-11-02 | 西安交通大学 | Low-temperature denitration catalyst and preparation method and application thereof |
Non-Patent Citations (2)
| Title |
|---|
| Comparison of low-temperature catalytic activity and H2O/SO2 resistance of the Ce-Mn/TiO2 NH3-SCR catalysts prepared by the reverse co-precipitation, co-precipitation and impregnation method;Cheng Chen 等;Applied Surface Science;第571卷;第151285 * |
| Effect of preferential exposure of anatase TiO2 {0 0 1} facets on the performance of Mn-Ce/TiO2 catalysts for low-temperature selective catalytic reduction of NOx with NH3;Quan Li 等;Chemical Engineering Journal;第369卷;26-34 * |
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