Preparation method of carrier-free catalyst
阅读说明：本技术 一种无载体型催化剂的制备方法 (Preparation method of carrier-free catalyst ) 是由 陶君 段钰锋 谷小兵 李银生 刘猛 李涛 于 2019-09-24 设计创作，主要内容包括：本发明涉及大气污染控制领域,尤其涉及一种无载体型催化剂的制备方法。包括如下步骤：将金属氧化物的硝酸盐置于溶剂中搅拌溶解后,调节溶液pH至2～5,得活性溶液；向所述活性溶液中加入氧化性溶液,搅拌后静置,再进行固液分离,得到固体样品；将所述固体样品依次进行烘干、研磨,得到无载体型催化剂。其中,所述硝酸盐为Mn(NO-3)-2、Ce(NO-3)-3、Fe(NO-3)-2或Co(NO-3)-2中的一种或多种以任意比例混配的混合物。解决传统无载体催化剂制备方法繁琐、应用成本高的问题。(The invention relates to the field of air pollution control, in particular to a preparation method of a carrier-free catalyst. The method comprises the following steps: after nitrate of metal oxide is placed in a solvent and stirred to be dissolved, adjusting the pH value of the solution to 2-5 to obtain an active solution; adding an oxidizing solution into the active solution, stirring, standing, and performing solid-liquid separation to obtain a solid sample; and drying and grinding the solid sample in sequence to obtain the carrier-free catalyst. Wherein the nitrate is Mn (NO) 3 ) 2 、Ce(NO 3 ) 3 、Fe(NO 3 ) 2 Or Co (NO) 3 ) 2 One or more of them can be mixed according to any proportion. Solves the problems of complicated preparation method and high application cost of the traditional unsupported catalyst.)
1. A preparation method of an unsupported catalyst is characterized by comprising the following steps: the method comprises the following steps:
after nitrate of metal oxide is placed in a solvent and stirred to be dissolved, adjusting the pH value of the solution to 2-5 to obtain an active solution; adding an oxidizing solution into the active solution, stirring, standing, and performing solid-liquid separation to obtain a solid sample; and drying and grinding the solid sample in sequence to obtain the carrier-free catalyst.
Wherein the nitrate is Mn (NO)3)2、Ce(NO3)3、Fe(NO3)2Or Co (NO)3)2One or more of them can be mixed according to any proportion.
2. The method of claim 1, wherein: the nitrate is Mn (NO)3)2、Ce(NO3)3、Fe(NO3)2And Co (NO)3)2In which Mn (NO)3)2:Ce(NO3)3:Fe(NO3)2:Co(NO3)2The mass ratio of (2-8): (14-34): (1-5): 0.1-2.0).
3. The method of claim 2, wherein: the preparation method specifically comprises the following steps:
(1) putting nitrate of metal oxide into deionized water, and stirring and dissolving to obtain a mixed solution;
(2) dropwise adding dilute nitric acid into the mixed solution, adjusting the pH of the solution to 3-4, and continuously stirring and dispersing to obtain an active solution;
(3) dropwise adding a strong oxidizing solution into the active solution, stirring and standing to obtain a layered solution;
(4) carrying out solid-liquid separation on the layered solution in a suction filtration mode to obtain a solid sample;
(5) and drying, cooling and grinding the solid sample in sequence to obtain the unsupported catalyst.
4. The production method according to claim 3, characterized in that: the step (2) specifically comprises: and (3) dropwise adding dilute nitric acid into the mixed solution, adjusting the pH of the solution to 3-4, then carrying out magnetic stirring at 70-90 ℃, and continuously dispersing for 3-4 h to obtain an active solution.
5. The production method according to claim 3, characterized in that: the step (3) specifically comprises: and dropwise adding a strong oxidizing solution into the active solution, continuously stirring at constant temperature for 5-7 h, and standing for 3-5 h to obtain a layered solution.
6. A method of manufacturing according to claim 3, wherein: the step (5) specifically comprises: and drying the solid sample at 150-180 ℃ for 20-28 h, cooling, grinding, and sieving with a 40-60-mesh sieve to obtain the carrier-free catalyst.
7. The production method according to claim 3, characterized in that: in the step (2), the volume fraction of the dilute nitric acid is 8-10%.
8. The production method according to claim 3, characterized in that: in the step (3), the strong oxidation solution is at least one of a potassium permanganate solution or a hydrogen peroxide solution.
9. The production method according to claim 3, characterized in that: in the step (3), the concentration of the potassium permanganate solution is 35-60%, and the concentration of the hydrogen peroxide solution is 40-70%.
10. An unsupported catalyst characterized by: the catalyst is prepared by the preparation method of any one of claims 1 to 9.
Technical Field
The invention relates to the field of air pollution control, in particular to a preparation method of a carrier-free catalyst.
Background
At present, coal serving as a main component in an energy consumption system structure in China still cannot be completely replaced by natural gas, nuclear energy and new energy, and a large amount of pollutants generated by coal combustion far exceed the self-regulation capacity of ecological environment.
Nitrogen Oxides (NO)x) As one of the most important atmospheric pollutants, the compounds are not only important precursors for causing nitric acid type acid rain, photochemical smog, haze and the like, but also cause serious damage to human respiratory systems. Along with the increasing requirements of people on environmental protection quality, China has NO in coal-fired flue gasxEmission limits are becoming more stringent: china currently requires NO in ultralow emission indexxEmission limit of 50mg/m3Beijing City local Standard (DB 11/139-2015) specifies NOxEmission limit of 30mg/m3. Flue gas NO of coal-fired power stationxThe emission is the most important man-made emission source, and China, as the largest coal producing country and consuming country in the world, faces extremely serious NOxPollution control pressure.
Mercury is the only heavy metal pollutant existing in the atmosphere mainly in a gaseous form, and has strong volatility, migration, bioaccumulation and high toxicity. Investigation showed that about 19% of the total mercury emissions in China are from coal-fired power plants and 33% are from coal-fired industrial boilers. From 1 month in 2015, the emission standard of atmospheric pollutants of thermal power plants clearly stipulates that the mercury emission concentration limit value of the domestic coal-fired power plants is 30 mu g/Nm3In 5 and 12 months in the same year, Beijing, Shanghai and the like, according to the mercury emission conditions of various regions, the mercury emission concentration limit value of the boiler in the region is further reduced to 0.5 mu g/Nm3And 10. mu.g/Nm3。
Selective Catalytic Reduction (SCR) is currently considered to be the most promising NO for coal combustionxRemoval technology of NO in the present stage of controlling coal-fired flue gasxThe effective means of emission is widely applied to coal-fired power plant devices nationwide. And the SCR device is utilized to cooperatively oxidize Hg in the flue gas0Is Hg2+And the subsequent wet desulphurization device (WFGD) is combined to realize the absorption and removal of mercury, so that the investment cost of the coal-fired power plant for controlling the pollution of nitrogen oxides and mercury can be greatly reduced, and the large-scale application is easier. Therefore, the denitration synergistic mercury oxidation catalyst is increasingly regarded as the technical core, and the transition metal oxide is the main active component of the double-effect catalyst due to excellent catalytic activity and low price.
The unsupported denitration synergistic mercury oxidation catalyst is a commonly used SCR catalyst, but the traditional liquid-phase coprecipitation method for preparing the unsupported catalyst has the following problems: 1. the active components are precipitated by a precipitator and are calcined at high temperature to complete the conversion of oxides, and the precipitator has large demand and fuzzy dosage proportion standard; 2. the secondary treatment process is complicated, the requirement on the calcining temperature is strict, the actual application cost is high, and the industrial application is difficult to realize.
Disclosure of Invention
The invention aims to solve the technical problems of complicated preparation method and high application cost of the traditional unsupported catalyst.
The technical scheme for solving the technical problems is as follows: a preparation method of an unsupported catalyst is characterized by comprising the following steps: the method comprises the following steps:
after nitrate of metal oxide is placed in a solvent and stirred to be dissolved, adjusting the pH value of the solution to 2-5 to obtain an active solution; adding an oxidizing solution into the active solution, stirring, standing, and performing solid-liquid separation to obtain a solid sample; and drying and grinding the solid sample in sequence to obtain the carrier-free catalyst.
Wherein the nitrate is Mn (NO)3)2、Ce(NO3)3、Fe(NO3)2Or Co (NO)3)2One or more ofThe mixture is mixed in any proportion.
It is to be noted that the nitrate may be Mn (NO)3)2、Ce(NO3)3、Fe(NO3)2Or Co (NO)3)2Any one of the above may be Mn (NO)3)2、Ce(NO3)3、Fe(NO3)2And Co (NO)3)2Any two of the above-mentioned materials can be mixed together according to any proportion, and can also be Mn (NO)3)2、 Ce(NO3)3、Fe(NO3)2And Co (NO)3)2Any three of the above-mentioned materials can be mixed according to any proportion, also can be Mn (NO)3)2、Ce(NO3)3、Fe(NO3)2And Co (NO)3)2A mixture compounded in any proportion.
Further, the nitrate is Mn (NO)3)2、Ce(NO3)3、Fe(NO3)2And Co (NO)3)2In which Mn (NO)3)2:Ce(NO3)3:Fe(NO3)2:Co(NO3)2The mass ratio of (2-8): (14-34): (1-5): 0.1-2.0).
Further, the preparation method specifically comprises the following steps:
(1) putting nitrate of metal oxide into deionized water, and stirring and dissolving to obtain a mixed solution;
(2) dropwise adding dilute nitric acid into the mixed solution, adjusting the pH of the solution to 3-4, and continuously stirring and dispersing to obtain an active solution;
(3) dropwise adding a strong oxidizing solution into the active solution, stirring and standing to obtain a layered solution;
(4) carrying out solid-liquid separation on the layered solution in a suction filtration mode to obtain a solid sample;
(5) and drying, cooling and grinding the solid sample in sequence to obtain the unsupported catalyst.
It should be noted that the amount of the strong oxidizing solution is excessive relative to the nitrate, and the amount of the strong oxidizing solution is 1.1 to 2.5 times of the equivalent amount of the nitrate of the metal oxide to ensure complete oxidation of the nitrate of the metal oxide, and studies show that the catalyst obtained by treating the nitrate of the metal oxide with the strong oxidizing solution in the amount is optimal in reaction activity when the pH is 3 to 4.
Further, the step (2) specifically includes: and (3) dropwise adding dilute nitric acid into the mixed solution, adjusting the pH of the solution to 3-4, then carrying out magnetic stirring at 70-90 ℃, and continuously dispersing for 3-4 h to obtain an active solution.
Further, the step (3) specifically includes: and dropwise adding a strong oxidizing solution into the active solution, continuously stirring at constant temperature for 5-7 h, and standing for 3-5 h to obtain a layered solution.
Further, the step (5) specifically includes: and drying the solid sample at 150-180 ℃ for 20-28 h, cooling, grinding, and sieving with a 40-60-mesh sieve to obtain the carrier-free catalyst.
Further, in the step (2), the volume fraction of the dilute nitric acid is 8-10%.
Further, in the step (3), the strong oxidation solution is at least one of a potassium permanganate solution or a hydrogen peroxide solution.
Further, in the step (3), the concentration of the potassium permanganate solution is 35-60%, and the concentration of the hydrogen peroxide solution is 40-70%.
An unsupported catalyst prepared by the method.
Compared with the prior art, the invention has the beneficial effects that:
1. the invention precipitates the active oxide by an in-situ generation method, can directly carry out liquid-phase oxidation-reduction reaction to finish the form conversion from the active precursor to the active oxide, and avoids the complex preparation process of coprecipitation and high-temperature calcination in the conventional liquid-phase coprecipitation method.
2. The method has the advantages of high liquid phase ion contact efficiency and chemical reaction efficiency, low consumption of required oxidant, high purity of active components in the prepared catalyst powder, no impurity, simple process, economy and high efficiency.
3. The invention adopts potassium permanganate or hydrogen peroxide as a strong oxidant, can quickly oxidize active metal ions in the liquid phase under the condition of low temperature, has high oxidation rate, wide material source, simple and stable storage, belongs to the traditional liquid-phase oxidation-reduction reaction, and is easy to maintain.
4. In the invention, cerium has stronger oxygen storage and release capacity, and can greatly improve the service life of the catalyst; iron may strengthen the catalyst pair N2Thereby reducing the generation of SCR reduction by-products; manganese has various stable metal valence states, conversion among different valence states can be realized at low temperature, the double-effect catalysis process is promoted to shift to the low-temperature direction, and simultaneously, the doping of the manganese enables SO4 2-Or SO3 2-The catalyst is easier to combine with manganese, thereby reducing the formation of ammonium sulfate to a certain extent and improving the sulfur resistance and water resistance of the catalyst. Therefore, the catalyst prepared by the invention has the characteristics of low temperature, low ash, low sulfur and high efficiency.
5. The method has the advantages of wide application range, simple process, economy and high efficiency, can be used for high-purity and high-efficiency preparation of the unsupported catalyst, can be used as important technical reserve in the targeted processes of coating method precursor preparation, layered distribution of the active structure of the catalyst and the like, and has great advantages in the large-scale industrial application field of the flue gas denitration and demercuration technology in the electric power industry and the non-electric industry.
Detailed Description
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms also include the plural forms unless the context clearly dictates otherwise, and further, it is understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of the stated features, steps, operations, devices, components, and/or combinations thereof.
Hereinafter, embodiments of the present invention will be described in detail. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.
The method takes one or a mixture of more of Mn, Ce, Fe and Co in any proportion as a catalytic component to prepare the carrier-free denitration and demercuration catalyst. Validation of catalyst vs NO on fixed bed Performance test apparatusxAnd Hg0Conversion activity, and the system accurately controls the concentration of gas components by adjusting mass flow meters of all gas distribution pipelines, wherein Hg is input and output0The concentration was measured on-line by using EMP-2/WLE-8 manufactured by NIC instruments of Japan, O2、NH3、NOxAnd selecting the ultraviolet smoke analyzer of the Qingdao Borui company for calibration and analysis. The experiment takes 80mg of catalyst as a research object, the total gas quantity of simulated flue gas is 1.0L/min, and the mercury-carrying N is2Flow rate 400mL/min, reaction temperature 170 deg.C, [ NO ]x]＝[NH3]＝300×10-6，[SO2]＝50×10-6，[O2]5% of Hg at the inlet0The concentration is 45.1 +/-1.0 mu g/m3The experimental time is 3.5 h.
Catalytic activity by NOxReduction efficiencies τ and Hg0The oxidation efficiency η was evaluated and calculated as shown in formulas (1) to (2):
τ＝(NOin-NOout)/NOin (1)
η＝(Hg0 in-Hg0 out)/Hg0 in (2)
in the formula: NOin、NOoutIs inlet and outlet NO of fixed bedxConcentration, 10-6；Hg0 in、Hg0 outThe concentration of mercury in the inlet and outlet elements is mu g/m3。
Example 1
(1) 0.586g Mn (NO) is weighed3)2、2.78g Ce(NO3)3、0.364g Fe(NO3)2And 0.116g Co (NO)3)2Dissolving in 100mL of deionized water, and stirring until the solution is completely dissolved to obtain a mixed solution;
(2) dropwise adding a dilute nitric acid solution with the volume fraction of 10% into the mixed solution until the pH of the solution is 4, then magnetically stirring at 80 ℃, and continuously dispersing for 3 hours to obtain an active solution;
(3) titrating excessive 50% potassium permanganate solution into the active solution in a forward direction, keeping sealing, continuing stirring at 80 ℃ for 6 hours, and then standing for 4 hours to obtain a layered solution;
(4) filtering and separating the layered solution, and drying the obtained solid sample in a drying oven at 150 ℃ for 24 hours;
(5) and after the catalyst sample is cooled, grinding and screening to 50 meshes to obtain the carrier-free catalyst.
Application to denitration and mercury removal: the resulting catalyst mass was 4.828g, NOxThe reduction efficiency is about 83.7 percent, Hg0The oxidation efficiency is stabilized at 91.5%.
Example 2
(1) 0.586g Mn (NO) is weighed3)2、2.78g Ce(NO3)3、0.364g Fe(NO3)2And 0.116g Co (NO)3)2Dissolving in 100mL of deionized water, and stirring until the solution is completely dissolved to obtain a mixed solution;
(2) dropwise adding a dilute nitric acid solution with the volume fraction of 10% into the mixed solution until the pH of the solution is 4, then magnetically stirring at 80 ℃, and continuously dispersing for 3 hours to obtain an active solution;
(3) titrating excessive 50% potassium permanganate solution into the active solution in a forward direction, keeping sealing, continuing stirring at 80 ℃ for 6 hours, and then standing for 4 hours to obtain a layered solution;
(4) filtering and separating the layered solution, and drying the obtained solid sample in a drying oven at 180 ℃ for 24 hours;
(5) and after the catalyst sample is cooled, grinding and screening to 50 meshes to obtain the carrier-free catalyst.
Application to denitration and mercury removal: the resulting catalyst mass was 5.126g, NOxThe reduction efficiency is about 84.1%, Hg0The oxidation efficiency was stabilized at 92.2%.
Example 3
(1) 0.586g Mn (NO) is weighed3)2、2.78g Ce(NO3)3、0.364g Fe(NO3)2And 0.116g Co (NO)3)2Dissolving in 100mL of deionized water, and stirring until the solution is completely dissolved to obtain a mixed solution;
(2) dropwise adding a dilute nitric acid solution with the volume fraction of 10% into the mixed solution until the pH of the solution is 4, then magnetically stirring at 90 ℃, and continuously dispersing for 3 hours to obtain an active solution;
(3) titrating excessive 50% potassium permanganate solution into the active solution in a forward direction, keeping sealing, continuously stirring for 6 hours at 90 ℃, and then standing for 4 hours to obtain a layered solution;
(4) filtering and separating the layered solution, and drying the obtained solid sample in a drying oven at 180 ℃ for 24 hours;
(5) and after the catalyst sample is cooled, grinding and screening to 50 meshes to obtain the carrier-free catalyst.
Application to denitration and mercury removal: the resulting catalyst mass was 5.267g, NOxThe reduction efficiency is about 83.5%, Hg0The oxidation efficiency was stabilized at 92.4%.
Example 4
(1) 0.586g Mn (NO) is weighed3)2、2.78g Ce(NO3)3、0.364g Fe(NO3)2And 0.116g Co (NO)3)2Dissolving in 100mL of deionized water, and stirring until the solution is completely dissolved to obtain a mixed solution;
(2) dropwise adding a dilute nitric acid solution with the volume fraction of 10% into the mixed solution until the pH of the solution is 5, then magnetically stirring at 90 ℃, and continuously dispersing for 3 hours to obtain an active solution;
(3) titrating excessive 40% hydrogen peroxide solution into the active solution in a positive direction, keeping sealing, continuously stirring for 6 hours at 90 ℃, and then standing for 4 hours to obtain a layered solution;
(4) filtering and separating the layered solution, and drying the obtained solid sample in a drying oven at 180 ℃ for 24 hours;
(5) and after the catalyst sample is cooled, grinding and screening to 50 meshes to obtain the carrier-free catalyst.
Application to denitration and mercury removal: the resulting catalyst mass was 5.204g, NOxThe reduction efficiency is about 84.3%, Hg0The oxidation efficiency is stabilized at 91.8%.
Example 5
(1) 0.586g Mn (NO) is weighed3)2、2.78g Ce(NO3)3、0.364g Fe(NO3)2And 0.116g Co (NO)3)2Dissolving in 100mL of deionized water, and stirring until the solution is completely dissolved to obtain a mixed solution;
(2) dropwise adding a dilute nitric acid solution with the volume fraction of 10% into the mixed solution until the pH of the solution is 5, then magnetically stirring at 70 ℃, and continuously dispersing for 3 hours to obtain an active solution;
(3) titrating excessive 70% hydrogen peroxide solution into the active solution in a positive direction, keeping sealing, continuously stirring for 6h at 70 ℃, and then standing for 4h to obtain a layered solution;
(4) filtering and separating the layered solution, and drying the obtained solid sample in a drying oven at 180 ℃ for 24 hours;
(5) and after the catalyst sample is cooled, grinding and screening to 40 meshes to obtain the carrier-free catalyst.
Application to denitration and mercury removal: the resulting catalyst had a mass of 4.102g, NOxThe reduction efficiency is about 81.5%, Hg0The oxidation efficiency is stabilized at 90.6%.
Example 6
(1) 0.586g Mn (NO) is weighed3)2、2.78g Ce(NO3)3、0.364g Fe(NO3)2And 0.116g Co (NO)3)2Dissolving in 100mL of deionized water, and stirring until the solution is completely dissolved to obtain a mixed solution;
(2) dropwise adding a dilute nitric acid solution with the volume fraction of 10% into the mixed solution until the pH of the solution is 4, then magnetically stirring at 70 ℃, and continuously dispersing for 4 hours to obtain an active solution;
(3) titrating excessive 55% hydrogen peroxide solution into the active solution in a positive direction, keeping sealing, continuously stirring for 5 hours at 70 ℃, and then standing for 3 hours to obtain a layered solution;
(4) filtering and separating the layered solution, and drying the obtained solid sample in a drying oven at 180 ℃ for 20 hours;
(5) and after the catalyst sample is cooled, grinding and screening to 60 meshes to obtain the carrier-free catalyst.
Application to denitration and mercury removal: the resulting catalyst mass was 4.020g, NOxThe reduction efficiency is about 80.4%, Hg0The oxidation efficiency is stabilized at 90.1%.
Example 7
(1) 0.117g Mn (NO) was weighed3)2、0.118g Ce(NO3)3、0.121g Fe(NO3)2And 0.012g Co (NO)3)2Dissolving in 30mL of deionized water, and stirring until the solution is completely dissolved to obtain a mixed solution;
(2) dropwise adding a dilute nitric acid solution with the volume fraction of 10% into the mixed solution until the pH of the solution is 2, then magnetically stirring at 70 ℃, and continuously dispersing for 4 hours to obtain an active solution;
(3) titrating excessive 55% hydrogen peroxide solution into the active solution in a positive direction, keeping sealing, continuously stirring for 5 hours at 70 ℃, and then standing for 3 hours to obtain a layered solution;
(4) filtering and separating the layered solution, and drying the obtained solid sample in a drying oven at 180 ℃ for 20 hours;
(5) and after the catalyst sample is cooled, grinding and screening to 60 meshes to obtain the carrier-free catalyst.
Application to denitration and mercury removal: the mass of the catalyst obtained was 1.020g, NOxThe reduction efficiency is about 81.4%, Hg0The oxidation efficiency is stabilized at 90.7%.
Example 8
(1) Weighing 1.055g Mn (NO)3)2、5.444g Ce(NO3)3、0.607g Fe(NO3)2And 0.232g Co (NO)3)2Dissolving in 500mL deionized water and stirringStirring until the mixture is completely dissolved to obtain a mixed solution;
(2) dropwise adding a dilute nitric acid solution with the volume fraction of 10% into the mixed solution until the pH of the solution is 5, then magnetically stirring at 70 ℃, and continuously dispersing for 4 hours to obtain an active solution;
(3) titrating excessive 55% hydrogen peroxide solution into the active solution in a positive direction, keeping sealing, continuously stirring for 5 hours at 70 ℃, and then standing for 3 hours to obtain a layered solution;
(4) filtering and separating the layered solution, and drying the obtained solid sample in a drying oven at 180 ℃ for 20 hours;
(5) and after the catalyst sample is cooled, grinding and screening to 60 meshes to obtain the carrier-free catalyst.
Application to denitration and mercury removal: the resulting catalyst mass was 8.143g, NOxThe reduction efficiency is about 82.4%, Hg0The oxidation efficiency was stabilized at 92.1%.
Example 9
(1) 0.586g Mn (NO) is weighed3)2、2.78g Ce(NO3)3And 0.364g Fe (NO)3)2Dissolving in 100mL of deionized water, and stirring until the solution is completely dissolved to obtain a mixed solution;
(2) dropwise adding a dilute nitric acid solution with the volume fraction of 10% into the mixed solution until the pH of the solution is 4, then magnetically stirring at 90 ℃, and continuously dispersing for 3 hours to obtain an active solution;
(3) titrating excessive 50% potassium permanganate solution into the active solution in a forward direction, keeping sealing, continuously stirring for 7 hours at 90 ℃, and then standing for 5 hours to obtain a layered solution;
(4) filtering and separating the layered solution, and drying the obtained solid sample in a drying oven at 180 ℃ for 28 hours;
(5) and after the catalyst sample is cooled, grinding and screening to 50 meshes to obtain the carrier-free catalyst.
Application to denitration and mercury removal: the resulting catalyst mass was 4.863g, NOxThe reduction efficiency is about 82.5%, Hg0The oxidation efficiency is stabilized at 91.4%.
Example 10
(1) Balance0.586g of Mn (NO) is taken3)2And 0.364g Fe (NO)3)2Dissolving in 80mL of deionized water, and stirring until the solution is completely dissolved to obtain a mixed solution;
(2) dropwise adding a dilute nitric acid solution with the volume fraction of 8% into the mixed solution until the pH of the solution is 5, then magnetically stirring at 90 ℃, and continuously dispersing for 3 hours to obtain an active solution;
(3) carrying out forward titration on excessive 36% potassium permanganate solution into the active solution, keeping the active solution sealed, continuing stirring for 6 hours at 90 ℃, and then standing for 4 hours to obtain a layered solution;
(4) filtering and separating the layered solution, and drying the obtained solid sample in a drying oven at 180 ℃ for 24 hours;
(5) and after the catalyst sample is cooled, grinding and screening to 50 meshes to obtain the carrier-free catalyst.
Application to denitration and mercury removal: the resulting catalyst mass was 3.753g, NOxThe reduction efficiency is about 80.9%, Hg0The oxidation efficiency is stabilized at 89.6%.
Example 11
(1) 0.586g Mn (NO) is weighed3)2And 0.116g Co (NO)3)2Dissolving in 60mL of deionized water, and stirring until the solution is completely dissolved to obtain a mixed solution;
(2) dropwise adding a dilute nitric acid solution with the volume fraction of 8% into the mixed solution until the pH of the solution is 4, then magnetically stirring at 90 ℃, and continuously dispersing for 4 hours to obtain an active solution;
(3) carrying out forward titration on excessive 36% potassium permanganate solution into the active solution, keeping the active solution sealed, continuing stirring for 6 hours at 90 ℃, and then standing for 4 hours to obtain a layered solution;
(4) filtering and separating the layered solution, and drying the obtained solid sample in a drying oven at 180 ℃ for 24 hours;
(5) and after the catalyst sample is cooled, grinding and screening to 50 meshes to obtain the carrier-free catalyst.
Application to denitration and mercury removal: the resulting catalyst mass was 2.753g, NOxThe reduction efficiency is about 81.9%, Hg0The oxidation efficiency is stabilized at 88.9%.
Example 12
(1) 0.586g Mn (NO) is weighed3)2Dissolving in 60mL of deionized water, and stirring until the solution is completely dissolved to obtain a mixed solution;
(2) dropwise adding a dilute nitric acid solution with the volume fraction of 8% into the mixed solution until the pH of the solution is 3, then magnetically stirring at 70 ℃, and continuously dispersing for 3 hours to obtain an active solution;
(3) carrying out forward titration on excessive 36% potassium permanganate solution into the active solution, keeping the active solution sealed, continuing stirring for 5 hours at 70 ℃, and then standing for 3 hours to obtain a layered solution;
(4) filtering and separating the layered solution, and drying the obtained solid sample in a drying oven at 180 ℃ for 24 hours;
(5) and after the catalyst sample is cooled, grinding and screening to 50 meshes to obtain the carrier-free catalyst.
Application to denitration and mercury removal: the mass of the catalyst obtained was 1.985g, NOxThe reduction efficiency is about 80.1%, Hg0The oxidation efficiency is stabilized at 83.4%.
The quality and denitration and mercury removal efficiency of the catalysts prepared from the different active components in examples 1-10 are shown in the table.
TABLE quality and denitration synergistic demercuration efficiency of catalysts prepared from different active components
As can be seen from the data in the table, the denitration and demercuration efficiency of the denitration synergistic mercury oxidation non-carrier catalyst prepared by the method is over 80%, the denitration efficiency of the catalyst prepared in example 4 is the highest, and the demercuration efficiency of the catalyst prepared in example 3 is the highest.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
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