Phosphoric acid modified cobalt-manganese-aluminum solid solution catalyst, preparation method thereof and application of phosphoric acid modified cobalt-manganese-aluminum solid solution catalyst in synergistic removal of non-methane hydrocarbon

Abstract

The invention discloses a phosphoric acid modified cobalt-manganese-aluminum solid solution catalyst, a preparation method thereof and application of the phosphoric acid modified cobalt-manganese-aluminum solid solution catalyst in synergic removal of non-methane hydrocarbon, and belongs to the technical field of gaseous pollutant control, the preparation method comprises the following steps: dissolving cobalt salt, manganese salt and gamma-Al2O3 in absolute ethyl alcohol, and uniformly stirring at room temperature to obtain a solution A; dissolving carbonate in deionized water, and uniformly stirring to obtain a solution B; dropwise adding the solution B into the solution A, aging at room temperature, filtering, washing and drying to obtain a white solid, and roasting to obtain a cobalt-manganese-aluminum solid solution catalyst; and dipping the cobalt-manganese-aluminum solid solution catalyst in a phosphoric acid solution, washing, filtering, and drying to obtain the phosphoric acid modified cobalt-manganese-aluminum solid solution catalyst. The cobalt-manganese-aluminum solid solution catalyst is prepared through simple aluminum doping and phosphoric acid modification, the stable structure and excellent performance of cobalt-manganese oxide are guaranteed, the simultaneous denitration and chlorobenzene removal efficiency is effectively improved, and the temperature interval of low-temperature removal of NOx is widened.

Description

Technical Field

[0001] The invention belongs to the technical field of gaseous pollutant control, and specifically relates to a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst, a preparation method thereof, and an application thereof in synergistically removing non-methane total hydrocarbons. Background Art

[0002] The coordinated control of nitrogen oxides (NOx) and volatile organic compounds (VOCs) has become a broad consensus among all sectors of society. my country's annual emissions of NOx and VOCs are still above 20 million tons, and NOx and VOCs will produce ozone through chemical reactions at a certain ratio. If the ratio of NOx and VOCs reduction is not appropriate, it will lead to an increase in ozone concentration. Therefore, only by achieving coordinated reduction of NOx and VOCs can the coordinated control of PM2.5 and ozone be achieved. In the face of actual engineering needs, the development of a flue gas coordinated denitrification and de-VOCs technology to simplify the flue gas multi-pollutant removal process and operation and maintenance costs will have broader application prospects.

[0003] Using the existing selective catalytic reduction (SCR) denitrification device to achieve efficient coordinated control of VOCs is the simplest and most effective technical method. However, traditional SCR catalysts have disadvantages such as poor low-temperature activity and easy poisoning, which makes it difficult to meet the complex working conditions and low exhaust temperature (<300℃) of the non-electric industry. Therefore, the development of a catalyst that can efficiently and synergistically remove NOx and VOCs in the medium and low temperature range (<300℃) is of great significance for controlling the emission of multiple pollutants in the non-electric industry. Transition metal oxides have attracted extensive attention from researchers in recent years due to their rich sources and low cost. Among them, cobalt (Co) and manganese (Mn) have special low-temperature activity due to their diverse valence states, good redox properties and flexible adjustability, and are expected to become a substitute for traditional SCR catalysts. However, the catalytic activity of pure cobalt manganese oxide is limited, and it is difficult to effectively remove NOx and VOCs at the same time. Therefore, it is necessary to further improve the catalytic activity and acidity of cobalt manganese oxide to achieve simultaneous denitrification and VOCs removal. Summary of the invention

[0004] The purpose of the present invention is to provide a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst and a preparation method thereof to solve the problem of limited catalytic activity of pure cobalt-manganese oxide. The purpose of the present invention is to provide a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst for use in medium and low temperature flue gas denitrification to solve the problem of low removal efficiency of NOx and VOCs.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] The first aspect of the present application provides a method for preparing a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst, comprising the following steps:

[0007] Step S1, dissolving cobalt salt, manganese salt and γ-Al2O3 in anhydrous ethanol, stirring evenly at room temperature to obtain solution A; dissolving carbonate in deionized water and stirring evenly to obtain solution B;

[0008] Step S2, adding solution B dropwise into solution A, aging at room temperature, filtering, washing, and drying to obtain a white solid, which is then calcined to obtain a cobalt-manganese-aluminum solid solution catalyst (referred to as CoMnAlO x );

[0009] Step S3, immersing the cobalt manganese aluminum solid solution catalyst in a H3PO4 solution, washing, filtering, and drying to obtain a phosphoric acid-modified cobalt manganese aluminum solid solution catalyst (referred to as CoMnAlO x -P).

[0010] As a further preferred embodiment of the present invention, γ-Al2O3 is prepared by the following steps: aluminum hydroxide is placed in a muffle furnace and calcined at 500-600°C for 3-4h to obtain γ-Al2O3.

[0011] As a further preferred embodiment of the present invention, the molar ratio of Co:Mn in the cobalt salt and the manganese salt is 1:2.

[0012] As a further preferred embodiment of the present invention, the addition amount of γ-Al2O3 in the cobalt-manganese-aluminum solid solution catalyst is 7wt%.

[0013] As a further preferred embodiment of the present invention, the carbonate is one of ammonium bicarbonate, sodium bicarbonate and sodium carbonate.

[0014] As a further preferred embodiment of the present invention, the concentration of carbonate in solution B is 1-3 mol / L.

[0015] As a further preferred embodiment of the present invention, the stirring speed in step S1 is 300-400 r / min; and the stirring time is 1-2 h.

[0016] As a further preferred embodiment of the present invention, the room temperature aging time in step S2 is 18-24 hours, and the drying temperature is 70-90°C.

[0017] As a further preferred embodiment of the present invention, the concentration of the H3PO4 solution in step S3 is 0.05-1 mol / L, and the immersion time is 1-2 h.

[0018] A phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst is prepared by the above preparation method.

[0019] The invention discloses an application of a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst for the synergistic removal of non-methane total hydrocarbons.

[0020] As a further preferred embodiment of the present invention, the flue gas is introduced into a reaction device containing the phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst to carry out simultaneous denitration and dechlorobenzene reactions within a temperature range of 60-400°C.

[0021] The prepared phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst has a denitration efficiency of more than 90% in the temperature range of 90-270°C and more than 99.5% of NO in the temperature range of 120-150°C. x Removal rate: The dechlorobenzene efficiency is over 90% at 210°C and over 95% at 240°C; and it exhibits excellent denitrification and dechlorobenzene efficiency in the presence of SO2 and H2O.

[0022] Beneficial effects of the present invention:

[0023] 1. The cobalt-manganese-aluminum solid solution catalyst of the present invention is prepared by simple aluminum doping and phosphoric acid modification, which can ensure the stable structure and excellent performance of cobalt-manganese oxide, effectively improve the efficiency of simultaneous denitration and dechlorobenzene and broaden the NO x The temperature range for medium and low temperature removal.

[0024] 2. The catalyst material cost of the present invention is low, the preparation method is simple, and the NO can be achieved in the medium and low temperature range while keeping the existing SCR process equipment unchanged. x And VOCs are removed efficiently at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below in conjunction with the accompanying drawings.

[0026] Figure 1 To prepare the catalyst (CoMnAlO x -P) Schematic diagram of the process;

[0027] Figure 2 Cobalt manganese oxide catalyst (CoMn2O4), cobalt manganese aluminum solid solution catalyst (CoMnAlO x ) and phosphoric acid modified cobalt manganese aluminum solid solution catalyst (CoMnAlO x -P) X-ray diffraction (XRD) characterization results. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Obviously, the following descriptions are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in the field related to the content disclosed in this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means, and should not be understood as insufficient content disclosed in this application.

[0030] However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of substantially the same structures may be omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the following description is provided for those skilled in the art to fully understand the present application and is not intended to limit the subject matter described in the claims.

[0031] If not otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution, and all technical features and optional technical features of the present application can be combined with each other to form a new technical solution.

[0032] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0033] Nitrogen oxides (NO x ) and chlorobenzene (CB) are important air pollutants. x It is one of the main pollutants that form acid rain, chemical smog and photochemical oxidants. It will lead to a decline in air quality, harm human health and damage the ecological environment. Chlorobenzene is a volatile organic compound (VOCs) that is toxic, persistent and bioaccumulative. It is harmful to the human nervous system, liver and other organs, and will also have a negative impact on the quality of the atmospheric environment. In the existing technology, the catalytic activity of pure cobalt manganese oxide is limited and meets the requirements of NO x It is difficult to effectively remove VOCs at the same time;

[0034] To achieve NO x In the present invention, the activity of cobalt manganese oxide is improved by appropriate amount of aluminum doping and phosphoric acid modification to achieve NO x The cobalt-manganese-aluminum solid solution catalyst was successfully synthesized by X-ray diffraction (XRD) technology. The cobalt-manganese-aluminum solid solution catalyst can not only achieve low-temperature denitration, but also achieve high-efficiency low-temperature conversion of CB.

[0035] The following is a detailed description of a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst of the present application, its preparation method, and its application in synergistic removal of non-methane total hydrocarbons.

[0036] The first aspect of the present application provides a method for preparing a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst, comprising the following steps:

[0037] Step S1, dissolving cobalt salt, manganese salt and γ-Al2O3 in anhydrous ethanol, stirring evenly at room temperature to obtain solution A; dissolving carbonate in deionized water and stirring evenly to obtain solution B;

[0038] Step S2, adding solution B dropwise into solution A, aging at room temperature, filtering, washing, and drying to obtain a white solid, which is then calcined to obtain a cobalt-manganese-aluminum solid solution catalyst (referred to as CoMnAlO x );

[0039] Step S3, immersing the cobalt manganese aluminum solid solution catalyst in a H3PO4 solution, washing, filtering, and drying to obtain a phosphoric acid-modified cobalt manganese aluminum solid solution catalyst (referred to as CoMnAlO x -P). The residual phosphoric acid is washed and filtered to remove it, which may enter the environment with the exhaust gas and cause environmental pollution.

[0040] In the present application, a cobalt-manganese-aluminum solid solution catalyst is synthesized by a coprecipitation method through heat treatment, wherein a precipitant (carbonate) is decomposed into a gas under high temperature conditions to release the cobalt-manganese-aluminum solid solution catalyst having a higher specific surface area and better adsorption capacity, and then an H3PO4 solution is used for impregnation treatment to improve the acid sites and active centers, enhance the anti-poisoning ability of the catalyst, and adjust the pore structure and specific surface area of ​​the catalyst, which is beneficial to gas adsorption to cause redox reaction and improve the catalytic activity of the phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst.

[0041] In some embodiments, γ-Al2O3 is prepared by the following steps: aluminum hydroxide is placed in a muffle furnace and calcined at 500-600°C for 3-4 hours to obtain γ-Al2O3. The prepared γ-Al2O3 has a large specific surface area and pore structure, which can provide a good dispersion site for active components, facilitate the adsorption of reactant molecules and the desorption of product molecules, thereby promoting the catalytic reaction. The prepared γ-Al2O3 also has high chemical activity: there are a large number of Lewis acid sites and Acidic sites can act as active centers to participate in catalytic reactions and enhance the activity of catalysts. In addition, γ-Al2O3 has good thermal stability and can maintain structural stability within a certain temperature range and withstand thermal shock during the reaction process.

[0042] In some embodiments, the molar ratio of Co:Mn in the cobalt salt and the manganese salt is 1:2. The molar ratio of 1:2 helps to form a stable crystal structure and exhibits higher catalytic activity and stability in the denitration and de-VOCs reaction.

[0043] In some embodiments, the amount of γ-Al2O3 added to the cobalt-manganese-aluminum solid solution catalyst is 4 wt% to 10 wt%. In the exemplary embodiment, it can be 4%, 5%, 6%, 7%, 8%, 9%, 10% and other typical but non-limiting addition amounts or a range between any two mass fractions. The preferred mass fraction is 7%.

[0044] In some embodiments, the stirring speed in step S1 is 300-400 r / min and the stirring time is 1-2 h, so that the raw materials are fully mixed.

[0045] In some embodiments, the carbonate is one of ammonium bicarbonate, sodium bicarbonate and sodium carbonate. The carbonate is used as a precipitant, and the amount of carbonate used is calculated according to the amount of manganese and cobalt used to ensure that manganese and cobalt are completely precipitated.

[0046] In certain embodiments, the concentration of carbonate in solution B is 1-3mol / L. Too high or too low a concentration of carbonate will affect the performance of the final phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst. Too high a concentration will cause serious agglomeration, causing the nucleation rate to far exceed the nucleation growth rate, forming larger agglomerates, making the particle distribution of the catalyst uneven, affecting its physical properties and catalytic performance. It is also possible to form a heterogeneous phase, which is prone to produce local chemical environment anomalies, promote the generation of some non-target phases, such as a mixed phase of some hydroxides or carbonates, rather than a single cobalt-manganese-aluminum solid solution phase, and the presence of these heterogeneous phases will interfere with the active center of the catalyst and reduce the catalytic efficiency. Too low a concentration is prone to incomplete precipitation, resulting in a relatively small number of active sites on the catalyst surface.

[0047] In some embodiments, the room temperature aging time in step S2 is 18-24 hours, and the drying temperature is 70-90°C. After precipitation at the aging time and aging temperature, there are sufficient conditions for crystallization and structural adjustment, which promotes the orderly arrangement of metal ions in the lattice, reduces lattice defects and disordered areas, and forms a cobalt-manganese-aluminum solid solution with high crystallinity, complete structure and stability. The uniform structure and fewer defects make the catalyst less susceptible to corrosion and poisoning by chemical substances when in contact with the reaction medium, have good chemical stability, can maintain activity in a more harsh reaction environment, and reduce the risk of deactivation.

[0048] In some embodiments, the concentration of the H3PO4 solution in step S3 is 0.05-1 mol / L, and the immersion time is 1-2 hours. Phosphoric acid treatment improves the acid sites and active centers, which can ensure the stable structure and excellent performance of cobalt manganese oxide, effectively improve the efficiency of simultaneous denitration and dechlorobenzene and broaden the NO x The temperature range for medium and low temperature removal.

[0049] The second aspect of the present application provides a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst prepared by the above-mentioned preparation method.

[0050] The third aspect of the present application provides an application of a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst for synergistic removal of non-methane total hydrocarbons.

[0051] In some embodiments, the simultaneous denitration and dechlorobenzene reaction is carried out in a temperature range of 60-400° C., and the oxygen content in the flue gas is 5%.

[0052] The catalytic performance evaluation in the examples and comparative examples of this application was carried out in a fixed bed reactor. During the test, the SO2 concentration was 50ppm and the H2O content was 5wt.%. 0.1g of catalyst (40-60 mesh) was weighed and loaded into a quartz reaction tube (inner diameter 10mm), and then the reaction mixture was introduced at a flow rate of 100mL / min. After the gas concentration stabilized, the NO x and CB concentration changes. x The conversion rate of CB is calculated as follows:

[0053] Conversion rate (%) = ([C]0-[C] t ) / [C]0*100%;

[0054] Among them, [C]0 and [C] t NO before and after the reaction x and CB concentrations.

[0055] Preparation Example

[0056] Preparation of γ-Al2O3:

[0057] Aluminum hydroxide is placed in a muffle furnace and calcined at 600°C for 4 hours to obtain γ-Al2O3.

[0058] Example 1

[0059] See also Figure 1 The preparation process shown in the figure, this embodiment provides a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst, which is prepared by the following steps:

[0060] Weigh a certain amount of cobalt nitrate, manganese nitrate and γ-Al2O3 and dissolve them in 30 mL of anhydrous ethanol, wherein the molar ratio of Co:Mn is 1:2 and the amount of γ-Al2O3 added is 7% (w / w), and stir evenly at room temperature to obtain solution A;

[0061] A certain amount of sodium bicarbonate was dissolved in 30 mL of deionized water and stirred at 300 r / min for 1 h to obtain solution B, wherein the concentration of the sodium bicarbonate solution was 1 mol / L;

[0062] Solution B was added dropwise to solution A, aged for 24 h, then centrifuged, washed and filtered, and dried overnight in a forced air drying oven at 80 °C to obtain a white solid;

[0063] The white solid was placed in a muffle furnace and calcined at 500°C for 3 h to obtain a black powder cobalt-manganese-aluminum solid solution catalyst;

[0064] The catalyst obtained above was immersed in 0.1 mol / L H3PO4 for 1 h, centrifuged and filtered, washed with deionized water and anhydrous ethanol three times respectively, and then dried in a 40°C forced air drying oven overnight to obtain the final product, a phosphoric acid-modified cobalt manganese aluminum solid solution catalyst, recorded as CoMnAlO x -P.

[0065] Comparative Example 1

[0066] The difference between this comparative example and Example 1 is that no γ-Al2O3 is added and phosphoric acid modification is performed, and the prepared catalyst is recorded as CoMn2O4.

[0067] Comparative Example 2

[0068] The difference between this comparative example and Example 1 is that no phosphoric acid modification is performed and the prepared catalyst is recorded as CoMnAlO x .

[0069] The products prepared in Example 1 and Comparative Examples 1-2 were analyzed by X-ray diffraction (XRD). Figure 2 As shown, according to Figure 2 It can be seen that the addition of aluminum and phosphoric acid modification did not change the catalyst crystal morphology. x -P catalyst still has a cobalt manganese oxide structure; it also shows that aluminum is uniformly incorporated into the cobalt manganese oxide lattice, which is significantly different from the carrier loading.

[0070] Example 2

[0071] 0.1 g of the catalysts in Example 1, Comparative Example 1 and Comparative Example 2 were weighed and loaded into a quartz reaction tube (inner diameter 10 mm), and then 100 mL / min of a reaction mixture (including nitrogen carrier gas, 5% O2, 500 ppm NOx , 500ppm NH3 and 50ppm CB), set the reaction temperature to 60-400℃, the heating rate to 10℃ / min, stabilize the reaction at each temperature point for 30min, and record the tail NO before and after the reaction x and CB concentration changes, and the CoMn2O4, CoMnAlO x and CoMnAlO x -P denitrification and dechlorobenzene efficiency. Compared with CoMn2O4 and CoMnAlO x Catalyst, phosphoric acid modified cobalt manganese aluminum solid solution catalyst CoMnAlO x -P has the best performance in denitrification and dechlorobenzene.

[0072] The relevant denitrification results are shown in Table 1:

[0073] Table 1

[0074]

[0075]

[0076] It can be seen from Table 1 that aluminum incorporation and phosphoric acid modification significantly improve the denitrification performance of cobalt manganese oxide. x -P catalyst can achieve more than 95% NO in the temperature range of 90-270℃ x The removal rate reaches more than 99.5% of NO in the temperature range of 120-150℃ x removal rate; significantly broadened the denitrification temperature range and achieved NO x Highly efficient removal at medium and low temperatures.

[0077] The relevant dechlorobenzene results are shown in Table 2:

[0078] Table 2

[0079]

[0080] It can be seen from Table 2 that the catalytic activity of cobalt manganese oxide is significantly enhanced by aluminum doping and phosphoric acid modification. x -P catalyst has greatly improved the efficiency of removing chlorobenzene. 90 (CB conversion efficiency is 90%) reduced from 400℃ to 210℃; at 240℃, the dechlorobenzene efficiency reached more than 95%.

[0081] Example 3

[0082] Compared with Example 1, the addition amount of γ-Al2O3 in this example is adjusted to 4% (w / w), and the other raw materials and preparation process remain the same as those in Example 1. The specific steps are as follows:

[0083] A phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst is prepared by the following steps:

[0084] Weigh a certain amount of cobalt nitrate, manganese nitrate and γ-Al2O3 and dissolve them in 30 mL of anhydrous ethanol, wherein the molar ratio of Co:Mn is 1:2 and the amount of γ-Al2O3 added is 4% (w / w), and stir evenly at room temperature to obtain solution A;

[0085] A certain amount of sodium bicarbonate was dissolved in 30 mL of deionized water and stirred at 300 r / min for 1 h to obtain solution B, wherein the concentration of the sodium bicarbonate solution was 1 mol / L;

[0086] Solution B was added dropwise to solution A, aged for 24 h, then centrifuged, washed and filtered, and dried overnight in a forced air drying oven at 80 °C to obtain a white solid;

[0087] The white solid was placed in a muffle furnace and calcined at 500°C for 3 h to obtain a black powder cobalt-manganese-aluminum solid solution catalyst;

[0088] The catalyst obtained above was immersed in 0.1 mol / L H3PO4 for 1 h, centrifuged and filtered, washed with deionized water and anhydrous ethanol three times respectively, and then dried in a 40°C forced air drying oven overnight to obtain the final product, a phosphoric acid-modified cobalt manganese aluminum solid solution catalyst, recorded as CoMnAlO x -P.

[0089] Example 4

[0090] Compared with Example 1, the addition amount of γ-Al2O3 in this example is adjusted to 10% (w / w), and the other raw materials and preparation process remain the same as those in Example 1. The specific steps are as follows:

[0091] A phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst is prepared by the following steps:

[0092] Weigh a certain amount of cobalt nitrate, manganese nitrate and γ-Al2O3 and dissolve them in 30 mL of anhydrous ethanol, wherein the molar ratio of Co:Mn is 1:2 and the amount of γ-Al2O3 added is 10% (w / w), and stir evenly at room temperature to obtain solution A;

[0093] A certain amount of sodium bicarbonate was dissolved in 30 mL of deionized water and stirred at 300 r / min for 1 h to obtain solution B, wherein the concentration of the sodium bicarbonate solution was 1 mol / L;

[0094] Solution B was added dropwise to solution A, aged for 24 h, then centrifuged, washed and filtered, and dried overnight in a forced air drying oven at 80 °C to obtain a white solid;

[0095] The white solid was placed in a muffle furnace and calcined at 500°C for 3 h to obtain a black powder cobalt-manganese-aluminum solid solution catalyst;

[0096] The catalyst obtained above was immersed in 0.1 mol / L H3PO4 for 1 h, centrifuged and filtered, washed with deionized water and anhydrous ethanol three times respectively, and then dried in a 40°C forced air drying oven overnight to obtain the final product, a phosphoric acid-modified cobalt manganese aluminum solid solution catalyst, recorded as CoMnAlO x -P.

[0097] Example 5

[0098] The phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst with the addition amount of γ-Al2O3 prepared in Example 1, Example 3 and Example 4 was used as the test sample to carry out flue gas denitration and dechlorobenzene tests. The test process and results are as follows:

[0099] Weigh 0.1g of CoMnAlO with different γ-Al2O3 addition amounts (4wt%, 7wt% and 10wt%) respectively. x The -P catalyst was loaded into a quartz reaction tube (10 mm inner diameter), and then a reaction mixture (including nitrogen carrier gas, 5% O2, 500 ppm NO) was introduced at 100 mL / min. x , 500ppmNH3 and 50ppmCB), set the reaction temperature to 60-400℃, the heating rate to 10℃ / min, stabilize the reaction at each temperature point for 30min, and record the tail NO before and after the reaction x and CB concentration, the CoMnAlO with different γ-Al2O3 addition amounts was calculated. x -P catalyst denitrification and dechlorobenzene efficiency.

[0100] CoMnAlO with different γ-Al2O3 addition amounts x -P catalyst denitrification results are shown in Table 3:

[0101] Table 3

[0102]

[0103]

[0104] According to the records, when the addition amount of γ-Al2O3 is 7wt%, the solid solution catalyst CoMnAlO x -P has the best performance in denitrification and dechlorobenzene removal. Combining CoMn2O4 and CoMnAlO x The test results show that when the amount of γ-Al2O3 is too much or too little, it will affect the CoMnAlO x -P denitrification and dechlorobenzene performance have a negative impact.

[0105] CoMnAlO with different γ-Al2O3 addition amounts x The results of dechlorobenzene with -P catalyst are shown in Table 4:

[0106] Table 4

[0107]

[0108] If the doping amount is too low, the electronic state of the metal atoms cannot be fully changed, so that the activity of the catalyst cannot be effectively improved; if the doping amount is too high, the active centers on the catalyst surface will be covered, reducing the catalytic activity.

[0109] From the results of the specific tests of the phosphoric acid-modified cobalt-manganese-aluminum solid solution catalysts prepared under different conditions recorded in Tables 1 to 4, it can be seen that the phosphoric acid-modified cobalt-manganese-aluminum solid solution catalysts in the present invention achieve the effect of reducing NO in industrial flue gas. x It can remove VOCs and VOCs simultaneously, and can achieve efficient removal in the medium and low temperature range. In addition, the phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst provided by the present invention can achieve NO removal in the medium and low temperature range while keeping the existing SCR process equipment unchanged. x The simultaneous and efficient removal of VOCs provides a feasible solution to solving the problem of multiple pollutants in flue gas.

[0110] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0111] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst, characterized in that: The steps include: Step S1, dissolving cobalt salt, manganese salt and γ-Al2O3 in anhydrous ethanol, stirring evenly at room temperature to obtain solution A; dissolving carbonate in deionized water and stirring evenly to obtain solution B; Step S2, adding solution B dropwise into solution A, aging at room temperature, filtering, washing, drying, and calcining to obtain a cobalt-manganese-aluminum solid solution catalyst; Step S3, immersing the cobalt-manganese-aluminum solid solution catalyst in a H3PO4 solution, washing, filtering, and drying to obtain a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst.

2. The method for preparing a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst according to claim 1, characterized in that: γ-Al2O3 is prepared by the following steps: aluminum hydroxide is calcined at a temperature of 500-600°C for 3-4 hours to obtain γ-Al2O3.

3. The method for preparing a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst according to claim 1, characterized in that: The molar ratio of Co:Mn in the cobalt salt and the manganese salt is 1:

2.

4. The method for preparing a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst according to claim 1, characterized in that: The addition amount of γ-Al2O3 in the cobalt-manganese-aluminum solid solution catalyst is 7wt%.

5. The method for preparing a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst according to claim 1, characterized in that: The stirring speed in step S1 is 300-400 r / min; the stirring time is 1-2 h; In step S2, the room temperature aging time is 18-24 hours, and the drying temperature is 70-90°C.

6. The method for preparing a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst according to claim 1, characterized in that: The carbonate is one of ammonium bicarbonate, sodium bicarbonate and sodium carbonate; The concentration of the carbonate is 1-3 mol / L.

7. The method for preparing a phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst according to claim 1, characterized in that: The concentration of the H3PO4 solution in step S3 is 0.05-1 mol / L, and the immersion time is 1-2 h.

8. A phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst, characterized in that: Prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the phosphoric acid-modified cobalt-manganese-aluminum solid solution catalyst as claimed in claim 8, characterized in that: Applied to the synergistic removal of non-methane hydrocarbons.

10. Use of the catalyst according to claim 9, characterized in that: The simultaneous denitration and dechlorobenzene reactions are carried out in the temperature range of 60-400°C.

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