CN117181257A - Carbon sponge supported nano-array monolithic catalyst and preparation method and application thereof - Google Patents
Carbon sponge supported nano-array monolithic catalyst and preparation method and application thereof Download PDFInfo
- Publication number
- CN117181257A CN117181257A CN202310982284.8A CN202310982284A CN117181257A CN 117181257 A CN117181257 A CN 117181257A CN 202310982284 A CN202310982284 A CN 202310982284A CN 117181257 A CN117181257 A CN 117181257A
- Authority
- CN
- China
- Prior art keywords
- nitrate
- carbon sponge
- catalyst
- nitrogen
- metal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000003054 catalyst Substances 0.000 title claims abstract description 70
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 39
- 229910052799 carbon Inorganic materials 0.000 title claims abstract description 39
- 238000002360 preparation method Methods 0.000 title claims abstract description 17
- 239000002243 precursor Substances 0.000 claims abstract description 24
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 19
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 17
- 238000001816 cooling Methods 0.000 claims abstract description 15
- 238000001027 hydrothermal synthesis Methods 0.000 claims abstract description 12
- 229940071125 manganese acetate Drugs 0.000 claims abstract description 12
- UOGMEBQRZBEZQT-UHFFFAOYSA-L manganese(2+);diacetate Chemical group [Mn+2].CC([O-])=O.CC([O-])=O UOGMEBQRZBEZQT-UHFFFAOYSA-L 0.000 claims abstract description 12
- 229910001960 metal nitrate Inorganic materials 0.000 claims abstract description 12
- 229910052751 metal Inorganic materials 0.000 claims abstract description 10
- 239000002184 metal Substances 0.000 claims abstract description 10
- 150000003839 salts Chemical class 0.000 claims abstract description 10
- 238000005406 washing Methods 0.000 claims abstract description 8
- 238000003756 stirring Methods 0.000 claims abstract description 7
- 238000001035 drying Methods 0.000 claims abstract description 5
- 239000012716 precipitator Substances 0.000 claims abstract description 5
- 229910001994 rare earth metal nitrate Inorganic materials 0.000 claims abstract description 3
- 229910002001 transition metal nitrate Inorganic materials 0.000 claims abstract description 3
- 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 claims description 16
- 238000000034 method Methods 0.000 claims description 14
- 229910021645 metal ion Inorganic materials 0.000 claims description 12
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 10
- 229920000877 Melamine resin Polymers 0.000 claims description 7
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims description 7
- 239000004202 carbamide Substances 0.000 claims description 7
- 235000013877 carbamide Nutrition 0.000 claims description 7
- 238000010000 carbonizing Methods 0.000 claims description 7
- JDSHMPZPIAZGSV-UHFFFAOYSA-N melamine Chemical compound NC1=NC(N)=NC(N)=N1 JDSHMPZPIAZGSV-UHFFFAOYSA-N 0.000 claims description 7
- 238000003763 carbonization Methods 0.000 claims description 6
- VCJMYUPGQJHHFU-UHFFFAOYSA-N iron(3+);trinitrate Chemical compound [Fe+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VCJMYUPGQJHHFU-UHFFFAOYSA-N 0.000 claims description 6
- 229910052757 nitrogen Inorganic materials 0.000 claims description 6
- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 claims description 4
- UFMZWBIQTDUYBN-UHFFFAOYSA-N cobalt dinitrate Chemical compound [Co+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O UFMZWBIQTDUYBN-UHFFFAOYSA-N 0.000 claims description 4
- 229910001981 cobalt nitrate Inorganic materials 0.000 claims description 4
- 238000004108 freeze drying Methods 0.000 claims description 4
- VKYKSIONXSXAKP-UHFFFAOYSA-N hexamethylenetetramine Chemical compound C1N(C2)CN3CN1CN2C3 VKYKSIONXSXAKP-UHFFFAOYSA-N 0.000 claims description 4
- KBJMLQFLOWQJNF-UHFFFAOYSA-N nickel(ii) nitrate Chemical compound [Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O KBJMLQFLOWQJNF-UHFFFAOYSA-N 0.000 claims description 4
- 238000001291 vacuum drying Methods 0.000 claims description 4
- 238000000352 supercritical drying Methods 0.000 claims description 3
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 claims description 2
- 235000012501 ammonium carbonate Nutrition 0.000 claims description 2
- 239000001099 ammonium carbonate Substances 0.000 claims description 2
- 239000012298 atmosphere Substances 0.000 claims description 2
- XTVVROIMIGLXTD-UHFFFAOYSA-N copper(II) nitrate Chemical compound [Cu+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O XTVVROIMIGLXTD-UHFFFAOYSA-N 0.000 claims description 2
- 235000010299 hexamethylene tetramine Nutrition 0.000 claims description 2
- 239000004312 hexamethylene tetramine Substances 0.000 claims description 2
- 230000001681 protective effect Effects 0.000 claims description 2
- 230000000630 rising effect Effects 0.000 claims description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 abstract description 9
- 229910052717 sulfur Inorganic materials 0.000 abstract description 9
- 239000011593 sulfur Substances 0.000 abstract description 9
- 238000006555 catalytic reaction Methods 0.000 abstract description 3
- 239000002699 waste material Substances 0.000 abstract description 3
- 239000000243 solution Substances 0.000 description 24
- 238000010438 heat treatment Methods 0.000 description 21
- 239000008367 deionised water Substances 0.000 description 10
- 229910021641 deionized water Inorganic materials 0.000 description 10
- 239000011259 mixed solution Substances 0.000 description 10
- 230000000694 effects Effects 0.000 description 8
- 230000003197 catalytic effect Effects 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- 239000011572 manganese Substances 0.000 description 5
- 239000012299 nitrogen atmosphere Substances 0.000 description 5
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 4
- 238000004090 dissolution Methods 0.000 description 4
- 239000003546 flue gas Substances 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 239000000758 substrate Substances 0.000 description 4
- 230000001133 acceleration Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 230000006835 compression Effects 0.000 description 3
- 238000000576 coating method Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000011056 performance test Methods 0.000 description 2
- 231100000572 poisoning Toxicity 0.000 description 2
- 230000000607 poisoning effect Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 239000002841 Lewis acid Substances 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000002485 combustion reaction Methods 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
- 238000009792 diffusion process Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 150000007517 lewis acids Chemical class 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000033116 oxidation-reduction process Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 239000002910 solid waste Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000013112 stability test Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 229910000314 transition metal oxide Inorganic materials 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Catalysts (AREA)
Abstract
The invention belongs to the technical field of catalysis, and discloses a carbon sponge supported nano-array monolithic catalyst, and a preparation method and application thereof, wherein the preparation method comprises the following steps: (1) preparing a nitrogen-doped carbon sponge; (2) preparing a precursor solution: dissolving metal salt in water, and then adding a precipitator to prepare a precursor solution; the metal salt is manganese acetate and metal nitrate, and the metal nitrate is rare earth metal nitrate and/or transition metal nitrate; (3) Adding a template agent into the precursor solution, stirring until the template agent is completely dissolved, adding nitrogen-doped carbon sponge, then performing hydrothermal reaction, cooling, washing and drying to obtain the carbon sponge supported nano-array monolithic catalyst. The preparation method is green and efficient, the denitration efficiency of the prepared catalyst can reach 100%, the catalyst has higher sulfur and water resistance, and the waste catalyst is easy to treat.
Description
Technical Field
The invention belongs to the technical field of catalysis, and particularly relates to a preparation method and application of a high-efficiency sulfur-resistant integral flexible catalyst for low-temperature denitration.
Background
Industrial flue gas denitration is one of important measures for improving the atmospheric environment. Aiming at the actual requirements of ultralow emission and low-temperature flue gas treatment, the research of low-temperature denitration technology is increasingly urgent. NH (NH) 3 SCR technology has been widely used for NOx removal in industrial boilers due to its excellent catalytic activity and low operating costs. V (V) 2 O 5 -WO 3 (MoO 3 )/TiO 2 Is the most widely used commercial catalyst. However, the biotoxicity and narrow operating temperature window (300-400 ℃) of vanadium species makes it difficult to apply directly to low temperature flue gas denitrification. Especially, the non-electric industry is a main battlefield for improving the environmental quality at present due to low smoke temperature and high emission. The transition metal oxide catalyst has good low-temperature SCR activity and becomes an important research point in the field of denitration in recent years. In particular, mn oxide catalysts have received much attention because of their excellent low-temperature catalytic activity and inherent environmental friendliness. But Mn oxide catalyst to SO 2 Very sensitive, severely limiting its industrial application. Although Mn oxide catalysts have been studied intensively, powder catalysts generally exhibit excellent low-temperature activity under laboratory conditions, application under practical engineering conditions remains a great challenge because industrial applications are generally aimed at reducing bed resistanceIt is required to prepare a monolithic structure.
The monolithic catalysts currently used are mostly prepared by extrusion molding or coating methods. The sample preparation is complex and the cost is high, and the active components are easy to fall off, so that the preparation of the monolithic catalyst by directly coating the active materials on the three-dimensional porous matrix is one of the new development directions of the low-temperature SCR catalyst. The three-dimensional porous matrix has a three-dimensional interconnection network, can provide a larger contact area and lower bed pressure drop for the reaction gases, and is hopeful to become an excellent carrier of the catalyst. However, it is difficult to mass-produce because of the complicated preparation process and the high preparation cost of most three-dimensional porous carriers.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a preparation method and application of a high-efficiency sulfur-resistant integral flexible catalyst for low-temperature denitration. The catalyst takes nitrogen-doped carbon sponge as a substrate, reduces the resistance of a catalyst bed layer by means of the porosity of up to 97%, provides more active sites, and combines the high oxidation-reduction performance of nano metal oxide. The catalyst prepared by the method has good flexibility, firm adhesion of active components, good low-temperature catalytic activity and stability, wider operating temperature window and good water and sulfur resistance.
The technical problems to be solved are as follows: the existing manganese-based integral denitration catalyst applied industrially has the disadvantages of complex preparation process, high cost, easy falling of active components, poor low-temperature activity, weak sulfur poisoning resistance and high treatment cost of the waste catalyst.
The technical scheme adopted by the invention is as follows:
a preparation method of a carbon sponge supported nano-array monolithic catalyst comprises the following steps:
(1) Preparing a nitrogen-doped carbon sponge;
(2) Preparing a precursor solution: dissolving metal salt in water, and then adding a precipitator to prepare a precursor solution; the metal salt is manganese acetate and metal nitrate, and the metal nitrate is rare earth metal nitrate and/or transition metal nitrate;
(3) Adding a template agent into the precursor solution, stirring until the template agent is completely dissolved, adding nitrogen-doped carbon sponge, then performing hydrothermal reaction, cooling, washing and drying to obtain the carbon sponge supported nano-array monolithic catalyst.
Preferably, the preparation of the nitrogen-doped carbon sponge of step (1): carbonizing melamine sponge in protective atmosphere at 500-800 ℃, and then cooling to obtain the nitrogen-doped carbon sponge.
Preferably, the heating rate of carbonization is 1-5 ℃/min, the carbonization temperature is 700+/-100 ℃, and the carbonization time is 3+/-2 h.
Preferably, the molar ratio of manganese acetate to metal nitrate in step (2) is 1-10; the mol ratio of the precipitant to the metal ions is 0.6+/-0.3; the molar ratio of the metal salt to the template agent in the step (3) is 0.5-5.0.
Preferably, the metal nitrate in the step (2) is one or more than two of cerium nitrate, cobalt nitrate, ferric nitrate, copper nitrate and nickel nitrate; the precipitant is one or more than two of urea, ammonium carbonate and hexamethylenetetramine.
Preferably, the molar ratio of manganese acetate to metal nitrate in step (2) is from 2 to 5.
Preferably, the temperature of the hydrothermal reaction in the step (3) is 250-400 ℃, the time of the hydrothermal reaction is 12-36h, and the temperature rising rate of the hydrothermal reaction is 1-5 ℃/min.
Preferably, the template agent in the step (3) is nitrogen tetrafluoride or hexadecyl trimethyl ammonium bromide, and the molar ratio of the metal salt to the template agent is 1-4; the drying is freeze drying, supercritical drying or vacuum drying.
The carbon sponge supported nano-array monolithic catalyst prepared by the method is applied to low-temperature denitration.
Compared with the prior art, the invention has the following beneficial effects:
(1) According to the invention, the nitrogen-doped carbon sponge with a three-dimensional interconnection network structure is used as a flexible carrier, so that a larger contact area can be provided, and the dispersion and chemical stability of active components (composite metal oxide) are facilitated. In addition, its unique network structure facilitates the diffusion and adsorption of the reactant gases in the catalytic reaction. Meanwhile, the bed resistance is small in the application process, and the method has good processability, so that the method can be suitable for different application environments. Compared with the traditional rigid substrate, the nitrogen-doped carbon sponge has the unique advantages of low cost, light weight, high porosity, strong processability and the like, and the pyridine-N, pyrrole-N and quaternary ammonium-N functional groups on the surface can improve the denitration efficiency of the carbon material.
(2) The invention adopts the environment-friendly transition metal element, the synthesis method is environment-friendly and efficient, the catalyst has excellent performance, the waste catalyst is easy to treat, such as direct combustion or compression landfill, and the solid waste is hardly generated.
(3) The surface of the catalyst prepared in the invention is rich in active surface oxygen and a large amount of Mn 3+ And Mn of 4+ A lewis acid site. Most importantly, the catalyst can follow different reaction mechanisms in different temperature ranges, and therefore, the catalyst can show excellent catalytic activity in the range of 100-400 ℃.
Drawings
FIG. 1 is a graph of the microscopic morphology of the catalyst obtained in example 1, in which the electron microscope model is SU8020, the acceleration voltage is 3.0kV, and the magnification is 150; the lower scale of the figure represents 300 microns.
FIG. 2 is a graph of the microscopic morphology of the catalyst obtained in example 1, in which the electron microscope model is SU8020, the acceleration voltage is 3.0kV, and the magnification is 1000; the lower scale of the figure represents 50 microns.
FIG. 3 is a graph of the microscopic morphology of the catalyst obtained in example 1, in which the electron microscope model is SU8020, the acceleration voltage is 3.0kV, and the magnification is 20000; the lower scale of the figure represents 2 microns.
FIG. 4 stability of the catalysts prepared in examples 1-5.
FIG. 5 sulfur and water resistance at 200℃of the catalysts prepared in examples 1-5.
FIG. 6 is a graph of the pressure strain curve of the catalyst of example 2.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent.
Example 1
Step one: and heating the melamine sponge to 600 ℃ at a heating rate of 2 ℃/min in a nitrogen atmosphere, carbonizing for 3 hours, and naturally cooling to room temperature to obtain the nitrogen-doped carbon sponge.
Step two: preparing an active precursor solution, dissolving 4mmol of manganese acetate and 1mmol of cerium nitrate (molar ratio of 4:1) in 40mL of deionized water to form a uniform precursor solution, and then adding 3mmol of urea (molar ratio of precipitant to metal ions of 0.6:1) into the precursor solution to prepare a mixed solution.
Step three: and 5mmol of nitrogen tetrafluoride (the molar ratio of the template agent to the metal ions is 1:1) is added into the mixed solution prepared in the step two, and stirring is continued until complete dissolution.
Step four: adding a piece of nitrogen-doped carbon sponge prepared in the first step into the solution prepared in the third step, transferring into a hydrothermal reaction kettle, heating to 300 ℃ at a heating rate of 2 ℃/min, reacting for 12 hours, naturally cooling to room temperature, and washing with deionized water.
Step five: and (3) freeze-drying the catalyst prepared in the step four at the temperature of 60 ℃ below zero for 24 hours to obtain the carbon sponge supported nano array integral catalyst.
Example 2
Step one: and heating the melamine sponge to 700 ℃ at a heating rate of 5 ℃/min in a nitrogen atmosphere, carbonizing for 3 hours, and naturally cooling to room temperature to obtain the nitrogen-doped carbon sponge.
Step two: an active precursor solution is prepared, 4mmol of manganese acetate and 2mmol of cerium nitrate (molar ratio 2:1) are dissolved in 40mL of deionized water to form a uniform precursor solution, and then 3.6mmol of urea (molar ratio of precipitant to metal ions is 0.6:1) is added into the precursor solution to prepare a mixed solution.
Step three: and 3mmol of nitrogen tetrafluoride (the molar ratio of the template agent to the metal ions is 1:2) is added into the mixed solution prepared in the step two, and stirring is continued until complete dissolution.
Step four: adding a piece of nitrogen-doped carbon sponge prepared in the first step into the solution prepared in the third step, transferring into a hydrothermal reaction kettle, heating to 250 ℃ at a heating rate of 3 ℃/min, reacting for 12 hours, naturally cooling to room temperature, and washing with deionized water.
Step five: and (3) vacuum drying the catalyst prepared in the step four at 100 ℃ for 12 hours to obtain the carbon sponge supported nano-array integral catalyst.
Example 3
Step one: and heating the melamine sponge to 800 ℃ at a heating rate of 3 ℃/min in a nitrogen atmosphere, carbonizing for 2 hours, and naturally cooling to room temperature to obtain the nitrogen-doped carbon sponge.
Step two: an active precursor solution is prepared, 5mmol of manganese acetate and 1mmol of ferric nitrate (molar ratio of 5:1) are dissolved in 40mL of deionized water to form a uniform precursor solution, and then 3.6mmol of urea (molar ratio of precipitant to metal ions is 0.6:1) is added into the precursor solution to prepare a mixed solution. Step three: to the mixed solution prepared in the second step, 1.5mmol of cetyltrimethylammonium bromide (molar ratio of template agent to metal ion 1:4) was added, and stirring was continued until complete dissolution.
Step four: adding a piece of nitrogen-doped carbon sponge prepared in the first step into the solution prepared in the third step, transferring into a hydrothermal reaction kettle, heating to 400 ℃ at a heating rate of 5 ℃/min, reacting for 24 hours, naturally cooling to room temperature, and washing with deionized water.
Step five: and (3) carrying out supercritical drying on the catalyst prepared in the step four for 12 hours to obtain the carbon sponge supported nano array integral catalyst.
Example 4
Step one: and heating the melamine sponge to 600 ℃ at a heating rate of 5 ℃/min in a nitrogen atmosphere, carbonizing for 3 hours, and naturally cooling to room temperature to obtain the nitrogen-doped carbon sponge.
Step two: preparing an active precursor solution, dissolving 4mmol of manganese acetate, 1mmol of cerium nitrate and 1mmol of cobalt nitrate (the molar ratio of the cerium nitrate to the cobalt nitrate is 4:1:1) in 40mL of deionized water to form a uniform precursor solution, and then adding 3.6mmol of urea (the molar ratio of a precipitator to metal ions is 0.6:1) into the precursor solution to prepare a mixed solution.
Step three: and 2mmol of nitrogen tetrafluoride (the molar ratio of the template agent to the metal ions is 1:3) is added into the mixed solution prepared in the step two, and stirring is continued until complete dissolution.
Step four: adding a piece of nitrogen-doped carbon sponge prepared in the first step into the solution prepared in the third step, transferring into a hydrothermal reaction kettle, heating to 250 ℃ at a heating rate of 5 ℃/min, reacting for 36h, naturally cooling to room temperature, and washing with deionized water.
Step five: and (3) freeze-drying the catalyst prepared in the step four at the temperature of 60 ℃ below zero for 24 hours to obtain the carbon sponge supported nano array integral catalyst.
Example 5
Step one: and heating the melamine sponge to 600 ℃ at a heating rate of 2 ℃/min in a nitrogen atmosphere, carbonizing for 3 hours, and naturally cooling to room temperature to obtain the nitrogen-doped carbon sponge.
Step two: preparing an active precursor solution, dissolving 4mmol of manganese acetate, 1mmol of cerium nitrate and 1mmol of nickel nitrate (the molar ratio of the cerium nitrate to the nickel nitrate is 4:1:1) in 40mL of deionized water to form a uniform precursor solution, and then adding 3.6mmol of urea (the molar ratio of a precipitator to metal ions is 0.6:1) into the precursor solution to prepare a mixed solution.
Step three: and 2mmol of cetyl trimethyl ammonium bromide (the molar ratio of the template agent to the metal ions is 1:3) is added into the mixed solution prepared in the step two, and the mixture is continuously stirred until the mixture is completely dissolved.
Step four: adding a piece of nitrogen-doped carbon sponge prepared in the first step into the solution prepared in the third step, transferring into a hydrothermal reaction kettle, heating to 400 ℃ at a heating rate of 2 ℃/min, reacting for 12 hours, naturally cooling to room temperature, and washing with deionized water.
Step five: and (3) vacuum drying the catalyst prepared in the step four at 100 ℃ for 12 hours to obtain the carbon sponge supported nano-array integral catalyst.
The analysis and catalytic performance test results for the samples in each example were as follows:
the product obtained in example 1 of the present invention was observed by using a scanning electron microscope, and the results are shown in FIGS. 1 to 3. As can be seen from the figure, the active components of the catalyst prepared by the method are uniformly distributed on the nitrogen-doped carbon sponge substrate, and the surface of the catalyst presents a uniformly distributed nano array structure, which indicates that the active components are well combined with the substrate.
The test conditions for denitration performance were as follows: the gas flow rate is 200mL/min, the NO concentration is 500ppm, and the NH concentration is high 3 At a concentration of 500ppm, O 2 Concentration is 5%, N 2 As balance gas, SO 2 At a concentration of 200ppm (in use), H 2 O concentration 5% by volume (when used), space velocity 12000h -1 . The catalyst denitration efficiency of each example is shown in table 1. It can be seen that the catalyst prepared by each example shows very high denitration activity in the temperature range of 100-400 ℃, the denitration activity is higher than 80% at 100 ℃, and the denitration activity can reach more than 95% at 400 ℃, which indicates that the catalyst prepared by the invention has a wider activity temperature window and is remarkably higher than similar integral catalysts reported in literature.
Table 1 results of performance test of the catalysts prepared in the respective preparation examples
From the results of stability tests on the catalysts prepared in the examples, it can be seen that the five catalysts all exhibited good stability at different test temperatures (fig. 4). SO in flue gas 2 And H 2 O has stronger inhibition effect on low-temperature SCR reaction. Therefore, the sulfur and water poisoning resistance of the low-temperature denitration catalyst is an important index for measuring the performance of the catalyst. Each example was tested for its water and sulfur resistance (200 ℃ C. Reaction) at 5% vol H 2 O and 200ppm SO 2 At the same time, when the catalyst is introduced into the reaction system (FIG. 5), the denitration efficiency is reduced to a certain extent, but the reduction amount is low, and particularly, the reduction amount of the catalyst in the embodiment 4 and the embodiment 5 is reduced by 7% and 11% respectively. At the stop of the feeding of H 2 O and SO 2 After all, a certain rise occurs. This illustrates the presence of H in the catalyst prepared by the process of the present invention 2 O and SO 2 Under the condition of (2), the prepared catalyst still has high sulfur and water resistance.
The compression curve was found to show almost complete recovery after 60% strain when tested for the mechanical properties of the catalyst prepared in example 2 (fig. 6). At 60% strain, the stress was 1.6kPa, indicating excellent flexibility of the catalyst. Furthermore, the compression stress-strain curve of the 5 th cycle was not significantly changed from that of the 1 st cycle, which proves that the catalyst prepared in the examples had excellent elasticity.
The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples, and any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principle of the present invention should be made in the equivalent manner, and the embodiments are included in the protection scope of the present invention.
Claims (10)
1. The preparation method of the carbon sponge supported nano array monolithic catalyst is characterized by comprising the following steps of:
(1) Preparing a nitrogen-doped carbon sponge;
(2) Preparing a precursor solution: dissolving metal salt in water, and then adding a precipitator to prepare a precursor solution; the metal salt is manganese acetate and metal nitrate, and the metal nitrate is rare earth metal nitrate and/or transition metal nitrate;
(3) Adding a template agent into the precursor solution, stirring until the template agent is completely dissolved, adding nitrogen-doped carbon sponge, then performing hydrothermal reaction, cooling, washing and drying to obtain the carbon sponge supported nano-array monolithic catalyst.
2. The method of claim 1, wherein the nitrogen-doped carbon sponge of step (1) is prepared by: carbonizing melamine sponge in protective atmosphere at 500-800 ℃, and then cooling to obtain the nitrogen-doped carbon sponge.
3. The preparation method according to claim 2, wherein the temperature rise rate of carbonization is 1-5 ℃/min, the carbonization temperature is 700+ -100 ℃, and the carbonization time is 3+ -2 h.
4. The method of claim 1, wherein the molar ratio of manganese acetate to metal nitrate in step (2) is 1-10; the mol ratio of the precipitant to the metal ions is 0.6+/-0.3; the molar ratio of the metal salt to the template agent in the step (3) is 0.5-5.0.
5. The method according to claim 4, wherein the metal nitrate in the step (2) is one or more of cerium nitrate, cobalt nitrate, ferric nitrate, copper nitrate and nickel nitrate; the precipitant is one or more than two of urea, ammonium carbonate and hexamethylenetetramine.
6. The method of claim 5, wherein the molar ratio of manganese acetate to metal nitrate in step (2) is 2-5.
7. The method according to any one of claims 1 to 6, wherein the hydrothermal reaction in step (3) is carried out at a temperature of 250 to 400 ℃ for 12 to 36 hours at a temperature rising rate of 1 to 5 ℃/min.
8. The method of claim 7, wherein the templating agent in step (3) is nitrogen tetrafluoride or cetyltrimethylammonium bromide and the molar ratio of metal salt to templating agent is 1-4; the drying is freeze drying, supercritical drying or vacuum drying.
9. The carbon sponge supported nano-array monolithic catalyst prepared by the method of any one of claims 1 to 8.
10. Use of the catalyst of claim 9 in low temperature denitration.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310982284.8A CN117181257A (en) | 2023-08-07 | 2023-08-07 | Carbon sponge supported nano-array monolithic catalyst and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310982284.8A CN117181257A (en) | 2023-08-07 | 2023-08-07 | Carbon sponge supported nano-array monolithic catalyst and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117181257A true CN117181257A (en) | 2023-12-08 |
Family
ID=89004232
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310982284.8A Pending CN117181257A (en) | 2023-08-07 | 2023-08-07 | Carbon sponge supported nano-array monolithic catalyst and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117181257A (en) |
-
2023
- 2023-08-07 CN CN202310982284.8A patent/CN117181257A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110732323A (en) | α -MnO for catalyzing oxidation of volatile organic compounds2Process for preparing catalyst | |
| CN109806884A (en) | A kind of graphene-manganese cerium low temperature SCR denitration catalyst and preparation method thereof | |
| CN113413904A (en) | g-C3N4Low-temperature NH of loaded manganese cerium composite oxide3-SCR catalyst, preparation method and application thereof | |
| CN113117722A (en) | For normal temperature NH3Preparation method of-SCR denitration atomic-level active site catalyst | |
| CN110787584A (en) | Application of cerium-based metal organic framework structure material in CO2Adsorption separation application of | |
| CN113000046A (en) | Modified manganese-based mullite catalyst for synergistic purification of nitrogen oxides and volatile organic compounds, and preparation method and application thereof | |
| CN112076738A (en) | Boron-doped defective zinc oxide and preparation method and application thereof | |
| CN108479845B (en) | Denitration catalyst and preparation method thereof | |
| CN113019410A (en) | Metal oxide-boron nitride composite catalyst for dry reforming of methane, and preparation method and application thereof | |
| CN111111641B (en) | Cerium dioxide-based catalyst and preparation method and application thereof | |
| CN112206768A (en) | Cerium-doped modified lanthanum-manganese composite oxide SCR denitration catalyst and preparation method thereof | |
| CN112642450A (en) | Preparation method of phosphorus-doped carbon aerogel supported manganese cerium catalyst | |
| CN108448123B (en) | Cerium-based catalyst for low-temperature water gas shift reaction and preparation method thereof | |
| CN117181257A (en) | Carbon sponge supported nano-array monolithic catalyst and preparation method and application thereof | |
| CN113877618B (en) | Preparation method of oxygen-doped graphite-phase carbon nitride-supported manganese-based low-temperature denitration catalyst and prepared denitration catalyst | |
| CN114308053A (en) | Denitration catalyst with high-entropy oxide as active component, and preparation and application thereof | |
| CN115245820A (en) | Spinel catalyst, preparation method and application thereof | |
| CN111185217A (en) | Solid phase method preparation method and application of chromium-based carbon nitride catalyst | |
| CN113751014A (en) | Monodisperse spindle-shaped monatomic catalyst for denitration and sulfur resistance and preparation method thereof | |
| CN113694920A (en) | Cordierite-based SCR catalyst, and preparation method and application thereof | |
| CN115779927B (en) | Cobalt-aluminum shell-core composite oxide loaded monoatomic iridium catalyst and preparation method and application thereof | |
| CN114643055B (en) | Nano-gold-loaded nano cerium oxide for catalyzing direct decomposition of nitrogen oxides and preparation method thereof | |
| CN114247468B (en) | Composite denitration catalyst, preparation method and application thereof | |
| CN113786835B (en) | Metal oxide catalyst applied to VOCs catalytic combustion and preparation method and application thereof | |
| CN115845867B (en) | For NH3Preparation method and application of Mn-based denitration catalyst degraded by SCR (selective catalytic reduction) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |