CN117380255A - Preparation method and application of catalyst for purifying nitrogen oxides - Google Patents
Preparation method and application of catalyst for purifying nitrogen oxides Download PDFInfo
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- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 title claims abstract description 216
- 239000003054 catalyst Substances 0.000 title claims abstract description 104
- 238000002360 preparation method Methods 0.000 title claims abstract description 20
- 238000002156 mixing Methods 0.000 claims abstract description 45
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 38
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 38
- 239000002002 slurry Substances 0.000 claims abstract description 36
- 238000000576 coating method Methods 0.000 claims abstract description 28
- 239000011248 coating agent Substances 0.000 claims abstract description 27
- 239000000919 ceramic Substances 0.000 claims abstract description 24
- 239000002131 composite material Substances 0.000 claims abstract description 24
- 239000002808 molecular sieve Substances 0.000 claims abstract description 22
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 claims abstract description 22
- 239000000843 powder Substances 0.000 claims abstract description 21
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 claims abstract description 20
- 239000008367 deionised water Substances 0.000 claims abstract description 18
- 229910021641 deionized water Inorganic materials 0.000 claims abstract description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 18
- UNJPQTDTZAKTFK-UHFFFAOYSA-K cerium(iii) hydroxide Chemical compound [OH-].[OH-].[OH-].[Ce+3] UNJPQTDTZAKTFK-UHFFFAOYSA-K 0.000 claims abstract description 17
- 238000000746 purification Methods 0.000 claims abstract description 13
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 36
- FYDKNKUEBJQCCN-UHFFFAOYSA-N lanthanum(3+);trinitrate Chemical compound [La+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O FYDKNKUEBJQCCN-UHFFFAOYSA-N 0.000 claims description 31
- VXAUWWUXCIMFIM-UHFFFAOYSA-M aluminum;oxygen(2-);hydroxide Chemical compound [OH-].[O-2].[Al+3] VXAUWWUXCIMFIM-UHFFFAOYSA-M 0.000 claims description 30
- 238000000034 method Methods 0.000 claims description 18
- 239000000243 solution Substances 0.000 claims description 17
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims description 9
- 229910017604 nitric acid Inorganic materials 0.000 claims description 9
- 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 8
- 239000011148 porous material Substances 0.000 claims description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 5
- 229910052802 copper Inorganic materials 0.000 claims description 5
- 239000010949 copper Substances 0.000 claims description 5
- 239000011259 mixed solution Substances 0.000 claims description 5
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 4
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 claims description 4
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 4
- 239000007789 gas Substances 0.000 claims description 2
- 238000011068 loading method Methods 0.000 abstract description 13
- 230000000052 comparative effect Effects 0.000 description 14
- 229910052878 cordierite Inorganic materials 0.000 description 14
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 14
- 238000001035 drying Methods 0.000 description 10
- 238000012360 testing method Methods 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 238000010926 purge Methods 0.000 description 3
- 238000004364 calculation method Methods 0.000 description 2
- 238000010531 catalytic reduction reaction Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000011056 performance test Methods 0.000 description 2
- 230000001052 transient effect Effects 0.000 description 2
- CNLWCVNCHLKFHK-UHFFFAOYSA-N aluminum;lithium;dioxido(oxo)silane Chemical compound [Li+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O CNLWCVNCHLKFHK-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910052642 spodumene Inorganic materials 0.000 description 1
- 230000002195 synergetic effect Effects 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
- 229910052845 zircon Inorganic materials 0.000 description 1
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical compound [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J29/00—Catalysts comprising molecular sieves
- B01J29/04—Catalysts comprising molecular sieves having base-exchange properties, e.g. crystalline zeolites
- B01J29/06—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof
- B01J29/70—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65
- B01J29/72—Crystalline aluminosilicate zeolites; Isomorphous compounds thereof of types characterised by their specific structure not provided for in groups B01J29/08 - B01J29/65 containing iron group metals, noble metals or copper
- B01J29/76—Iron group metals or copper
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9404—Removing only nitrogen compounds
- B01D53/9409—Nitrogen oxides
- B01D53/9413—Processes characterised by a specific catalyst
- B01D53/9418—Processes characterised by a specific catalyst for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Combustion & Propulsion (AREA)
- Organic Chemistry (AREA)
- Materials Engineering (AREA)
- Crystallography & Structural Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- Environmental & Geological Engineering (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Catalysts (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
Abstract
The invention relates to the technical field of automobile exhaust purification, and provides a preparation method and application of a catalyst for purifying nitrogen oxides, wherein the preparation method comprises the following steps: s1, preparing composite sol: uniformly mixing silica sol, nano aluminum sol and aluminum sol to obtain composite sol; the mass ratio of the silica sol to the nano aluminum sol is 4:6-12:13; s2, preparing catalyst slurry: adding deionized water into the composite sol, uniformly mixing, adding molecular sieve powder containing cerium hydroxide, and uniformly mixing to obtain catalyst slurry; s3, preparing a catalyst for purifying nitrogen oxides: and (3) coating the catalyst slurry on the surface of ceramic, and roasting to obtain the nitrogen oxide purifying catalyst. Through the technical scheme, the problems of low loading capacity and high falling rate of the catalyst for purifying nitrogen oxides in the prior art are solved.
Description
Technical Field
The invention relates to the technical field of automobile exhaust purification, in particular to a preparation method and application of a catalyst for purifying nitrogen oxides.
Background
Nitrogen oxides are one of the main atmospheric pollutants. The nitrogen oxides in the automobile exhaust are very high. With the development of the automotive field, the emission of nitrogen oxides is increasing, which causes the continuous increase of atmospheric pollution. Therefore, the purification of nitrogen oxides in automobile exhaust is of great significance.
Currently, selective Catalytic Reduction (SCR) technology is considered as one of the most effective methods for purifying nitrogen oxides, and a catalyst is the core of the selective catalytic reduction technology. At present, the preparation of the catalyst for purifying nitrogen oxides mainly comprises the step of coating catalyst slurry on the surface of a ceramic carrier. However, at present, the catalyst has low loading and high shedding rate, and the purification rate of nitrogen oxides is affected. Therefore, research on a novel preparation method of a catalyst for purifying nitrogen oxides is needed to improve the loading and reduce the falling rate.
Disclosure of Invention
The invention provides a preparation method and application of a catalyst for purifying nitrogen oxides, which solve the problems of low loading capacity and high falling rate of the catalyst for purifying nitrogen oxides in the related technology.
The technical scheme of the invention is as follows:
the invention provides a preparation method of a catalyst for purifying nitrogen oxides, which comprises the following steps:
s1, preparing composite sol: uniformly mixing silica sol, nano aluminum sol and aluminum sol to obtain composite sol;
the mass ratio of the silica sol to the nano aluminum sol is 4:6-12:13;
s2, preparing catalyst slurry: adding deionized water into the composite sol, uniformly mixing, adding molecular sieve powder containing cerium hydroxide, and uniformly mixing to obtain catalyst slurry;
s3, preparing a catalyst for purifying nitrogen oxides: and coating the catalyst slurry on the surface of ceramic, and roasting to obtain the catalyst for purifying nitrogen oxides.
As a further technical scheme, in step S2, the mass ratio of the composite sol to the molecular sieve powder containing cerium hydroxide is 2:1.
In step S1, the nano-alumina sol is a lanthanum nitrate modified nano-alumina sol, and the alumina sol is a self-made alumina sol made of lanthanum nitrate, pseudo-boehmite and nitric acid.
As a further technical scheme, in step S2, the preparation method of the molecular sieve powder containing cerium hydroxide includes: and (3) dissolving cerium nitrate in a mixed solution of ammonia water and triethanolamine, uniformly mixing, adding a copper molecular sieve and nano aluminum oxide, uniformly mixing, and roasting to obtain the molecular sieve powder containing cerium hydroxide.
As a further technical scheme, the mass ratio of the cerium nitrate to the ammonia water to the triethanolamine to the copper molecular sieve to the nano alumina is 1:4:40:750-850:30.
As a further technical scheme, the preparation method of the lanthanum nitrate modified nano-alumina sol comprises the following steps: adding lanthanum nitrate into deionized water, uniformly mixing, adding nano aluminum sol dry powder, and mixing until the solution becomes light blue transparent solution, thus obtaining the lanthanum nitrate modified nano aluminum sol.
As a further technical scheme, the mass ratio of the lanthanum nitrate to the deionized water to the nano aluminum sol dry powder is 1-2:4:1.
As a further technical scheme, the preparation method of the self-made aluminum sol comprises the following steps: adding lanthanum nitrate into deionized water, uniformly mixing, adding pseudo-boehmite, uniformly mixing, finally adding nitric acid, and mixing until the solution becomes white semitransparent jelly-like solution, thereby obtaining the self-made aluminum sol.
As a further technical scheme, the mass ratio of the lanthanum nitrate to the deionized water to the pseudo-boehmite to the nitric acid is 4:18:3-5:1.
As a further technical scheme, the pseudo-boehmite comprises a first pseudo-boehmite and a second pseudo-boehmite, the pore capacities of the first pseudo-boehmite and the second pseudo-boehmite are different, and the mass ratio of the first pseudo-boehmite to the second pseudo-boehmite is 5:1.
As a further technical scheme, the average pore volume of the first pseudo-boehmite is 1mL/g, and the average pore volume of the second pseudo-boehmite is 0.6mL/g.
As a further technical scheme, in step S3, the coating is divided into a first-stage coating and a second-stage coating, wherein the first-stage coating is to coat the catalyst slurry on one end of the ceramic surface, and the second-stage coating is to coat the catalyst slurry on the other end of the ceramic surface, and the first-stage coating is to dry the catalyst slurry at 80-100 ℃ for 2-5min.
As a further technical scheme, the ceramic is one of cordierite, spodumene, mullite and zircon.
As a further technical scheme, in the step S3, the roasting temperature is 450-550 ℃ and the roasting time is 1-3h.
The invention also provides application of the nitrogen oxide purifying catalyst obtained by the preparation method of the nitrogen oxide purifying catalyst in purifying automobile exhaust.
The working principle and the beneficial effects of the invention are as follows:
1. in the invention, the molecular sieve powder containing cerium hydroxide is mixed with the composite sol, so that the uniformity of catalyst slurry is improved, and the loading capacity of the catalyst for purifying nitrogen oxides is increased in the subsequent coating process. Wherein, through the synergistic blending of silica sol, nano aluminum sol and aluminum sol, the shedding rate of the catalyst for purifying nitrogen oxides is reduced.
2. According to the invention, the lanthanum nitrate is used for modifying the nano aluminum sol, so that the loading capacity of the catalyst for purifying nitrogen oxides is further increased, and the purification rate of the catalyst for purifying nitrogen oxides is improved.
3. In the invention, lanthanum nitrate, pseudo-boehmite and nitric acid are utilized to self-prepare aluminum sol, so that the active components in the catalyst for purifying nitrogen oxides are increased, and the purification rate of the catalyst for purifying the nitrogen oxides is further improved.
4. In the invention, when the self-made aluminum sol is prepared, two pseudo-boehmite with different pore capacities are selected, which is favorable for uniformly dispersing lanthanum nitrate in the self-made aluminum sol, thereby further increasing the loading capacity of the catalyst for purifying nitrogen oxides and improving the purifying rate of the catalyst for nitrogen oxides.
Detailed Description
The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In the following examples and comparative examples, the model of the copper molecular sieve was SSZ-13, the model of the nano alumina was LAE-5, the model of the silica sol was GSW-30, the model of the nano alumina sol was JHASH-15, the alumina sol was A-4 type alumina sol, the model of the first pseudo-boehmite was ZTL-MAH, and the model of the second pseudo-boehmite was ZTL-CAH.
In the following examples and comparative examples, unless otherwise specified;
the preparation method of the cerium hydroxide-containing molecular sieve powder comprises the following steps: according to parts by weight, 1 part of cerium nitrate is dissolved in a mixed solution of 4 parts of ammonia water and 40 parts of triethanolamine, the mixed solution is uniformly mixed, 800 parts of copper molecular sieve and 30 parts of nano alumina are added, the mixed solution is uniformly mixed, evaporated to dryness, and the mixture is baked for 1.5 hours at 400 ℃ under the protection of inert gas and then ground to obtain cerium hydroxide-containing molecular sieve powder;
the preparation method of the lanthanum nitrate modified nano aluminum sol comprises the following steps: adding 4 parts of lanthanum nitrate into 16 parts of deionized water, uniformly mixing, adding 4 parts of nano aluminum sol dry powder, and mixing until the solution becomes light blue transparent solution to obtain lanthanum nitrate modified nano aluminum sol;
the preparation method of the self-made aluminum sol comprises the following steps: adding 12 parts of lanthanum nitrate into 54 parts of deionized water, uniformly mixing, adding 10 parts of first pseudo-boehmite and 2 parts of second pseudo-boehmite, uniformly mixing, finally adding 3 parts of nitric acid, and mixing until the solution becomes white semitransparent jelly-like solution, thus obtaining the self-made alumina sol.
Example 1
A method for preparing a catalyst for purifying nitrogen oxides, which comprises the following steps:
s1, preparing composite sol: according to the weight parts, 8 parts of silica sol, 12 parts of nano aluminum sol and 26 parts of aluminum sol are uniformly mixed to obtain composite sol;
s2, preparing catalyst slurry: adding 23 parts of deionized water into the composite sol according to parts by weight, uniformly mixing, adding 23 parts of cerium hydroxide-containing molecular sieve powder, and uniformly mixing to obtain catalyst slurry;
s3, preparing a catalyst for purifying nitrogen oxides: firstly, coating catalyst slurry on one end of the surface of cordierite ceramic, drying at 80 ℃ for 5min, coating catalyst slurry on the other end of the surface of cordierite ceramic, drying at 80 ℃ for 5min, and roasting at 450 ℃ for 3h to obtain the purified nitrogen oxide catalyst.
Example 2
A method for preparing a catalyst for purifying nitrogen oxides, which comprises the following steps:
s1, preparing composite sol: according to the weight parts, 8 parts of silica sol, 12 parts of lanthanum nitrate modified nano-alumina sol and 26 parts of self-made alumina sol are uniformly mixed to obtain composite sol;
s2, preparing catalyst slurry: adding 23 parts of deionized water into the composite sol according to parts by weight, uniformly mixing, adding 23 parts of cerium hydroxide-containing molecular sieve powder, and uniformly mixing to obtain catalyst slurry;
s3, preparing a catalyst for purifying nitrogen oxides: firstly, coating catalyst slurry on one end of the surface of cordierite ceramic, drying at 80 ℃ for 5min, coating catalyst slurry on the other end of the surface of cordierite ceramic, drying at 80 ℃ for 5min, and roasting at 450 ℃ for 3h to obtain the purified nitrogen oxide catalyst.
Example 3
A method for preparing a catalyst for purifying nitrogen oxides, which comprises the following steps:
s1, preparing composite sol: according to the weight parts, 8 parts of silica sol, 18 parts of lanthanum nitrate modified nano-alumina sol and 26 parts of self-made alumina sol are uniformly mixed to obtain composite sol;
s2, preparing catalyst slurry: adding 26 parts of deionized water into the composite sol according to parts by weight, uniformly mixing, adding 26 parts of cerium hydroxide-containing molecular sieve powder, and uniformly mixing to obtain catalyst slurry;
s3, preparing a catalyst for purifying nitrogen oxides: firstly, coating catalyst slurry on one end of the surface of cordierite ceramic, drying at 90 ℃ for 3.5min, coating catalyst slurry on the other end of the surface of cordierite ceramic, drying at 90 ℃ for 3.5min, and roasting at 500 ℃ for 2h to obtain the purified nitrogen oxide catalyst.
Example 4
A method for preparing a catalyst for purifying nitrogen oxides, which comprises the following steps:
s1, preparing composite sol: according to the weight parts, 8 parts of silica sol, 24 parts of lanthanum nitrate modified nano aluminum sol and 26 parts of self-made aluminum sol are uniformly mixed to obtain composite sol;
s2, preparing catalyst slurry: adding 29 parts of deionized water into the composite sol according to parts by weight, uniformly mixing, adding 29 parts of cerium hydroxide-containing molecular sieve powder, and uniformly mixing to obtain catalyst slurry;
s3, preparing a catalyst for purifying nitrogen oxides: firstly, coating catalyst slurry on one end of the surface of cordierite ceramic, drying for 2min at 100 ℃, then coating the catalyst slurry on the other end of the surface of cordierite ceramic, drying for 2min at 100 ℃, and roasting for 1h at 550 ℃ to obtain the purified nitrogen oxide catalyst.
Example 5
The difference between this embodiment and embodiment 2 is that in step S1, the self-made alumina sol is different, and in this embodiment, the preparation method of the self-made alumina sol is as follows: adding 12 parts of lanthanum nitrate into 54 parts of deionized water according to parts by weight, uniformly mixing, adding 12 parts of first pseudo-boehmite, uniformly mixing, finally adding 3 parts of nitric acid, and mixing until the solution becomes white semitransparent jelly-like solution, thus obtaining self-made aluminum sol.
Example 6
The difference between this embodiment and embodiment 2 is that in step S1, the self-made alumina sol is different, and in this embodiment, the preparation method of the self-made alumina sol is as follows: adding 12 parts of lanthanum nitrate into 54 parts of deionized water, uniformly mixing, adding 12 parts of second pseudo-boehmite, uniformly mixing, finally adding 3 parts of nitric acid, and mixing until the solution becomes white semitransparent jelly-like solution, thus obtaining self-made aluminum sol.
Comparative example 1
A method for preparing a catalyst for purifying nitrogen oxides, which comprises the following steps:
s1, preparing catalyst slurry: adding 23 parts of deionized water into 46 parts of silica sol, uniformly mixing, adding 23 parts of cerium hydroxide-containing molecular sieve powder, and uniformly mixing to obtain catalyst slurry;
s2, preparing a catalyst for purifying nitrogen oxides: firstly, coating catalyst slurry on one end of the surface of cordierite ceramic, drying at 80 ℃ for 5min, coating catalyst slurry on the other end of the surface of cordierite ceramic, drying at 80 ℃ for 5min, and roasting at 450 ℃ for 3h to obtain the purified nitrogen oxide catalyst.
Comparative example 2
The present comparative example differs from comparative example 1 only in that in step S1, the silica sol is replaced with an equivalent amount of lanthanum nitrate modified nano-alumina sol.
Comparative example 3
The present comparative example differs from comparative example 1 only in that in step S1, the silica sol is replaced with an equivalent amount of self-made alumina sol.
Comparative example 4
The present comparative example differs from comparative example 1 only in that in step S1, the silica sol was replaced with 14.5 parts of lanthanum nitrate modified nano-alumina sol and 31.5 parts of self-made alumina sol.
The purified nitrogen oxide catalysts prepared in examples 1-6 and comparative examples 1-4 were subjected to the following performance tests:
(1) loading amount: the weighing method is adopted for measurement, and the calculation formula is as follows:
loading= (weight of purified nitrogen oxide catalyst-weight of cordierite ceramic)/volume of cordierite ceramic;
(2) shedding rate: at a position 2cm away from the section of the catalyst for purifying the nitrogen oxide, uniformly purging with 10bar of compressed air, wherein the purging time is 2min, and the calculation formula is as follows:
the falling rate (%) = (weight of nitrogen oxide purifying catalyst before purging-weight of nitrogen oxide purifying catalyst after purging)/(weight of nitrogen oxide purifying catalyst-weight of cordierite ceramic) ×100;
(3) purification rate: at 400℃the exhaust model gas (NO 200ppm, NH by volume 3 200ppm、O 2 10vol%、H 2 O 5vol%、N 2 Residual) was passed over the nitrogen oxide-purifying catalyst at a space velocity of 50000/h, and the nitrogen oxide-purifying rate was measured.
The test results are shown in table 1 below.
Table 1 results of performance test of nitrogen oxide purifying catalyst
As shown in the table, the purified nitrogen oxide catalyst obtained by the preparation method has higher loading capacity, higher purification rate and lower shedding rate, wherein the loading capacity can reach 281g/L, the purification rate can reach 98.7% at the highest, and the shedding rate can reach 0.61% at the lowest, so that the catalyst can meet the industrial production and application. Examples 2-6 and comparative examples 1-4 show that compared with the combined use of single silica sol or lanthanum nitrate modified nano-alumina sol and self-made alumina sol, the silica sol, the lanthanum nitrate modified nano-alumina sol and the self-made alumina sol are cooperatively blended, so that the loading capacity and the purification rate of the nitrogen oxide purifying catalyst are greatly improved, and the falling rate is obviously reduced.
Comparison of the embodiment 1 and the embodiment 2 shows that compared with the conventional three-component blend of silica sol, nano aluminum sol and aluminum sol, the three-component blend of silica sol, lanthanum nitrate modified nano aluminum sol and self-made aluminum sol can further improve the loading amount and the purification rate of the nitrogen oxide purifying catalyst and further reduce the falling rate.
Comparison of example 2 with examples 5-6 shows that when preparing self-made alumina sol, the purification rate of the catalyst to nitrogen oxides can be further improved by selecting two pseudo-boehmite with different pore capacities.
The purified nitrogen oxide catalyst prepared in example 2 was applied to Xu Gong T4 engines and subjected to steady state NRSC and transient NRTC bench experiments, the test results of which are shown in table 2 below.
Table 2 example 2 catalyst bench test results for purifying nitrogen oxides
As can be seen from Table 2, the purified nitrogen oxide catalyst prepared in example 2 of the present invention can be successfully applied to Xu Gong T4 engines, wherein NRSC steady-state bench test NO x Conversion is 96.77%, NRTC transient bench test NO x The conversion rate is 95.85%, which shows that the purified nitrogen oxide catalyst prepared in the example 2 has good catalytic activity and meets the national non-road T4 stage emission requirements.
The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.
Claims (10)
1. The preparation method of the catalyst for purifying nitrogen oxides is characterized by comprising the following steps:
s1, preparing composite sol: uniformly mixing silica sol, nano aluminum sol and aluminum sol to obtain composite sol;
the mass ratio of the silica sol to the nano aluminum sol is 4:6-12:13;
s2, preparing catalyst slurry: adding deionized water into the composite sol, uniformly mixing, adding molecular sieve powder containing cerium hydroxide, and uniformly mixing to obtain catalyst slurry;
s3, preparing a catalyst for purifying nitrogen oxides: and coating the catalyst slurry on the surface of ceramic, and roasting to obtain the catalyst for purifying nitrogen oxides.
2. The method for preparing a catalyst for purifying nitrogen oxides according to claim 1, wherein in the step S2, the mass ratio of the composite sol to the molecular sieve powder containing cerium hydroxide is 2:1.
3. The method for preparing a catalyst for purifying nitrogen oxides according to claim 1 or 2, wherein in the step S1, the nano-alumina sol is lanthanum nitrate modified nano-alumina sol, and the alumina sol is self-made alumina sol made of lanthanum nitrate, pseudo-boehmite and nitric acid.
4. The method for preparing a catalyst for purifying nitrogen oxides according to claim 1, wherein in step S2, the method for preparing the molecular sieve powder containing cerium hydroxide comprises the following steps: and (3) dissolving cerium nitrate in a mixed solution of ammonia water and triethanolamine, uniformly mixing, adding a copper molecular sieve and nano aluminum oxide, uniformly mixing, and roasting to obtain the molecular sieve powder containing cerium hydroxide.
5. The method for preparing the catalyst for purifying nitrogen oxides according to claim 3, wherein the method for preparing the lanthanum nitrate modified nano-alumina sol is as follows: adding lanthanum nitrate into deionized water, uniformly mixing, adding nano aluminum sol dry powder, and mixing until the solution becomes light blue transparent solution, thus obtaining the lanthanum nitrate modified nano aluminum sol.
6. The method for preparing the catalyst for purifying nitrogen oxides according to claim 3, wherein the method for preparing the self-made aluminum sol is as follows: adding lanthanum nitrate into deionized water, uniformly mixing, adding pseudo-boehmite, uniformly mixing, finally adding nitric acid, and mixing until the solution becomes white semitransparent jelly-like solution, thereby obtaining the self-made aluminum sol.
7. The method for preparing a catalyst for purifying nitrogen oxides according to claim 6, wherein the pseudo-boehmite comprises a first pseudo-boehmite and a second pseudo-boehmite, the pore capacities of the first pseudo-boehmite and the second pseudo-boehmite are different, and the mass ratio of the first pseudo-boehmite to the second pseudo-boehmite is 5:1.
8. The method for preparing a catalyst for purifying nitrogen oxides according to claim 1, wherein in the step S3, the coating is divided into a first stage coating and a second stage coating, the first stage coating is to coat the catalyst slurry on one end of the ceramic surface, the first stage coating is to dry the ceramic surface at 80-100 ℃ for 2-5min, and the second stage coating is to coat the catalyst slurry on the other end of the ceramic surface, and the second stage coating is to dry the ceramic surface at 80-100 ℃ for 2-5min.
9. The method for preparing a catalyst for purifying nitrogen oxides according to claim 1, wherein in the step S3, the roasting temperature is 450-550 ℃ and the roasting time is 1-3 hours.
10. Use of a purified nitrogen oxide catalyst according to any one of claims 1-9 in the purification of automotive exhaust gas.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2308596A1 (en) * | 2009-10-07 | 2011-04-13 | Ford Global Technologies, LLC | Cu/zeolite SCR catalyst for NOx reduction in exhaust gases and manufacture method thereof |
| CN104338545A (en) * | 2014-10-21 | 2015-02-11 | 无锡威孚环保催化剂有限公司 | Effective SCR (selective catalytic reduction) catalyst applied to purification of nitrogen oxide in tail gas of diesel engine |
| WO2015184911A1 (en) * | 2014-06-06 | 2015-12-10 | 四川中自尾气净化有限公司 | Process for preparing vanadium-base scr catalyst coating for purifying tail gas of diesel vehicle |
| CN109364935A (en) * | 2018-12-10 | 2019-02-22 | 江苏奥利思特环保科技有限公司 | A kind of low-temperature denitration catalyst and preparation method |
| CN110215931A (en) * | 2019-06-18 | 2019-09-10 | 安徽艾可蓝环保股份有限公司 | Cupric molecular screen material and preparation method thereof and catalyst |
| CN114904512A (en) * | 2022-05-07 | 2022-08-16 | 南开大学深圳研究院 | Mullite-type loaded honeycomb ceramic catalyst surface active coating and preparation method thereof |
| CN115463685A (en) * | 2022-10-27 | 2022-12-13 | 淄博恒亿化工科技有限公司 | Preparation method and application of composite molecular sieve catalyst for synthesizing nitroaromatic compound |
-
2023
- 2023-12-05 CN CN202311650163.XA patent/CN117380255B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2308596A1 (en) * | 2009-10-07 | 2011-04-13 | Ford Global Technologies, LLC | Cu/zeolite SCR catalyst for NOx reduction in exhaust gases and manufacture method thereof |
| WO2015184911A1 (en) * | 2014-06-06 | 2015-12-10 | 四川中自尾气净化有限公司 | Process for preparing vanadium-base scr catalyst coating for purifying tail gas of diesel vehicle |
| CN104338545A (en) * | 2014-10-21 | 2015-02-11 | 无锡威孚环保催化剂有限公司 | Effective SCR (selective catalytic reduction) catalyst applied to purification of nitrogen oxide in tail gas of diesel engine |
| CN109364935A (en) * | 2018-12-10 | 2019-02-22 | 江苏奥利思特环保科技有限公司 | A kind of low-temperature denitration catalyst and preparation method |
| CN110215931A (en) * | 2019-06-18 | 2019-09-10 | 安徽艾可蓝环保股份有限公司 | Cupric molecular screen material and preparation method thereof and catalyst |
| CN114904512A (en) * | 2022-05-07 | 2022-08-16 | 南开大学深圳研究院 | Mullite-type loaded honeycomb ceramic catalyst surface active coating and preparation method thereof |
| CN115463685A (en) * | 2022-10-27 | 2022-12-13 | 淄博恒亿化工科技有限公司 | Preparation method and application of composite molecular sieve catalyst for synthesizing nitroaromatic compound |
Non-Patent Citations (2)
| Title |
|---|
| ZHANG XIN-YAN等: ""Green synthesis of Cu-SSZ-13 zeolite by seed-assisted route for effective reduction of nitric oxide"", 《JOURNAL OF CLEANER PRODUCTION》, vol. 236, 15 July 2019 (2019-07-15), pages 1 - 10, XP085774290, DOI: 10.1016/j.jclepro.2019.117667 * |
| 卫金秋等: ""船用选择性催化还原脱硝催化剂涂覆工艺 研究进展"", 《环境污染与防治》, vol. 45, no. 7, 31 July 2023 (2023-07-31), pages 1018 - 1023 * |
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