CN113198451B - Monolithic catalyst, preparation method and application - Google Patents
Monolithic catalyst, preparation method and application Download PDFInfo
- Publication number
- CN113198451B CN113198451B CN202110538751.9A CN202110538751A CN113198451B CN 113198451 B CN113198451 B CN 113198451B CN 202110538751 A CN202110538751 A CN 202110538751A CN 113198451 B CN113198451 B CN 113198451B
- Authority
- CN
- China
- Prior art keywords
- dpf
- product
- catalyst
- monolithic catalyst
- temperature
- 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.)
- Active
Links
Images
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
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/10—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of rare earths
-
- 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
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/002—Mixed oxides other than spinels, e.g. perovskite
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/105—General auxiliary catalysts, e.g. upstream or downstream of the main catalyst
- F01N3/106—Auxiliary oxidation catalysts
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/24—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
- F01N3/28—Construction of catalytic reactors
- F01N3/2803—Construction of catalytic reactors characterised by structure, by material or by manufacturing of catalyst support
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
- Y02A50/2351—Atmospheric particulate matter [PM], e.g. carbon smoke microparticles, smog, aerosol particles, dust
Abstract
The invention discloses an integral catalyst, a preparation method and application thereof. The invention provides a method for preparing Ce by a sol-gel method 1‑ x Ti x O 2 The method of the composite oxide, then the composite oxide is used as a carrier, and an impregnation method is adopted to load alkali metal to obtain M/Ce 1‑ x Ti x O 2 Catalyst, finally coating the catalyst on DPF carrier to obtain M/Ce 1‑x Ti x O 2 The DPF monolithic catalyst is applied to the CDPF field, has low price compared with a noble metal catalyst, and has the characteristics of strong catalytic oxidation effect, high oxidation efficiency and low loading capacity, 8 percent of Cs/Ce 0.92 Ti 0.08 O 2 The activity of the catalyst is highest, wherein T i At 319 ℃ T 90 The temperature is 421 ℃, the soot combustion rate is greatly improved, and 8 percent Cs/Ce is obtained by coating the soot combustion rate on a DPF carrier 0.92 Ti 0.08 O 2 Monolithic catalyst for DPF, results show Ce 0.92 Ti 0.08 O 2 The loading of 2.5 wt% DPF, T, achieves the lowest loading at high efficiency in this experimental range i At 323 ℃ T 90 491 ℃.
Description
Technical Field
The invention relates to an integral catalyst, in particular to an integral catalyst, a preparation method and application thereof.
Background
In recent years, haze affects parts of areas in China all the year round, and harmful substances PM (carbon smoke particles) in tail gas of diesel vehicles are one of main reasons for causing haze weather, so that the health of human beings is seriously affected. A highly efficient diesel exhaust Particulate trap dpf (diesel Particulate filter) is indispensable. The structure of the filter screen is provided with a plurality of parallel channels along the axial direction, and the parallel channels are staggered to block holes to form a filter screen structure which can only allow gas to pass through. Therefore, when diesel vehicle tail gas passes through DPF, the separation that dams of particulate matter is realized through the surface screening principle under the pressure drive, and the great PM particulate matter of volume is just caught and is depositd in filter wall and inside the porous medium structure, and DPF is in the operation in-process, and the particulate matter of catching can block up the filter and cause exhaust back pressure to rise thereby to lead to the purification efficiency step-down or even filter damage, consequently the soot particulate matter that dams at the wall is removed through the mode of oxidation burning, and this is exactly the regeneration process of DPF. The temperature of the tail gas of the diesel vehicle is 150 ℃ and 500 ℃, and the soot particles can be combusted only when the temperature reaches above 600 ℃. Catalytic diesel particulate trap (CDPF) technology is required to remove soot at ambient diesel exhaust temperatures without the addition of external energy, and the core content of CDPF is the catalyst.
At present, the Ce-Ti material is mainly focused on energy and environmental problems such as photocatalysis, nitrogen oxide reduction and the like, is rarely applied to the field of carbon smoke oxidation, and has potential research value for catalyzing and oxidizing the carbon smoke.
In conclusion, the development of the integral catalyst with low cost, good activity, high efficiency and low loading capacity has important significance for eliminating the soot of the diesel vehicle.
Disclosure of Invention
The invention aims to provide an integral catalyst, a preparation method and application thereof. The invention provides a method for preparing Ce by a sol-gel method 1-x Ti x O 2 The method of the composite oxide, then the composite oxide is used as a carrier, and an impregnation method is adopted to load alkali metal to obtain M/Ce 1-x Ti x O 2 Catalyst, finally coating the catalyst on DPF carrier to obtain M/Ce 1-x Ti x O 2 The monolithic DPF catalyst is applied to the CDPF field, has low price compared with a noble metal catalyst, and has catalysisStrong oxidation effect, high oxidation efficiency and low carrying capacity.
The technical scheme of the invention is as follows: a preparation method of a monolithic catalyst comprises the following steps:
(1) preparation of Ce by sol-gel method 1-x Ti x O 2 Carrier:
dissolving 1-3g of solid cerous nitrate in 30mL of absolute ethyl alcohol according to the following proportion, and then adding 10mL of deionized water to obtain a product A; the chemical formula of the solid cerium nitrate is Ce (NO) 3 ) 2 ·6H 2 O；
Regulating the pH value of the product A with glacial acetic acid to make the pH value of the product A be 2.5-3.5 to obtain a product B;
thirdly, under the stirring state, dropwise adding butyl titanate into the product B, then heating in a water bath at 50-70 ℃, and stirring for reaction for 2-4h to obtain a reaction solution, namely a product C;
fourthly, performing ultrasonic cleaning on the cordierite-based diesel vehicle particulate matter catcher-DPF in water for 1.5 to 2.5 hours, and drying at 90 to 110 ℃ to obtain a D product;
fifthly, putting the product D into the product C, heating in water bath at 30-50 ℃, aging for 6-10h, and drying at 60-80 ℃ for 46-50h to obtain a product E;
sixthly, roasting the E product at the temperature of 400-600 ℃ to obtain Ce 1-x Ti x O 2 The load is 1.25-3.75 wt% of integral catalyst of DPF, which is F product; and said Ce is 1-x Ti x O 2 X is more than or equal to 0.07 and less than or equal to 0.09;
(2) impregnation method for preparing M/Ce 1-x Ti x O 2 Catalyst:
adding F into alkali metal carbonate solution to control the active component load of carbonate solution to Ce 1-x Ti x O 2 6-10% of the carrier mass, ultrasonic treatment for 1.5-2.5h, drying at 70-90 ℃, then heating to 450-550 ℃ at the speed of 2-4 ℃/min, roasting, and keeping the temperature for 1.5-2.5h to obtain M/Ce 1-x Ti x O 2 The metal of M is Cs, K or Na, and x is more than or equal to 0.07 and less than or equal to 0.09.
In the preparation method of the monolithic catalyst, in the step (i), 2g of solid cerium nitrate is dissolved in 30mL of absolute ethyl alcohol according to the following proportion, and then 10mL of deionized water is added.
In the preparation method of the monolithic catalyst, in the step II, the pH value of the product A is adjusted by glacial acetic acid to ensure that the pH value of the product A is 2.
In the preparation method of the monolithic catalyst, in the third step, the molar ratio of Ce to Ti is 1-x: and x, dropwise adding butyl titanate into the product B, heating in a water bath at 60 ℃, and stirring to react for 3 hours to obtain a reaction solution.
In the preparation method of the monolithic catalyst, in the step (IV), the cordierite-based diesel particulate filter-DPF is subjected to ultrasonic treatment in water for 2 hours and dried at 100 ℃.
In the preparation method of the monolithic catalyst, in the fifth step, the product D is put into the product C, is heated in a water bath at 40 ℃, is aged for 7 hours, and is dried for 48 hours at 70 ℃.
In the preparation method of the monolithic catalyst, in the step sixthly, the D product is roasted at the temperature of 500 ℃ to obtain Ce 1- x Ti x O 2 The load is 2.5 wt% of DPF, and is E product; and said Ce is 1-x Ti x O 2 Wherein x is 0.08.
In the aforementioned method for preparing the monolithic catalyst, in the step (c), the product E is added to the alkali metal carbonate solution, and the loading amount of the active component of the carbonate solution is controlled to Ce 1-x Ti x O 2 Ultrasonic treatment for 2h, drying at 80 deg.C, heating to 500 deg.C at 3 deg.C/min, calcining, and maintaining for 2h to obtain M/Ce 1-x Ti x O 2 Finished DPF.
In the above-mentioned preparation method of the monolithic catalyst, in the step (c), the alkali metal carbonate solution is Cs 2 CO 3 A solution; the M/Ce 1-x Ti x O 2 In the DPF, the M metal is Cs, and x is 0.08.
The application of the monolithic catalyst is M/Ce prepared by the preparation method of the monolithic catalyst 1- x Ti x O 2 DPF integral catalyst for diesel vehicleIn the tail gas DPF reaction system, carbon smoke particles are converted into nontoxic and pollution-free CO 2 The reaction temperature is 310-420 ℃, and the total flow of the gas is controlled to be 400-550 mL/min.
Compared with the prior art, the invention has the following beneficial effects:
the invention adopts a simpler sol-gel method to prepare Ce 1-x Ti x O 2 The composite oxide is used as a carrier, and an impregnation method is adopted to load alkali metal to obtain M/Ce 1-x Ti x O 2 Catalyst, finally selecting the catalyst with the best activity to be coated on DPF carrier to obtain M/Ce 1-x Ti x O 2 a/DPF monolithic catalyst.
The molar content of Ti is adjustable, wherein a certain amount of Ti is doped into CeO 2 Within the crystal, CeO is not changed 2 The Ce-O-Ti bond is formed under the condition of the structure, the fluorite structure of the catalyst filled with cubic gaps is reserved, and the ion mobility in the catalyst is enhanced, so that the activity of the catalyst is improved. Wherein Ce 1-x Ti x O 2 The composite oxide is widely applied to the fields of photocatalysis and denitration, and the research on carbon smoke catalysis is less.
The results show that Ce 0.92 Ti 0.08 O 2 Ignition temperature T of catalyst oxidation soot i At 343 ℃ and a temperature T at which 90% conversion occurs 90 458 ℃ lower than that of pure CeO 2 T of i ＝391℃，T 90 At 512 ℃. The catalytic activity is higher than that of the systems common in catalytic oxidation of soot, such as Ce 0.92 Ti 0.08 O 2 T of 50 (425 ℃) lower than Ce produced by Liu 0.6 Zr 0.4 O 2 T of catalyst 50 (460 ℃ C.), lower than Ce produced by Ve nkataswamy 0.7 Fe 0.3 O 2 T of catalyst 50 (512 ℃ C.). The alkali metal can improve the activity of the catalyst on the soot combustion, because the alkali metal in the carbonate can generate C-O-M, and the C-O-M reacts with the soot to generate CO 2 Then is reduced into C-M and oxidized into C-O-M, and the circulation is favorable for O in soot combustion 2 The efficient utilization of the water is realized.
The experimental result shows that the concentration of the C is 8 percent/Ce 0.92 Ti 0.08 O 2 The activity of the catalyst is highest, wherein T i At 319 ℃ C., T 90 The temperature is 421 ℃, and the soot combustion rate is greatly improved. Finally, the catalyst with the best activity is selected to be 8 percent Cs/Ce 0.92 Ti 0.08 O 2 Coating on DPF carrier to obtain 8% Cs/Ce 0.92 Ti 0.08 O 2 Monolithic catalyst for DPF, results show Ce 0.92 Ti 0.08 O 2 The loading of DPF2.5 wt% achieves the lowest loading at high efficiency in this experimental range, where T i At 323 ℃ T 90 491 ℃ because the DPF filter body has larger volume and is heated uniformly to a degree lower than that of the powdery catalyst, the overall soot combustion efficiency is reduced. But achieves near complete conversion of soot below 500 c compared to most other monolithic catalysts. T of monolithic catalyst 25Ag/Ce-A/DPF prepared by Valeria, for example 90 T of 20Cu/Ce-A/DPF at 580 deg.C 90 It was 600 ℃ and the weight of the catalyst and the ceramic carrier was 1g/0.5 g.
8% Cs/Ce of the invention 0.92 Ti 0.08 O 2 The DPF monolithic catalyst has the advantages of low cost, simple method and high catalytic activity. Wherein Ce 1-x Ti x O 2 The composite oxide is widely applied to the fields of photocatalysis and denitration, and the Ce of the invention 1- x Ti x O 2 The composite oxide also has a high effect on the combustion of soot.
In conclusion, the invention provides a sol-gel method for preparing Ce 1-x Ti x O 2 The method of the composite oxide, then the composite oxide is used as a carrier, and an impregnation method is adopted to load alkali metal to obtain M/Ce 1-x Ti x O 2 Catalyst, finally coating the catalyst on DPF carrier to obtain M/Ce 1-x Ti x O 2 The DPF monolithic catalyst is applied to the CDPF field, has low price compared with a noble metal catalyst, and has the beneficial effects of strong catalytic oxidation effect, high oxidation efficiency and low loading capacity.
Drawings
FIG. 1 is Ce prepared in examples 1-3 of the present invention 1-x Ti x O 2 Catalyzing CO in soot process 2 Graph of concentration (a) and soot conversion (b);
FIG. 2 shows M/Ce prepared in examples 4-6 of the present invention 1-x Ti x O 2 M is Cs, K or Na, x is 0.08 and Ce 0.92 Ti 0.08 O 2 Catalyzing CO in soot process 2 Graph of concentration (a) and soot conversion (b);
FIG. 3 is a 8% Cs/Ce solution prepared according to examples 7-9 of the present invention 1-x Ti x O 2 Catalyst for catalyzing CO in soot process by using monolithic catalyst of 0.08 x in DPF 2 Graph of concentration (a) and soot conversion (b);
FIG. 4 shows catalyst Ce prepared by the present invention 0.92 Ti 0.08 O 2 (a) And 8% Cs/Ce 0.92 Ti 0.08 O 2 (b) A TEM image of (B);
FIG. 5 shows DPF carrier and the monolithic catalyst 8% Cs/Ce prepared by the invention 0.92 Ti 0.08 O 2 SEM picture of/DPF-2; wherein [ DPF (a) ], 8% Cs/Ce 0.92 Ti 0.08 O 2 /DPF-2(b,c)】。
Detailed Description
The invention is further illustrated by the following figures and examples, which are not to be construed as limiting the invention.
Example 1: ce 0.91 Ti 0.09 O 2 Preparing a catalyst;
2g of solid cerium nitrate (Ce (NO) 3 ) 2 ·6H 2 O) is dissolved in 30mL of absolute ethyl alcohol, 10mL of deionized water is added, the pH value of the solution is adjusted to 3 by glacial acetic acid, 0.1568mL of butyl titanate is added dropwise under the stirring state, the solution is heated to 60 ℃ in a water bath, the stirring reaction is continued for 3h to obtain reaction liquid, the reaction liquid is stopped to be stirred, the aging is carried out for 7h at the water bath temperature of 40 ℃ to form gel, the gel is dried for 48h at the temperature of 70 ℃, the dried solid particles are roasted at the temperature of 500 ℃, and the grinding is carried out to obtain Ce 0.91 Ti 0.09 O 2 A carrier powder.
Example 2: ce 0.92 Ti 0.08 O 2 Preparing a catalyst;
2g of solid cerium nitrate (Ce (NO) 3 ) 2 ·6H 2 O) is dissolved in 30mL of absolute ethyl alcohol, 10mL of deionized water is added, the pH value of the solution is adjusted to 3 by glacial acetic acid, 0.1394mL of butyl titanate is added dropwise under the stirring state, the solution is heated to 60 ℃ in a water bath, the stirring reaction is continued for 3h to obtain reaction liquid, the reaction liquid is stopped to be stirred, the aging is carried out for 7h at the water bath temperature of 40 ℃ to form gel, the gel is dried for 48h at the temperature of 70 ℃, the dried solid particles are roasted at the temperature of 500 ℃, and the grinding is carried out to obtain Ce 0.94 Ti 0.06 O 2 A carrier powder.
Example 3: ce 0.93 Ti 0.07 O 2 Preparing a catalyst;
2g of solid cerium nitrate (Ce (NO) 3 ) 2 ·6H 2 O) is dissolved in 30mL of absolute ethyl alcohol, 10mL of deionized water is added, the pH value of the solution is adjusted to 3 by glacial acetic acid, 0.1219mL of butyl titanate is added dropwise under the stirring state, the solution is heated to 60 ℃ in a water bath, the stirring reaction is continued for 3h to obtain reaction liquid, the reaction liquid is stopped to be stirred, the aging is carried out for 7h at the water bath temperature of 40 ℃ to form gel, the gel is dried for 48h at the temperature of 70 ℃, the dried solid particles are roasted at the temperature of 500 ℃, and the grinding is carried out to obtain Ce 0.96 Ti 0.04 O 2 A carrier powder.
Example 4: 8% Na/Ce 0.92 Ti 0.08 O 2 Preparing a catalyst;
207.27mg of sodium carbonate was dissolved in 5mL of deionized water, and 1gCe was added to the sodium carbonate solution 0.92 Ti 0.08 O 2 Subjecting the composite oxide powder to ultrasonic treatment for 2h, drying at 80 ℃, heating to 500 ℃ at a speed of 3 ℃/min, roasting, keeping the temperature for 2h, and grinding to obtain 8% Na/Ce 0.92 Ti 0.08 O 2 A catalyst.
Example 5: 8% K/Ce 0.92 Ti 0.08 O 2 Preparing a catalyst;
118.10mg of potassium carbonate was dissolved in 5mL of deionized water, and 1gCe was added to the potassium carbonate solution 0.92 Ti 0.08 O 2 Composite oxide powder, ultrasonic treatment for 2 hr, drying at 80 deg.C, and then 3 deg.C/mHeating to 500 ℃ in, roasting, keeping the temperature for 2h, and grinding to obtain 8% K/Ce 0.92 Ti 0.08 O 2 A catalyst.
Example 6: 8% Cs/Ce 0.92 Ti 0.08 O 2 Preparing a catalyst;
106.59mg of cesium carbonate was dissolved in 5mL of deionized water, and 1gCe was added to the cesium carbonate solution 0.92 Ti 0.08 O 2 Carrying out ultrasonic treatment on the composite oxide powder for 2h, drying at 80 ℃, then heating to 500 ℃ at the speed of 3 ℃/min, roasting, keeping the temperature for 2h, and grinding to obtain 8% Cs/Ce 0.92 Ti 0.08 O 2 A catalyst.
Example 7: ce 0.92 Ti 0.08 O 2 8% Cs/Ce loading of 1.25 wt% DPF 0.92 Ti 0.08 O 2 Preparation of DPF-1 monolithic catalyst;
firstly, the DPF carrier is ultrasonically treated in water for 2 hours and dried at 100 ℃. 6g of solid cerium nitrate (Ce (NO) 3 ) 2 ·6H 2 O) is dissolved in 90mL of absolute ethyl alcohol, 30mL of deionized water is added, the pH value of the solution is adjusted to 3 by glacial acetic acid, 0.418mL of butyl titanate is added dropwise under the stirring state, the solution is heated to 60 ℃ in a water bath, the stirring reaction is continued for 3h to obtain sol, a dried DPF carrier is put into the sol, the sol is kept still for 6h at the water bath temperature of 40 ℃, the DPF after being soaked in the sol is put into a drying box to be dried for 46h at the temperature of 70 ℃, and the roasting is carried out at the temperature of 500 ℃ to obtain Ce 0.92 Ti 0.08 O 2 Monolithic catalyst Ce with load of 1.25 wt% of DPF 0.92 Ti 0.08 O 2 /DPF-1；
69.64mg of cesium carbonate was dissolved in 50mL of deionized water, and Ce was added to the cesium carbonate solution 0.92 Ti 0.08 O 2 The DPF monolithic catalyst is treated by ultrasonic for 2h, dried at 80 ℃, then heated to 500 ℃ at the speed of 3 ℃/min for roasting, and the temperature is kept for 2h, thus obtaining the Ce 0.92 Ti 0.08 O 2 8% Cs/Ce loading of 1.25 wt% DPF 0.92 Ti 0.08 O 2 Monolithic catalyst for DPF-1.
Example 8: ce 0.92 Ti 0.08 O 2 8% Cs/Ce loading of 2.5 wt% DPF 0.92 Ti 0.08 O 2 Preparation of DPF-2 monolithic catalyst;
firstly, the DPF carrier is ultrasonically treated in water for 2 hours and dried at 100 ℃. 6g of solid cerium nitrate (Ce (NO) 3 ) 2 ·6H 2 O) is dissolved in 90mL of absolute ethyl alcohol, 30mL of deionized water is added, the pH value of the solution is adjusted to 3 by glacial acetic acid, 0.418mL of butyl titanate is added dropwise under the stirring state, the solution is heated to 60 ℃ in a water bath, the stirring reaction is continued for 3h to obtain sol, a dried DPF carrier is put into the sol, the sol is kept stand for 8h at the temperature of 40 ℃ in the water bath, the DPF after being soaked in the sol is put into a drying box to be dried for 48h at the temperature of 70 ℃, the calcination is carried out at the temperature of 500 ℃, the steps from the soaking to the calcination are repeated for twice to obtain the Ce product 0.92 Ti 0.08 O 2 Ce loaded in 2.5 wt% of DPF 0.92 Ti 0.08 O 2 a/DPF-2 monolithic catalyst;
139.28mg of cesium carbonate was dissolved in 50mL of deionized water, and Ce was added to the cesium carbonate solution 0.92 Ti 0.08 O 2 The DPF monolithic catalyst is treated by ultrasonic for 2h, dried at 80 ℃, then heated to 500 ℃ at the speed of 3 ℃/min for roasting, and the temperature is kept for 2h, thus obtaining the Ce 0.92 Ti 0.08 O 2 8% Cs/Ce loading of 2.5 wt% DPF 0.92 Ti 0.08 O 2 Monolithic catalyst for DPF-2.
Example 9: ce 0.92 Ti 0.08 O 2 8% Cs/Ce loading of 3.75 wt% DPF 0.92 Ti 0.08 O 2 Preparation of DPF-3 monolithic catalyst;
firstly, the DPF carrier is ultrasonically treated in water for 2 hours and dried at 100 ℃. 6g of solid cerium nitrate (Ce (NO) 3 ) 2 ·6H 2 O) is dissolved in 90mL of absolute ethyl alcohol, 30mL of deionized water is added, the pH value of the solution is adjusted to 3 by glacial acetic acid, 0.418mL of butyl titanate is added dropwise under the stirring state, the solution is heated to 60 ℃ in a water bath, the stirring reaction is continued for 3 hours to obtain sol, a dried DPF carrier is put into the sol, the sol is kept still for 10 hours at the temperature of 40 ℃ in the water bath, the DPF after being soaked with the sol is put into a drying box to be dried for 550 hours at the temperature of 70 ℃, the roasting is carried out at the temperature of 500 ℃, the step of soaking to roasting is repeated twice to obtain Ce 0.92 Ti 0.08 O 2 Ce loaded in DPF of 3.75 wt% 0.92 Ti 0.08 O 2 a/DPF-3 monolithic catalyst;
208.92mg of cesium carbonate was dissolved in 50mL of deionized water, and Ce was added to the cesium carbonate solution 0.92 Ti 0.08 O 2 The DPF monolithic catalyst is treated by ultrasonic for 2h, dried at 80 ℃, then heated to 500 ℃ at the speed of 3 ℃/min for roasting, and the temperature is kept for 2h, thus obtaining the Ce 0.92 Ti 0.08 O 2 8% Cs/Ce loading of 3.75 wt% DPF 0.92 Ti 0.08 O 2 Monolithic catalyst for DPF-3.
Example 10; ce 0.92 Ti 0.08 O 2 8% Cs/Ce loading of 2.5 wt% DPF 0.92 Ti 0.08 O 2 Preparation of DPF monolithic catalyst;
firstly, the DPF carrier is ultrasonically treated for 1.5h in water and dried at 90 ℃. 6g of solid cerium nitrate (Ce (NO) 3 ) 2 ·6H 2 O) is dissolved in 90mL of absolute ethyl alcohol, 30mL of deionized water is added, the pH value of the solution is adjusted to 2.5 by glacial acetic acid, 0.418mL of butyl titanate is added dropwise under the stirring state, the solution is heated to 50 ℃ in a water bath, the stirring reaction is continued for 2 hours to obtain sol, a dried DPF carrier is put into the sol, the sol is kept still for 10 hours at the temperature of 30 ℃ in the water bath, the DPF after being soaked with the sol is put into a drying box to be dried for 50 hours at the temperature of 60 ℃, the roasting is carried out at the temperature of 400 ℃, the step of soaking to roasting is repeated twice to obtain Ce 0.92 Ti 0.08 O 2 Ce loaded in 2.5 wt% of DPF 0.92 Ti 0.08 O 2 a/DPF monolithic catalyst;
139.28mg of cesium carbonate was dissolved in 50mL of deionized water, and Ce was added to the cesium carbonate solution 0.92 Ti 0.08 O 2 The DPF monolithic catalyst is subjected to ultrasonic treatment for 1.5h, dried at 70 ℃, then heated to 450 ℃ at the speed of 2 ℃/min for roasting, and kept warm for 2.5h to obtain Ce 0.92 Ti 0.08 O 2 8% Cs/Ce loading of 2.5 wt% DPF 0.92 Ti 0.08 O 2 a/DPF monolithic catalyst.
Example 11; ce 0.92 Ti 0.08 O 2 8% Cs/Ce loading of 2.5 wt% DPF 0.92 Ti 0.08 O 2 Preparation of DPF monolithic catalyst;
firstly, the DPF carrier is subjected to ultrasonic treatment in water for 2.5 hours and is dried at 110 ℃. 6g of solid cerium nitrate (Ce (NO) 3 ) 2 ·6H 2 O) is dissolved in 90mL of absolute ethyl alcohol, 30mL of deionized water is added, the pH value of the solution is adjusted to 2.5 by glacial acetic acid, 0.418mL of butyl titanate is added dropwise under the stirring state, the solution is heated to 70 ℃ in a water bath, the stirring reaction is continued for 4 hours to obtain sol, a dried DPF carrier is put into the sol, the solution is kept stand for 6 hours at the water bath temperature of 50 ℃, the DPF after being soaked in the sol is put into a drying box to be dried for 46 hours at the temperature of 80 ℃, the calcination is carried out at the temperature of 600 ℃, the steps from the soaking to the calcination are repeated for two times to obtain Ce 0.92 Ti 0.08 O 2 Ce loaded in 2.5 wt% of DPF 0.92 Ti 0.08 O 2 a/DPF monolithic catalyst;
139.28mg of cesium carbonate was dissolved in 50mL of deionized water, and Ce was added to the cesium carbonate solution 0.92 Ti 0.08 O 2 The DPF monolithic catalyst is subjected to ultrasonic treatment for 2.5h, dried at 90 ℃, then heated to 550 ℃ at the speed of 4 ℃/min for roasting, and the temperature is kept for 1.5h, thus obtaining Ce 0.92 Ti 0.08 O 2 8% Cs/Ce loading of 2.5 wt% DPF 0.92 Ti 0.08 O 2 a/DPF monolithic catalyst.
Experiments prove that:
ce prepared in examples 1-3 of the invention 1-x Ti x O 2 X is more than or equal to 0.07 and less than or equal to 0.09; examples 4-6 preparation of M/Ce with different alkali metals loading 1-x Ti x O 2， M metal is Cs, K or Na, and x is 0.08; examples 7-9 catalysts of different loadings were prepared and coated onto cordierite DPF filters to obtain monolithic catalysts of different catalyst loadings for catalytic oxidation of soot particles.
15mg of soot particles and 150mg of powdered catalyst were weighed out and ground in an agate mortar for 10min to be in close contact. The sample was placed in a quartz tube of 5mm diameter for the experiment, with a heating rate of 3 ℃/min, from 150 ℃ to 650 ℃. At 150 ℃, the concentration of N is 300mL/min 2 The pretreatment was carried out under a gas stream for 0.5 h. With N 2 As an equilibrium gas, the reaction gas contained 2000ppm NO and 10% O 2 The gas flow rate was 500 mL/min. Outlet end CO 2 The concentration was measured by an LB-MS5X gas analyzer. The characteristic temperatures recorded at 10%, 50% and 90% soot conversion are T 10 、T 50 、T 90 Wherein T 90 Representing the burn-off temperature of the soot. By T i Representing the ignition temperature of soot, i.e. outlet CO 2 Temperature at which the concentration reaches 0.01%. The activity test of the monolithic catalyst is to dissolve the soot particles in ethanol, and then immerse the dried monolithic catalyst in the ethanol solution containing the soot particles for 30min of ultrasonic treatment. The monolithic catalyst evenly coated with the soot particles is dried for 12 hours, and then the monolithic catalyst is put into a quartz tube with the diameter of 50mm, and the activity test experiment is the same as that of the powdery catalyst.
1. Ce prepared by FIG. 1 inventive examples 1-3 1-x Ti x O 2 Catalyzing CO in soot process 2 The graph of concentration (a) and soot conversion (b) shows that Ce with different Ti contents 1-x Ti x O 2 Composite oxide catalytic oxidation of Ce in soot activity 0.92 Ti 0.08 O 2 The catalyst has the best activity and the ignition temperature T of the oxidation soot i At 343 ℃ and a temperature T at which 90% conversion occurs 90 At 458 ℃;
2. M/Ce prepared by FIG. 2 examples 4-6 of the invention 1-x Ti x O 2 M is Cs, K or Na, x is 0.08 and Ce 0.92 Ti 0.08 O 2 Catalyzing CO in soot process 2 The graphs of the concentration (a) and the soot conversion (b) show that different alkali metal loading Ce can be seen 1-x Ti x O 2 M/Ce of catalyst 1-x Ti x O 2 Catalyst catalytic oxidation soot activity, 8% Cs/Ce 0.92 Ti 0.08 O 2 Has the best activity, T i At 319 ℃ T 90 At 421 ℃;
3. FIG. 3 8% Cs/Ce prepared by the invention of examples 7-9 1-x Ti x O 2 Catalyst for catalyzing CO in soot process by using monolithic catalyst of 0.08 x in DPF 2 Concentration (a) and soot conversion (b) 8% Cs/Ce in the graph 0.92 Ti 0.08 O 2 Example 7,/DPF-1, 8% Cs/Ce 0.92 Ti 0.08 O 2 Example 8,/DPF-2, 8% Cs/Ce 0.92 Ti 0.08 O 2 Example 9 for DPF-3 it can be seen that the activity of the monolithic catalyst for oxidizing soot at different catalyst loadings, Ce in example 8 0.92 Ti 0.08 O 2 The monolithic catalyst with 2.5 wt% DPF has the best catalysis and activity, T i At 323 ℃ T 90 491 ℃.
4. Ce of example 2 of the present invention can be seen from FIG. 4 0.92 Ti 0.08 O 2 The catalyst is composed of irregular particles, and the agglomeration or accumulation of the nano particles forms a mesoporous structure. Example 6 of the present invention is at Ce 0.92 Ti 0.08 O 2 The catalyst is loaded with the alkali metal Cs, and the loaded alkali metal does not change the particle structure of the catalyst, so that the Cs is highly dispersed on the surface of the catalyst.
5. It is found from fig. 5 that the DPF sample without catalyst coating (fig. 5a) has a relatively flat cross section and relatively sharp corners; after coating the catalyst, inventive example 8: 8% Cs/Ce 0.92 Ti 0.08 O 2 The cross section of the DPF-2 (FIG. 5b) becomes uneven, and the edges become blunt and rounded, giving a coating feeling. According to fig. 5c, after magnification, a significant particle growth was seen over the surface of the DPF sample, indicating that the catalyst had been uniformly coated on the DPF filter body.
Claims (9)
1. A preparation method of a monolithic catalyst is characterized by comprising the following steps: the method comprises the following steps:
(1) preparation of Ce by sol-gel method 1-x Ti x O 2 Carrier:
dissolving 1-3g of solid cerium nitrate in 30mL of absolute ethyl alcohol according to the following proportion, and then adding 10mL of deionized water to obtain a product A; the chemical formula of the solid cerium nitrate is Ce (NO) 3 ) 2 ·6H 2 O；
Regulating the pH value of the product A with glacial acetic acid to make the pH value of the product A be 2.5-3.5 to obtain a product B;
thirdly, under the stirring state, dropwise adding butyl titanate into the product B, then heating in a water bath at 50-70 ℃, and stirring for reaction for 2-4h to obtain a reaction solution, namely a product C;
fourthly, performing ultrasonic cleaning on the cordierite-based diesel vehicle particulate matter catcher-DPF in water for 1.5 to 2.5 hours, and drying at 90 to 110 ℃ to obtain a D product;
fifthly, putting the product D into the product C, heating in a water bath at 30-50 ℃, aging for 6-10h, and drying at 60-80 ℃ for 46-50h to obtain a product E;
sixthly, roasting the E product at the temperature of 400-600 ℃ to obtain Ce 1-x Ti x O 2 The load is 1.25-3.75 wt% of integral catalyst of DPF, which is F product; and said Ce is 1-x Ti x O 2 X is more than or equal to 0.07 and less than or equal to 0.09;
(2) impregnation method for preparing M/Ce 1-x Ti x O 2 Catalyst:
adding F into alkali metal carbonate solution to control the load of active component M in the carbonate solution to Ce 1- x Ti x O 2 Carrying out ultrasonic treatment for 2h according to the mass percent of the carrier, drying at 80 ℃, then heating to 500 ℃ at 3 ℃/min, roasting, and keeping the temperature for 2h to obtain M/Ce 1-x Ti x O 2 The metal of M is Cs, K or Na, and x is more than or equal to 0.07 and less than or equal to 0.09.
2. The process for preparing a monolithic catalyst according to claim 1, characterized in that: in the step I, 2g of solid cerous nitrate is dissolved in 30mL of absolute ethyl alcohol according to the following proportion, and then 10mL of deionized water is added.
3. The process for preparing a monolithic catalyst according to claim 1, characterized in that: and in the second step, the pH value of the product A is adjusted by glacial acetic acid to ensure that the pH value of the product A is 2.
4. The process for preparing a monolithic catalyst according to claim 1, characterized in that: in the third step, in a stirring state, according to the molar ratio of Ce to Ti of 1-x: and x, dropwise adding butyl titanate into the product B, heating in a water bath at 60 ℃, and stirring to react for 3 hours to obtain a reaction solution.
5. The process for preparing a monolithic catalyst according to claim 1, characterized in that: in the step IV, performing ultrasonic treatment on a cordierite-based diesel vehicle particulate matter catcher-DPF in water for 2 hours, and drying at 100 ℃.
6. A process for the preparation of a monolithic catalyst according to claim 1, characterized in that: in the fifth step, the product D is put into the product C, is heated in water bath for 7 hours at the temperature of 40 ℃, and is dried for 48 hours at the temperature of 70 ℃.
7. The process for preparing a monolithic catalyst according to claim 1, characterized in that: in the step, the E product is roasted at 500 ℃ to obtain Ce 1-x Ti x O 2 The load is 2.5 wt% of DPF, and is F product; and said Ce is 1- x Ti x O 2 Wherein x is 0.08.
8. The process for preparing a monolithic catalyst according to claim 1, characterized in that: in the step (c), the alkali metal carbonate solution is Cs 2 CO 3 A solution; the M/Ce 1-x Ti x O 2 In the DPF, the M metal is Cs, and x is 0.08.
9. Use of a monolithic catalyst prepared according to the preparation process of any one of claims 1 to 8, characterized in that: is M/Ce prepared by the preparation method of the monolithic catalyst 1-x Ti x O 2 The DPF integrated catalyst is used in a diesel vehicle tail gas DPF reaction system to convert carbon smoke particles into nontoxic and pollution-free CO 2 The reaction temperature is 310-420 ℃, and the total flow of the gas is controlled to be 400-550 mL/min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110538751.9A CN113198451B (en) | 2021-05-18 | 2021-05-18 | Monolithic catalyst, preparation method and application |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110538751.9A CN113198451B (en) | 2021-05-18 | 2021-05-18 | Monolithic catalyst, preparation method and application |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113198451A CN113198451A (en) | 2021-08-03 |
| CN113198451B true CN113198451B (en) | 2022-08-12 |
Family
ID=77031642
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110538751.9A Active CN113198451B (en) | 2021-05-18 | 2021-05-18 | Monolithic catalyst, preparation method and application |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113198451B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103028417A (en) * | 2013-01-18 | 2013-04-10 | 江苏蓝烽新材料科技有限公司 | Catalytic agent for reducing combustion temperature of carbon cigarette pellet of diesel vehicle and preparation method of catalytic agent |
| CN104640616A (en) * | 2012-09-21 | 2015-05-20 | 克拉里安特国际有限公司 | Method for purifying exhaust gas and for regenerating an oxidation catalytic converter |
| CN105126819A (en) * | 2015-09-01 | 2015-12-09 | 中国石油大学(北京) | Composite oxide catalyst for eliminating NH3, NO and soot particles at same time and preparation method and purpose of composite oxide catalyst |
| CN108561211A (en) * | 2018-04-20 | 2018-09-21 | 中自环保科技股份有限公司 | It is a kind of that there is low back pressure, the DPF of low light-off temperature Catalytic Layer and its preparation process |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104971735B (en) * | 2015-06-19 | 2018-03-09 | 中国科学院上海硅酸盐研究所 | A kind of efficient diesel car tail gas refining oxidation catalyst and its preparation method and application |
| US10906031B2 (en) * | 2019-04-05 | 2021-02-02 | Paccar Inc | Intra-crystalline binary catalysts and uses thereof |
-
2021
- 2021-05-18 CN CN202110538751.9A patent/CN113198451B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104640616A (en) * | 2012-09-21 | 2015-05-20 | 克拉里安特国际有限公司 | Method for purifying exhaust gas and for regenerating an oxidation catalytic converter |
| CN103028417A (en) * | 2013-01-18 | 2013-04-10 | 江苏蓝烽新材料科技有限公司 | Catalytic agent for reducing combustion temperature of carbon cigarette pellet of diesel vehicle and preparation method of catalytic agent |
| CN105126819A (en) * | 2015-09-01 | 2015-12-09 | 中国石油大学(北京) | Composite oxide catalyst for eliminating NH3, NO and soot particles at same time and preparation method and purpose of composite oxide catalyst |
| CN108561211A (en) * | 2018-04-20 | 2018-09-21 | 中自环保科技股份有限公司 | It is a kind of that there is low back pressure, the DPF of low light-off temperature Catalytic Layer and its preparation process |
Non-Patent Citations (2)
| Title |
|---|
| 含钾催化剂的制备及催化碳烟燃烧性能;刘雪松;《中国优秀硕士学位论文全文数据库 工程科技Ⅰ辑》;20210115;B016-1269 * |
| 大孔铈基复合氧化物同时消除柴油机尾气中碳烟颗粒和氮氧化物的研究;程颖;《中国博士学位论文全文数据库 工程科技Ⅰ辑》;20190215;B027-26 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113198451A (en) | 2021-08-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5047114B2 (en) | Method for producing powder containing cerium oxide | |
| CN110013849B (en) | Ag-silver-doped modified manganese-based mullite oxidation catalyst and preparation and application thereof | |
| CN103212413B (en) | Thermal stabilization core-shell structure nano three-way catalyst and preparation method thereof | |
| JP4012320B2 (en) | Exhaust gas purification catalyst for lean combustion engine | |
| CN109174094A (en) | A kind of preparation method and application of Rutile Type solid-solution material | |
| CN108816246B (en) | High-dispersion anti-sintering diesel vehicle ASC catalyst and preparation method thereof | |
| CN109589960B (en) | A kind of wall-flow type low precious metal content catalyst, preparation method and applications | |
| CN112058261B (en) | Integral diesel exhaust oxidation catalyst, preparation method and application | |
| CN107684907A (en) | A kind of noble metal catalyst for CWO industrial wastewater, preparation method and applications | |
| CN108479788B (en) | Non-noble metal supported catalyst and preparation method and application thereof | |
| CN103877994B (en) | Small utility gasoline engine ternary catalyst for metal honeycomb carrier and preparation method | |
| CN113385188B (en) | Integral cDPF composite material for diesel vehicle and preparation method thereof | |
| CN113198451B (en) | Monolithic catalyst, preparation method and application | |
| JP2006305406A (en) | CATALYST FOR REMOVING NOx IN EXHAUST GAS | |
| EP0722767A1 (en) | Catalyst for purifying exhaust gases | |
| CN113262780A (en) | High-activity and high-stability manganese-based carbon smoke catalyst and preparation method and application thereof | |
| CN106984318A (en) | A kind of bimetallic cobalt-base catalyst and preparation method and application | |
| CN112844394A (en) | CuO-CeO2Preparation method of supported catalyst and application of supported catalyst in tail gas NOxAnd application in anaerobic elimination of CO | |
| CN113710351A (en) | Catalyzed gasoline particulate filter | |
| CN108940384B (en) | Catalyst for soot combustion reaction and preparation method and application thereof | |
| CN103861664A (en) | Oxidation catalyst for diesel engine exhaust | |
| CN111379613B (en) | Diesel particulate trap loaded with macroporous perovskite oxide and application thereof | |
| CN114160148A (en) | Cu-based catalyst for hydrogen production by methanol reforming and preparation method and application thereof | |
| JP4753613B2 (en) | NOx purification catalyst | |
| CN111250078A (en) | MnOx @ Eu-CeOx low-temperature SCR flue gas denitration catalyst and preparation method and application thereof |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |