CN102247886B - Manganese-zirconium dual metal modified selective catalytic reduction catalyst for molecular sieve type diesel engine - Google Patents

Manganese-zirconium dual metal modified selective catalytic reduction catalyst for molecular sieve type diesel engine Download PDF

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CN102247886B
CN102247886B CN2011101189229A CN201110118922A CN102247886B CN 102247886 B CN102247886 B CN 102247886B CN 2011101189229 A CN2011101189229 A CN 2011101189229A CN 201110118922 A CN201110118922 A CN 201110118922A CN 102247886 B CN102247886 B CN 102247886B
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manganese
catalyst
zirconium
molecular sieve
catalytic reduction
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CN102247886A (en
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宋崇林
吕刚
宾峰
张清茂
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Tianjin University
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    • 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
    • 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
    • Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
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    • Y02C20/10—Capture or disposal of greenhouse gases of nitrous oxide (N2O)

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Abstract

The invention discloses a manganese-zirconium dual metal modified selective catalytic reduction catalyst for a molecular sieve type diesel engine. In the catalyst, manganese and zirconium elements enter a molecular sieve by a liquid ion exchange-immersion method; by taking the total weight of the modified powdered catalyst as reference, the manganese element accounts for 4.5 to 7.5 percent, and the zirconium element accounts for 4.5 to 15 percent; by taking the total weight of a supported catalyst as reference, a coating accounts for 5 to 15 percent; urea or ammonia is adopted as a reducing agent to remove NOx in exhaust gas of the diesel engine by virtue of selective catalytic reduction reaction; the novel SCR (selective catalytic reduction) catalyst for the diesel vehicle is prepared from non-toxic molecular sieve and low-toxic manganese and zirconium elements, so that the toxicity of the catalyst to a human body is reduced; and simultaneously a high-activity temperature window of the catalyst in the SCR reaction of the diesel vehicle is enlarged. According to the modification method, the supporting capacity is improved, the supporting proportion is more flexible and adjustable, and further optimization of the catalyst performance is facilitated.

Description

The manganese zirconium dual metal modified selective catalytic reduction catalyst for molecular sieve type diesel engine
Technical field
The invention belongs to the use for diesel engine cleaning catalyst, be specifically related to the molecular sieve type use for diesel engine catalyst of a kind of manganese, zirconium double metal modification.
Background technology
The exhaust emissions of diesel engine for automobile is one of important pollution sources at present, the nitrogen oxide of its discharging (NOx) and particle (PM) serious harm health.The corrective measure of burning due to cylinder combustion is difficult to reduce simultaneously NOx and PM discharging, so exhaust gas aftertreatment techniques becomes the inevitable choice of Exhaust Control for Diesel Engine.SCR (SCR) technology take urea or ammonia as reducing agent has high NOx purification efficiency, and by with coupling, the optimization of combustion modifications measure, also can reduce simultaneously the fuel consume of PM discharging and engine, be one of the most promising efficient post-processing technology.Current business-like SCR catalyst is mainly with V 2O 5Be the loaded catalyst of major catalyst, its effective temperature window is less, and particularly minimum effective temperature 300 ℃ of left and right, is difficult to satisfy diesel vehicle under Chinese city road exercising condition, to the actual requirement of SCR catalyst low-temperature activity.While V 2O 5Belong to highly toxic substance, because catalyst in use unavoidably can run off, so catalytic component based on vanadium is larger to human health damage.
At present, adopt the good SCR catalyst of low toxicity catalysis material research and development low-temperature catalytic activity, become the study hotspot of domestic and international association area, wherein the research of molecular sieve catalysis material is particularly active.By the exchange modification of metal pair molecular screen material, can improve the SCR catalytic performance of molecular screen material, enlarge the high activity temperature window.Particularly adopt various metals that molecular sieve is carried out composite modified, can bring into play the synergistic function between different metal, improve greatly the catalytic performance of molecular sieve catalyst.On the other hand, for simple liquid ion-exchange, the species of metal ion of load and load capacity are all fewer on molecular sieve, such as zirconium just can not enter in type ZSM 5 molecular sieve by ion-exchange.But if ion-exchange and two kinds of method of modifying of dipping can be combined, not only can improve the load capacity of metal, and proportion of composing that can the flexible modulation carried metal, be conducive to simplify the further raising of preparation technology and catalyst performance.The present invention carries out modification with manganese nitrate and zirconium nitrate mixed solution to H/ZSM-5 type molecular screen material exactly, and finally prepares the molecular sieve type SCR catalyst of manganese, zirconium double metal modification through coating load.
Summary of the invention
The objective of the invention is, the mixed solution that utilizes manganese nitrate and zirconium nitrate is the molecular sieve pulverulent material of 16: 1 for H/ZSM-5, sial ratio to model, carry out a step liquid ion-exchange-dipping modification, thereby the ZSM-5 molecular sieve type SCR powder catalyst of a series of manganese, zirconium double metal modification is provided.By the load of powder catalyst on cordierite honeycomb ceramic carrier, obtain the supported SCR catalyst that purifies for diesel vehicle NOx simultaneously.
The objective of the invention is to be achieved through the following technical solutions: manganese, zirconium dual metal modified selective catalytic reduction catalyst for molecular sieve type diesel engine, its manganese, zr element are to enter in molecular sieve by liquid ion-exchange-dipping, take through the gross weight of the powder catalyst after ion-exchange-dipping modification as benchmark, it is 4.5～7.5% that manganese element accounts for percentage by weight, and it is 4.5～15% that zr element accounts for percentage by weight.The gross weight of the loaded catalyst after the load coating is as benchmark, and the shared percentage by weight of its floating coat is 5～15%.This selective catalytic reduction catalysts, adopting urea or ammonia is reducing agent, removes NOx in diesel exhaust gas by selective catalytic reduction reaction.
Manganese, zirconium dual metal modified selective catalytic reduction catalyst for molecular sieve type diesel engine, its modification comprises the following steps:
(1) 4～7g manganese nitrate and 4～15g zirconium nitrate are dissolved in the 200ml deionized water, then weighing 15～18.5g model is that H/ZSM-5, sial ratio are that the molecular sieve powder of 16: 1 joins in the mixed solution of manganese nitrate and zirconium nitrate, return stirring 4～6h in the water-bath of 70～80 ℃ carries out ion-exchange;
(2) reflux condensate device that removes in ion-exchange step continues to add the thermal agitation dipping under 70～80 ℃, until the liquid component evaporate to dryness;
(3) with the dry 12～24h under 90～110 ℃ of the pressed powder after ion-exchange-dipping, then calcine 2～3h under 550～650 ℃.
The beneficial effect of characteristics of the present invention and generation is: adopt the manganese element of nontoxic H/ZSM-5 molecular sieve and low toxicity and zr element to prepare the automobile-used SCR catalyst of novel diesel, this series powder and loaded catalyst have not only reduced the bio-toxicity of original SCR catalyst; The high activity temperature window, particularly low temperature active that have also enlarged simultaneously diesel vehicle SCR reacting middle catalyst have had raising by a relatively large margin, are particularly suitable for the low national conditions of diesel engine truck exhaust temperature in Chinese city.In addition, one step of bimetallic liquid ion-exchange-dipping method of modifying for ZSM-5 molecular sieve can when effectively improving content of metal, make two kinds of carried metal proportion of composing adjustable flexibly, not only simplify modified technique, and be conducive to the further optimization of catalyst performance.
Description of drawings
Fig. 1 is selective catalytic reduction catalysts hot laboratory evaluating apparatus schematic diagram.
Wherein: 1-air steel cylinder; The 2-nitrogen cylinder; The 3-NOx steel cylinder; The 4-NH3 steel cylinder; 5-triple channel flow controller; The 6-flow controller; The 7-mixing kettle; The 8-reactor; The 9-thermorelay; The 10-temperature indicator; 11-reaction final vacuum outlet (leading to gas analyzer).
Fig. 2 is that the NOx removal efficiency of ZSM-5 molecular sieve powder catalyst after embodiment 1～4 modification is with the situation of change of reaction temperature.
Fig. 3 is SCR catalyst performance engine evaluation system schematic diagram.
Wherein: the 12-diesel engine; The 13-constant displacement pump; 14-NH 3Storage tank; 15-NH 3Jet; The 16-SCR catalyst converter; The 17-dynamometer machine; 18-bypassing exhaust valve
Fig. 4 is the engine evaluation result of embodiment 1～4 loaded catalyst NOx purifying property.
The specific embodiment
Below by specific embodiment, principle steps of the present invention is described in detail, need to prove that the present embodiment is narrative, rather than determinate, can not limit protection scope of the present invention with this embodiment.
The molecular sieve type selective catalytic reduction catalyst for diesel engine of manganese, zirconium double metal modification, it is characterized in that manganese, zr element are to enter in molecular sieve by liquid ion-exchange-dipping, take through the gross weight of the powder catalyst after ion-exchange-dipping modification as benchmark, it is 4.5～7.5% that manganese element accounts for percentage by weight, and it is 4.5～15% that zr element accounts for percentage by weight; The gross weight of the loaded catalyst after the load coating is as benchmark, and the shared percentage by weight of its floating coat is 5～15%.
It is reducing agent that the molecular sieve type selective catalytic reduction catalyst for diesel engine of manganese, zirconium double metal modification adopts urea or ammonia, removes NOx in diesel exhaust gas by selective catalytic reduction reaction.
The preparation method of this catalyst modification comprises the following steps:
(1) with 4～7g manganese nitrate (molecular formula: Mn (NO 3) 24H 2O； Molecular weight: 251.01) and 4～15g zirconium nitrate (molecular formula: Zr (NO 3) 45H 2O； Molecular weight: 429.32) be dissolved in the 200ml deionized water, then weighing 15～18.5g model is that H/ZSM-5, sial ratio are that the molecular sieve powder of 16: 1 joins in the mixed solution of manganese nitrate and zirconium nitrate, return stirring 4～6h in the water-bath of 70～80 ℃ carries out ion-exchange;
(2) reflux condensate device that removes in ion-exchange step continues to add the thermal agitation dipping under 70～80 ℃, until the liquid component evaporate to dryness;
(3) with the dry 12～24h under 90～110 ℃ of the pressed powder after ion-exchange-dipping, then calcine 2～3h under 550～650 ℃.
The NOx catalytically active assessment test of embodiment 1～4 modified molecular screen powder is to carry out on selective catalytic reduction catalysts hot laboratory evaluating apparatus shown in Figure 1.
It is that 3L/min, nitrogen are that 3L/min, NOx are that the flow velocity of 4.8mL/min enters respectively in mixing kettle 7 and mixes according to air that air in steel cylinder 1～3, nitrogen and NOx control meter 5 by multichannel flow.Then mist enters in reactor 8 again.And the NH in steel cylinder 4 3Gas enters reactor 8 with the flow velocity of 5mL/min under the control of single channel mass flow controller 6, the SCR catalytic reaction occurs the catalyst surface of gaseous mixture in reactor that flows out with mixing kettle 7.The temperature range of reactor is 150-600 ℃, is controlled by relay 9, and the actual temperature in reactor is shown by temperature indicator 10.Reacted gaseous mixture enters infrared gas analyser after 11 mouthfuls of discharges wherein NOx is carried out quantitative analysis.In addition, in the setting test, the ratio of reaction mixture gas rate of flow of fluid and catalyst volume is 60000h -1
Embodiment 1～4 loaded catalyst NOx catalytically active assessment test is what to carry out on SCR catalyst activity engine evaluation system shown in Figure 3.
Its test method is: use the running status of dynamometer machine 17 Control experiment engines 12, make delivery temperature in the SCR catalyst converter reach successively the equilibrium temperature of prior setting; Meanwhile adjust bypassing exhaust valve 18, take the ratio that keeps extraction flow and catalyst volume in the SCR catalytic converter as 60000h -1 Constant displacement pump 13 is with NH 3With the NOx mol ratio be that the ratio of 1.05: 1 enters the liquefied ammonia in storage tank 14 in blast pipe through jet 15 metered injections.NH after vaporization 3Gas with enter SCR catalyst converter 16 after the exhaust of engine 12 mixes and carry out the SCR catalytic reaction.NOx concentration after reaction in gaseous mixture is measured by chemiluminescence detector.
Consider integrality of the invention process, embodiment is divided into manganese, zirconium double metal modification and two processes of load coating.
Embodiment 1
(1) modification
5.8g manganese nitrate and 4.3g zirconium nitrate are dissolved in the 200ml deionized water, then weighing 17.9g model is that H/ZSM-5, sial ratio are that the molecular sieve powder of 16: 1 adds in the mixed solution of manganese nitrate and zirconium nitrate, and in the water-bath of 70 ℃ return stirring 6h, carry out ion-exchange.Then remove reflux condensate device, continue to add the thermal agitation dipping under 70 ℃, until the liquid component evaporate to dryness.Pressed powder after ion-exchange-dipping after dry 16h under 100 ℃, is calcined 3h under 550 ℃.
(2) load
Determine to apply 5～6% coating on the 1kg cordierite honeycomb ceramic carrier.
Need 20g γ-Al according to the molecular sieve powder after every 100g modification 2O 3, 5g boehmite, 10g cerium zirconium, 5g polyethylene glycol (mean molecule quantity 4000) and 50g nitric acid ratio, take modified molecular screen powder, γ-Al 2O 3, boehmite, cerium zirconium and polyethylene glycol, and under agitation, with modified molecular screen powder, γ-Al 2O 3, boehmite, cerium zirconium and polyethylene glycol be dispersed in the salpeter solution of 20 times of ratios of dilution, obtains faint yellow slurry.With gained slurry sealing, standing, obtain stable slurry after the week.
The 1kg cordierite honeycomb ceramic carrier of weighing is immersed in stable slurry, and dipping is 4 hours under 60 ℃.Dipping takes out ceramic monolith after finishing from slurries, blow residual liquid in the duct off, dry 8h under 80 ℃, then at 550 times calcining 3h.After the ceramic monolith after load is cooling, claim its weight, this weight and cordierite honeycomb ceramic initial weight poor is the gross weight of coating.
Repeatedly repeated impregnations, drying and calcination process until the percentage by weight of coating is near pre-determined percentage by weight, then are calcined 3h with the cordierite honeycomb ceramic carrier after the load coating under 550 ℃.
Be 20～40 purpose particles with the modified molecular screen powder through grinding, compressing tablet, fragmentation, screening.The modified molecular screen particle is carried out atomic absorption spectrophotometer detect, the percetage by weight that measures manganese in the modified molecular screen powder is 6.14%, and the percetage by weight of zirconium is 4.46%.Adopt SCR catalyst activity laboratory evaluation device shown in Figure 1, the performance of modified molecular screen particulate burning purifying NOx is estimated, result as shown in Figure 2.
In addition, through weighing and calculating, the loaded catalyst floating coat weight of the present embodiment accounts for 5.7% of loaded catalyst gross weight.Adopt SCR catalyst activity engine evaluation system shown in Figure 3, estimate the NOx catalytic purification performance of the present embodiment loaded catalyst, result as shown in Figure 4.
Embodiment 2
(1) modification
5.5g manganese nitrate and 8g zirconium nitrate are dissolved in the 200ml deionized water.Then weighing 17.2g model is that H/ZSM-5, sial ratio are that the molecular sieve powder of 16: 1 adds in the mixed solution of manganese nitrate and zirconium nitrate, and in the water-bath of 80 ℃ return stirring 4h, carry out ion-exchange.Then remove reflux condensate device, continue to add the thermal agitation dipping under 80 ℃, until the liquid component evaporate to dryness.Pressed powder after ion-exchange-dipping after dry 24h under 90 ℃, is calcined 3h under 600 ℃.
(2) load
Determine to apply 10～11% coating on the 1kg cordierite honeycomb ceramic carrier.
Need 20g γ-Al according to the molecular sieve powder after every 100g modification 2O 3, 5g boehmite, 10g cerium zirconium, 5g polyethylene glycol (mean molecule quantity 4000) and 50g nitric acid ratio, take modified molecular screen powder, γ-Al 2O 3, boehmite, cerium zirconium and polyethylene glycol, and under agitation, with modified molecular screen powder, γ-Al 2O 3, boehmite, cerium zirconium and polyethylene glycol be dispersed in the salpeter solution of 20 times of ratios of dilution, obtains faint yellow slurry.With gained slurry sealing, standing, obtain stable slurry after the week.
The 1kg cordierite honeycomb ceramic carrier of weighing is immersed in stable slurry, and dipping is 4 hours under 60 ℃.Dipping takes out ceramic monolith after finishing from slurries, blow residual liquid in the duct off, dry 8h under 80 ℃, then at 550 times calcining 3h.After the ceramic monolith after load is cooling, claim its weight, this weight and cordierite honeycomb ceramic initial weight poor is the gross weight of coating.
Repeatedly repeated impregnations, drying and calcination process, until the percentage by weight of coating enters pre-determined weight percentage ranges, then calcine 3h with the cordierite honeycomb ceramic carrier after the load coating under 550 ℃.
Be 20～40 purpose particles with the modified molecular screen powder through grinding, compressing tablet, fragmentation, screening.The modified molecular screen particle is carried out atomic absorption spectrophotometer detect, the percetage by weight that measures manganese in the modified molecular screen powder is 5.79%, and the percetage by weight of zirconium is 8.25%.Adopt SCR catalyst activity laboratory evaluation device shown in Figure 1, the performance of the present embodiment modified molecular screen particulate burning purifying NOx is estimated, result as shown in Figure 2.
In addition, through weighing and calculating, the loaded catalyst floating coat weight of the present embodiment accounts for 10.4% of loaded catalyst gross weight.Adopt SCR catalyst activity engine evaluation system shown in Figure 3, estimate the NOx catalytic purification performance of loaded catalyst in the present embodiment, result as shown in Figure 4.
Embodiment 3
(1) modification
6.8g manganese nitrate and 10g zirconium nitrate are dissolved in the 200ml deionized water.Then weighing 16.5g model is that H/ZSM-5, sial ratio are that the molecular sieve powder of 16: 1 adds in the mixed solution of manganese nitrate and zirconium nitrate, and in the water-bath of 70 ℃ return stirring 6h, carry out ion-exchange.Then remove reflux condensate device, continue to add the thermal agitation dipping under 70 ℃, until the liquid component evaporate to dryness.Pressed powder after ion-exchange-dipping after dry 12h under 110 ℃, is calcined 2h under 650 ℃.
(2) load
Determine to apply 9～10% coating on the 1kg cordierite honeycomb ceramic carrier.
Need 20g γ-Al according to the molecular sieve powder after every 100g modification 2O 3, 5g boehmite, 10g cerium zirconium, 5g polyethylene glycol (mean molecule quantity 4000) and 50g nitric acid ratio, take modified molecular screen powder, γ-Al 2O 3, boehmite, cerium zirconium and polyethylene glycol, and under agitation, with modified molecular screen powder, γ-Al 2O 3, boehmite, cerium zirconium and polyethylene glycol be dispersed in the salpeter solution of 20 times of ratios of dilution, obtains faint yellow slurry.With gained slurry sealing, standing, obtain stable slurry after the week.
The 1kg cordierite honeycomb ceramic carrier of weighing is immersed in stable slurry, and dipping is 4 hours under 60 ℃.Dipping takes out ceramic monolith after finishing from slurries, blow residual liquid in the duct off, dry 8h under 80 ℃, then at 550 times calcining 3h.After the ceramic monolith after load is cooling, claim its weight, this weight and cordierite honeycomb ceramic initial weight poor is the gross weight of coating.
Repeatedly repeated impregnations, drying and calcination process, until the percentage by weight of coating enters pre-determined weight percentage ranges, then calcine 3h with the cordierite honeycomb ceramic carrier after the load coating under 550 ℃.
Be 20～40 purpose particles with the modified molecular screen powder through grinding, compressing tablet, fragmentation, screening.The modified molecular screen particle is carried out atomic absorption spectrophotometer detect, the percetage by weight that measures manganese in the modified molecular screen powder is 7.28%, and the percetage by weight of zirconium is 10.5%.Adopt SCR catalyst activity laboratory evaluation device shown in Figure 1, the performance of the modified molecular screen particulate burning purifying NOx of the present embodiment is estimated, result as shown in Figure 2.
In addition, through weighing and calculating, the loaded catalyst floating coat weight of the present embodiment accounts for 9.6% of loaded catalyst gross weight.Adopt SCR catalyst activity engine evaluation system shown in Figure 3, estimate the NOx catalytic purification performance of loaded catalyst in the present embodiment, result as shown in Figure 4.
Embodiment 4
(1) modification
4.5g manganese nitrate and 14g zirconium nitrate are dissolved in the 200ml deionized water.Then weighing 16.1g model is that H/ZSM-5, sial ratio are that the molecular sieve powder of 16: 1 adds in the mixed solution of described manganese nitrate and zirconium nitrate, and in the water-bath of 80 ℃ return stirring 4h, carry out ion-exchange.Then remove reflux condensate device, continue to add the thermal agitation dipping under 80 ℃, until the liquid component evaporate to dryness.Pressed powder after ion-exchange-dipping after dry 12h under 110 ℃, is calcined 2h under 650 ℃.
(2) load
Determine to apply 14～15% coating on the 1kg cordierite honeycomb ceramic carrier.
Need 20g γ-Al according to the molecular sieve powder after every 100g modification 2O 3, 5g boehmite, 10g cerium zirconium, 5g polyethylene glycol (mean molecule quantity 4000) and 50g nitric acid ratio, take modified molecular screen powder, γ-Al 2O 3, boehmite, cerium zirconium and polyethylene glycol, and under agitation, with modified molecular screen powder, γ-Al 2O 3, boehmite, cerium zirconium and polyethylene glycol be dispersed in the salpeter solution of 20 times of ratios of dilution, obtains faint yellow slurry.With gained slurry sealing, standing, obtain stable slurry after the week.
The 1kg cordierite honeycomb ceramic carrier of weighing is immersed in stable slurry, and dipping is 4 hours under 60 ℃.Dipping takes out ceramic monolith after finishing from slurries, blow residual liquid in the duct off, dry 8h under 80 ℃, then at 550 times calcining 3h.After the ceramic monolith after load is cooling, claim its weight, this weight and cordierite honeycomb ceramic initial weight poor is the gross weight of coating.
Repeatedly repeated impregnations, drying and calcination process, until the percentage by weight of coating enters pre-determined weight percentage ranges, then calcine 3h with the cordierite honeycomb ceramic carrier after the load coating under 550 ℃.
Be 20～40 purpose particles with the modified molecular screen powder through grinding, compressing tablet, fragmentation, screening.The modified molecular screen particle is carried out atomic absorption spectrophotometer detect, the percetage by weight that measures manganese in the modified molecular screen powder is 4.77%, and the percetage by weight of zirconium is 14.7%.Adopt SCR catalyst activity laboratory evaluation device shown in Figure 1, the performance of the modified molecular screen particulate burning purifying NOx of the present embodiment is estimated, result as shown in Figure 2.
In addition, through weighing and calculating, the loaded catalyst floating coat weight of the present embodiment accounts for 14.4% of loaded catalyst gross weight.Adopt SCR catalyst activity engine evaluation system shown in Figure 3, estimate the NOx catalytic purification performance of loaded catalyst in the present embodiment, result as shown in Figure 4.

Claims (2)

1. manganese zirconium dual metal modified selective catalytic reduction catalyst for molecular sieve type diesel engine, it is characterized in that manganese, zr element are to enter in molecular sieve by liquid ion-exchange-dipping, take through the gross weight of the powder catalyst after ion-exchange-dipping modification as benchmark, it is 4.5～7.5% that manganese element accounts for percentage by weight, and it is 4.5～15% that zr element accounts for percentage by weight; The gross weight of the cordierite honeycomb ceramic carrier after the load coating is as benchmark, and the shared percentage by weight of its floating coat is 5～15%; Described modification comprises the following steps:
(1) 4～7g manganese nitrate and 4～15g zirconium nitrate are dissolved in the 200mL deionized water, then weighing 15～18.5g model is that H/ZSM-5, sial ratio are that the molecular sieve powder of 16: 1 joins in the mixed solution of manganese nitrate and zirconium nitrate, return stirring 4～6h in the water-bath of 70～80 ℃ carries out ion-exchange;
(2) reflux condensate device that removes in ion-exchange step continues to add the thermal agitation dipping under 70～80 ℃, until the liquid component evaporate to dryness;
(3) with the pressed powder after ion-exchange-dipping under 90～110 ℃, then dry 12～24h calcines 2～3h under 550～650 ℃.
2. according to manganese zirconium dual metal modified selective catalytic reduction catalyst for molecular sieve type diesel engine claimed in claim 1, it is characterized in that adopting urea or ammonia is reducing agent, removes NOx in diesel exhaust gas by selective catalytic reduction reaction.
CN2011101189229A 2011-05-10 2011-05-10 Manganese-zirconium dual metal modified selective catalytic reduction catalyst for molecular sieve type diesel engine Expired - Fee Related CN102247886B (en)

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CN105709813A (en) * 2016-01-22 2016-06-29 柳州市海达新型材料科技有限公司 Sulfur-resistant SCR (selective catalytic reduction) catalyst and preparation method thereof
CN107029781B (en) * 2016-02-04 2019-08-09 中触媒新材料股份有限公司 Iron and cerium modified beta-molecular sieve selective reduction catalyst and preparation method and application
CN105944749B (en) * 2016-05-05 2018-08-24 合肥神舟催化净化器股份有限公司 Use for diesel engine compound oxidizing catalyst based on modified molecular screen major catalyst
CN106762041A (en) * 2016-12-28 2017-05-31 中船动力研究院有限公司 Boat diesel engine catalytic reduction device with NOx trap function
CN113387784B (en) * 2021-07-12 2022-10-11 山东新和成药业有限公司 Acid-base catalyst and application thereof in delta-damascenone synthesis

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CN101972648A (en) * 2010-09-10 2011-02-16 常州大学 Modified Mn-Zr catalyst as well as preparation method and application thereof to preparing dimethyl ether

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