CN109289832A - Diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable and preparation method thereof - Google Patents

Diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable and preparation method thereof Download PDF

Info

Publication number
CN109289832A
CN109289832A CN201810949835.XA CN201810949835A CN109289832A CN 109289832 A CN109289832 A CN 109289832A CN 201810949835 A CN201810949835 A CN 201810949835A CN 109289832 A CN109289832 A CN 109289832A
Authority
CN
China
Prior art keywords
catalyst
scr catalyst
tail gas
zirconium
preparation
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.)
Granted
Application number
CN201810949835.XA
Other languages
Chinese (zh)
Other versions
CN109289832B (en
Inventor
徐海迪
陈耀强
王云
王健礼
林青瑾
刘双
刘静莹
焦毅
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sichuan University
Original Assignee
Sichuan University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Sichuan University filed Critical Sichuan University
Priority to CN201810949835.XA priority Critical patent/CN109289832B/en
Publication of CN109289832A publication Critical patent/CN109289832A/en
Application granted granted Critical
Publication of CN109289832B publication Critical patent/CN109289832B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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
    • B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/24—Chromium, molybdenum or tungsten
    • B01J23/30—Tungsten
    • 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
    • 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
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/0201—Impregnation
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/03—Precipitation; Co-precipitation
    • B01J37/031—Precipitation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/01—Engine exhaust gases
    • B01D2258/012—Diesel engines and lean burn gasoline engines
    • 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
    • B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
    • 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
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Biomedical Technology (AREA)
  • Environmental & Geological Engineering (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Catalysts (AREA)

Abstract

The diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable provided by the invention, chemical formula WO3/CexZr1‑xO2+Al2O3, by tungsten load general formula be CexZr1‑xO2+Al2O3Composite oxide material on be made, in which: 0 < x < 1, Al2O3In CexZr1‑ xO2+Al2O3Mass fraction in composite oxides is 6-12%, WO3Mass fraction is to be less than or equal to 15% greater than 0 in the catalyst.The Al2O3Modified WO3/CeZrO2Composite oxides NH3The preparation method of SCR catalyst, is configured to salting liquid by soluble cerium salt, zirconates and aluminium salt, and composite oxides Ce is made with corresponding alkali solution precipitatexZr1‑xO2+Al2O3, then load tungsten and be made.The catalyst keeps even improving low temperature active simultaneously while improving hydrothermal stability, to exhaust gas from diesel vehicle NOxWith more low activity temperature and broader complete conversion temperature window.

Description

Diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable and preparation method thereof
Technical field
The invention belongs to SCR catalyst catalysis technical fields, and in particular to one kind converts motor-driven vehicle for low temperature purification Gas NOxThe non-vanadium base WO of gas3/CeZrO2Composite oxides NH3SCR catalyst.
Background technique
Nitrogen oxygen with the promulgation for the discharged nitrous oxides regulation that countries in the world are increasingly stringenter, in lean combustion motor-vehicle tail-gas Compound (NOx) purification has become current one of environmental problem in the urgent need to address.NOxCan bring as acid rain, photochemical fog, The environmental problems such as greenhouse effects and ozone hole cause serious harm to human health and ecological environment.95% in atmosphere NOxFlue gas (46%) from motor-vehicle tail-gas (49%) and thermal power plant is discharged.Ammine selectivity catalytic reduction NOx (NH3- SCR) be most application prospect at present exhaust gas from diesel vehicle NOxPurification techniques is obtained in American-European-Japanese equal developed countries Industrial applications and current and future Chinese Control exhaust gas from diesel vehicle NOxOne of major technique of discharge.
V2O5-WO3(MO3)/TiO2Catalyst series (i.e. catalytic component based on vanadium) have been successfully applied to Section IV (state IV) and V (state V) for purifying its tail gas NO on stage diesel vehiclex, with the promulgation of the 6th stringenter stage (i.e. state six) discharge standard, Such catalyst is not able to satisfy state six and higher standard to exhaust gas from diesel vehicle NOxDischarge requirement.Mainly due to vanadium base There are still some inevitable disadvantages for catalyst: effective operation window (300-400 DEG C) of such catalyst does not adapt to bavin Oily tailstock gas temperature range (175-550 DEG C)；NH under high temperature (450 DEG C)3Non-selective oxidation make NOxUnder purifying rate is quick Drop, and generate a large amount of greenhouse gases N2O leads to principal product N2Selectivity be substantially reduced, secondary pollution also is caused to atmosphere； The thermal stability of catalytic component based on vanadium is poor, V2O5With very strong bio-toxicity.In exhaust gas from diesel vehicle after-treatment system, NH3-SCR Device is in grain catcher rear end, and the periodic regeneration of the grain catcher in exhaust gas from diesel vehicle can be such that exhaust temperature moment reaches To 800 DEG C or more, vanadium species can be sintered at such high temperatures, and main carriers TiO2Rutile will be changed by anatase Catalyst activity mutually is greatly reduced or even complete deactivation, the serious service life for reducing catalyst.Therefore, in reality Existing NH3While SCR catalyst is environmentally protective and catalytic activity is excellent, hydro-thermal performance resistant to high temperatures be can not ignore.
Ce base catalyst has obtained extensive concern in recent years, due to excellent Oxygen storage capacity, redox property And thermal stability, and cerium is resourceful.Pass through solid acid WO3Modified CeZrO2Obtained WO3/CeZrO2Catalyst is not only It is environmentally protective and have excellent NH3SCR activity, before there is in diesel vehicle denitration under lean burn conditions preferable application Scape.Since diesel vehicle normal operating temperature is 200-450 DEG C, and temperature when cold start-up and idling is lower, and the row of diesel vehicle It sails mileage and is up to hundreds of thousands of kilometers, this just needs SCR catalyst to be provided simultaneously with high low temperature active and long life (i.e. Gao Shui Thermal stability).But WO3/CeZrO2Catalyst can generate Ce after hydrothermal aging2(WO4)3, cause catalyst surface acidity and Oxidation-reduction quality reduces, to make the NH of catalyst3- SCR is greatly reduced.Al is adulterated using coprecipitation2O3In CeZrO2Middle system Standby WO3/CeZrAlOxCatalyst can be effectively improved the hydrothermal stability of catalyst, through 800 DEG C/10%H2O/ air speed 30000h-1After/12h hydrothermal aging, 20% and 25% has been respectively increased in NO average conversion and highest NO conversion ratio.But WO3/ CeZrAlOxThe fresh activity (before aging) of catalyst is significantly lower than WO3/CeZrO2Catalyst, this is because amphoteric oxide Al2O3Doping and reduce active specy CeOxWith content (Haidi Xu, Shuang Liu, the Yun Wang of surface acidity Deng Applied Surface Science, 2018,427:656-669).Therefore, WO3/CeZrO2The low temperature active of catalyst and There are certain contradiction between hydrothermal stability, how while improving hydrothermal stability it to be able to maintain WO again3/CeZrO2Catalysis Agent low temperature active decides that can the technology be widely used in the NO purification of exhaust gas from diesel vehicle.
Summary of the invention
In view of the above-mentioned deficiencies in the prior art, it is an object of the present invention to which the diesel car tail gas refining for providing a kind of hydrothermally stable is low Warm SCR catalyst and preparation method thereof, the catalyst keep even improving low temperature simultaneously while improving hydrothermal stability Activity, to exhaust gas from diesel vehicle NOxWith more low activity temperature and broader complete conversion temperature window.
The diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable provided by the invention is Al2O3Modified WO3/ CexZr1-xO2The SCR catalyst that composite oxides obtain, chemical formula WO3/CexZr1-xO2+Al2O3, wherein WO3It is supported on logical Formula is CexZr1-xO2+Al2O3Composite oxides on, in which: 0 < x < 1, Al2O3In CexZr1-xO2+Al2O3In composite oxides Mass fraction be 6-12%, WO3Mass fraction is to be less than or equal to 15% greater than 0 in the catalyst.
Further, the WO3Mass fraction in the catalyst is 6-12%.
Further, the CexZr1-xO2In, preferably 0.5 < x < 0.8, further preferably 0.68.
Further, CexZr1-xO2+Al2O3Composite oxides be by CexZr1-xO2With Al2O3It is obtained by mechanical mixture It arrives.
The preparation method of above-mentioned SCR catalyst provided by the invention is configured to salt by soluble cerium salt, zirconates and aluminium salt Composite oxides Ce is made with corresponding alkali solution precipitate in solutionxZr1-xO2+Al2O3, then load tungsten and be made.
Further, the preparation method the following steps are included:
(1) according to chemical formula CexZr1-xO2, in which: 0 < x < 1 weighs cerium source, zirconium source, and weighs silicon source, tungsten source, molten respectively Solution is configured in deionized water；
(2) the cerium source solution of preparation and zirconium source solution are uniformly mixed to get mixed solution, it is molten with ammonium hydroxide-ammonium carbonate buffering Liquid carries out cocurrent titration as precipitating reagent, with mixed solution, is co-precipitated cerium and zirconium, controls in titration coprecipitation process PH=8.2~8.5, ammonium hydroxide adjusts gained suspension pH=10 after co-precipitation, stands after adjusting not less than for 24 hours；
(3) the precipitating suspension after standing step (2) is aged 6~8h at 96~98 DEG C, and ageing terminates to be cooled to room Temperature, filtering, and filter cake to last time filtrate is washed with deionized and is in neutrality；
(4) by after gained filtration cakes torrefaction, 550-650 DEG C of predecomposition roasts 3~5h in Muffle furnace, obtains CexZr1-xO2It is yellow Color powder；
(5) silicon source solution and ammonium hydroxide-ammonium carbonate buffer solution are subjected to cocurrent titration, control pH=in titration process 8.2~8.5, ammonium hydroxide adjusts gained suspension pH=10 after co-precipitation, stands after adjusting not less than for 24 hours；
(6) suspension obtained by step (5) is aged, is filtered and is washed according to the condition of step (3), according still further to step (4) condition is dried and roasts, and obtains Al2O3White powder；
(7) by step (4) resulting CexZr1-xO2Yellow powder and step (6) resulting Al2O3White powder mixing ball It is milled to and is sufficiently mixed uniformly, obtain CexZr1-xO2+Al2O3Mixed oxide powder, mixed proportion control are CexZr1-xO2+Al2O3 Al in composite oxides2O3Mass fraction be 6-12%；
(8) gained mixed oxide powder and tungsten source solution are subjected to load tungsten using equi-volume impregnating, then in 80 After~100 DEG C of dry 8~12h, in Muffle furnace 500-600 DEG C of 3~5h of roasting to get arrive WO3/CexZr1-xO2+Al2O3Catalysis Agent powder, the load capacity of tungsten meet WO in gained catalyst fines3Mass fraction be greater than 0 be less than or equal to 15%.
Further, in step (1) cerium source in carbonic acid Asia cerium, cerous nitrate, ammonium ceric nitrate, cerous carbonate, cerous nitrate Any one or a few.
Further, zirconium source is selected from zirconium carbonate, zirconyl carbonate, zirconium nitrate, zirconyl nitrate, acetic acid zirconium, acetic acid in step (1) Any one or a few in oxygen zirconium.
Further, silicon source is aluminum nitrate in step (1).
Further, any one or a few in ammonium metatungstate, ammonium paratungstate, ammonium tungstate of tungsten source in step (1).
Further, the molar concentration rate of ammonia and ammonium carbonate is (0.5~3) in the buffer solution of the ammonium hydroxide-ammonium carbonate: 1, the concentration of preferably ammonia and carbonic acid ammonia is 2.5-3.5mol/L, further preferably 3mol/L.
Further, when preparing zirconium source solution, tungsten source solution, deionized water and zirconium source, tungsten source mass ratio be 91~ 3): 1, when preparing silicon source solution, the mass ratio of deionized water and silicon source is (1~4): 1.
Further, step (4) drying condition is in 80~100 DEG C of dry 20~30h.
Further, the ammoniacal liquor mass concentration of pH is adjusted as 25%-28% in step (2) and step (5).
Further, step (3) can be aged under 96~98 DEG C of oil baths or water bath condition.
Further, step (3) be washed with deionized filter cake to neutrality be washing to last time filtrate pH=6.8~ 7.5。
Further, step (7) ball milling condition are as follows: in ball grinder, zirconium ball is added, is 400~600r/min in revolving speed 5~20min of lower ball milling.
The WO that the present invention is prepared3/CexZr1-xO2+Al2O3Catalyst fines, in application, being preferably prepared into monoblock type Catalyst, the preparation method is as follows:
(1) by WO3/CexZr1-xO2+Al2O3Fine catalyst is uniformly mixed with deionized water, bonding agent and slurries is made, control Slurrying fluid solid content is 45~50%；
(2) gained catalyst slurry is coated uniformly on cordierite ceramic honeycomb matrix, control catalysis Upper carrying capacity of the agent powder on matrix is 150~160g/L；
(3) cordierite substrates after coating step are after 100~120 DEG C of dry 8~12h, 500-600 DEG C in Muffle furnace 3~5h is roasted to get WO is arrived3/CexZr1-xO2+Al2O3Monoblock type SCR catalyst.
Further, it is Φ 11mm*25mm/400cpsi that the cordierite, which selects specification,.
Further, any one or a few in boehmite, silica solution, acetic acid zirconium of bonding agent.With it is existing Technology is compared, beneficial effects of the present invention:
1. the present invention uses and Ce is first prepared separatelyxZr1-xO2Composite oxides and Al2O3, then the two ball milling mixing is uniform, Ce is preparedxZr1-xO2+Al2O3Composite oxides prepare WO as catalyst carrier, then using equi-volume impregnating3/ CexZr1-xO2+Al2O3Catalyst.To make active specy CeOxIt is more exposed to catalyst surface and participates in SCR reaction, it is acid Position WOxIt is evenly distributed on CexZr1-xO2+Al2O3Carrier surface, to make catalyst that there is more surface acidities and redox Property.It is demonstrated experimentally that the present invention effectively improves the low-temperature SCR activity of catalyst, the NO initiation temperature (T of catalyst50) from 197 DEG C 178 DEG C are reduced to, the complete conversion temperature (T of NO90) 210 DEG C are reduced to from 230 DEG C, complete conversion temperature window is from 230-397 DEG C It widens to 210-455 DEG C, has effectively widened complete conversion window, improve the low temperature NO transformation efficiency of catalyst, can meet and work as Exhaust gas from diesel vehicle NO under preceding city operating condition purifies demand.And WO prepared by the present invention3/CexZr1-xO2+Al2O3Catalyst tool There is higher hydrothermal stability, is conducive to extend the service life of diesel vehicle SCR catalyst.
2. the present invention does not use the V with bio-toxicity2O5, but use Rare-Earth Ce O2As active component, to human body without It does harm to, to more environment-friendly.
3. the present invention provides a kind of inexpensive, nontoxic, easy preparation and to diesel vehicle NOxWith efficient cryogenic purification Catalyst and preparation method.
Detailed description of the invention
Fig. 1 is 2 WO of embodiment3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3Catalyst and pair prepared using coprecipitation 2 WO of ratio3/Ce0.68Zr0.32 AlOxThe H of catalyst2- TPR figure.
Fig. 2 is 2 WO of embodiment3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3Catalyst and use coprecipitation preparation pair 2 WO of comparative example3/Ce0.68Zr0.32 AlOxThe NH of catalyst3- TPD figure.
Fig. 3 is 2 WO of embodiment3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3Catalyst is free of Al2O3Comparative example 1WO3/ 90%Ce0.68Zr0.32O2Catalyst and 2 WO of comparative example for using coprecipitation preparation pair3/Ce0.68Zr0.32 AlOxCatalyst Fresh catalyst activity experimental result.
Fig. 4 is each catalyst hydrothermal aging catalyst activity experimental result in Fig. 3.
Specific embodiment
The present invention is further described through below by embodiment, the present embodiment is served only for carrying out into one the present invention Step explanation, but should not be understood as limiting the scope of the invention, all to make some nonessential change based on the content of present invention The scope of protection of the invention is belonged into the technology realized after adjustment.
Embodiment 1
10%WO3/Ce0.68Zr0.32O2+ 8%Al2O3The preparation of catalyst
(1) 15.70g cerous nitrate is dissolved in 32.2g deionized water, 6.23g zirconium nitrate is dissolved in 12.9g deionized water In, until completely dissolved, zirconium nitrate dissolution is added cerous nitrate solution and stirs evenly.
(2) ammonium hydroxide-ammonium carbonate buffer solution that ammonia and carbonic acid ammonium concentration are 3mol/L is prepared as precipitating reagent, with step (1) resulting mixed solution cocurrent is co-precipitated and is controlled pH=8.2~8.5, and 28% concentrated ammonia liquor tune is added after precipitating PH=10 is saved and controlled, and is placed not less than for 24 hours.
(3) gained precipitating suspension in step (2) is aged 6h under 98 DEG C of oil bath or water bath condition；
(4) it after being cooled to room temperature suspension obtained by step (3), filters and repeatedly washs filter cake with deionized water to pH= 6.8~7.5；
(5) by filter cake obtained by step (4) in 100 DEG C it is dry for 24 hours after, in Muffle furnace 600 DEG C of predecomposition roasting 4h to get To Ce0.68Zr32O2Yellow powder；
(6) under agitation, 8.87g aluminum nitrate is dissolved in 18g deionized water and prepares aluminum nitrate solution and ammonia and carbon Sour ammonium concentration is that ammonium hydroxide-ammonium carbonate buffer solution of 3mol/L carries out cocurrent titration, controls pH=8.2~8.5, co-precipitation After plus 28% concentrated ammonia liquor adjust the suspension pH=10 after co-precipitation, stand after adjusting not less than for 24 hours；
(7) step (6) resulting suspension is aged according to the condition of step (3), the condition of step (4) is taken out Filter washing, step (5) condition be dried and roast to get to Al2O3White powder；
(8) by step (6) resulting Ce0.68Zr0.32O2Yellow powder and step (7) resulting Al2O3White powder mixing It is put into the ball grinder of Φ 65mm afterwards, while 3 Φ 12mm, 4 Φ 8mm, 6 Φ 6mm, 10 Φ 5mm, 4 Φ 3mm is added Zirconium ball in ball grinder, ball milling 10min, revolving speed 600r/min obtain 92%Ce0.68Zr0.32O2+ 8%Al2O3Mixed oxide Yellow powder；
(9) 1.12g ammonium metatungstate is added using load in incipient impregnation normal direction mixed oxide powder, it is dry in 100 DEG C After dry 12h, in Muffle furnace 550 DEG C of roasting 4h to get arrive 10%WO3/ 92%Ce0.68Zr0.32O2+ 8%Al2O3Powder catalytic Agent.
Prepare integral catalyzer:
By resulting 10%WO3/ 92%Ce0.68Zr0.32O2+ 8%Al2O3Fine catalyst and deionized water, bonding agent are mixed It closes and slurries is uniformly made, control slurry solid content is 50%, is coated uniformly on Φ 11mm*25mm/400cpsi cordierite ceramic bee On nest matrix, controlling carrying capacity on catalyst powder is 150g/L, after 100 DEG C of dry 12h, 550 DEG C of roasting 4h in Muffle furnace, Obtain 10%WO3/ 92%Ce0.68Zr0.32O2+ 8%Al2O3Monolithic catalyst sample.
Embodiment 2
10%WO3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3The preparation of catalyst
(1) 15.35g cerous nitrate is dissolved in 31.5g deionized water, 6.09g zirconium nitrate is dissolved in 12.6g deionized water In, until completely dissolved, zirconium nitrate dissolution is added cerous nitrate solution and stirs evenly.
(2) it prepares ammonia and carbonic acid ammonium concentration is 3mol/L ammonium hydroxide-ammonium carbonate buffer solution as precipitating reagent, with step (1) resulting mixed solution cocurrent is co-precipitated and is controlled pH=8.2~8.5, and 28% concentrated ammonia liquor tune is added after precipitating PH=10 is saved and controlled, and is placed not less than for 24 hours.
(3) gained precipitating suspension in step (2) is aged 6h under 98 DEG C of oil bath or water bath condition；
(4) it after being cooled to room temperature suspension obtained by step (3), filters and repeatedly washs filter cake with deionized water to pH= 6.8~7.5；
(5) by filter cake obtained by step (4) in 80 DEG C it is dry for 24 hours after, in Muffle furnace 600 DEG C of predecomposition roasting 4h to get To Ce0.68Zr32O2Yellow powder；
(6) under agitation, 11.09g aluminum nitrate is dissolved in 22.5g deionized water prepare aluminum nitrate solution and ammonia and Carbonic acid ammonium concentration is that ammonium hydroxide-ammonium carbonate buffer solution of 3mol/L carries out cocurrent titration, controls pH=8.2~8.5, coprecipitated Suspension pH=10 after shallow lake plus after 28% concentrated ammonia liquor adjusting co-precipitation, stands after adjusting not less than for 24 hours；
(7) step (6) resulting suspension is aged according to the condition of step (3), the condition of step (4) is taken out Filter washing, step (5) condition be dried and roast to get to Al2O3White powder；
(8) by step (6) resulting Ce0.68Zr0.32O2Yellow powder and step (7) resulting Al2O3White powder mixing It is put into the ball grinder of Φ 65mm afterwards, while 3 Φ 12mm, 4 Φ 8mm, 6 Φ 6mm, 10 Φ 5mm, 4 Φ 3mm is added Zirconium ball in ball grinder, ball milling 10min, revolving speed 600r/min obtain 90%Ce0.68Zr0.32O2+ 10%Al2O3Mixed oxidization Object yellow powder；
(9) 1.12g ammonium metatungstate is added using load in incipient impregnation normal direction mixed oxide powder, it is dry in 100 DEG C After dry 12h, in Muffle furnace 550 DEG C of roasting 4h to get arrive 10%WO3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3Powder catalytic Agent.
Prepare integral catalyzer:
By the resulting 10%WO of step3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3It is fine catalyst and deionized water, Nian Jie Agent, which is uniformly mixed, is made slurries, and control slurry solid content is 45%, is coated uniformly on Φ 11mm*25mm/400cpsi cordierite pottery In porcelain honeycomb substrate, controlling carrying capacity on catalyst powder is 160g/L, after 100 DEG C of dry 12h, 550 DEG C of roastings in Muffle furnace 4h is burnt to get 10%WO is arrived3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3Monolithic catalyst sample.
Embodiment 3
10%WO3/ 88%Ce0.68Zr0.32O2+ 12%Al2O3The preparation of catalyst
(1) 15.01g cerous nitrate is dissolved in 30.8g deionized water, 5.96g zirconium nitrate is dissolved in 12.3g deionized water In, until completely dissolved, zirconium nitrate dissolution is added cerous nitrate solution and stirs evenly.
(2) ammonium hydroxide-ammonium carbonate buffer solution that ammonia and carbonic acid ammonium concentration are 3mol/L is prepared as precipitating reagent, with step (1) resulting mixed solution cocurrent is co-precipitated and is controlled pH=8.2~8.5, and 25% concentrated ammonia liquor tune is added after precipitating PH=10 is saved and controlled, and is placed not less than for 24 hours.
(3) gained precipitating suspension in step (2) is aged 6h under 98 DEG C of oil bath or water bath condition；
(4) it after being cooled to room temperature suspension obtained by step (3), filters and repeatedly washs filter cake with deionized water to pH= 6.8~7.5；
(5) by filter cake obtained by step (4) after 80~100 DEG C of dryings for 24 hours, 600 DEG C of predecomposition roast 4h in Muffle furnace, Obtain Ce0.68Zr32O2Yellow powder；
(6) under agitation, 13.31g aluminum nitrate is dissolved in 27g deionized water and prepares aluminum nitrate solution and ammonia and carbon Sour ammonium concentration is that ammonium hydroxide-ammonium carbonate buffer solution of 3mol/L carries out cocurrent titration, controls pH=8.2~8.5, co-precipitation After plus 25% concentrated ammonia liquor adjust the suspension pH=10 after co-precipitation, stand after adjusting not less than for 24 hours；
(7) step (6) resulting suspension is aged according to the condition of step (3), the condition of step (4) is taken out Filter washing, step (5) condition be dried and roast to get to Al2O3White powder；
(8) by step (6) resulting Ce0.68Zr0.32O2Yellow powder and step (7) resulting Al2O3White powder mixing It is put into the ball grinder of Φ 65mm afterwards, while 3 Φ 12mm, 4 Φ 8mm, 6 Φ 6mm, 10 Φ 5mm, 4 Φ 3mm is added Zirconium ball in ball grinder, ball milling 10min, revolving speed 600r/min obtain 88%Ce0.68Zr0.32O2+ 12%Al2O3Mixed oxidization Object yellow powder；
(9) 1.12g ammonium metatungstate is added using load in incipient impregnation normal direction mixed oxide powder, it is dry in 100 DEG C After dry 12h, in Muffle furnace 550 DEG C of roasting 4h to get arrive 10%WO3/ 88%Ce0.68Zr0.32O2+ 12%Al2O3Powder catalytic Agent.
Prepare integral catalyzer:
By resulting 10%WO3/ 88%Ce0.68Zr0.32O2+ 12%Al2O3Fine catalyst and deionized water, bonding agent are mixed It closes and slurries is uniformly made, control slurry solid content is 45%, is coated uniformly on Φ 11mm*25mm/400cpsi cordierite ceramic bee On nest matrix, controlling carrying capacity on catalyst powder is 150~160g/L, after 120 DEG C of dry 10h, 550 DEG C of roastings in Muffle furnace 4h is burnt to get 10%WO is arrived3/ 88%Ce0.68Zr0.32O2+ 32%Al2O3Monolithic catalyst sample.
Embodiment 4
6%WO3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3The preparation of catalyst
(1) 16.03g cerous nitrate is dissolved in 32.9g deionized water, 6.36g zirconium nitrate is dissolved in 13.16g deionized water In, until completely dissolved, zirconium nitrate dissolution is added cerous nitrate solution and stirs evenly.
(2) it prepares ammonia and carbonic acid ammonium concentration is 3mol/L ammonium hydroxide-ammonium carbonate buffer solution as precipitating reagent, with step (1) resulting mixed solution cocurrent is co-precipitated and is controlled pH=8.2~8.5, and 28% concentrated ammonia liquor tune is added after precipitating PH=10 is saved and controlled, and is placed not less than for 24 hours.
(3) gained precipitating suspension in step (2) is aged 6h under 98 DEG C of oil bath or water bath condition；
(4) it after being cooled to room temperature suspension obtained by step (3), filters and repeatedly washs filter cake with deionized water to pH= 6.8~7.5；
(5) by filter cake obtained by step (4) in 80 DEG C it is dry for 24 hours after, in Muffle furnace 600 DEG C of predecomposition roasting 4h to get To Ce0.68Zr32O2Yellow powder；
(6) under agitation, 11.58g aluminum nitrate is dissolved in 23.5g deionized water prepare aluminum nitrate solution and ammonia and Carbonic acid ammonium concentration is that ammonium hydroxide-ammonium carbonate buffer solution of 3mol/L carries out cocurrent titration, controls pH=8.2~8.5, coprecipitated Suspension pH=10 after shallow lake plus after 28% concentrated ammonia liquor adjusting co-precipitation, stands after adjusting not less than for 24 hours；
(7) step (6) resulting suspension is aged according to the condition of step (3), the condition of step (4) is taken out Filter washing, step (5) condition be dried and roast to get to Al2O3White powder；
(8) by step (6) resulting Ce0.68Zr0.32O2Yellow powder and step (7) resulting Al2O3White powder mixing It is put into the ball grinder of Φ 65mm afterwards, while 3 Φ 12mm, 4 Φ 8mm, 6 Φ 6mm, 10 Φ 5mm, 4 Φ 3mm is added Zirconium ball in ball grinder, ball milling 10min, revolving speed 600r/min obtain 90%Ce0.68Zr0.32O2+ 10%Al2O3Mixed oxidization Object yellow powder；
(9) 0.672g ammonium metatungstate is added using load in incipient impregnation normal direction mixed oxide powder, it is dry in 100 DEG C After dry 12h, in Muffle furnace 550 DEG C of roasting 4h to get arrive 6%WO3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3Powder catalytic Agent.
Prepare integral catalyzer:
By the resulting 6%WO of step3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3It is fine catalyst and deionized water, Nian Jie Agent, which is uniformly mixed, is made slurries, and control slurry solid content is 45%, is coated uniformly on Φ 11mm*25mm/400cpsi cordierite pottery In porcelain honeycomb substrate, controlling carrying capacity on catalyst powder is 160g/L, after 100 DEG C of dry 12h, 550 DEG C of roastings in Muffle furnace 4h is burnt to get 10%WO is arrived3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3Monolithic catalyst sample.
Embodiment 5
8%WO3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3The preparation of catalyst
(1) 15.69g cerous nitrate is dissolved in 32.2g deionized water, 6.22g zirconium nitrate is dissolved in 12.88g deionized water In, until completely dissolved, zirconium nitrate dissolution is added cerous nitrate solution and stirs evenly.
(2) it prepares ammonia and carbonic acid ammonium concentration is 3mol/L ammonium hydroxide-ammonium carbonate buffer solution as precipitating reagent, with step (1) resulting mixed solution cocurrent is co-precipitated and is controlled pH=8.2~8.5, and 28% concentrated ammonia liquor tune is added after precipitating PH=10 is saved and controlled, and is placed not less than for 24 hours.
(3) gained precipitating suspension in step (2) is aged 6h under 98 DEG C of oil bath or water bath condition；
(4) it after being cooled to room temperature suspension obtained by step (3), filters and repeatedly washs filter cake with deionized water to pH= 6.8~7.5；
(5) by filter cake obtained by step (4) in 80 DEG C it is dry for 24 hours after, in Muffle furnace 600 DEG C of predecomposition roasting 4h to get To Ce0.68Zr32O2Yellow powder；
(6) under agitation, 11.34g aluminum nitrate is dissolved in 23g deionized water and prepares aluminum nitrate solution and ammonia and carbon Sour ammonium concentration is that ammonium hydroxide-ammonium carbonate buffer solution of 3mol/L carries out cocurrent titration, controls pH=8.2~8.5, co-precipitation After plus 28% concentrated ammonia liquor adjust the suspension pH=10 after co-precipitation, stand after adjusting not less than for 24 hours；
(7) step (6) resulting suspension is aged according to the condition of step (3), the condition of step (4) is taken out Filter washing, step (5) condition be dried and roast to get to Al2O3White powder；
(8) by step (6) resulting Ce0.68Zr0.32O2Yellow powder and step (7) resulting Al2O3White powder mixing It is put into the ball grinder of Φ 65mm afterwards, while 3 Φ 12mm, 4 Φ 8mm, 6 Φ 6mm, 10 Φ 5mm, 4 Φ 3mm is added Zirconium ball in ball grinder, ball milling 10min, revolving speed 600r/min obtain 90%Ce0.68Zr0.32O2+ 10%Al2O3Mixed oxidization Object yellow powder；
(9) 0.896g ammonium metatungstate is added using load in incipient impregnation normal direction mixed oxide powder, it is dry in 100 DEG C After dry 12h, in Muffle furnace 550 DEG C of roasting 4h to get arrive 8%WO3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3Powder catalytic Agent.
Prepare integral catalyzer:
By the resulting 8%WO of step3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3It is fine catalyst and deionized water, Nian Jie Agent, which is uniformly mixed, is made slurries, and control slurry solid content is 45%, is coated uniformly on Φ 11mm*25mm/400cpsi cordierite pottery In porcelain honeycomb substrate, controlling carrying capacity on catalyst powder is 160g/L, after 100 DEG C of dry 12h, 550 DEG C of roastings in Muffle furnace 4h is burnt to get 8%WO is arrived3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3Monolithic catalyst sample.
Embodiment 6
12%WO3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3The preparation of catalyst
(1) 15.01g cerous nitrate is dissolved in 30.8g deionized water, 5.95g zirconium nitrate is dissolved in 12.32g deionized water In, until completely dissolved, zirconium nitrate dissolution is added cerous nitrate solution and stirs evenly.
(2) it prepares ammonia and carbonic acid ammonium concentration is 3mol/L ammonium hydroxide-ammonium carbonate buffer solution as precipitating reagent, with step (1) resulting mixed solution cocurrent is co-precipitated and is controlled pH=8.2~8.5, and 28% concentrated ammonia liquor tune is added after precipitating PH=10 is saved and controlled, and is placed not less than for 24 hours.
(3) gained precipitating suspension in step (2) is aged 6h under 98 DEG C of oil bath or water bath condition；
(4) it after being cooled to room temperature suspension obtained by step (3), filters and repeatedly washs filter cake with deionized water to pH= 6.8~7.5；
(5) by filter cake obtained by step (4) in 80 DEG C it is dry for 24 hours after, in Muffle furnace 600 DEG C of predecomposition roasting 4h to get To Ce0.68Zr32O2Yellow powder；
(6) under agitation, 10.84g aluminum nitrate is dissolved in 22.0g deionized water prepare aluminum nitrate solution and ammonia and Carbonic acid ammonium concentration is that ammonium hydroxide-ammonium carbonate buffer solution of 3mol/L carries out cocurrent titration, controls pH=8.2~8.5, coprecipitated Suspension pH=10 after shallow lake plus after 28% concentrated ammonia liquor adjusting co-precipitation, stands after adjusting not less than for 24 hours；
(7) step (6) resulting suspension is aged according to the condition of step (3), the condition of step (4) is taken out Filter washing, step (5) condition be dried and roast to get to Al2O3White powder；
(8) by step (6) resulting Ce0.68Zr0.32O2Yellow powder and step (7) resulting Al2O3White powder mixing It is put into the ball grinder of Φ 65mm afterwards, while 3 Φ 12mm, 4 Φ 8mm, 6 Φ 6mm, 10 Φ 5mm, 4 Φ 3mm is added Zirconium ball in ball grinder, ball milling 10min, revolving speed 600r/min obtain 90%Ce0.68Zr0.32O2+ 10%Al2O3Mixed oxidization Object yellow powder；
(9) 1.344g ammonium metatungstate is added using load in incipient impregnation normal direction mixed oxide powder, it is dry in 100 DEG C After dry 12h, in Muffle furnace 550 DEG C of roasting 4h to get arrive 12%WO3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3Powder catalytic Agent.
Prepare integral catalyzer:
By the resulting 12%WO of step3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3It is fine catalyst and deionized water, Nian Jie Agent, which is uniformly mixed, is made slurries, and control slurry solid content is 45%, is coated uniformly on Φ 11mm*25mm/400cpsi cordierite pottery In porcelain honeycomb substrate, controlling carrying capacity on catalyst powder is 160g/L, after 100 DEG C of dry 12h, 550 DEG C of roastings in Muffle furnace 4h is burnt to get 12%WO is arrived3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3Monolithic catalyst sample.
Comparative example 1
10%WO3/Ce0.68Zr0.32O2The preparation of catalyst is (without Al2O3It is modified)
(1) 17.06g cerous nitrate being dissolved in 35g deionized water, 6.77g zirconium nitrate is dissolved in 14g deionized water, to After being completely dissolved, zirconium nitrate dissolution is added cerous nitrate solution and stirs evenly.
(2) ammonium hydroxide-ammonium carbonate buffer solution that ammonia and carbonic acid ammonium concentration are 3mol/L is prepared as precipitating reagent, with step (1) resulting mixed solution cocurrent is co-precipitated and is controlled pH=8.2~8.5, and 28% concentrated ammonia liquor tune is added after precipitating PH=10 is saved and controlled, and is placed not less than for 24 hours.
(3) gained precipitating suspension in step (2) is aged 6h under 98 DEG C of oil bath or water bath condition；
(4) it after being cooled to room temperature suspension obtained by step (3), filters and repeatedly washs filter cake with deionized water to pH= 6.8~7.5；
(5) by filter cake obtained by step (4) in 80 DEG C it is dry for 24 hours after, in Muffle furnace 600 DEG C of predecomposition roasting 4h to get To Ce0.68Zr32O2Yellow powder；Then 1.12g ammonium metatungstate is added in load, after 100 DEG C of dry 12h, 550 in Muffle furnace DEG C roasting 4h to get arrive 10%WO3/Ce0.68Zr0.32O2Fine catalyst.
(6) by step (5) resulting 10%WO3/Ce0.68Zr0.32O2Fine catalyst is mixed with deionized water, bonding agent Slurries are uniformly made, control slurry solid content is 45%, is coated uniformly on Φ 11mm*25mm/400cpsi cordierite ceramic honeycomb On matrix, controlling carrying capacity on catalyst coat is 160g/L, after 110 DEG C of dry 10h, 550 DEG C of roasting 4h in Muffle furnace, i.e., Obtain 10%WO3/Ce0.68Zr0.32O2Monolithic catalyst sample.
Comparative example 2
Al is adulterated using coprecipitation2O3Prepare 10%WO3/Ce0.68Zr0.32AlOxCatalyst
(1) 15.35g cerous nitrate is dissolved in 31.5g deionized water, 6.09g zirconium nitrate is dissolved in 12.6g deionized water In, 11.09g aluminum nitrate, which is dissolved in 22.5g deionized water, prepares aluminum nitrate solution, until completely dissolved, zirconium nitrate solution and nitre Sour aluminum solutions are added in cerous nitrate solution stir evenly simultaneously.
(2) ammonium hydroxide-ammonium carbonate buffer solution that ammonia and carbonic acid ammonium concentration are 3mol/L is prepared as precipitating reagent, with step (1) resulting mixed solution cocurrent is co-precipitated, and controls pH=8.2~8.5, and 25% concentrated ammonia liquor tune is added after precipitating PH=10 is saved and controlled, and is placed not less than for 24 hours.
(3) gained precipitating suspension in step (2) is aged 6h under 98 DEG C of oil bath or water bath condition；
(4) it after being cooled to room temperature suspension obtained by step (3), filters and repeatedly washs filter cake with deionized water to pH= 6.8~7.5；
(5) by filter cake obtained by step (4) in 100 DEG C it is dry for 24 hours after, in Muffle furnace 600 DEG C of predecomposition roasting 4h to get To Ce0.68Zr32AlOxYellow powder, wherein Al2O3The mass fraction of composite oxides, which is accounted for, as the molar ratio of 10%, Ce and Zr is 0.68:0.32；Then 1.12g ammonium metatungstate is added in load, after 100 DEG C of dry 12h, 550 DEG C of roasting 4h in Muffle furnace, i.e., Obtain 10%WO3/Ce0.68Zr0.32AlOxFine catalyst.
(6) by step (5) resulting 10%WO3/Ce0.68Zr0.32AlOxFine catalyst and deionized water, bonding agent are mixed It closes and slurries is uniformly made, control slurry solid content is 42%, is coated uniformly on Φ 11mm*25mm/400cpsi cordierite ceramic bee On nest matrix, controlling carrying capacity on catalyst coat is 160g/L, after 100 DEG C of dry 8h, 550 DEG C of roasting 4h in Muffle furnace, Obtain 10%WO3/Ce0.68Zr0.32AlOxMonolithic catalyst sample.
Above embodiments and comparative example catalyst are subjected to NH on fixed bed reactors3The evaluation examination of-SCR reactivity It tests.Reaction mixture gas forms by volume are as follows: 500ppm NO, 500ppm NH3, 5%O2, 5%H2O, total gas flow rate are 1.25L/min N2As Balance Air, air speed 30000h-1, reaction temperature is 170~500 DEG C；The gas of reactor inlet and outlet Form equal using gas infrared radiation detection apparatus detection.
The catalyst of embodiment and comparative example preparation is as shown in table 1 to the conversion ratio of NO.Letter represents catalyst in bracket State, wherein F represents fresh sample, and HA represents hydrothermal aging sample；Hydrothermal aging conditions are as follows: 800 DEG C of temperature, moisture content 10%, Air speed 30000h-1, time 12h.
Table 1
Sample NO initiation temperature The complete conversion temperature of NO Highest NO conversion ratio
Embodiment 1 (F) 183 218 100%
Embodiment 1 (HA) 263 - 85%
Embodiment 2 (F) 178 210 100%
Embodiment 2 (HA) 240 313 95%
Embodiment 3 (F) 187 217 100%
Embodiment 3 (HA) 255 - 88%
Embodiment 4 (F) 190 228 100%
Embodiment 4 (HA) 267 - 82%
Embodiment 5 (F) 185 222 100%
Embodiment 5 (HA) 258 - 88%
Embodiment 6 (F) 187 226 100%
Embodiment 6 (HA) 260 - 85%
Comparative example 1 (F) 185 223 100%
Comparative example 1 (HA) 363 - 52%
Comparative example 2 (F) 197 230 99%
Comparative example 2 (HA) 310 - 74%
It can be learnt from table 1:
(1) the NO initiation temperature of 6 kinds of embodiment catalyst of ball-milling method preparation and complete conversion temperature are significantly lower than altogether The precipitation method preparation 2 catalyst of comparative example, be free of Al2O31 catalyst of comparative example it is suitable or lower.
(2) after the processing of the hydrothermal aging of the same terms, compared with comparative example 1, embodiment keeps higher SCR living Property, and the highest NO conversion ratio of comparative example 1 is only 52%；Compared with comparative example 2, the highest NO conversion ratio of embodiment is maintained at 82%-95%, comparative example 2 are only 74%, illustrate WO of the invention3/CexZr1-xO2+Al2O3Catalyst ratio does not carry out Al2O3Change The WO of property3/CexZr1-xO2The WO of catalyst and coprecipitation preparation3/CexZr1-xAlO2Catalyst has higher hydrothermally stable Property.
Fig. 1 is embodiment 2WO of the present invention using ball-milling method preparation3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3Catalyst With the comparative example 2WO using coprecipitation preparation3/Ce0.68Zr0.32AlOxThe H of catalyst2- TPR figure.2 catalyst of embodiment H2- TPR reduction peak area and peak intensity are significantly greater than and are better than 2 catalyst of comparative example, the H of 2 catalyst of embodiment2Consumption (789 μm of ol/g) be 1.7 times of 2 catalyst of comparative example (454 μm of ol/g), illustrates the species that restore of 2 catalyst of embodiment Amount has more surface-active species than 2 catalyst of comparative example far more than 2 catalyst of comparative example, i.e. 2 catalyst of embodiment CeOxAnd surface oxygen species；And the beginning reduction temperature of 2 catalyst of embodiment is down to 270 DEG C, far below 2 catalyst of comparative example 380 DEG C, illustrate that the species that restore of 2 catalyst surface of embodiment compare ratio 2 catalyst and are easier to be reduced；Therefore, real Applying 2 catalyst of example has higher low-temperature SCR activity than comparative example 2
Fig. 2 is embodiment 2WO of the present invention using ball-milling method preparation3/ 90%Ce0.68Zr0.32O2+ 10%Al2O3Catalyst With the comparative example 2WO using coprecipitation preparation3/Ce0.68Zr0.32 AlOxThe NH of catalyst3- TPD figure.2 catalyst of embodiment NH3- TPD peak area and intensity are significantly greater than 2 catalyst of comparative example, illustrate table of 2 catalyst of embodiment than 2 catalyst of comparative example Face has more acidic sites, can adsorb more reducing agent NH3NH occurs with NO3- SCR reaction；Therefore, embodiment 2 is than comparison Example 2 has higher low-temperature SCR activity.
Fig. 3 and Fig. 4 is embodiment 2WO of the present invention using ball-milling method preparation respectively3/ 90%Ce0.68Zr0.32O2+ 10% Al2O3Catalyst is free of Al2O3Comparative example 1WO3/Ce0.68Zr0.32O2Catalyst and the comparative example for using coprecipitation preparation pair 2 WO3/Ce0.68Zr0.32 AlOxThe fresh and hydrothermal aging catalyst activity experimental result of catalyst.Although the work of embodiment 2 Property species CeO2Content will be lower than comparative example 1, but its low temperature active is higher than comparative example 1；And embodiment 2 each element composition with Comparative example 2 is identical, but its low temperature active is apparently higher than comparative example 2.After the processing of the same terms hydrothermal aging, embodiment 2 is still protected Hold high NO conversion ratio and wide conversion temperature window (NOxConversion ratio be greater than 90% temperature range), and comparative example 1 and 2 is most High NO conversion ratio is only difference 52% and 74%.

Claims (10)

1. the diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable, it is characterised in that chemical formula WO3/CexZr1-xO2+ Al2O3, wherein WO3Being supported on general formula is CexZr1-xO2+Al2O3Composite oxide material on, in which: 0 < x < 1, Al2O3? CexZr1-xO2+Al2O3Mass fraction in composite oxides is 6-12%, WO3Mass fraction is to be less than greater than 0 in the catalyst Equal to 15%.
2. the diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable according to claim 1, which is characterized in that described WO3Mass fraction in the catalyst is 6-12%.
3. the diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable according to claim 1, which is characterized in that described CexZr1-xO2In, 0.5 < x < 0.8.
4. the diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable according to claim 1, which is characterized in that CexZr1-xO2+Al2O3Composite oxides be by CexZr1-xO2With Al2O3It is mixed to get by mechanical ball mill.
5. the preparation method of the diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable described in claim 1, feature exist In, comprising the following steps:
(1) according to chemical formula CexZr1-xO2, in which: 0 < x < 1 weighs cerium source, zirconium source, and weighs silicon source, tungsten source, is dissolved in water respectively It is configured to solution；
(2) the cerium source solution of preparation and zirconium source solution are uniformly mixed to get mixed solution, are made with ammonium hydroxide-ammonium carbonate buffer solution For precipitating reagent, cocurrent titration is carried out with mixed solution, is co-precipitated cerium and zirconium, controls pH=in titration coprecipitation process 8.2~8.5, ammonium hydroxide adjusts gained suspension pH=10 after co-precipitation, stands after adjusting not less than for 24 hours；
(3) the precipitating suspension after standing step (2) is aged 6~8h at 96~98 DEG C, and ageing terminates to be cooled to room temperature, mistake Filter, and filter cake to last time filtrate is washed with deionized and is in neutrality；
(4) by after gained filtration cakes torrefaction, 550-650 DEG C of predecomposition roasts 3~5h in Muffle furnace, obtains CexZr1-xO2Yellow powder End；
(5) silicon source solution and ammonium hydroxide-ammonium carbonate buffer solution are subjected to cocurrent titration, controlled in titration process pH=8.2~ 8.5, ammonium hydroxide adjusts gained suspension pH=10 after co-precipitation, stands after adjusting not less than for 24 hours；
(6) suspension obtained by step (5) is aged, is filtered and is washed according to the condition of step (3), according still further to step (4) Condition be dried and roast, obtain Al2O3White powder；
(7) by step (4) resulting CexZr1-xO2Yellow powder and step (6) resulting Al2O3White powder mixing and ball milling is to filling Divide and be uniformly mixed, obtains CexZr1-xO2+Al2O3Mixed oxide powder, mixed proportion control are CexZr1-xO2+Al2O3Composite oxygen Al in compound2O3Mass fraction be 6-12%；
(8) gained mixed oxide powder and tungsten source solution are subjected to load tungsten using equi-volume impregnating, then in 80~100 After DEG C dry 8~12h, 500-600 DEG C of 3~5h of roasting is in Muffle furnace to get to WO3/CexZr1-xO2+Al2O3Catalyst powder End, the load capacity of tungsten meet WO in gained catalyst fines3Mass fraction be greater than 0 be less than or equal to 15%.
6. the preparation method of the diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable according to claim 5, feature It is, cerium source is selected from least one of carbonic acid Asia cerium, cerous nitrate, ammonium ceric nitrate, cerous carbonate, cerous nitrate in step (1)；Zirconium Source is selected from least one of zirconium carbonate, zirconyl carbonate, zirconium nitrate, zirconyl nitrate, acetic acid zirconium, zirconium oxyacetate；Silicon source is nitric acid Aluminium；Tungsten source is selected from least one of ammonium metatungstate, ammonium paratungstate, ammonium tungstate.
7. the preparation method of the diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable according to claim 5, feature It is, the molar concentration rate of ammonia and ammonium carbonate is (0.5~3) in the buffer solution of the ammonium hydroxide-ammonium carbonate: 1.
8. the preparation method of the diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable according to claim 5, feature It is, step (4) drying condition is in 80~100 DEG C of dry 20~30h.
9. the preparation method of the diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable according to claim 5, feature It is, the ammoniacal liquor mass concentration that pH is adjusted in step (2) and step (5) is 25%-28%.
10. the preparation method of the diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable according to claim 5, special Sign is, step (7) ball milling condition are as follows: in ball grinder, zirconium abrading-ball is added, in the case where revolving speed is 400~600r/min ball milling 5~ 20min。
CN201810949835.XA 2018-08-20 2018-08-20 Diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable and preparation method thereof Active CN109289832B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810949835.XA CN109289832B (en) 2018-08-20 2018-08-20 Diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810949835.XA CN109289832B (en) 2018-08-20 2018-08-20 Diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable and preparation method thereof

Publications (2)

Publication Number Publication Date
CN109289832A true CN109289832A (en) 2019-02-01
CN109289832B CN109289832B (en) 2019-08-02

Family

ID=65165366

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810949835.XA Active CN109289832B (en) 2018-08-20 2018-08-20 Diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable and preparation method thereof

Country Status (1)

Country Link
CN (1) CN109289832B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111558297A (en) * 2020-05-12 2020-08-21 山东交通学院 Method for reducing exhaust emission of engine
CN113318728A (en) * 2021-06-25 2021-08-31 北京化工大学 Three-dimensional ordered macroporous tungsten-cerium-zirconium composite oxide catalyst and preparation method and application thereof

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102039205A (en) * 2009-10-21 2011-05-04 中国石油化工股份有限公司 Monolithic nitrogen oxide selective reduction catalyst and preparation method thereof
CN104741114A (en) * 2015-04-09 2015-07-01 北京华电光大环保技术有限公司 Flat-plate type high-temperature SCR (Selective Catalytic Reduction) denitration catalyst and preparation method thereof

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102039205A (en) * 2009-10-21 2011-05-04 中国石油化工股份有限公司 Monolithic nitrogen oxide selective reduction catalyst and preparation method thereof
CN104741114A (en) * 2015-04-09 2015-07-01 北京华电光大环保技术有限公司 Flat-plate type high-temperature SCR (Selective Catalytic Reduction) denitration catalyst and preparation method thereof

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
HAIDI XU: "Promotional effect of Al2O3 on WO3/CeO2-ZrO2 monolithic catalyst for selective catalytic reduction of nitrogen oxides with ammonia after hydrothermal aging treatment", 《APPLIED SURFACE SCIENCE》 *
付伟良: "W掺入对Ti0.8Zr0.2Ce0.2O2.4/Al2O3-TiO2-SiO2催化脱硝性能的优化", 《无机材料学报》 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111558297A (en) * 2020-05-12 2020-08-21 山东交通学院 Method for reducing exhaust emission of engine
CN113318728A (en) * 2021-06-25 2021-08-31 北京化工大学 Three-dimensional ordered macroporous tungsten-cerium-zirconium composite oxide catalyst and preparation method and application thereof
CN113318728B (en) * 2021-06-25 2023-06-27 北京化工大学 Three-dimensional ordered large Kong Wushi zirconium composite oxide catalyst and preparation method and application thereof

Also Published As

Publication number Publication date
CN109289832B (en) 2019-08-02

Similar Documents

Publication Publication Date Title
CN104998680B (en) A kind of anti-SO2And H2The low-temperature denitration catalyst and preparation method thereof of O poisonings
CN105688974B (en) One kind is with SBA-15/TiO2For the denitrating catalyst and preparation method thereof of carrier
CN104971729B (en) A kind of propane catalytic burning integral type catalyst and preparation method thereof
RU2476381C2 (en) Composition based on zirconium oxide, titanium oxide or mixed zirconium and titanium oxide, applied on aluminium oxide or aluminium oxyhydroxide carrier, methods of its obtaining and its application as catalyst
CN104540782B (en) Composites of mixed metal oxides for oxygen storage
CN103908970B (en) For the monoblock type SCR honeycomb catalyst and preparation method thereof of exhaust gas from diesel vehicle process
US20100247411A1 (en) Highly acidic compositions comprising zirconium oxide, titanium oxide and tungsten oxide and treatment of exhaust gases therewith
CN103260748B (en) The alumina catalyst carrier of resistant to sulfur
CN103908959A (en) Ce-Zr composite alumina oxide material and preparation method thereof
CN106732758A (en) A kind of low-temperature denitration catalyst and preparation method thereof
WO2009094891A1 (en) A cu-ce-al catalyst for removing soot particles and nox simultaneously and its preparation method
CN109277098B (en) Heat-staple Si modification SCR catalyst of high-temperature water and preparation method thereof
CN109289832B (en) Diesel car tail gas refining low-temperature SCR catalyst of hydrothermally stable and preparation method thereof
CN108554462A (en) A kind of cerium tungsten titanium denitrating catalyst and its preparation method and application
CN105107520A (en) Double perovskite type metal oxide catalyst and preparation method thereof
CN111111642B (en) Denitration catalyst and preparation method and application thereof
CN109277099A (en) Heat-staple diesel car tail gas refining SCR catalyst of high-temperature water and preparation method thereof
JP4450763B2 (en) Precious metal-containing composite metal oxide for exhaust gas purification catalyst and method for producing the same
CN105879869A (en) Catalyst used for hydrogen selective reduction of nitric oxide as well as preparation method and application thereof
CN113262780A (en) High-activity and high-stability manganese-based carbon smoke catalyst and preparation method and application thereof
CN109046324B (en) Medium-low temperature denitration catalyst with mesoporous cerium oxide as carrier and preparation method thereof
CN110697768A (en) Mesoporous TiO 22Material, catalyst, preparation method of material and catalyst, and denitration method
CN107073444A (en) Heat-staple NH3SCR catalyst composition
CN115318303A (en) Catalyst for removing soot particles of diesel vehicle at low temperature and preparation method thereof
CN103599768A (en) Zirconium/lanthanum-modified gamma-alumina catalyst coating material and preparation method 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