CN1132678C - Prepn process of composite oxide solid solution based on cerium oxide and zirconium oxide - Google Patents
Prepn process of composite oxide solid solution based on cerium oxide and zirconium oxide Download PDFInfo
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- CN1132678C CN1132678C CN 02110041 CN02110041A CN1132678C CN 1132678 C CN1132678 C CN 1132678C CN 02110041 CN02110041 CN 02110041 CN 02110041 A CN02110041 A CN 02110041A CN 1132678 C CN1132678 C CN 1132678C
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Abstract
The present invention relates to a preparation technology of a composite oxide solid solution based on cerium oxide and zirconium oxide. The composite oxide comprises 10 to 90 wt % of zirconium oxide and 10 to 90 wt % of cerium oxide. The preparation technology is characterized in that rare earth sol containing cerium and zirconium sol are mixed in proportion, and an obtained mixture is precipitated by alkali; then, obtained precipitates are thermally treated, dried and calcined to prepare a composite oxide solid solution, wherein before thermal treatment, the precipitates are washed by water or after thermal treatment, the precipitates are washed by water and then are dried. The preparation technology is a preparation method which is different from the existing technologies. The preparation technology improves a microstructure of a cerium zirconium solid solution. The prepared composite oxide solid solution has the advantages of better thermal stability and larger specific surface area.
Description
Technical field
The present invention relates to contain the preparation method of the composite oxide solid solution of cerium, zirconium.This type of composite oxide solid solution can be used for cleaning catalyst for tail gases of automobiles and other catalysis material.
Background technology
Along with the increasingly stringent of legislations of environmental protection in the world wide, it is more and more important to be used to the catalytic conversion technique handled with the cleaning atmospheric pollution thing.The core material that this type of catalyzed conversion usually adopts catalyst to transform as pollutant.Along with the progressively raising of catalyst performance, adopt rare earth oxide and composite oxides thereof to improve activity of such catalysts, stability and selectivity and seem very important as catalysis material.For example cleaning catalyst for tail gases of automobiles (" three-way catalyst ") thus the oxygen storage capacity that adopts cerium zirconium compound oxide to improve catalyst improves the activity that the catalyst that contains noble metal transforms carbon monoxide, nitrogen oxide and hydrocarbon.Be used for catalyst that catalytic organism burns and the catalyst (as catalyst for phenylethylene dehydrogenation, ethylene oxychlorination catalyst, hydro carbons selective oxidation catalyst, Oxydehydrogenation catalyst etc.) that is used for other chemical processes and also usually add the performance that the component that contains rare earth compound is improved catalyst.This class catalyst all contains a certain amount of cerium zirconium compound oxide as major catalyst or co-catalyst composition.Usually these compound or combination oxides exist with the form of mixture or solid solution.
The catalysis material that is wherein adopted based on the catalysis material requirement of said process has high heat endurance, bigger specific area; Then require when having high heat endurance and bigger serface, also to have oxygen storage capacity preferably for cleaning catalyst for tail gases of automobiles.By in cerium zirconium compound oxide, adding the third or multiplely being selected from other rare-earth compound or the alkaline earth element compound can improve heat endurance, specific area and the oxygen storage capacity that contains cerium, zirconium mixed oxide.
Patent CN 1193948A discloses a kind of based on zirconia and cerium oxide composition, Preparation Method And The Use, 900 ℃ down the specific area of calcining after 6 hours be at least 30m
2/ g, and exist with the pure solid solution form of cerium oxide in zirconia.
Patent CN 1263868A discloses a kind of nanometer cerium zirconium oxide, Preparation Method And The Use, comprises the CeO of 4～98% (wt)
2With 1～95% (wt) ZrO
2, its composite oxides are to decompose and to obtain through preceding (the surpassing) that contain hydrazine or the hydrazonium salt thing that becomes under 200～1000 ℃.
Patent USP 6133194 discloses a kind of preparation method who contains the solid solution of cerium zirconium, adopts the method that adds surfactant in preparation (worker) process to improve the heat endurance and the oxygen storage capacity of products therefrom.
Said method can obtain having the cerium zirconium sosoloid of certain oxygen storage capacity and heat endurance.
Summary of the invention
Technical problem to be solved by this invention provides a kind of preparation technology based on cerium oxide and zirconic composite oxide solid solution, further improve distribution, the thing phase of reunion, the stabilizing agent of particle and suppress crystal grain grow up and sintering obtains that heat endurance is better, specific area cerium zirconium sosoloid more greatly.
A kind of preparation technology of the present invention based on cerium oxide and zirconic composite oxide solid solution, these composite oxides comprise zirconia 10～90% (wt), cerium oxide 10～90% (wt), it is characterized in that it being to mix through alkali precipitation in proportion, sediment heat treatment, oven dry, calcining are made with zirconium colloidal sol, wherein to washing or after heat treatment, wash with water earlier oven dry again before the sediment heat treatment earlier with water by containing cerium mischmetal colloidal sol.
Containing cerium mischmetal colloidal sol is to be made according to the prior art mode by the rare earths salt that contains cerium, and containing zirconium colloidal sol equally is to be that predecessor makes according to the prior art mode with the zirconates.The rare earths salt that contains cerium can be single compound solution, also can be the mixing salt solution that contains other rare earth element, alkaline earth element or nonmetalloid.The acid ion of this salting liquid can be determined according to the purposes of composite oxide solid solution, mainly be to consider its purposes not to be produced bad reaction or introduces other impurity, for being used for auto-exhaust catalyst, can be acetate, nitrate, the best is a nitrate.When the salting liquid that contains cerium is mixed solution, also be to have added one or more rare earth oxides, alkaline earth element oxide or nonmetal oxide in the composite oxide solid solution, to improve the performance of composite oxides.In lanthana, praseodymium oxide, neodymia, yittrium oxide, hafnium oxide, barium monoxide, sulphur, boron, the fluorine one or more are arranged usually.This is on the books in prior art, as just being documented in rare-earth metal doped in the composite oxides, alkaline-earth metal (existing with oxide form) among the CN1193948A.According to the present invention, other rare earth except that cerium, zirconium, alkaline earth element oxide and nonmetallic content preferably are not more than 20% for being not more than 35.0% (wt), and wherein the content of the oxide of alkaline earth element and nonmetalloid is for being not more than 10% (wt).
Should be noted that and comprise hafnium in the composite oxides of the present invention in addition.This is because hafnium is to coexist as in the zirconium ore source or zirconium compounds that can exploit with zirconium.According to the character in mining source, the content of hafnium is illustrated in 0.1% (wt) to changing between 3.0% (wt) with oxide form.
Composite oxide solid solution of the present invention obtains two class cerium zirconium sosoloids, one class is the cerium zirconium sosoloid of cerium oxide in zirconia, zirconia content is more than 50% (wt), and this cerium zirconium sosoloid is at least 35m in the aging specific area of calcining after 6 hours under 1000 ℃
2/ g changes the proportioning of kind, quantity and the cerium zirconium of additive, more particularly 45m at least
2More than/the g.Another kind of is the cerium zirconium sosoloid of zirconia in cerium oxide, and wherein the content of cerium oxide is more than 50% (wt), and this cerium zirconium sosoloid is at least 20m in the aging specific area of calcining after 6 hours under 1000 ℃
2/ g changes the proportioning of kind, quantity and the cerium zirconium of additive equally, more particularly 30m at least
2More than/the g.
In the preparation process of the present invention, describedly precipitate with alkaline matter, preferred ammoniacal liquor avoids introducing other impurity.Its concentration is 0.1-10.0mol/L.Contain cerium colloidal sol and mix the back with zirconium colloidal sol be precipitated as hydroxide under alkali condition, precipitation temperature is room temperature～100 ℃.
Actual to sedimentary heat treatment is maturation process to hydroxide, at 100 ℃--and carry out under-300 ℃ the temperature, the time is 0.5-24 hour, preferred 2～8 hours.
Water washs after the sediment heat treatment, washing electrical conductivity＜1000m.s/cm, and the filter cake after the filtration is in oven dry below 200 ℃, calcining then.Washing precipitate before heat treatment washs electrical conductivity＜1000m.s/cm equally.
The temperature of calcining is 300-1000 ℃, and the time is 1～8 hour, and amino-oxide is converted into oxide.
The final products that adopt the present invention to obtain can provide with powder type, also can provide with other form.
Solid solution of the present invention exists with pure solid solution form, and can be recorded by XRD.
The specific area of this explanation indication refers to the BET specific area.
The composite oxide solid solution of the cerium zirconium that employing the present invention obtains can be used for the preparation of multiple catalysis material, as cleaning catalyst for tail gases of automobiles, catalytic incineration catalyst, ethylene oxychlorination catalyst, catalyst for phenylethylene dehydrogenation, selective oxidation catalyst, Oxydehydrogenation catalyst and other can adopt the material of product of the present invention.
Advantage of the present invention:
1, particle agglomeration has obtained effective dispersion.
2, the cerium zirconium sosoloid grain size that obtains is little.
3, cube phase content increases in the cerium zirconium sosoloid.
4, stabilizing agent has obtained even distribution, has suppressed growing up and sintering of grain size.
Thereby further improved the heat endurance of cerium zirconium sosoloid, increased aging specific area.
5, simplified production technology.
The specific embodiment
The present invention is not limited by following examples.
Embodiment one
1. get cerium colloidal sol 3.0L (TREO:50g/L), mix with zirconium colloidal sol 1.0L (ZrO2:50g/L), mixed sols adds in the ammoniacal liquor of 6.0mol/L and precipitates, and controls final PH＞9.0, and electrical conductivity to the washing lotion is washed less than 500ms/um with pure water in the precipitation back that finishes.Use centrifuge dewatering, obtain cerium zirconium hydroxide.Hydroxide adds the water making beating, slurry is heat-treated 250 ℃ of the temperature of processing, 6 hours time.Cold filtration after heat treatment finishes, the slip that obtains spraying oven dry, the cerium zirconium hydroxide of oven dry obtained the cerium Zirconium oxide in 4 hours 600 ℃ of calcinations, and after 6 hours, test its aging specific area is 22.3m to the cerium Zirconium oxide 1000 ℃ of calcinations
2/ g.
X-ray diffraction the analysis showed that the oxide that is obtained exists with pure solid solution phase form, and x-ray diffraction pattern is seen (1) bar line among Fig. 1.
2. get cerium colloidal sol 2.4L (TREO:50g/L), mix with zirconium colloidal sol 1.2L (ZrO2:50g/L), the lanthanum nitrate hexahydrate that adds 0.4L (TREO:50g/L) in mixed sols again mixes, precipitate in the ammoniacal liquor of mixed colloidal sol adding 6.0mol/L, control final PH＞9.0, electrical conductivity is washed to the washing lotion less than 500ms/um with pure water in the precipitation back that finishes.Use centrifuge dewatering, obtain containing lanthanum cerium zirconium hydroxide.Hydroxide adds the water making beating, slurry is heat-treated 250 ℃ of the temperature of processing, 6 hours time.Cold filtration after heat treatment finishes, the slip that obtains spraying oven dry, the cerium zirconium hydroxide that contains lanthanum of oven dry obtained the cerium Zirconium oxide in 4 hours 650 ℃ of calcinations, and after 6 hours, test its aging specific area is 34.2m to the cerium Zirconium oxide 1000 ℃ of calcinations
2/ g.
X-ray diffraction the analysis showed that the oxide that is obtained exists with pure solid solution phase form, and x-ray diffraction pattern is seen (2) bar line among Fig. 1.
3. get cerium colloidal sol 2.4L (TREO:50g/L), mix, in mixed sols, add the praseodymium nitrate neodymium (Nd of 0.4L (TREO:50g/L) again with zirconium colloidal sol 1.2L (ZrO2:50g/L)
2O
3: Pr
6O
11=75: 25) solution mixes, and mixed colloidal sol adds in the ammoniacal liquor of 6.0mol/L and precipitates, and controls final PH＞9.0, and electrical conductivity is washed to the washing lotion less than 500ms/um with pure water in the precipitation back that finishes.Use centrifuge dewatering, obtain containing lanthanum cerium zirconium hydroxide.Hydroxide adds the water making beating, slurry is heat-treated 250 ℃ of the temperature of processing, 6 hours time.Cold filtration after heat treatment finishes, the slip that obtains spraying oven dry, the cerium zirconium hydroxide that contains lanthanum of oven dry obtained the cerium Zirconium oxide in 4 hours 650 ℃ of calcinations, and after 6 hours, test its aging specific area is 36.3m to the cerium Zirconium oxide 1000 ℃ of calcinations
2/ g.X-ray diffraction the analysis showed that the oxide that is obtained exists with pure solid solution phase form, and x-ray diffraction pattern is seen (3) bar line among Fig. 1.
4. get cerium colloidal sol 1.2L (TREO:50g/L), mix, in mixed sols, add the praseodymium nitrate neodymium (Nd of 0.4L (TREO:50g/L) again with zirconium colloidal sol 2.4L (ZrO2:50g/L)
2O
3: Pr
6O
11=75: 25) solution mixes, and mixed colloidal sol adds in the ammoniacal liquor of 6.0mol/L and precipitates, and controls final PH＞9.0, and electrical conductivity is washed to the washing lotion less than 500ms/um with pure water in the precipitation back that finishes.Use centrifuge dewatering, obtain containing lanthanum cerium zirconium hydroxide.Hydroxide adds the water making beating, slurry is heat-treated 250 ℃ of the temperature of processing, 6 hours time.Cold filtration after heat treatment finishes, the slip that obtains spraying oven dry, the cerium zirconium hydroxide that contains lanthanum of oven dry obtained the cerium Zirconium oxide in 4 hours 650 ℃ of calcinations, and after 6 hours, test its aging specific area is 46.8m to the cerium Zirconium oxide 1000 ℃ of calcinations
2/ g.
X-ray diffraction the analysis showed that the oxide that is obtained exists with pure solid solution phase form, and x-ray diffraction pattern is seen (4) bar line among Fig. 1.
5. get cerium colloidal sol 1.2L (TREO:50g/L), mix with zirconium colloidal sol 2.4L (ZrO2:50g/L), the lanthanum nitrate hexahydrate that adds 0.4L (TREO:50g/L) in mixed sols again mixes, precipitate in the ammoniacal liquor of mixed colloidal sol adding 6.0mol/L, control final PH＞9.0, electrical conductivity is washed to the washing lotion less than 500ms/um with pure water in the precipitation back that finishes.Use centrifuge dewatering, obtain containing lanthanum cerium zirconium hydroxide.Hydroxide adds the water making beating, slurry is heat-treated 250 ℃ of the temperature of processing, 6 hours time.Cold filtration after heat treatment finishes, the slip that obtains spraying oven dry, the cerium zirconium hydroxide that contains lanthanum of oven dry obtained the cerium Zirconium oxide in 4 hours 650 ℃ of calcinations, and after 6 hours, test its aging specific area is 43.7m to the cerium Zirconium oxide 1000 ℃ of calcinations
2/ g.
X-ray diffraction the analysis showed that the oxide that is obtained exists with pure solid solution phase form.
Above embodiment cerium colloidal sol is made according to the prior art mode by cerous nitrate solution, and zirconium colloidal sol is made according to the prior art mode by zirconium nitrate.
Claims (7)
1, a kind of preparation technology based on cerium oxide and zirconic composite oxide solid solution, these composite oxides comprise zirconia 10～90% (wt), cerium oxide 10～90% (wt), the rare earth element of other that one or more are represented with oxide form, alkaline earth element, and nonmetalloid, its total amount is 0～35% (wt), it is characterized in that it being to mix in proportion through alkali precipitation with zirconium colloidal sol by containing cerium mischmetal colloidal sol, to sediment heat treatment, oven dry, calcining makes, wherein to washing or after heat treatment, wash with water earlier oven dry again before the sediment heat treatment earlier with water, to sedimentary heat treatment temperature is 100 ℃-300 ℃, time is 0.5-24hr, calcining heat is 300～1000 ℃, and the time is 1～8 hour.
2, preparation technology according to claim 1, optional rare earth element, the alkaline earth element of other that it is characterized in that representing with oxide form in the described composite oxide solid solution, and nonmetalloid is in lanthana, praseodymium oxide, neodymia, yittrium oxide, hafnium oxide, barium monoxide, sulphur, boron, the fluorine one or more.
3, preparation technology according to claim 1 and 2, it is characterized in that described composite oxide solid solution a kind of be the cerium zirconium sosoloid of cerium oxide in zirconia, zirconia content is more than 50% (wt), and this cerium zirconium sosoloid is at least 35m in the aging specific area of calcining after 6 hours under 1000 ℃
2/ g; Another kind is the cerium zirconium sosoloid of zirconia in cerium oxide, and wherein the content of cerium oxide is more than 50% (wt), and this cerium zirconium sosoloid is at least 20m in the aging specific area of calcining after 6 hours under 1000 ℃
2/ g.
4, preparation technology according to claim 3, it is characterized in that described composite oxide solid solution a kind of be the cerium zirconium sosoloid of cerium oxide in zirconia, zirconia content is more than 50% (wt), and this cerium zirconium sosoloid is at least 45m in the aging specific area of calcining after 6 hours under 1000 ℃
2/ g; Another kind is the cerium zirconium sosoloid of zirconia in cerium oxide, and wherein the content of cerium oxide is more than 50% (wt), and this cerium zirconium sosoloid is at least 30m in the aging specific area of calcining after 6 hours under 1000 ℃
2/ g.
5, preparation technology according to claim 1 is characterized in that the described cerium mischmetal colloidal sol that contains is for containing cerium mischmetal nitric acid or organic acid colloidal sol.
6, preparation technology according to claim 1 is characterized in that the alkaline matter that described alkali precipitation adopts is an ammoniacal liquor, and its concentration is 0.1-10.0mol/L.
7, preparation technology according to claim 1 is characterized in that precipitation temperature is room temperature～100 ℃.
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| CN1317074C (en) * | 2003-03-14 | 2007-05-23 | 中国科学院大连化学物理研究所 | Zirconium-base composite oxide catalyst, preparing method and use thereof |
| KR20040100136A (en) * | 2003-05-21 | 2004-12-02 | 한화석유화학 주식회사 | Method for doping metal oxides |
| CN101850247A (en) * | 2010-06-02 | 2010-10-06 | 淄博加华新材料资源有限公司 | Preparation method of composite oxide of cerium oxide and tin oxide |
| JP5861475B2 (en) * | 2012-01-31 | 2016-02-16 | マツダ株式会社 | Exhaust gas component purification catalyst material and particulate filter with catalyst material comprising the same |
| EP3710549A4 (en) * | 2017-11-15 | 2021-08-18 | Saint-Gobain Ceramics&Plastics, Inc. | Composition for conducting material removal operations and method for forming same |
| CN110342931A (en) * | 2019-07-11 | 2019-10-18 | 河北铭万精细化工有限公司 | A kind of preparation method of ceramic nano zirconium oxide powder |
| CN115382535B (en) * | 2022-09-20 | 2023-10-31 | 潍坊正轩稀土催化材料有限公司 | Preparation method of manganese-based cerium-zirconium solid solution capable of replacing noble metal and applied to VOC (volatile organic compound) catalyst |
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Address after: 255400. Linzi, Zibo, Shandong, Macun Patentee after: Zibo Xuan rare earth functional materials Limited by Share Ltd Address before: 255400 Qi Town, Linzi District, Shandong, Zibo Patentee before: Zibo Huaqing Powder Material Techn Co., Ltd. |
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Granted publication date: 20031231 Termination date: 20170301 |