AU2008361642A1 - A prepositive oxidation catalyst for diesel vehicles and its preparation method - Google Patents
A prepositive oxidation catalyst for diesel vehicles and its preparation method Download PDFInfo
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Description
Description A prepositive oxidation catalyst for diesel vehicles and its preparation method Field of technology The present invention relates to a technology for purification of diesel vehicles exhaust, in particular, relates to a prepositive oxidation catalyst for the oxidation of CO and HC in diesel vehicles exhaust to CO 2 and H 2 0, and relates to the preparation method thereof. Background Art Exhaust gases from diesel vehicles mainly contain carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NO,) and particulate matters (PM, which consists of dry carbonsmokes, liquid hydrocarbons and small amounts of sulfates). In Figure 1, the diesel exhaust gas from engine 3 (diesel buner) is discharged through the exhaust pipe 4, the diesel exhaust gas is treated by the prepositive oxidation catalyst I in combination with the soot oxidation catalyst for regenerating the diesel particulate filter (DPF) 2, which is coated on the DPF. The prepositive oxidation catalyst can convert the gaseous pollutants CO and HC to CO 2 and H 2 0 at the temperature of diesel exhaust itself; The oxidation catalysts for DPF regeneration can oxidize the PM trapped by DPF under the combustion temperature of oil injected into the DPF, so as to regenerate the DPF. Due to the characteristics of lean bum of diesel engine, the temperature of diesel 5 2629237_1 (GHMatters) exhaust is quite low (200-400*C), and the 02 concentration is relatively high (>6%); Particularly, SO 2 concentration is high in diesel exhaust. Therefore, it is necessary that the oxidation catalysts for diesel vehicles possess high low-temperature activity and high sulfur- poisoning resistance. Typically, oxidation catalysts for diesel vehicles (DOC for short in following description) is composed of active components, washcoat and support (cordierite honeycomb ceramics or metal honeycombs). The active components of DOC are precious metals, such as Pt, Rh and Pd, or their mixtures. The precious metals endow the DOC with high low-temperature activity which is applicable to the conversion of CO and HC in low temperature of exhaust gases to CO 2 and H 2 0 in light-duty diesel automobiles. Higher loading amount of precious metals helps to enhance the activity of DOC for the conversion of CO and HC, however, which also leads to accelerating the deposition of sulfates and hereby sulfur -poisoning of the catalysts. To reduce the formation of sulfates on the surface of DOC catalyst, various methods are adopted, such as reducing the loading amount of precious metals, adding additives or modifying support/washcoat so as to improve the sulfur- poisoning resistance. In general, loading type of precious metal catalysts are prepared by impregnation method. First, the washcoated support is impregnated in precious-metal ion-containing solutions. After purging, the support is dried and calcined, the precious metals are thus loaded on the support. One of main disadvantages of supports such as cordierite etc. are the low binding intensity of washcoats on support due to the smooth pore surface in cordierite honeycomb ceramics. These defects may lead to the fall off of washcoats and 6 26292371 (GHMatters) DOC catalysts, resulting in the invalidation of catalytic converters. Disclosure of the invention The present invention aims to provide a prepositive oxidation catalyst for diesel vehicles and its preparation method, said catalyst exhibits high low-temperature activity and high resistance to SO 2 - poisoning and strong adhesive force of washcoats on support . To achieve the above objective, one technical solution of the present invention is a prepositive oxidation catalyst for diesel vehicles is provided, said oxidation catalyst for diesel vehicles is prepared by the following steps: (1) Ceramic honeycomb or metal honeycombis provided and used as support. Zirconium salt solution, TiO 2 -based oxide powders and H 2 0 are mixed, or TiO 2 -based oxide powders and H 2 0 are mixed to prepare a slurry for the preparation of washcoat on the support surface; (2) Incipient wetness impregnation method is used to load at least one precious metal(s) selected from the group consisting of platinum (Pt), rhodium (Rh) and palladium (Pd) ; (3)The loaded support obtained from (3) is dried and calcined to obtain the prepositive oxidation catalyst for diesel vehicles. Another technical solution of the present invention is: the preparation method of prepositive oxidation catalyst for diesel vehicles is provided. Said method comprises: (1) Zirconium salt solution and H 2 0 are mixed in such a weight ratio that the content of zirconium in the mixed solution is 0.5-30wt% as calculated by ZrO 2 , then TiO 2 -based oxide powders are added, or TiO 2 -based oxide powders and H 2 0 are mixed. 7 2829237_1 (GHMaters) After that the mixture is stirred for 1-10h to prepare a slurry for washcoating. The solid content in the slurry is adjusted to a weight percent of 5-50wt% by adding H 2 0, wherein the content of zirconium as calculated by ZrO 2 is 0-30 wt% of the total solid weight and the content of TiO 2 was 50-100wt% of the total solid weight. (2) Honeycomb support with cell density of 200-500 cell/in 2 is dipped in the as-prepared slurry in step (1) for 2-30 s, and then purged by high-pressure gas to remove the excess slurry so as to ensure the even distribution of the slurry gel on honeycomb surface and the unobstructed cells. After that, the washcoated support was dried at 100-200'C for l-Oh. The process was repeated for several times to adjust the coating amount of washcoat precursor to 30-150g/L. Then the coated support is calcined at 300~600*C for 1-5 h to obtain the washcoated support. (3) . The water absorption rate of 2-30wt% of the washcoated support obtained in step (2) is measured firstly. Then, the soluble precious metal salt solution of Pt, Pd or Rh is prepared based on the water absorption rate of the support. Incipient wetness impregnation method is used to load at least one precious metal selected from the group consisting of Pt, Rh and Pd. The loading amount of precious metal is 0.1-3wt% of the washcoat weight. After impregnation , the loaded support is dried at 100-200*C for 1-lOh,followed by calcination at 300~600*C for [-5 h, thus, the oxidation catalyst is obtained. Wherein Said ceramic honeycomb support can be cordierite, mullite or silica carbide, and said metal honeycomb support can be FeCrAl-based high-temperature alloy. 8 2629237_1 (GHMatters) Said TiO 2 -based oxide powders are a mixture of TiO 2 , W0 3 , SiO 2 and A1 2 0 3 , in which the TiO 2 content is 40-100 wt%, the W0 3 content is 0-15 wt%, the SiO 2 content is 0-15 wt% and the A1 2 0 3 content is 0-15 wt%. Said zirconium salt solution can be a solution of zirconium acetate, zirconium citrate or zirconium nitrate mixed with H 2 0. The content of zirconium in each solution is 0.5-30 wt% as calculated by ZrO 2 . Said soluble precious metal salt comprised the follows: chloroplatinate H 2 PtCl 6 , dinitrotetrammine platium (NH 3
)
4 Pt(NO 3
)
2 , platinum nitrate Pt(N0 3
)
2 , palladium chloride PdCl 2 , palladium nitrate Pd(N0 3
)
2 , rhodium nitrate Rh(NO 3
)
3 or rhodium chloride RhC13. The advantageous effects of the present invention: A high- performance prepositive oxidation catalyst for diesel vehicles and its preparation method are provided. In the diesel exhaust post processing system, the DOC catalyst can be operated even at very low temperatures without an increase in back pressure, and thus, gaseous pollutants CO and HC in exhaust can be oxidized to CO 2 and H 2 0 under the diesel exhaust temperature. The preparation method provided in this invention is simple, low cost and easy for industrialization. Zirconium salt and TiO 2 -based oxide powders are used for preparing washcoate on the support serface by the method according the present invention, which can be enhance the acidity of the washcoats, and thus reduces the adsorption of SO 2 and SO 3 on catalyst. The strong adhesive force between washcoat and support result in a good mechanical performance. Furthermore, the 9 2629237_1 (GHMatters) thermal stability and resistance to SO 2 - poisoning of the catalyst are high. After high temperature ageing, the loaded precious metal can be kept in a high dispersion. These effects endow the prepositive DOC with high low-temperature activity and good anti-aging properties. Brief Description of the Drawings Fig. I is the structure scheme of the diesel exhaust post processing system. Example The present invention aims to provide a preparation method of washcoat whith oxidation catalyst activities on the ceramic or metal honeycomb support, which is capable of removing CO and HC from diesel exhaust gas in an efficient manner. In Fig. I, the diesel exhaust gas from engine 3 (diesel buner) is discharged into the exhaust pipe 4, then the diesel exhaust gas is treated by the prepositive oxidation catalyst 1 in combination with the oxidation catalyst for regenerating the diesel particulate filter (DPF) 2, which is coated on the DPF. In present invention, the prepositive oxidation catalyst is a washcoat with oxidation catalyst activity of reducing CO and HC compounds, which is prepared using zirconium salt and TiO 2 -based oxide powders by in-situ method on ceramic/metal honeycomb support. The prepositive DOC can reduce the CO and HC pollutions to CO 2 and H 2 0 depending on the temperature of diesel exhaust itself. The follows are the embodiments to further illustrate the invention. Example 1. TiO 2 -based oxide powders ( W0 3 content= 8wt% ,TiO 2 content= 92wt% ) and 10 2289237_1 (GHMatters)
H
2 0 were mixed by a such a weight ratio that the solid content of the mixture was 40%. The mixture was stirred for 10h to obtain a slurry for washcoating. Cordierite honeycomb support with cell density of 200 cell/in 2 was dipped in the as-prepared slurry for 10 s, and then purged by high-pressure gas to remove the excess slurry so as to ensure the even distribution of the slurry gel on honeycomb surface and the unobstructed cells. After that, the support was dried at 1500C for 1 h and calcined at 450 *C for I h to obtain the washcoated support. The coating amount of washcoats was I 00g/L. The water absorption rate of the washcoated support was measured to be 108g/L. Pt(N0 3
)
2 solution was adopted as the precursor. Incipient wetness impregnation method was used to load Pt by dipping the washcoated support in the Pt(N0 3
)
2 solution, then the impregnated support was dried at 150*C for I h and calcined at 450*C for lh to obtain the oxidation catalyst marked TiZrO-f ,the loading amount of Pt is I wt% of the washcoat weight. Example 2. Zirconium acetate solution (ZrO 2 content = 20wt%), TiO 2 -based mixed powders (W0 3 content= 8wt%,TiO 2 content= 92wt%) and H 2 0 were mixed by the weight ratio of ZrO 2
:H
2 0:TiO 2 =2wt%:60wt%:38wt%. The mixture was stirred for 10h to obtain the as-prepared slurry (solid content = 40wt%). Cordierite honeycomb support with cell density of 200 cell/in 2 was dipped in the as-prepared slurry for 10 s, and then was purged by high-pressure gas to remove the excess slurry so as to ensure the even distribution of the slurry gel on honeycomb surface and the unobstructed cells.. After that, the support was dried at 150*C for 1 h and calcined at 450*C for 1 h to obtain the It 2e29237.1 (GHMatters) washcoated catalyst support. Coating amount of the washcoat was 1 OOg/L. Water absorption rate of the washcoated support was measured to be 1 I4g/L. Pt(N0 3
)
2 was adopted as the precursor. Incipient wetness impregnation method was used to load Pt by dipping the washcoated support in the Pt(N0 3
)
2 solution , then the impregnated support was dried at 1500C for I h and calcined at 450*C for lh to obtain the oxidation catalyst marked TiZr5-fthe loading amount of Pt is Iwt% of the washcoat weight. Example 3. The oxidation catalyst marked TiZrl0-f was prepared by the same process as in example 2, Except the ZrO 2 content in the slurry was adjusted to 1Owt%. Example 4. The oxidation catalyst marked TiZrl5-f was prepared by the same process as in example 2, Except the ZrO 2 content in the slurry was adjusted to 15wt%. Example 5. Zirconium acetate solution(Zirconium content=20wt% as calculated by ZrO 2 ),
H
2 0 and TiO 2 -based oxide powders (W0 3 content= 8wt%, TiO 2 content= 92wt%) were mixed by the weight ratio of ZrO 2
:H
2 0:TiO 2 = 2wt%:60wt%:38wt%. The mixture was stirred for 10h to obtain the as-prepared slurry (solid content = 40wt%). Cordierite honeycomb support with cell density of 200 cell/in 2 was dipped in the as-prepared slurry for 10 s, and then purged by high-pressure gas to remove the excess slurry so as to ensure the even distribution of the slurry gel on honeycomb surface and the unobstructed cells. After that, the support was dried at 1500C for I h and calcined at 450*C for 1h to obtain the washcoated catalyst support. Coating amount of the 12 2629237_1 (GHMatter) washcoats was 1 OOg/L. Water absorption rate of the washcoated support was measured to be I1 4g/L. Pd(N0 3
)
2 and Pt(N0 3
)
2 were adopted as the precursor. Incipient wetness impregnation method was used to load Pd and Pt by dipping the washcoated support in Pd(N0 3
)
2 and Pt(N0 3
)
2 mixed impregnation solution(Pd:Pt=lmol:lmol), then the impregnated support was dried at 1500C for 1 h and calcined at 4500C for 1 h to obtain the DOC catalyst, the total loading amount of Pd and Pt is I wt% of the washcoat weight. Example 6. Zirconium citric acid, TiO 2 -based oxide powders (TiO 2 content= 89wt%,SiO 2 content=10 wt%, Al 2 0 3 content=I wt%) and H 2 0 were mixed according to the weight ratio of zirconium citric acid :H 2 0:TiO 2 =2.9wt%:60wt%:38wt%. The solid content in the mixture was adjusted to 35wt% ( Zirconium content=l 0 wt% of the total solid as calculated by ZrO 2 ) by adding H 2 0.The mixture was stirred for 10h to obtain the as-prepared slurry. Cordierite honeycomb support with cell density of 200 cell/in 2 was dipped in the as-prepared slurry for 10 s, and then purged by high-pressure gas to remove the excess slurry so as to ensure the even distribution of the slurry gel on honeycomb surface and the unobstructed cells. After that, the support was dried at 150 0C for I h and calcined at 450*C for I h to obtain the washcoated catalyst support. Coating amount of the washcoat was 82g/L. Water absorption rate of the washcoated support was measured to be 97g/L. H 2 PtCl 6 was adopted as the precursor. Incipient wetness impregnation method was used to load Pt by dipping the washcoated support in the H 2 PtCI 6 solution , and then the impregnated support was dried at 1500C for I h and 13 2629237_1 (GHMatters) calcined at 4500C for I h to obtain the DOC catalyst, the loading amount of Pt is I wt% of the washcoats weight. Example 7 Zirconium nitrate, H 2 0 and TiO 2 -based oxide powders (TiO 2 content= 90wt%, SiO 2 content=10 wt%)were mixed by the weight ratio of zirconium nitrate :H 2 0:TiO 2 = 3.5wt%:60wt%:38wt%. The mixture was stirred for 10h to obtain the as-prepared slurry (solid content = 40wt%). Cordierite honeycomb support with cell density of 200 cell/in 2 was dipped in the as-prepared slurry for 10 s, and then was purged by high-pressure gas to remove the excess slurry so as to ensure the even distribution of the slurry gel on honeycomb surface and the unobstructed cells. After that, the support was dried at 150*C for 1 h and calcined at 450*C for I h to obtain the washcoated catalyst support. Coating amount of the washcoat was 97g/L. Water absorption rate of the washcoated support was measured to be 105g/L. Pt(N0 3
)
2 was adopted as the precursor. Incipient wetness impregnation method was used to load Pt by dipping the washcoated support in the Pt(N0 3
)
2 solution , and then the impregnated support was dried at 150*C for 1 h and calcined at 450*C for I h to obtain the DOC catalyst, the loading amount of Pt is 1 wt% of the washcoats weight. Example 8. Zirconium nitrate, H 2 0 and TiO 2 -based oxide powders (TiO 2 content= 90wt%, SiO 2 content=10 wt%) were mixed by the weight ratio of zirconium nitrate :H 2 0:TiO 2 = 3.5wt%:60wt%:38wt%. The mixture was stirred for 10h to obtain the as-prepared 14 2629237_1 (GHMatters) slurry (solid content = 40wt%). Cordierite honeycomb support with cell density of 200 cell/in 2 were dipped in the as-prepared slurry for 10 s, and then purged by high-pressure gas to remove the excess slurry so as to ensure the even distribution of the slurry gel on honeycomb surface and the unobstructed cells. After that, the support was dried at 150 *C for I h and calcined at 4500C for lh to obtain the washcoated catalyst support. Coating amount of the washcoat was 97g/L. Water absorption rate of the washcoated support was measured to be 11 6g/L. Rh(N0 3
)
3 was adopted as the precursor. Incipient wetness impregnation method was used to load Rh by dipping the washcoated support in the Rh(N0 3
)
3 solution, and then the impregnated support was dried at 150*C for I h and calcined at 450*C for I h to obtain the DOC catalyst, the loading amount of Rh is 1 wt% of the washcoat weight. Example 9. Zirconium nitrate, H 2 0 and TiO 2 -based oxide powders (TiO 2 content= 89wt%, SiO 2 content=10 wt%, Al 2 0content=l wt%) were mixed by the weight ratio of zirconium nitrate :H 2 0:TiO 2 = 3.5wt%:60wt%:38wt%. The mixture was stirred for 10h to obtain the as-prepared slurry (solid content = 40wt%). Cordierite honeycomb support with cell density of 200 cell/in 2 were dipped in the as-prepared slurry for 10 s, and then purged by high-pressure gas to remove the excess slurry so as to ensure the even distribution of the slurry gel on honeycomb surface and the unobstructed cells. After that, the support was dried at 150*C for 1 h and calcined at 4500C for I h to obtain the washcoated support. Coating amount of the washcoat was 97g/L. Water absorption rate of the washcoated support was measured to be 107g/L. Pd(N03)2 was adopted as 15 2629237_1 (GHMatters) the precursor. Incipient wetness impregnation method was used to load Pd by dipping the washcoated support in the Pd(N0 3
)
3 solution , and then the impregnated support was dried at 15000 for I h and calcined at 45000 for lh to obtain the DOC catalyst, the loading amount of Pd is Iwt% of the washcoats weight. Example 10. Zirconium nitrate, H20 and TiO 2 -based oxide powders (TiO 2 content= 89wt%, SiO 2 content=10 wt%, A1 2 0 3 content=1 wt%) were mixed by the weight ratio of zirconium nitrate :H 2 0:TiO 2 = 3.5wt%:60wt%:38wt%. The mixture was stirred for IOh to obtain the as-prepared slurry (solid content = 40wt%). Cordierite honeycomb support with cell density of 200 cell/in 2 was dipped in the as-prepared slurry for 10 s, and then was purged by high-pressure gas to remove the excess slurry so as to ensure the even distribution of the slurry gel on honeycomb surface and the unobstructed cells. After that, the support was dried at 15000 for 1 h and calcined at 45000 for I h to obtain the washcoated support. Coating amount of the washcoats was 97g/L. Water absorption rate of the washcoated support was measured to be 107g/L. Pd(N0 3
)
2 and Pt(N0 3
)
2 were adopted as the precursor. Incipient wetness impregnation method was used to load Pd and Pt by dipping the washcoated support in Pd(NO 3
)
2 and Pt(N0 3
)
2 mixed impregnation solution(Pd:Pt=lmol:lmol), then the impregnated support was dried at 150*C for I h and calcined at 4500C for lh to obtain the DOC catalyst, the total loading amount of Pd and Pt is 1 wt% of the washcoats weight. Example 11. The samples of TiZrO-f catalyst obtained from example 1, TiZr5-f catalyst 16 2629237_1 (GHMatters) obtained from example 2, TiZr1O-f catalyst obtained from example 3 and TiZrl5-f catalyst obtained from example 4 were made in size of 9mmx9mmx48mm(dimension according to the direction of the passageways of the cells is 48mm). The samples were put in tube furnace and treated at 60000 for I 00h under air flow containing 10% water vapor to obtain hydrothermal-deteriorated DOC catalysts which were defined as TiZr0-a, TiZr5-a, TiZr10-a and TiZrl5-a, respectively. Example 12. The samples of TiZrO-f catalyst obtained from example 1, TiZr5-f catalyst obtained from example 2, TiZrlO-f catalyst obtained from example 3 and TiZrl5-f catalyst obtained from example 4 were made in size of 9mmx9mmx48mm(dimension according to the direction of the passageways of the cells is 48mm). The samples were treated at 450 0C for 100h under air flow containing 30ppm SO 2 to obtain sulfur-deteriorated DOCs which were defined as TiZrO-s, TiZr5-s, TiZrl0-s and TiZrl 5-s, respectively. Test example 1. The catalysts, such as TiZrO-f (example 1), TiZr5-f (example 2), TiZrlO-f (example 3) , TiZrl5-f (example 4), TiZrO-a (example 11) , TiZr5-a (example 11), TiZrlO-a (example 11) , TiZrI5-a (example 1 1), TiZrO-s (example 12), TiZr5-s (example 12), TiZrl0-s (example 12) and TiZrI5-s (examplel2) were taken as testing examples to test the light-off characteristics of the catalysts under the gas mixture of modeling diesel vehicles exhaust. The samples were made in size of 9mmx9mmx48mm (dimension according to the direction of the passageways of the 17 2629237_1 (GHMatters) cells is 48mm) and packaged with quartz cotton, then were put into a stainless tube reactor prior to the gas mixture was passed through the reactor continuously. The modeling diesel vehicles exhaust gas consists of CO (1000 ppm), CO 2 (13%), C 3
H
8 (500ppm), NOx (700ppm), 02 (7%) and N 2 (as balance gas), space velocity of the gas mixture was 60000h'. The reactor was heating up from room temperature to 450 0 at a heating rate of 10 *C/min. The concentrations of CO and C 3
H
8 in the gas mixture after passing through the catalysts were on line determined by a FTIR spectroscopy gas analyzer Nicolet 380. The test results showed that the prepositive oxidation catalyst for diesel vehicles provided by this invention could reduce the CO and HC at low temperatures excellently , and that the catalysts possessed high hydro-thermal stability and SO 2 . poisoning resistance ,as shown in Table 1. Table I showed the catalytic performances of the catalysts from example I example 2 , example 3 , example 4 , example 6 , example I I and example 12 in the oxidization of CO and C 3
H
8 , Table 1 The catalytic performances of catalysts in the oxidization of CO and C 3
H
8 Conversion temperature ( *C ) Catalyst CO HC T50 T90 T5o T90 TiZrO 115 120 145 170 TiZr5 140 150 160 175 TiZrlO 145 165 175 195 TiZrl5 145 170 180 215 TiZrO-a 195 250 275 320 TiZr5-a 170 225 230 265 TiZrlO-a 160 210 220 235 TiZrl5-a 175 215 225 255 18 2629237_i (GHMatter) TiZrO-s 175 255 260 315 TiZr5-s 160 215 200 230 TiZrlO-s 155 175 175 200 TiZrl5-s 185 220 210 235 19 2629237_1 (GHMatters)
Claims (9)
1. A prepositive oxidation catalyst for diesel vehicles , characterized in that it is prepared by the following steps: (1) Ceramic honeycomb or metal honeycomb is used as support, zirconium salt solution, TiO 2 -based oxide powders and H 2 0 are mixed, or TiO 2 -based oxide powders and H 2 0 are mixed to prepare the slurry for the preparation of the washcoat on the support; (2) Incipient wetness impregnation method is used to load at least one of the precious metal selected from the group consisting of Pt, Rh and Pd; (3) The loaded support obtained from step (2) is dried and calcined to obtain the prepositive oxidation catalyst for diesel vehicles.
2. A method for preparing the catalyst according to claim 1 characterized in that it comprises the following steps: (1) Zirconium salt solution and H 2 0 are mixed in such a weight ratio that the zirconium content in the mixed solution is 0.5-30wt% as calculated by ZrO 2 , then TiO 2 -based oxide powders are added, or TiO 2 -based oxide powders and H 2 0 are mixed, after that the mixture is stirred for 1-1Oh to prepare a slurry, H 2 0 is added to adjust the solid content in the slurry to a weight percent of 5-50wt%, wherein the zirconium content as calculated by ZrO 2 is 0-30 wt% of the total solid weight and the TiO 2 content is 50-100wt% of the total solid weight; (2) Ceramic honeycomb support with cell density of 200-500 cell/in 2 is dipped in the as-prepared slurry in step (1) for 2-30 s, then is purged by high-pressure gas to remove the excess slurry so as to ensure the even distribution of the slurry gel on the surface of honeycomb support and the unobstructed cells, after that, the dipped support 2 2629237_1 (GHMatters) is dried at 100-200*C for 1-10h, the process is repeated for several times to adjust the coating amount of washcoat precursor to 30-150g/L, then the coated support is calcined at 300~600*C for 1-5 h to obtain the washcoated support; (3) The water absorption rate of 2-30wt% of the washcoated support obtained in step (2) is measured firstly, then the soluble precious metal salt solution of Pt, Pd or Rh is prepared based on the water absorption rate of the support, incipient wetness impregnation method is used to load at least one of the precious metal selected from the group consisting of Pt, Rh and Pd, the loading amount of precious metal is 0.1-3wt% of the washcoat weight, after impregnation , the loaded support is dried at 100~200"C for 1-10h, followed by calcination at 300~600*C for 1-5 h, thus, the oxidation catalyst is obtained.
3. The prepositive oxidation catalyst for diesel vehicles according to claims, wherein said ceramic honeycomb support can be cordierite, mullite or silica carbide, and said metal honeycomb support can be FeCrAl-based high-temperature alloy.
4. The prepositive oxidation catalyst for diesel vehicles according to claim], wherein said TiO 2 -based oxide powders are a mixture of TiO 2 , W0 3 , SiO 2 and A1 2 0 3 , in which the TiO 2 content is 40-100 wt%, the W0 3 content is 0- 15 wt%, the SiO 2 content is 0-15 wt% and the A1 2 0 3 content is 0-15 wt%.
5. The prepositive oxidation catalyst for diesel vehicles according to claim 1, wherein said zirconium salt solution can be a solution of zirconium acetate, zirconium citrate or zirconium nitrate mixed with H 2 0, in which the zirconium content is 0.5-30 wt% as calculated by ZrO 2 . 3 2629237_1 (GHMatlers)
6. The method for preparing the prepositive oxidation catalyst according to claim 2, wherein said soluble precious metal salt comprises the follows: chloroplatinate H 2 PtCl 6 , dinitrotetrammine platium (NH 3 ) 4 Pt(NO 3 ) 2 , platinum nitrate Pt(N0 3 ) 2 , palladium chloride PdCl 2 , palladium nitrate Pd(N0 3 ) 2 , rhodium nitrate Rh(N0 3 ) 3 or rhodium chloride RhCl 3 .
7. The method according to claim 2, wherein said ceramic honeycomb support can be cordierite, mullite or silica carbide, and said metal honeycomb support can be FeCrAl-based high- temperature alloy.
8. The method according to claim 2,wherein said TiO 2 -based oxide powders are a mixture of TiO 2 , W0 3 , SiO 2 and A1 2 0 3 , in which the TiO 2 content is 40-100 wt%, the W0 3 content is 0-15 wt%, the SiO 2 content is 0-15 wt% and the A1 2 0 3 content is 0-I5 wt%.
9. The method according to claim 2, wherein said zirconium salt solution can be a solution of zirconium acetate, zirconium citrate or zirconium nitrate mixed with H 2 0, in which the zirconium content is 0.5-30 wt% as calculated by ZrO 2 . 4 2629237_1 (GHMatters)
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| CN200810119916.3 | 2008-09-09 | ||
| CN2008101199163A CN101352682B (en) | 2008-09-09 | 2008-09-09 | Method for preparing front-located oxidation catalyst for diesel car |
| PCT/CN2008/073915 WO2010028531A1 (en) | 2008-09-09 | 2008-12-31 | A prepositive oxidation catalyst for diesel vehicles and its preparation method |
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| AU2008361642A1 true AU2008361642A1 (en) | 2010-03-18 |
| AU2008361642B2 AU2008361642B2 (en) | 2013-09-12 |
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| CN110463401A (en) * | 2019-08-26 | 2019-11-19 | 太湖县恒心农业发展有限公司 | A kind of vegetable cultivation seed infuser device |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101352682B (en) * | 2008-09-09 | 2012-02-08 | 清华大学 | Method for preparing front-located oxidation catalyst for diesel car |
| CN103861664B (en) * | 2012-12-14 | 2017-11-10 | 上海郎特汽车净化器有限公司 | A kind of diesel engine vent gas oxidation catalyst |
| KR101550614B1 (en) * | 2014-02-11 | 2015-09-08 | 현대자동차 주식회사 | Catalyst carrier for purification of exhausted gas, method for preparing the same, and catalyst for purification of exhausted gas |
| CN109372612A (en) * | 2018-11-06 | 2019-02-22 | 广州航海学院 | A kind of diesel engine exhaust gas treatment device and method |
| CN110721706B (en) * | 2019-10-30 | 2023-03-28 | 中国石油化工股份有限公司 | Oxidation catalyst for purifying CO and preparation method and application thereof |
| CN113713838B (en) * | 2021-11-04 | 2022-01-04 | 中汽研（天津）汽车工程研究院有限公司 | Preparation method of integral oxidation type catalyst for diesel vehicle |
| CN114768795A (en) * | 2022-03-30 | 2022-07-22 | 安徽方信立华环保科技有限公司 | Preparation method of honeycomb catalyst for treating CO in sintering flue gas |
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| JPH0724774B2 (en) * | 1988-11-25 | 1995-03-22 | 株式会社日本触媒 | Exhaust gas treatment catalyst carrier, method for producing the same, and exhaust gas treatment catalyst containing the carrier |
| CN1548225A (en) * | 2003-05-21 | 2004-11-24 | 中国科学院生态环境研究中心 | Prepn of oxidizing catalyst for controlling exhaust of diesel truck |
| CN1995713A (en) * | 2006-12-13 | 2007-07-11 | 北京英泰世纪环境科技有限公司 | Metal carrier triple-effect catalytic unit and method for making same |
| CN100998941B (en) * | 2007-01-04 | 2012-09-05 | 华东理工大学 | Precatalyst and its preparation method |
| CN101352682B (en) * | 2008-09-09 | 2012-02-08 | 清华大学 | Method for preparing front-located oxidation catalyst for diesel car |
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| CN110463401A (en) * | 2019-08-26 | 2019-11-19 | 太湖县恒心农业发展有限公司 | A kind of vegetable cultivation seed infuser device |
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| Publication number | Publication date |
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| WO2010028531A1 (en) | 2010-03-18 |
| AU2008361642B2 (en) | 2013-09-12 |
| CN101352682A (en) | 2009-01-28 |
| CN101352682B (en) | 2012-02-08 |
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