• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    PURPOSE: An intake catalyst having hexagonal monolith structure is provided to increase adsorbing rate of NOx by applying the monolith structure to the catalyst having a constant content of Pt and BaO to reduce a thickness difference of wash-coat. CONSTITUTION: The catalyst comprises the platinum(Pt) and the barium oxide(BaO) elements in an aluminum carrier to form the hexagonal monolith structure. The catalyst is produced by applying a wash-coat slurry on a monolith substrate made of ceramic material and having hexagonal cells. The catalyst may have an even wash-coating thickness of less than 100microns. The wash-coating thickness is determined by using laser beam to measure phase difference of light waves and/or by means of exhaust gas analyzer to measure a change of NOx amount.
    公开号:KR20030005929A
    申请号:KR1020010041421
    申请日:2001-07-11
    公开日:2003-01-23
    发明作者:유철호
    申请人:현대자동차주식회사；
    IPC主号:
    专利说明:

    A intake catalyst having hexagonal monolith structure
    [6] The present invention relates to a storage catalyst having a hexagonal monolith structure, and more particularly, by having a hexagonal monolith structure in a storage catalyst in which a predetermined amount of platinum (Pt) and barium oxide (BaO) are supported on an alumina carrier. The present invention relates to an oxidation catalyst which reduces the loss of fuel efficiency due to theoretical fuel consumption by increasing the occlusion efficiency of NOx by reducing the change of washcoat thickness.
    [7] The occluded catalyst does not reduce NOx under lean conditions, that is, oxygen-rich conditions, and thus it is a catalyst for storing NO as NO 3 in BaO of the occluded catalyst and then reducing it to nitrogen under theoretical fuel ratio conditions. Therefore, NOx purification is performed in the period of theoretical performance ratio driving. However, when sulfur is included in the gasoline fuel discharged to the sulfur oxides in the combustion process, so BaO of storing catalyst is accounted for SO 3 and the space become NO 3 adsorption affinity is larger than NO 3 reduced to NO 3 absorption-storage capability of the storage catalyst (See FIG. 3). For this reason, desulfurization is important in occluding catalysts.
    [8] In general, when the desulfurization of the sorbent catalyst is operated for about 100 to 200 sec at an air-fuel ratio of 0.98, the temperature of the sorbent catalyst is 650 ° C or higher, and sulfur in the sorbent catalyst is desulfurized. In order to promote this desulfurization, the washcoat thickness of the occluded catalyst should be uniform to less than 100 μm.
    [9] Most automotive absorbent catalysts are made by applying a washcoat slurry to a substrate using a ceramic monolith substrate. However, since the cell shape of the substrate is rectangular, there is a problem that a uniform washcoat thickness cannot be obtained when the washcoat slurry is applied (see FIG. 1).
    [10] Accordingly, the present inventors have been devised to solve the above problems of the prior art, and have completed the present invention by having a hexagonal monolithic structure of an automobile occluding type catalyst.
    [11] Accordingly, the present invention provides a hexagonal monolithic structure of the occlusive catalyst in which a predetermined amount of platinum (Pt) and barium oxide (BaO) is supported on the alumina carrier, thereby applying a washcoat slurry to prepare the occlusive catalyst. It is an object of the present invention to provide an occlusion type catalyst which can reduce the change in the thickness of the gas and increase the occlusion efficiency of the NOx, thereby reducing the loss of fuel economy due to the theoretical air fuel operation.
    [1] Figure 1 shows a stored catalyst having a conventional rectangular monolithic structure.
    [2] Figure 2 shows an occluding catalyst having a hexagonal monolithic structure of the present invention.
    [3] 3 shows the purification mechanism of the occlusion catalyst.
    [4] Figure 4 shows the distribution of washcoat thickness of the conventional catalyst having a rectangular monolith structure and the catalyst having a hexagonal monolith structure of the present invention.
    [5] 5 shows the NOx storage efficiency of the conventional catalyst having a rectangular monolith structure and the catalyst having a hexagonal monolith structure according to the present invention.
    [12] The invention relates to a storage catalyst comprising a predetermined amount of platinum (Pt) and barium oxide (BaO) supported on an alumina carrier, wherein the storage catalyst has a hexagonal monolith structure.
    [13] Referring to the present invention in more detail as follows.
    [14] The storage catalyst according to the present invention may be prepared by applying a washcoat slurry to a substrate using a ceramic monolith substrate. At this time, the cell shape of the substrate to be used is characterized in that the washcoat slurry is applied with a hexagon in the present invention (see Fig. 2).
    [15] Such an occlusion-type catalyst according to the present invention maintains the washcoat coating thickness uniformly below 100 μm.
    [16] Hereinafter, the present invention will be described in detail based on the following examples, but the present invention is not limited thereto.
    [17] Examples and Comparative Examples
    [18] An occlusion type catalyst was prepared by a conventional method using a ceramic monolith substrate having a hexagonal cell shape (Example).
    [19] An occlusion type catalyst was prepared by a conventional method using a ceramic monolith substrate having a rectangular cell shape (Comparative Example).
    [20] Test Example 1
    [21] The washcoat thicknesses of the storage catalysts according to the examples and the comparative examples were measured by a method of measuring the phase difference of the wave shape using a thickness measuring apparatus using a laser beam, and the results are shown in FIG. 4.
    [22] As shown in FIG. 4, the occlusive catalyst of the embodiment of the present invention was confirmed that the washcoat thickness was maintained at 100 μm.
    [23] Test Example 2
    [24] The NOx storage efficiency of the catalysts according to the Examples and Comparative Examples was measured using an exhaust gas analyzer, and the results are shown in FIG. 5.
    [25] As shown in Figure 5, it was confirmed that the storage catalyst of the embodiment according to the present invention has excellent NOx storage efficiency.
    [26] As described above, the occlusion type catalyst according to the present invention has a small change in washcoat thickness and a coating thickness of 100 μm or less, which is excellent in desulfurization ability, thereby increasing the occlusion efficiency of NOx and reducing fuel loss due to theoretical fuel efficiency operation. It has the effect of improving fuel economy.
    权利要求:
    Claims (1)
    [1" claim-type="Currently amended] A platinum catalyst in which a predetermined amount of platinum (Pt) is supported on an alumina carrier, wherein the platinum catalyst has a hexagonal monolith structure.
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    同族专利:
    公开号 | 公开日
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    2001-07-11|Application filed by 현대자동차주식회사
    2001-07-11|Priority to KR1020010041421A
    2003-01-23|Publication of KR20030005929A
    优先权:
    申请号 | 申请日 | 专利标题
    KR1020010041421A|KR20030005929A|2001-07-11|2001-07-11|A intake catalyst having hexagonal monolith structure|
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