Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Exhaust gas purification catalyst and method for producing the same

A technology of exhaust gas purification and catalyst, which is applied in the direction of catalyst activation/preparation, physical/chemical process catalyst, catalyst carrier, etc., can solve the problem of lack of exhaust gas purification performance, etc., and achieve the effect of excellent purification performance

Active Publication Date: 2021-10-26
CATALER CORP
View PDF8 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] However, in conventional exhaust gas purification catalysts as described above, the catalyst layer itself is formed on a base material that does not have exhaust gas purification performance, for example, a honeycomb base material made of cordierite.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Exhaust gas purification catalyst and method for producing the same
  • Exhaust gas purification catalyst and method for producing the same
  • Exhaust gas purification catalyst and method for producing the same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0165] (1) Formation of the lower layer

[0166] Use 50g as CeO of the 1st CZ 2 :ZrO 2 = 35:65 (mass ratio), ceria-zirconia composite oxide with a secondary particle diameter of 1 μm, 50 g of CeO as the second CZ 2 :ZrO 2 =35:65 (weight ratio), ceria-zirconia composite oxide having a secondary particle diameter of 30 μm, 100 g of alumina, and 300 g of water were mixed to prepare a slurry for the lower layer.

[0167] This underlayer slurry was applied to a substrate, and heated at 250° C. for 1 hour to form a lower layer on the substrate (coating amount: 200 g / L).

[0168] (2) Formation of the upper layer

[0169] Use 50g of CeO as the upper layer with CZ 2 :ZrO 2 =20:80 (weight ratio), the ceria-zirconia composite oxide that the secondary particle diameter is 1 μ m is immersed in the aqueous solution that contains the rhodium nitrate of 0.2g / L equivalent, is then heated at 250 ℃ for 1 hour, and then heated at 500 ℃ for 1 hour to obtain Rh-loaded CZ.

[0170] 50 g of R...

Embodiment 2~16 and comparative example 6~12

[0209] (1) Preparation of catalyst

[0210] As the first CZ and the second CZ, CZ having the particle diameters described in Table 2 or Table 3 were used respectively, and the usage ratio of the two was set according to Table 2 or Table 3, and it was formed on the substrate in the same manner as in Example 1. Lower layer (coating amount: 200g / L).

[0211] Next, CZ carrying Rh was prepared in the same manner as in Example 1 except that CZ having the particle diameters described in Table 1 was used as CZ for the upper layer, and CZ carrying Rh was formed in the same manner as in Example 1 using this CZ carrying Rh. An upper layer (coating amount: 100 g / L) was formed on the base material of the lower layer, thereby preparing an exhaust gas purification catalyst.

[0212] (2) Evaluation

[0213] Using the exhaust gas purification catalyst prepared above, the measurement of the particle size of the oxide particles and the evaluation of the exhaust gas purification performance wer...

Embodiment 17

[0215] In this example, the effect of loading a small amount of Rh on the second CZ in the lower layer was investigated.

[0216] (1) Formation of the lower layer

[0217] As the 2nd CZ, use CeO 2 :ZrO 2 =35:65 (weight ratio), ceria-zirconia composite oxide with a secondary particle diameter of 30 μm, 50 g of the second CZ is immersed in an aqueous solution containing 0.25 g / L equivalent of rhodium nitrate, and then heated at 250° C. After 1 hour, further firing at 500° C. for 1 hour, the second CZ carrying Rh was obtained.

[0218] Use 50g as CeO of the 1st CZ 2 :ZrO 2 = 35:65 (weight ratio), ceria-zirconia composite oxide with a secondary particle diameter of 1 μm, 50 g of the above Rh-loaded 2nd CZ as the 2nd CZ, 50 g of alumina, and 200 g of water were mixed to prepare a slurry for the lower layer .

[0219] This underlayer slurry was applied to a substrate, and heated at 250° C. for 1 hour to form a lower layer on the substrate (coating amount: 150 g / L).

[0220] (...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
particle sizeaaaaaaaaaa
particle sizeaaaaaaaaaa
particle diameteraaaaaaaaaa
Login to View More

Abstract

An exhaust gas purification catalyst comprising a lower layer and an upper layer, wherein the lower layer contains cerium oxide-based oxide particles, and the upper layer contains metal oxide particles and a noble metal supported on the metal oxide particles, wherein the exhaust gas purification catalyst is characterized in that , the Rh content in the lower layer is 0.25 g / L or less, and the particle size distribution of the cerium oxide-based oxide particles contained in the lower layer observed by scanning electron microscopy has a first peak and a second peak, so The first peak has a peak top in the region of 0.90 to 6.50 μm, and the second peak has a peak top in the region of 9.50 to 34.0 μm.

Description

technical field [0001] The present invention relates to an exhaust gas purifying catalyst and a manufacturing method thereof. Background technique [0002] A three-way catalyst in which a noble metal is supported on an inorganic oxide is known as an exhaust gas purification catalyst used for treating exhaust gas from automobiles or the like. Three-way catalysts are widely used as catalysts capable of effectively removing hydrocarbons (HC), nitrogen oxides (NOx) and carbon monoxide (CO) simultaneously. Exhaust gas purification catalysts typified by three-way catalysts often contain rhodium (Rh) excellent in NOx purification activity. [0003] The exhaust gas removal performance of the exhaust gas purification catalyst is most efficient when the air-fuel ratio is a stoichiometric air-fuel ratio (so-called "stoichiometric ratio") near 14.6. However, cars often don't drive at an air-fuel ratio close to stoichiometric. It is known that when the air-fuel ratio is varied by engi...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): B01J23/63B01D53/94B01J37/02F01N3/10B01J35/00
CPCB01J23/63B01D53/945B01D2255/1023B01D2255/1025B01D2255/2065B01D2255/407B01D2255/9022B01D2255/9202B01D2258/01F01N3/2803F01N2330/30F01N2370/02F01N2510/06F01N2510/0684B01J37/0244B01J23/10B01J35/30B01J35/396B01J35/40B01D53/94B01J37/02F01N3/10B01J35/19F01N3/101
Inventor 三隅宝松枝悟司
Owner CATALER CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products