CZMLA Catalyst Support Material for Thermal Stability and Oxygen Storage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current catalyst support materials, such as zirconia-stabilized ceria, face limitations in thermal stability and oxygen storage capacity, especially after aging at high temperatures, which affects their performance in three-way catalytic converters for automobile engine exhaust.
Innovation Solution
A new catalyst support material composition, CZMLA, with a formula x(Ce1-wZr wO2): yM: zL: (1-x-y-z)Al2O3, where w ranges from 0 to 0.8 and x, y, z represent weight percentages, is developed, offering improved thermal stability and oxygen storage capacity, potentially reducing the need for Ce-ZrO2 and lowering manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If zirconia-stabilized ceria is used as catalyst support, then oxygen storage capacity is improved, but thermal stability deteriorates after aging at high temperature
Solution Approach 1:
The patent applies composite materials by combining ceria (CeO2) with zirconia (ZrO2) and alumina (Al2O3) to create a composite catalyst support structure. The ceria provides high oxygen storage capacity while zirconia and alumina contribute thermal stability, especially after aging at high temperatures. This composite approach allows the material to maintain both high OSC and thermal stability, resolving the contradiction between these two properties.
2Area of stationary object
If high surface area alumina is used as catalyst support, then catalytic active sites are increased, but oxygen storage capacity deteriorates
Solution Approach 1:
The patent merges the functions of different materials by combining high surface area alumina (for catalytic active sites) with ceria-zirconia composite (for oxygen storage capacity). The resulting composite catalyst support integrates both functionalities, allowing the material to provide both high surface area for catalysis and sufficient oxygen storage capacity, thus resolving the contradiction between these two requirements.
3Reliability
If Ce-ZrO2 is used extensively to improve OSC and thermal stability, then performance is improved, but manufacturing cost increases
Solution Approach 1:
The patent applies parameter changes by optimizing the composition ratios of CeO2, ZrO2, and Al2O3 in the catalyst support. By adjusting these parameters, the patent achieves high catalytic performance and thermal stability while reducing the proportion of expensive Ce-ZrO2 material. This optimized composition maintains reliability while lowering manufacturing costs through more efficient material utilization.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
CZMLA exhibits high thermal stability and oxygen storage capacity, maintaining a surface area of at least 80 m^2/g after aging, and requires less Ce-ZrO2, achieving similar performance to conventional TWCs with reduced activation energy and lower PGM usage.
Implementation Method 1
zirconia-stabilized ceria and other ceria based oxides play a major role in oxygen storage and release under lean and rich fuel conditions
Implementation Method 2
High efficient catalytic performance also relates to high specific surface area and thermal stability, as well as high oxygen storage capacity
Implementation Method 3
The function of the catalyst is to change most of the pollution of the atmosphere from mobile engine exhaust consisting of carbon monoxide (CO), all kinds of hydrogen carbon compounds (HC), and nitrogen oxygen compounds (NO x ) into innocuous carbon dioxide (CO 2 ), water (H 2 O), and Nitrogen (N 2 )
Implementation Method 4
The catalyst support materials provided herein include layer texture materials comprising a catalyst support core covered by a solid solution... The coated powders are then calcined in a furnace at a higher temperature that ranges between about 500 and about 1100°C for about 3-6 hours
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A new type of catalyst support with oxygen storage capacity (OSC) and methods of making the same are disclosed. The composition ratio is x(Ce1-wZrw02) : yM : zL : (1 -x-y-z)AI203, where Ce1-wZrw02 is the oxygen storage composition with stabilizer Zr02, molar ratio (w) in the range of 0 to about 0.8, and a weight ratio (x) of about 0.05 to about 0.8; M is an interactive promoter for oxygen storage capacity with a weight ratio (y) of 0 to about 0.10; and L is a stabilizer for the support Al203 with weight ratio (z) of from 0 to about 0.10. In some cases, M or L can act as both OSC promoter and thermal stabilizer. The weight percentage range of ceria-zirconia and other metal and rare earth oxides (x+y+z) is from about 5 to about 80% relative to total oxides. Combining platinum group metals (PGM) and adhesive with the catalyst supports, a new wash coat made therefrom is provided that comprises a mixture of catalyst support materials according to the relationship (a)RE-Ce- Zr02 + (3)CZMLA + (1 -a-ß)RE-AI203, where RE-Ce-Zr02 is a commercial OSC material of rare earth elements stabilized ceria zirconia having a weight ratio (a) ranging from 0 to about 0.7; CZMLA is the catalyst support material of the present disclosure having a weight ratio (ß) ranging from about 0.2 to about 1 such that (a+ß) 203 is rare earth element stabilized alumina having a weight ratio equal to (1 -a-ß). The new wash coat made therefrom exhibits a lower activation temperature compared with traditional formulation of wash coat by at least 50°C. The new wash coat made therefrom also requires less RE-Ce-Zr02 oxide and/or less PGM in the formulation of emission control catalyst for gasoline and diesel engines.