Wall-flow Catalyst Partition with Overlapping End Layers
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Solution Overview
Problem
Existing wall-flow exhaust gas purification catalysts experience excessive pressure loss and reduced purification performance due to the broad distribution of catalyst layers, leading to incomplete detoxification of exhaust gases.
Innovation Solution
A wall-flow exhaust gas purification catalyst with a first catalyst layer formed near the inflow-side end and a second catalyst layer near the outflow-side end, partially overlapping in the extending direction of the partition, to concentrate catalyst metal in regions that maximize purification performance while minimizing pressure loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the catalyst layer is formed broadly over the entire partition, then the purification performance is improved, but the pressure loss increases excessively
Solution Approach 1:
The patent applies local quality by forming catalyst layers only in specific regions (inflow-side and outflow-side ends) of the partition rather than uniformly across the entire partition. This concentrates the catalyst metal in areas where it most effectively prevents harmful component slip-through, maintaining high purification performance while reducing overall catalyst metal usage and pressure loss.
Solution Approach 2:
The patent segments the catalyst layer formation into two distinct regions: a first catalyst layer at the inflow-side end and a second catalyst layer at the outflow-side end. This segmentation allows the catalyst to be strategically positioned where it provides maximum benefit in preventing slip-through, while leaving the middle region without catalyst to minimize pressure loss.
2Loss of energy
If the catalyst layer is formed concentrated at the ends of the partition, then the pressure loss is reduced, but harmful components may slip through the region without catalyst layer
Solution Approach 1:
The first catalyst layer is formed at the inflow-side end to preliminarily treat the exhaust gas before it enters the catalyst-free middle region. This preliminary catalytic action prevents harmful components from accumulating or slipping through during their passage through the partition, even though the middle region lacks catalyst.
Solution Approach 2:
The patent applies local quality by forming catalyst layers only in specific regions (inflow-side and outflow-side ends) of the partition rather than uniformly across the entire partition. This concentrates the catalyst metal in areas where it most effectively prevents harmful component slip-through, maintaining high purification performance while reducing overall catalyst metal usage and pressure loss.
3Reliability
If the catalyst layer covers the entire partition length, then complete detoxification is achieved, but the cost of catalyst metal increases
Solution Approach 1:
The patent applies local quality by forming catalyst layers only in specific regions (inflow-side and outflow-side ends) of the partition rather than uniformly across the entire partition. This concentrates the catalyst metal in areas where it most effectively prevents harmful component slip-through, maintaining high purification performance while reducing overall catalyst metal usage and pressure loss.
Solution Approach 2:
The patent uses partial action by forming catalyst layers only at the ends of the partition rather than covering the entire length. This partial coverage is sufficient to prevent slip-through of harmful components, achieving effective detoxification without the excessive catalyst metal usage that would result from complete coverage.
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
This configuration enhances exhaust gas purification efficiency by preventing 'slip through' of harmful components and reducing pressure loss, resulting in improved emissions control and purification performance.
Implementation Method 1
The components of the exhaust gas are purified (detoxified) by contact between the exhaust gas and a catalyst layer (catalyst metal).
Implementation Method 2
The exhaust gas discharged from the internal combustion engine flows into and within the entrance cell from the exhaust gas inflow-side end, passes through the pores of the porous partition, and flows out from the exhaust gas outflow-side end of the exit cell.
Data Source
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AI summary
An exhaust gas purification catalyst is provided that has an excellent exhaust gas purification performance while suppressing pressure loss increases. The exhaust gas purification catalyst 10 is provided with a substrate having a wall-flow structure and having a partition 26; a first catalyst layer 261 formed, in a region of an interior part of the partition 26 that is in contact with an entrance cell 24, along the extending direction of the partition 26 from an exhaust gas inflow-side end 24a for less than the total length Lw of the partition 26; and a second catalyst layer 262 formed, in a region of an interior part of the partition 26 that is in contact with an exit cell 25, along the extending direction of the partition 26 from the exhaust gas outflow-side end 25a for less than the total length Lw of the partition 26. The first catalyst layer 261 and the second catalyst layer 262 are configured to partially overlap with each other in the extending direction.