Honeycomb Structured Body Catalyst Distribution
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Solution Overview
Problem
Honeycomb structured bodies used as catalyst supporting carriers for exhaust gas conversion experience a reduction in performance due to catalyst sintering at high temperatures, leading to a loss of highly dispersed catalyst state over time.
Innovation Solution
A honeycomb structured body with a catalyst distribution where 5% or less of the catalyst is supported on the surface of inorganic fiber matter, with the majority supported on high specific surface area inorganic particles and binder, preventing sintering and maintaining high dispersion and surface area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the honeycomb structured body uses high specific surface area materials to highly disperse the catalyst, then the exhaust-gas converting performance is improved, but the catalyst sintering occurs at high temperatures leading to loss of highly dispersed state
Solution Approach 1:
The invention applies different materials with different properties to different regions of the honeycomb structured body. Specifically, it uses heat-resistant materials (such as cordierite, mullite, or alumina) for the cell walls to prevent catalyst sintering, while using high specific surface area materials (such as active alumina or inorganic fibers) in specific regions to maintain catalyst dispersion. This local differentiation allows the structure to simultaneously achieve both high exhaust-gas converting performance and stable catalyst dispersion at high temperatures.
Solution Approach 2:
The invention employs composite materials combining heat-resistant base materials with high specific surface area materials. The cell walls are constructed as composites of heat-resistant materials (providing thermal stability) and high surface area materials (providing catalyst support). This composite structure enables the honeycomb body to maintain both structural integrity at high temperatures and sufficient surface area for catalyst dispersion, thereby resolving the contradiction between productivity and reliability.
2Productivity
If the catalyst is highly dispersed on high specific surface area materials, then the conversion performance is enhanced, but the catalyst particles sinter and form bulky particles over time at high temperatures
Solution Approach 1:
The invention creates regions with different material properties within the honeycomb structure. Heat-resistant materials are positioned in areas where thermal stability is critical for preventing sintering, while high specific surface area materials are positioned where catalyst dispersion is most needed for conversion performance. This spatial differentiation allows the catalyst to remain highly dispersed on heat-resistant surfaces for extended periods at high temperatures.
Solution Approach 2:
The invention changes the thermal and surface area parameters of the supporting materials to optimize catalyst performance and stability. By selecting materials with specific combinations of heat resistance and surface area characteristics, the catalyst can maintain its dispersed state for longer durations at operating temperatures, thereby extending the effective service life while maintaining high conversion performance.
3Reliability
If the honeycomb structured body is designed for long-term high temperature use, then the catalyst sintering is prevented, but the specific surface area is reduced
Solution Approach 1:
The invention uses composite materials that combine the heat resistance of materials like cordierite or mullite with the high surface area characteristics of active alumina or inorganic fibers. This composite approach allows the structure to maintain both high specific surface area for catalyst support and sufficient heat resistance to prevent sintering during long-term operation, thereby resolving the contradiction between reliability and surface area.
Solution Approach 2:
The invention implements local quality differentiation where heat-resistant materials form the structural framework resistant to sintering, while high surface area materials are incorporated in regions where catalyst support is most beneficial. This localized approach ensures that the overall specific surface area remains high while the heat-resistant components prevent catalyst sintering during prolonged high-temperature exposure.
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 maintains superior exhaust-gas converting performance by preventing catalyst sintering and retaining high specific surface area even after long-term use at high temperatures.
Implementation Method 1
a catalyst is supported on cell walls of the honeycomb fired body
Data Source
Figure 1(a)~1(b)
Figure 2
Figure 3(a)~3(g)
AI summary
The present invention aims to provide a honeycomb structured body which is excellent in exhaust-gas conversion performance when used as a catalyst supporting carrier, and the honeycomb structured body of the present invention is configured by a large number of cells longitudinally placed in parallel with one another with a cell wall therebetween, and comprises inorganic particles, an inorganic fiber matter, an inorganic binder and a catalyst, wherein an area occupied by the catalyst supported on a surface of the inorganic fiber matter is 5% or less of the sum of an area occupied by the catalyst supported on a surface of the inorganic particles, an area occupied by the catalyst supported on a surface of the inorganic fiber matter, and an area occupied by the catalyst supported on the surface of the inorganic binder.