Porous Exhaust Catalyst Support to Suppress Metal Sintering
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Solution Overview
Problem
Existing exhaust gas purification catalysts suffer from catalyst metal deterioration due to sintering under high-temperature conditions, leading to a decline in purification performance, as they fail to adequately inhibit particle growth and aggregation.
Innovation Solution
The catalyst metal particle growth is suppressed by controlling the pore diameter distribution of the support, with a ratio of pore diameters P10 to P90 between 0.25 and 0.6, ensuring a uniform distribution that enhances catalyst metal dispersion and heat resistance, allowing for reduced catalyst metal usage while maintaining or improving purification performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional supports are used, then the catalyst can be manufactured with standard processes, but the catalyst metal undergoes sintering and particle growth under high-temperature conditions, leading to performance degradation
Solution Approach 1:
The invention changes the physical parameters of the support by controlling its pore diameter distribution (P10: 5-20 nm, P90: 20-50 nm, and P10/P90 ratio: 0.25-0.6). This parameter optimization prevents catalyst metal sintering by providing an ideal pore structure that restrains metal particle migration and aggregation, thereby maintaining catalyst stability and extending catalyst life under high-temperature conditions.
Solution Approach 2:
The invention utilizes a porous support material with specifically controlled pore diameter distribution. The porous structure with optimized pore sizes (P10: 5-20 nm, P90: 20-50 nm) provides physical constraints that prevent catalyst metal particles from migrating and sintering, while maintaining high surface area for catalytic activity. This porous structure design directly addresses the sintering issue by creating a stabilizing physical environment for the catalyst metal.
2Quantity of substance
If the amount of catalyst metal is reduced to save cost and energy, then manufacturing cost decreases, but purification performance may be insufficient
Solution Approach 1:
The invention optimizes the support's pore diameter distribution parameters (P10: 5-20 nm, P90: 20-50 nm, P10/P90 ratio: 0.25-0.6) to enhance catalyst metal dispersion. This parameter optimization allows for highly dispersed loading of catalyst metal, maximizing the utilization efficiency of each metal particle. Consequently, sufficient purification performance can be achieved with reduced catalyst metal quantity, lowering both material cost and energy consumption.
Solution Approach 2:
The optimized porous support structure serves itself by providing inherent dispersion and stabilization functions for the catalyst metal. The specific pore diameter distribution (P10: 5-20 nm, P90: 20-50 nm) creates a self-organizing environment that automatically prevents metal particle aggregation and maintains high dispersion throughout the catalyst's operational life, eliminating the need for additional expensive metal quantities to compensate for poor dispersion.
3Manufacturing precision
If the pore diameter distribution is not controlled, then the support can be manufactured with simpler processes, but the catalyst metal dispersion is insufficient, leading to reduced purification performance
Solution Approach 1:
The invention specifies precise parameter ranges for pore diameter distribution (P10: 5-20 nm, P90: 20-50 nm, P10/P90 ratio: 0.25-0.6) that can be achieved through controlled manufacturing processes. These parameter specifications balance manufacturing feasibility with performance requirements, allowing for highly uniform pore structures that enhance catalyst metal dispersion while remaining attainable through industrial manufacturing methods.
4Reliability
If the catalyst metal is highly dispersed, then purification performance improves, but the catalyst metal is more susceptible to sintering and particle growth
Solution Approach 1:
The invention employs a porous support with specifically controlled pore diameter distribution (P10: 5-20 nm, P90: 20-50 nm) that provides physical confinement for highly dispersed catalyst metal particles. The porous structure acts as a stabilizing matrix that maintains high dispersion while preventing particle migration and sintering through the controlled pore architecture, thereby simultaneously achieving high purification performance and compositional stability.
Solution Approach 2:
The invention optimizes the support's pore diameter parameters (P10: 5-20 nm, P90: 20-50 nm, P10/P90 ratio: 0.25-0.6) to create an ideal environment for highly dispersed catalyst metal. These parameter changes in the support structure provide sufficient surface area and pore volume to maintain high dispersion while the specific pore size distribution creates physical barriers that restrain particle growth, resolving the contradiction between dispersion and stability.
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 approach results in a longer catalyst life, improved purification performance, and reduced energy and cost, with the catalyst maintaining effectiveness under high-temperature conditions.
Implementation Method 1
A primary cause of this is the sintering (particle growth due to sintering) of the catalyst metal under high-temperature conditions (for example, 800°C to 1000°C).
Implementation Method 2
Exhaust gas purification catalysts are typically provided with a catalyst layer that contains a precious metal that functions as a catalyst
Data Source
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AI summary
An exhaust gas purification catalyst is provided for which a purification performance is excellent and particle growth of a catalyst metal is suppressed. The exhaust gas purification catalyst is provided with a substrate and a catalyst layer formed on the substrate. The catalyst layer contains a catalyst metal that functions as an oxidation and/or reduction catalyst and contains a support that supports the catalyst metal. The support is constituted of a porous ceramic that, in its volumetric pore diameter distribution measured based on a nitrogen gas adsorption method, has a pore diameter P10 corresponding to a cumulative 10% from a small pore side and a pore diameter P90 corresponding to a cumulative 90% from the small pore side that are both in a range from 5 to 50 nm.