Nanoparticle Coated Substrates for Three-Way Catalytic Converters
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Solution Overview
Problem
Traditional three-way catalytic converters suffer from aging issues due to high temperature exhaust gases, leading to reduced catalytic activity and increased emissions, as precious metal nanoparticles sinter or coalesce, necessitating higher metal loads that are costly and wasteful.
Innovation Solution
Coated substrates with oxidative and reductive catalytically active particles, comprising composite nanoparticles bonded to micron-sized carrier particles, are used to constrain particle mobility, reducing sintering and maintaining catalytic activity over time, allowing for lower precious metal usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional catalytic converters use separate washcoat layers for oxidative and reductive catalysts, then catalytic activity is maintained, but device complexity and manufacturing steps increase
Solution Approach 1:
The patent combines oxidative and reductive catalysts into a single integrated washcoat layer on the catalytic converter substrate. This merging of previously separate washcoat layers into one unified layer reduces manufacturing complexity while maintaining the dual catalytic functions through spatial distribution of different catalyst particles within the same layer.
2Reliability
If precious metal nanoparticles are used as catalysts, then catalytic activity is high, but aging occurs due to sintering at high temperatures
Solution Approach 1:
The patent introduces a washcoat material as an intermediary substance that supports and stabilizes the precious metal nanoparticles. This washcoat acts as a mediator between the catalyst particles and the high-temperature exhaust environment, preventing direct contact and sintering while maintaining catalytic activity over extended periods.
Solution Approach 2:
The patent creates a composite material structure combining precious metal nanoparticles with washcoat support materials. This composite approach integrates the high catalytic activity of metal nanoparticles with the thermal stability and protective properties of the washcoat support, preventing aging while maintaining performance.
3Reliability
If higher precious metal loads are used to counteract aging, then catalytic activity is maintained, but cost and waste increase
Solution Approach 1:
The patent changes the physical and chemical parameters of the catalyst system by optimizing nanoparticle size, washcoat composition, and particle distribution. These parameter changes enable higher catalytic activity at lower precious metal loads, reducing both cost and waste while maintaining effective catalytic performance.
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
The coated substrates stabilize catalytic activity, reduce emissions, and lower the light-off temperatures for hydrocarbons, carbon monoxide, and nitrogen oxides, achieving performance comparable to or better than commercial systems with reduced platinum group metal loading.
Implementation Method 1
precious metal nano-particles in the washcoat layer increased mobility—which results in these particles moving more quickly through the washcoat layers. When the precious metal nano-particles encounter one another as they move through the washcoat layer, they can sinter or coalesce into larger metal particles
Implementation Method 2
the carbon monoxide and hydrocarbons are oxidized and converted into carbon dioxide
Implementation Method 3
With the assistance of the active catalysts, the carbon monoxide and hydrocarbons are oxidized
Implementation Method 4
the nitrogen oxides are reduced and converted into nitrogen
Implementation Method 5
the nitrogen oxides are reduced and converted into nitrogen
Data Source
AI summary
The present disclosure relates to a substrate comprising nanomaterials for treatment of gases, washcoats for use in preparing such a substrate, and methods of preparation of the nanomaterials and the substrate comprising the nanomaterials. More specifically, the present disclosure relates to a substrate comprising nanomaterial for three-way catalytic converters for treatment of exhaust gases.