Gold Nanoparticle Catalyst Using Polyelectrolyte Binding
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Solution Overview
Problem
Current catalysts for reducing diesel soot combustion temperature are limited by the aggregation of gold nanoparticles, which reduces their catalytic activity, and existing stabilizing agents inhibit catalytic performance, especially at high temperatures.
Innovation Solution
A method involving the formation of gold nanoparticles prior to attachment to substrate particles, using a polyelectrolyte to bind them electrostatically, and employing polymethylacrylic acid as a capping agent to maintain catalytic activity and stability, allowing for high temperature operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If stabilizing agents are used to prevent aggregation of gold nanoparticles, then the stability of gold nanoparticles is improved, but the catalytic activity is reduced due to surface coating
Solution Approach 1:
The patent uses citrate as an intermediary substance that temporarily stabilizes gold nanoparticles during synthesis but is subsequently removed. The citrate acts as a mediator that enables nanoparticle formation and stabilization during the manufacturing process, then is eliminated to restore full catalytic activity in the final product.
Solution Approach 2:
The patent applies preliminary stabilization using citrate during the nanoparticle formation process, then removes the stabilizing agent before the catalyst is used. This preliminary action allows the nanoparticles to be formed and stabilized during manufacturing, but the stabilizer is removed in advance to ensure full catalytic performance during actual use.
2Stability of the object's composition
If chemical methodologies are used for stabilization and reduction of nanoparticles, then the nanoparticles are stabilized and reduced, but the catalytic activity is significantly inhibited due to surface coverage by stabilizing agents
Solution Approach 1:
Citrate serves as a temporary intermediary that facilitates nanoparticle stabilization during synthesis but is removed before the catalyst enters service. This intermediary approach allows chemical stabilization during manufacturing while ensuring no residual stabilizing agents remain to inhibit catalytic activity during operation.
Solution Approach 2:
The patent employs discarding of the citrate stabilizing agent after it has fulfilled its temporary role during nanoparticle formation. The citrate is removed through washing and drying processes, discarding the stabilizing agent that is no longer needed once the nanoparticles are formed and immobilized on the substrate.
3Reliability
If gold nanoparticles are incorporated into a catalyst, then catalytic activity at room temperature is achieved, but the nanoparticles aggregate to form larger particles and lose catalytic activity
Solution Approach 1:
Citrate acts as a temporary intermediary stabilizer during nanoparticle formation that prevents aggregation during synthesis. The citrate is then removed to leave bare, highly active nanoparticles that are prevented from aggregating by their immobilization on the substrate surface rather than by chemical stabilization.
Solution Approach 2:
The patent extracts and removes the citrate stabilizing agent from the final catalyst product. By taking out the stabilizing agent through washing and drying, the patent eliminates substances that would coat and inhibit the nanoparticle surfaces, leaving only the essential gold nanoparticles immobilized on the substrate.
4Stability of the object's composition
If stabilizing agents are used to prevent aggregation, then nanoparticle aggregation is reduced, but the stabilizing agent covers the surface of nanoclusters and inhibits catalytic activity
Solution Approach 1:
Citrate functions as a temporary intermediary that prevents aggregation during nanoparticle formation but is subsequently removed. This intermediary approach allows aggregation prevention during manufacturing without leaving residual coating on the final catalyst surface that would inhibit catalytic activity.
Solution Approach 2:
The citrate stabilizing agent is discarded through washing and drying processes after it has fulfilled its temporary function of preventing aggregation during synthesis. This discarding ensures that no stabilizing agent remains to cover the nanoparticle surfaces and inhibit catalytic activity in the final product.
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 method results in a catalyst with improved catalytic activity and stability, capable of oxidizing CO at room temperature and reducing diesel soot combustion temperature, maintaining performance even after extreme thermal treatment.
Implementation Method 1
combining the solutions to form substrate particles having gold nanoparticles thereon
Data Source
AI summary
A method for the manufacture of a catalyst comprising substrate particles having gold nanoparticles thereon, the method comprising providing a first solution comprising gold nanoparticles; providing a second solution comprising substrate particles having polyelectrolyte on the surface thereof; and combining the solutions to form substrate particles having gold nanoparticles thereon. A catalyst comprising substrate particles having gold nanoparticles thereon, wherein the gold nanoparticles comprise capping agent comprising polyelectrolyte. A catalyst as a component of a cigarette filter, an air conditioning unit, an exhaust, or a diesel exhaust.