Gold-Iron Proximity Catalyst for Low-Temp NOx Purification
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Solution Overview
Problem
Conventional NOX purification catalysts using precious metals like platinum, gold, and rhodium exhibit low performance at low temperatures and in oxidizing atmospheres, limiting fuel economy improvements and facing resource depletion challenges.
Innovation Solution
A nitrogen oxide purification catalyst comprising particles with gold and iron atoms in close proximity, supported on metal oxide carriers like Al2O3, SiO2, or CeO2-ZrO2, with an average particle size of 0.2 to 100 nm, achieving effective NOX purification at low temperatures and in oxidizing conditions while reducing precious metal usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional precious metal catalysts (platinum, gold, rhodium) are used, then catalytic activity is maintained, but NOX purification performance is low at low temperature and in oxidizing atmosphere
Solution Approach 1:
The patent uses a composite catalyst system combining precious metal particles (platinum, gold, or rhodium) with iron oxide particles. The iron oxide component enables low-temperature and oxidizing atmosphere purification capabilities, while the precious metal particles maintain catalytic activity. This composite structure resolves the contradiction by integrating the strengths of both materials.
Solution Approach 2:
Iron oxide acts as an intermediary substance that facilitates NOX purification under low-temperature and oxidizing conditions. The iron oxide particles interact with NOX molecules, enabling purification reactions that conventional precious metal catalysts cannot perform efficiently under these conditions.
2Reliability
If high temperature operation is used to improve NOX purification performance, then purification efficiency increases, but fuel economy deteriorates
Solution Approach 1:
The composite catalyst system allows the vehicle to operate at lower temperatures while maintaining effective NOX purification. The iron oxide component specifically enables low-temperature activity, eliminating the need for high-temperature operation and thus improving fuel economy during steady-state driving conditions.
3Reliability
If reducing atmosphere is created to improve NOX purification, then purification performance increases, but fuel consumption increases due to temporary stoichiometric or rich conditions
Solution Approach 1:
The iron oxide-containing composite catalyst enables effective NOX purification in oxidizing atmosphere, eliminating the need to create reducing conditions through temporary stoichiometric or rich fuel mixtures. This allows the engine to maintain lean burn conditions during steady-state operation, improving fuel economy.
Solution Approach 2:
Instead of using the conventional approach of creating reducing atmosphere for NOX purification, the patent inverts the approach by using iron oxide to enable purification in oxidizing atmosphere. This inversion eliminates the need for fuel-rich conditions and improves fuel consumption.
4Quantity of substance
If precious metal amounts are reduced to address resource depletion, then cost and resource sustainability improve, but catalytic activity and purification performance decrease
Solution Approach 1:
The patent combines small amounts of precious metal particles with iron oxide particles to create a composite catalyst. The iron oxide component compensates for the reduced precious metal content by providing additional purification pathways, particularly for low-temperature and oxidizing condition NOX removal, thereby maintaining overall catalytic activity with reduced precious metal usage.
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 catalyst demonstrates superior NOX purification performance at low temperatures and in oxidizing atmospheres, allowing for improved fuel economy without the need for high temperatures or reducing atmospheres, and reduces the amount of precious metals required.
Implementation Method 1
a nitrogen oxide purification catalyst comprised of particles including gold atoms and iron atoms and able to purify NOX at a low temperature and/or in an oxidizing atmosphere
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3A~3B
AI summary
The present invention relates to a catalyst able to exhibit an NOx purification performance at a low temperature and/or in an oxidizing atmosphere, that is, a nitrogen oxides purification catalyst composed of particles having an average particle size of 0.2 to 100 nm and including gold atoms and iron atoms in a state of close proximity.