Cation-Controlled BEA Zeolite Hydrocarbon Traps for Hydrothermal Stability
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Solution Overview
Problem
Existing hydrocarbon traps based on BEA zeolites suffer from poor hydrothermal stability and limited adsorption capacity below 300°C, especially during the cold start phase of vehicle operation, and are inadequate under high moisture conditions.
Innovation Solution
A hydrocarbon adsorbent is developed by controlling the cation composition within the BEA zeolite framework, specifically adjusting the sodium-to-aluminum molar ratio to 0.7 or less, and incorporating metal ions and oxides within and on the surface of the zeolite particles, enhancing hydrothermal stability and adsorption performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If Cu-loaded BEA zeolite is used to enhance adsorption capacity, then hydrocarbon adsorption performance is improved, but hydrothermal stability deteriorates under high-temperature and high-moisture conditions
Solution Approach 1:
The patent changes the cation composition parameters by controlling the Na/Al ratio within the BEA zeolite framework to achieve optimal balance between adsorption capacity and hydrothermal stability
Solution Approach 2:
The patent creates a composite material system combining BEA zeolite with controlled cation composition (Na+, H+, Cu2+) to achieve synergistic effects that simultaneously improve adsorption capacity and thermal stability
2Quantity of substance
If BEA zeolite with higher Al content is used to increase adsorption capacity, then hydrocarbon adsorption performance is improved, but structural stability under hydrothermal conditions deteriorates
Solution Approach 1:
The patent optimizes the Si/Al ratio parameter within a specific range (1-50) and controls the Na/Al ratio (≤0.7) to achieve the optimal balance between adsorption capacity and framework stability
Solution Approach 2:
The patent introduces different cations (Na+, H+, Cu2+) at specific locations within the zeolite framework to locally enhance both adsorption sites and structural stability
3Ease of manufacture
If conventional BEA zeolite is used for hydrocarbon trap, then manufacturing simplicity is maintained, but performance during cold start phase deteriorates due to limited activity below 300°C
Solution Approach 1:
The patent modifies the cation composition parameters (introducing Cu2+ and controlling Na+/H+ ratio) to lower the activation temperature and enhance catalytic activity during the cold start phase
Solution Approach 2:
The patent uses Cu2+ cations as intermediary catalytic sites that facilitate hydrocarbon oxidation at lower temperatures, bridging the gap between cold start conditions and TWC activation temperature
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 adsorbent maintains structural integrity and exhibits improved hydrocarbon adsorption and oxidation capabilities even under high-temperature and high-humidity conditions, effectively adsorbing and oxidizing hydrocarbons during the cold start phase.
Implementation Method 1
A hydrocarbon trap is a device that adsorbs hydrocarbons during the cold start phase
Implementation Method 2
subsequently desorbs them when the temperature reaches the activation temperature of the TWC (approximately 200-300° C.)
Implementation Method 3
metal ions chemically bonded to the BEA zeolite particles; and metal oxides disposed on an outer surface of the BEA zeolite particles
Data Source
AI summary
The present invention relates to a hydrocarbon adsorbent with enhanced hydrothermal stability and a method for manufacturing the same by controlling the cation ratio within BEA zeolite. More specifically, the invention provides a hydrocarbon adsorbent in which the cation composition within the BEA zeolite structure is precisely controlled to enable effective adsorption and oxidation of hydrocarbons emitted during the cold-start period, thereby improving hydrothermal stability and maintaining structural integrity under harsh conditions. The hydrocarbon adsorbent according to the present invention exhibits improved hydrothermal stability and maintains excellent hydrocarbon adsorption and desorption performance even after undergoing high-temperature hydrothermal treatment in the presence of moisture.