Pt-Pd Oxidation Catalyst for Low-Temperature NO Conversion
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Solution Overview
Problem
Existing exhaust-gas purification systems face inefficiencies in removing nitrogen oxides at low temperatures, as conventional catalysts like Pt are ineffective in promoting NO to NO2 conversion, leading to inadequate nitrogen oxide and particulate matter removal, and require complex temperature elevation methods or costly plasma generation systems.
Innovation Solution
An oxidation catalyst comprising 1 to 55% palladium by weight relative to platinum, supported on a refractory inorganic oxide, effectively promotes NO to NO2 conversion even at low temperatures, enhancing nitrogen oxide removal and particulate matter purification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional Pt catalyst is used to promote NO oxidation to NO2, then the catalyst shows activity at high temperatures, but the catalyst is ineffective at low temperatures for NO to NO2 conversion
Solution Approach 1:
The invention changes the chemical composition parameters of the catalyst by introducing Pd alongside Pt, with specific weight ratios (0.1-10 wt% Pd relative to Pt), to achieve effective NO oxidation at low temperatures while maintaining high-temperature activity
Solution Approach 2:
The invention uses a composite catalyst material combining Pt and Pd metals supported on refractory inorganic oxide, leveraging the synergistic effects of both precious metals to achieve broad temperature range activity for NO oxidation
2Reliability
If plasma generation system is used to form NO2, then nitrogen oxide purification is enhanced, but system complexity and cost increase significantly
Solution Approach 1:
The invention replaces the complex plasma generation system with a simpler chemical catalyst (Pt-Pd based) that achieves the same NO2 formation function through catalytic oxidation, eliminating the need for electrical plasma generation equipment
Solution Approach 2:
The invention uses a conventional catalyst material (Pt and Pd on support) that is easier and cheaper to implement than plasma generation systems, accepting that the catalyst will require periodic replacement rather than investing in complex durable plasma equipment
3Reliability
If temperature elevation method is used to improve nitrogen oxide removal, then purification efficiency increases, but system complexity and operational cost increase
Solution Approach 1:
The invention changes the catalyst's active temperature range by introducing Pd, allowing effective NO oxidation at lower temperatures without requiring external heating systems or temperature elevation methods
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 system efficiently converts NO to NO2 at low temperatures, improving nitrogen oxide removal and particulate matter purification, reducing system complexity and costs associated with plasma generation.
Implementation Method 1
an oxidation catalyst containing platinum and palladium as catalytically active components which contains 1 to 55% by weight of the palladium relative to 100% by weight of the platinum for efficiently promoting oxidation of NO to NO2 even in a low temperature range
Implementation Method 2
promoting oxidation of nitrogen monoxide to nitrogen dioxide
Data Source
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AI summary
An oxidation catalyst that efficiently promotes oxidation of NO to NO2 even in a low temperature range, and an exhaust-gas purification system and method that efficiently removes exhaust-gas components even in a low temperature range are provided. This invention provides an oxidation catalyst comprising platinum and palladium as catalytically active components, which promotes oxidation of nitrogen monoxide to nitrogen dioxide, wherein the oxidation catalyst comprises 1 to 55% by weight of the palladium relative to 100% by weight of the platinum.