Layered Catalyst Article for Low-Temperature NOx and Hydrocarbon Oxidation
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Solution Overview
Problem
Current catalyst systems struggle with high hydrocarbon concentrations inhibiting CO, hydrocarbon, and NO oxidation, requiring high NO to NO2 oxidation activity at low temperatures, and face challenges with sulfur and impurities affecting performance, necessitating improved durability and efficiency in diesel exhaust gas treatment.
Innovation Solution
A zoned and partitioned catalyst article with distinct catalytic layers, including platinum group metals and porous support materials, is designed to optimize hydrocarbon and NOx/SOx conversions by separating reactions and enhancing catalyst stability through tailored PGM distribution and promoter use.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If high hydrocarbon concentrations are present in exhaust gas, then fuel consumption is reduced, but CO, hydrocarbon, and NO oxidation is inhibited and light-off temperature increases
Solution Approach 1:
The catalyst is divided into multiple zones with different functionalities: a first zone optimized for hydrocarbon oxidation and a second zone optimized for CO and NO oxidation. This segmentation allows each zone to perform its specific function efficiently without interference from high hydrocarbon concentrations in other zones.
Solution Approach 2:
Different catalyst compositions are applied in different spatial locations within the catalyst structure. The first zone contains catalyst components with high hydrocarbon oxidation activity, while the second zone contains components optimized for CO and NO oxidation, ensuring each location has the quality needed for its specific function.
2Device complexity
If catalyst volume is reduced to meet emission standards, then device complexity is reduced, but oxidation activity and performance under varying temperatures may be compromised
Solution Approach 1:
The catalyst is segmented into functional zones that can be optimized for different reactions, allowing compact design while maintaining high activity for multiple oxidation reactions within a reduced overall volume.
Solution Approach 2:
The catalyst uses composite material structures with multiple active components distributed in specific zones, enabling high oxidation activity for different pollutants within a compact volume by combining the benefits of different catalyst materials in a unified structure.
3Productivity
If sulfur and impurities are present in exhaust gas, then combustion efficiency is maintained, but catalyst performance and durability are affected
Solution Approach 1:
The catalyst structure segments different functional regions, with certain zones designed to be more resistant to sulfur poisoning and impurity accumulation, protecting the overall catalyst durability while maintaining combustion efficiency.
Solution Approach 2:
The catalyst design accepts the presence of sulfur and impurities as inevitable byproducts of combustion, but structures the catalyst zones to tolerate or even utilize these conditions, converting the potential harm into acceptable performance under real-world operating conditions.
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 article achieves efficient oxidation and storage of emissions, maintaining high performance under varying temperatures and impurity exposure, meeting stringent emission standards with optimized catalyst volume and reduced undesired gas component levels.
Implementation Method 1
platinum group metal (PGM) elements, such as platinum (Pt) and palladium (Pd), which can be used for making a zoned catalyst article (1) for oxidizing carbon monoxide (CO), hydrocarbons (HCs), hydrogen (H2) and nitrogen oxide (NOx) emissions
Implementation Method 2
oxidizing carbon monoxide (CO), hydrocarbons (HCs), hydrogen (H2) and nitrogen oxide (NOx) emissions
Implementation Method 3
porous support materials such as aluminum oxide (Al2O3), silicon oxide (SiO2), titanium oxide (TiO2)
Implementation Method 4
the article further suitable for use as a temporary NOx and hydrocarbon storage for reduction of total NOx and hydrocarbon emissions
Data Source
AI summary
A zoned and partitioned catalyst article including platinum group metal (PGM) elements, such as platinum (Pt) and palladium (Pd), and porous support materials such as aluminum oxide (Al2O3), silicon oxide (SiO2), titanium oxide (TiO2) and optionally including other metal oxides and promoters, which can be used for making a zoned catalyst article (1) for oxidizing carbon monoxide (CO), hydrocarbons (HCs), hydrogen (H2) and nitrogen oxide (NOx) emissions, the article further suitable for use as a temporary NOx and hydrocarbon storage for reduction of total NOx and hydrocarbon emissions.