Metal-Promoted Pt Catalysts for Exhaust Gas Treatment
Solution Overview
Problem
Existing three-way catalysts (TWCs) for gasoline engines face challenges in achieving optimal performance during cold start and hot transient stages, particularly in NOx reduction, and are economically and environmentally unsustainable due to high palladium (Pd) usage and market price fluctuations.
Innovation Solution
Incorporation of alkaline earth and transition metals such as Mn, Mg, Zn, or Fe into platinum (Pt)-containing TWC catalysts to enhance catalytic performance, allowing partial or complete substitution of Pd, thereby improving NOx, CO, and hydrocarbon conversions while reducing Pd loadings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If Pd-containing catalysts are used to improve oxidation performance, then CO and HC oxidation efficiency is improved, but NOx reduction performance deteriorates
Solution Approach 1:
The patent combines Pd and Pt metals in a single catalytic layer, merging the oxidation advantages of Pd with the NOx reduction capabilities of Pt to achieve balanced performance in both oxidation and reduction reactions
Solution Approach 2:
The patent uses composite catalytic materials containing both Pd and Pt metals along with metal oxides (Mn, Mg, Fe, Cu, or Zn), creating a composite catalyst that leverages the complementary properties of different materials to simultaneously improve oxidation and reduction performance
2Productivity
If Pt is used to improve overall TWC performance, then oxidation performance is improved, but NOx reduction performance deteriorates
Solution Approach 1:
The patent combines Pd and Pt metals in a single catalytic layer, merging the oxidation advantages of Pd with the NOx reduction capabilities of Pt to achieve balanced performance in both oxidation and reduction reactions
Solution Approach 2:
The patent uses composite catalytic materials containing both Pd and Pt metals along with metal oxides (Mn, Mg, Fe, Cu, or Zn), creating a composite catalyst that leverages the complementary properties of different materials to simultaneously improve oxidation and reduction performance
3Productivity
If high Pd loading is used to improve catalytic performance, then oxidation efficiency is improved, but cost and resource sustainability deteriorate
Solution Approach 1:
The patent changes the metal composition parameters by introducing Pt and metal oxides to replace a portion of Pd, adjusting the metallic phase composition to achieve cost-effective catalyst formulations with reduced Pd loading while maintaining or improving catalytic performance
Solution Approach 2:
The patent uses composite catalytic materials containing both Pd and Pt metals along with metal oxides (Mn, Mg, Fe, Cu, or Zn), creating a composite catalyst that leverages the complementary properties of different materials to simultaneously improve oxidation and reduction performance
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 modified TWCs demonstrate improved catalytic performance under various conditions, including cold start and hot transient stages, while reducing Pd usage, thus enhancing economic sustainability and resource conservation.
Implementation Method 1
A commonly used catalyst for gasoline engine exhaust treatments is the TWC (three way catalyst). TWCs perform three main functions: (1) oxidation of CO; (2) oxidation of unburnt HCs; and (3) reduction of NOx.
Implementation Method 2
Incorporation of alkaline earth and transition metals such as Mn, Mg, Zn, or Fe into platinum (Pt)-containing TWC catalysts to enhance catalytic performance
Data Source
Figure 1~2b
Figure 3a~3d
Figure 4a~4d
AI summary
A three-way catalyst article, and its use in an exhaust system for internal combustion engines, is disclosed. The catalyst article for treating exhaust gas comprising: a substrate comprising an inlet end and an outlet end with an axial length L, a first catalytic region comprising a first platinum group metal (PGM) component and a first metal component, wherein the first PGM component comprises platinum, palladium, or a combination thereof; wherein the first metal component is Mn, Mg, Fe, Cu, Zn, or a combination thereof; and wherein the molar ratio between the first metal component and the first PGM component in the first catalytic region is from 120: 1 to 1:5.