Nickel-Copper Three-Way Catalyst for Enhanced Oxygen Storage
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Solution Overview
Problem
Conventional cerium-based three-way catalysts do not generate sufficient oxygen for the oxidation of hydrocarbons and carbon monoxide during long and rich air/fuel excursions, necessitating a catalyst with enhanced oxygen storage capacity and water-gas-shift activity to effectively reduce vehicle exhaust emissions.
Innovation Solution
A three-way catalyst comprising a mixture of nickel and copper on a non-reactive carrier, such as zirconium oxide, cordierite, or silica gel, which provides supplemental oxygen storage and catalytic water-gas-shift reactions to oxidize carbon monoxide and hydrocarbons, and reduce nitrogen oxides during lean-to-rich and rich-to-lean transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional cerium-based oxides are used as OSC materials, then the catalyst can provide oxygen storage capacity for oxidation of CO and HC, but the oxygen generation is insufficient during long and rich air/fuel excursions
Solution Approach 1:
The patent changes the chemical composition parameters of the OSC material by incorporating nickel and copper oxides in specific ratios (Ni:Cu = 90:10 to 50:50) to enhance oxygen storage capacity and water-gas-shift activity, allowing sufficient oxygen generation during extended rich excursions
Solution Approach 2:
The patent creates a composite OSC material combining nickel oxide, copper oxide, and cerium-based oxides to achieve synergistic effects that improve both oxygen storage capacity and water-gas-shift activity beyond what conventional cerium-based oxides alone can provide
2Device complexity
If conventional cerium-based oxides are used, then the catalyst structure is simple and well-established, but the water-gas-shift activity is insufficient for effective CO removal after OSC depletion
Solution Approach 1:
The patent develops a composite catalyst material incorporating nickel oxide, copper oxide, and cerium-based oxides where the nickel and copper components provide enhanced water-gas-shift activity while the cerium-based oxides maintain oxygen storage capacity, achieving both improved productivity and reasonable structural complexity
3Productivity
If nickel-based catalysts are used to provide OSC and WGS functions, then CO and HC removal is improved, but copper is needed to enhance water-gas-shift activity and lower reaction temperatures
Solution Approach 1:
The patent optimizes the Ni:Cu ratio parameter (90:10 to 50:50) to balance water-gas-shift activity and oxidation catalysis, with copper content specifically tuned to lower reaction temperatures while nickel content maintains high CO and HC removal efficiency
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 nickel-copper catalyst achieves enhanced CO and HC conversion efficiencies, increased oxygen storage capacity, and NOx reduction, with improved durability and flexibility in exhaust systems, outperforming conventional nickel-based catalysts by catalyzing reactions at lower temperatures and minimizing deactivation.
Implementation Method 1
the catalyst is capable of providing supplemental oxygen storage capacity for the oxidation of carbon monoxide and hydrocarbons during lean-to-rich transitions
Implementation Method 2
stimulate the oxidation reaction of HC and CO and the reduction of NOx
Implementation Method 3
the reduction of NOx to nitrogen
Implementation Method 4
removal of carbon monoxide and hydrocarbons via catalytic water-gas-shift (WGS) and steam-reforming operations
Implementation Method 5
removal of carbon monoxide and hydrocarbons via catalytic water-gas-shift (WGS) and steam-reforming operations
Data Source
AI summary
A three-way catalyst including a mixture of nickel and copper is provided for reducing carbon monoxide, hydrocarbon emissions, and nitrogen oxides from vehicle engine exhausts. The catalyst is impregnated onto a carrier substrate which is non-reactive with nickel and copper. When used in a vehicle exhaust gas treatment system, the nickel-copper catalyst provides improved efficiency in reducing CO, HC, and NOx emissions over the use of conventional three-way-catalysts and provides enhanced oxygen storage capacity (OSC) and water-gas-shift (WGS) functions.