Palladium Fixation via Gallic Acid Complexes for Catalyst Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional three-way catalysts (TWCs) face limitations in controlling PGM particle size and metal-support interactions, leading to reduced performance and increased PGM costs, with existing synthesis methods being complex and costly for commercial-scale production.

Innovation Solution

A method involving a complex of a compound of formula (I) and palladium, applied to a support material, then heated to form nanoparticles, which are disposed on a substrate, simplifying the process and improving PGM fixation and distribution, allowing for superior catalytic activity and reduced PGM loading.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional incipient wetness impregnation with inorganic PGM precursors is used, then PGM can be deposited onto oxide support, but control over PGM particle size and metal-support interaction is limited due to metal migration and grain growth during high temperature calcination

Engineering Contradiction:
Improvecontrol over PGM particle size and metal-support interactionVSAvoidPGM migration and grain growth during calcination
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent applies preliminary action by using a polymer coating on the support material before PGM deposition. This polymer layer is applied in advance to control the subsequent PGM particle formation, preventing migration and grain growth during calcination by providing a template that directs PGM deposition and maintains particle size control throughout the thermal processing.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If multiple impregnation and filtration steps are used as described in US 2012/0077669 A1, then supported metal catalysts can be formed, but the process complexity and production cost increase

Engineering Contradiction:
Improveformation of supported metal catalystsVSAvoidnumber of synthesis steps
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges multiple separate steps (polymer coating, drying, and PGM impregnation) into a single combined impregnation step where PGM precursors are deposited directly onto polymer-coated supports in one operation, eliminating the need for separate filtration and multiple drying cycles while maintaining catalyst formation quality.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If higher PGM loading is used, then TWC performance can be maintained, but PGM costs increase

Engineering Contradiction:
ImproveTWC performanceVSAvoidPGM loading
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies local quality by creating uniform polymer coating layers on support materials that provide localized control over PGM distribution. This ensures optimal PGM utilization at each location, achieving high catalytic performance with reduced overall PGM loading through improved dispersion and prevention of agglomeration.

Inventive Principle:
Principle #3Local quality

4Stability of the object's composition

If uniform PGM particle size distribution is achieved, then metal sintering due to Ostwald Ripening is reduced, but more precise control mechanisms are required

Engineering Contradiction:
ImprovePGM particle size distribution uniformityVSAvoidcontrol over particle size distribution
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent uses polymer coatings as intermediary materials between the support and PGM precursors. These polymer intermediaries control the nucleation and growth of PGM particles, ensuring uniform particle size distribution by providing consistent binding sites and preventing direct metal-metal contact that would lead to Ostwald ripening and sintering.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 method results in enhanced catalytic activity, durability, and reduced PGM costs by achieving favorable three-way catalytic activity and light-off performance, with improved PGM distribution and reduced sintering, suitable for stoichiometric gasoline engines.

Implementation Method 1

heating the loaded support material to form nanoparticles of the PGM on the support material

Methodology Applied
Scientific EffectThermal decomposition: Decomposition (biological)

Implementation Method 2

providing a complex of a compound of formula (I) and PGM

Methodology Applied
Scientific EffectComplex formation: Chemical Bonding

Data Source

PatentEP4403257A1Palladium fixing using gallic acid or its derivative
Publication Date: 2024.07.24 JOHNSON MATTHEY PLC
  • EP4403257A1 patent drawingFigure 1~2
  • EP4403257A1 patent drawingFigure 3A~3B
  • EP4403257A1 patent drawingFigure 3C~4

AI summary

A method of manufacturing a catalyst article, the method comprising: providing a complex of a compound of formula (I): and a PGM, R1 is H or C1-C6 alkyl, R2 is H, OH, or O-C1-C4 alkyl, the PGM comprising palladium; providing a support material; applying the complex to the support material to form a loaded support material; disposing the loaded support material on a substrate; and heating the loaded support material to form nanoparticles of the PGM on the support material.