Co-supported Ru-Pd Catalyst for Aromatic Ring Hydrogenation

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Solution Overview

Problem

Current methods for hydrogenating aromatic carboxylic acids face challenges with high costs and rapid activity degradation of rhodium catalysts, and selectivity issues with ruthenium catalysts, which require additional steps and reduce efficiency.

Innovation Solution

A co-supported ruthenium-palladium catalyst is used, where ruthenium and palladium coexist in every particle on the surface of a support, enabling high activity and selectivity in hydrogenating aromatic rings without the need for activation operations or additional steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a rhodium catalyst is used for hydrogenating aromatic carboxylic acid, then high activity and high selectivity are achieved, but the catalyst cost is very high and activity degrades rapidly requiring frequent activation

Engineering Contradiction:
Improvecatalyst activity stabilityVSAvoidcatalyst cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses a bimetallic catalyst composed of ruthenium and palladium supported on a carrier. This composite structure combines the advantages of both metals: ruthenium provides cost-effectiveness and stability, while palladium enhances catalytic activity and selectivity. The synergistic interaction between the two metals resolves the contradiction by achieving rhodium-like performance at lower cost with improved stability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes the weight ratio of ruthenium to palladium (specifically 1:1 to 2:1) and controls the particle size distribution of the metals on the carrier. By adjusting these parameters, the catalyst achieves maximum activity and stability, resolving the contradiction between cost and performance.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If a ruthenium catalyst is used for hydrogenating aromatic carboxylic acid, then catalyst cost is reduced, but selectivity decreases due to reduction of carboxyl group occurring

Engineering Contradiction:
Improvecatalyst costVSAvoidproduct selectivity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

Palladium acts as an intermediary metal that modifies the catalytic behavior of ruthenium. The presence of palladium on the catalyst surface suppresses the unwanted carboxyl group reduction while maintaining aromatic ring hydrogenation activity. This intermediary effect resolves the selectivity issue while keeping the catalyst cost low.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates local active sites with specific Ru-Pd compositions and structures on the carrier surface. These localized regions provide the necessary selectivity control, ensuring that hydrogenation occurs at the aromatic ring while the carboxyl group remains intact. This local quality approach maintains high selectivity despite using inexpensive ruthenium as the base metal.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If a ruthenium catalyst is used for hydrogenating aromatic carboxylic acid, then catalyst cost is reduced, but additional steps are required involving conversion to ester or inorganic salt

Engineering Contradiction:
Improvecatalyst costVSAvoidprocess steps
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The Ru-Pd bimetallic catalyst performs multiple functions simultaneously: it hydrogenates the aromatic ring, maintains carboxyl group integrity, and operates directly on the carboxylic acid without requiring pre-conversion. This multi-functionality eliminates the need for additional esterification or salt formation steps, simplifying the overall process while using cost-effective ruthenium-based catalyst.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

This approach allows for the production of alicyclic carboxylic acids with high selectivity and stability, reducing production costs and simplifying the process by maintaining catalyst activity over extended use periods.

Implementation Method 1

hydrogenating an aromatic carboxylic acid selected from the group consisting of trimellitic acid, trimesic acid, and pyromellitic acid in the presence of a hydrogenation catalyst in which ruthenium and palladium are co-supported

Methodology Applied
Scientific EffectHydrogenation: Hydrogenation

Implementation Method 2

a hydrogenation catalyst in which ruthenium and palladium are co-supported

Methodology Applied
Scientific EffectCatalysis: Catalysis

Data Source

PatentEP2682380B1Method for producing alicyclic carboxylic acid and catalyst used in same
Publication Date: 2018.07.04 MITSUBISHI GAS CHEM CO INC
  • EP2682380B1 patent drawingFigure 1~2
  • EP2682380B1 patent drawingFigure 3~4
  • EP2682380B1 patent drawingFigure 5(1)

AI summary

Provided is a method for producing an alicyclic carboxylic acid by hydrogenating an aromatic ring of an aromatic carboxylic acid, which comprises using a catalyst containing ruthenium and palladium as a catalyst, and also provided is a co-supported ruthenium-palladium catalyst in which ruthenium and palladium are present in a form of particles containing both the ruthenium and palladium on a surface of a support. A catalyst has been developed which uses a relatively inexpensive noble metal, ruthenium, which has an activity equivalent to that of a rhodium catalyst, and which does not undergo decrease in activity as observed in a rhodium catalyst, and thereby an industrially simple method for producing an alicyclic carboxylic acid has been established.