Iron-Based Catalyst for Oxidative Esterification

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Solution Overview

Problem

Existing catalysts for direct oxidative esterification of aldehydes to carboxylic esters suffer from low mechanical and chemical stability, high by-product formation, particularly methyl isobutyrate, and inefficient use of precious metal components, leading to catalyst deactivation and contamination issues.

Innovation Solution

A novel process for producing a mixed oxide support and catalyst using silicon, aluminum, and magnesium oxides, with controlled grain size distribution and processing steps to enhance stability and reduce by-product formation, involving spray drying, calcination, and classification to minimize fines content and sintering, and the use of a protective shell structure to maintain catalyst activity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If lead-containing catalysts are used for high conversion and selectivity, then catalytic performance is improved, but environmental contamination and treatment complexity increase

Engineering Contradiction:
Improvecatalytic performanceVSAvoidenvironmental contamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces expensive and environmentally problematic lead-containing catalysts with cheaper, environmentally benign iron-based catalysts. The iron catalyst achieves comparable catalytic performance without the environmental contamination issues associated with lead, effectively substituting a harmful catalyst with a safe alternative that maintains functional effectiveness.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent modifies the catalyst composition by changing the metal component from lead to iron while adjusting the support material composition (using specific ratios of silicon dioxide, aluminum oxide, and magnesium oxide). This parameter change in catalyst composition enables maintaining high catalytic activity and selectivity while eliminating environmental contamination problems.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If nickel oxide and gold nanoparticles are used for high activity and selectivity, then catalytic performance is improved, but mechanical stability deteriorates

Engineering Contradiction:
Improvecatalytic activityVSAvoidmechanical stability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent changes the catalyst composition from nickel oxide and gold nanoparticles to iron-based catalysts on a specific mixed oxide support. This compositional parameter change maintains high catalytic activity and selectivity while significantly improving mechanical stability and resistance to abrasion, as iron-based catalysts on properly formulated supports exhibit better structural integrity during operation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite catalyst system consisting of iron-based active components supported on a composite material comprising silicon dioxide, aluminum oxide, and magnesium oxide in specific ratios. This composite structure provides both high catalytic performance and enhanced mechanical stability, as the mixed oxide support framework reinforces the structural integrity while the iron components provide the necessary catalytic activity.

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If catalyst production is simplified, then manufacturing ease is improved, but by-product formation increases

Engineering Contradiction:
Improveproduction simplicityVSAvoidby-product formation
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent optimizes the support material composition by adjusting the ratios of silicon dioxide, aluminum oxide, and magnesium oxide. This compositional parameter optimization simplifies the catalyst production process while simultaneously reducing by-product formation. The specific ratio ranges provided in the patent enable easier manufacturing without compromising product selectivity, as the optimized support structure inherently promotes desired reactions and suppresses unwanted by-products.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If drying time and storage time are extended between process steps, then catalytic performance is enhanced, but production time increases

Engineering Contradiction:
Improvecatalytic performanceVSAvoidproduction time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent optimizes the drying and storage parameters by specifying precise temperature ranges (30-250°C for drying) and time intervals. These optimized parameters enable adequate catalyst performance enhancement while minimizing unnecessary production time delays. The patent identifies the minimum effective drying time and storage duration required to achieve desired catalytic properties, avoiding excessive time consumption while ensuring catalyst readiness for optimal performance.

Inventive Principle:
Principle #35Parameter changes

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 process results in a catalyst with improved mechanical and chemical stability, reduced by-product formation, and prolonged activity, achieving higher MMA purities and selectivity, while minimizing the loss of precious metals and reducing environmental contamination.

Implementation Method 1

spray-drying of the suspension from process step (i) at a temperature T2 of > 110° C. to obtain a solid-state material

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

calcination of the solid-state material from (ii) at a temperature T3 between 300 and 800° C.

Methodology Applied
Scientific EffectThermal decomposition: Pyrolysis

Implementation Method 3

the catalytic oxidative esterification of aldehydes for preparation of carboxylic esters

Methodology Applied
Scientific EffectCatalysis: Catalysis

Data Source

PatentUS20230256416A1Method for producing a mixed oxide carrier and further finishing thereof into a catalyst for producing alkyl methacrylates
Publication Date: 2023.08.17 ROHM GMBH

AI summary

A new method can be used for producing suitable improved carrier materials as a base material for catalysts for carrying out a direct oxidative esterification. In general, the catalyst is used to convert aldehydes with alcohols in the presence of oxygenic gases directly to the corresponding ester, for example, where (meth)acrolein can be converted to methyl(meth)acrylate. The catalysts used are characterized in particular by high mechanical and chemical stability as well as by good catalytic performance even over very long periods of time. This applies in particular to an improvement of catalyst service life, activity and selectivity in comparison to other catalysts.