Tungsten Oxide Catalyst for Methylbenzene Partial Oxidation
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Solution Overview
Problem
Conventional catalysts for gas-phase oxidation of methylbenzenes to produce aromatic aldehydes suffer from low selectivity and yield, difficulty in separation and purification, and short lifespan due to complex compositions and low heat stability, limiting their industrial practicality.
Innovation Solution
A novel catalyst system comprising tungsten oxide with a small amount of alkali metals (Li, Na, K, Rb, Cs) and additional elements (Fe, Co, Ni, etc.) supported on fire-resistant inorganic carriers, optimized for high selectivity and yield, with specific atomic ratios and calcination processes to enhance stability and activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional complex oxide catalysts are used for gas-phase oxidation of methylbenzenes, then the conversion rate of p-xylene is improved, but the selectivity and yield of terephthalaldehyde deteriorate
Solution Approach 1:
The patent changes the chemical composition parameters of the catalyst by using tungsten oxide as the main component with specific promoters (Fe, Co, Ni, Cu, Mn) and alkali metal modifiers (Na, K, Rb, Cs) in controlled amounts. This parameter optimization resolves the contradiction by achieving both high conversion rate and high selectivity/yield through precise compositional control
Solution Approach 2:
The patent creates a composite catalyst material combining tungsten oxide with multiple metal promoters and alkali metal modifiers. This composite structure allows synergistic effects where the tungsten oxide provides high conversion activity while the promoters and modifiers enhance selectivity and yield, resolving the contradiction between productivity and manufacturing precision
2Productivity
If catalysts with multiple components are used to increase conversion rate, then productivity is improved, but the complexity of catalyst preparation and separation purification deteriorates
Solution Approach 1:
The patent segments the catalyst into distinct functional components: tungsten oxide as the main catalyst, metal promoters (Fe, Co, Ni, Cu, Mn) for selectivity enhancement, and alkali metal modifiers (Na, K, Rb, Cs) for yield optimization. This segmentation allows each component to be optimized independently while simplifying the overall preparation process through a systematic approach
Solution Approach 2:
The patent optimizes the parameter ranges of each component (tungsten oxide as main component, specific amounts of promoters and modifiers) to achieve the desired performance. By controlling these parameters within specific ranges, the patent simplifies catalyst preparation and separation while maintaining high productivity
3Productivity
If catalysts containing Sb component are used to achieve high conversion rate, then productivity is improved, but heat stability and life span deteriorate due to sublimation at high temperature
Solution Approach 1:
The patent extracts and removes the Sb component from the catalyst composition entirely. Instead, it uses tungsten oxide as the main component with alternative metal promoters and alkali metal modifiers. This extraction eliminates the sublimation issue while maintaining high conversion rate through the selected alternative components
Solution Approach 2:
The patent replaces the unstable Sb component with more stable alternative materials (tungsten oxide, Fe, Co, Ni, Cu, Mn, and alkali metals) that maintain structural integrity at high temperatures. This substitution ensures long-term reliability and heat stability while preserving productivity
4Productivity
If conventional catalysts are used to produce aromatic aldehydes, then the reaction can proceed, but the separation and purification of products becomes difficult due to low selectivity
Solution Approach 1:
The patent optimizes the compositional parameters of the catalyst (tungsten oxide with specific promoters and modifiers) to achieve high selectivity for aromatic aldehyde production. This parameter optimization makes the desired product the major component, thereby simplifying separation and purification processes while maintaining high reaction rate
Solution Approach 2:
The patent uses a composite catalyst material with specific metal combinations (tungsten oxide, Fe, Co, Ni, Cu, Mn, and alkali metals) that synergistically enhance selectivity for aromatic aldehyde formation. This composite structure concentrates the reaction toward the desired product, making separation and purification easier while preserving productivity
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 catalyst achieves high selectivity and yield of aromatic aldehydes, improves heat stability, and maintains performance over extended reaction times, making it suitable for industrial applications by preventing complete oxidation and side reactions.
Implementation Method 1
a catalyst for gas phase oxidation of methylbenzenes in the presence of molecular oxygen to produce corresponding aromatic aldehydes
Implementation Method 2
partial oxidation of methylbenzenes... to produce corresponding aromatic aldehydes... preventing complete oxidation and side reactions
Data Source
AI summary
A catalyst for gas phase oxidation of methylbenzenes in the presence of molecular oxygen to produce corresponding aromatic aldehydes, a method for preparing the catalyst, and a method for producing aromatic aldehydes from methylbenzenes by using the catalyst. The catalyst comprises a compound represented by the following formula (1):WaXbYcOx (1)wherein W represents a tungsten atom, X represents one or more alkali metals selected from the group consisting of Li, Na, K, Rb, and Cs, Y represents one or more elements selected from the group consisting of Fe, Co, Ni, Cu, Mn, Re, Cr, V, Nb, Ti, Zr, Zn, Cd, Y, La, Ce, B, Al, Sn, Mg, Ca, Sr, and Ba, O stands for an oxygen atom, and the ratio of a:b:c is 12:0.001˜1:0˜5.