Mo-Fe-Al-P Oxide Catalyst for Low-Temperature Formaldehyde Selectivity
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Solution Overview
Problem
Existing catalysts for methanol oxidation to formaldehyde suffer from low activity, high reaction temperatures, and instability, leading to reduced catalyst life and insufficient formaldehyde selectivity.
Innovation Solution
A catalyst with the formula MoFeaAlbPcOx, where a=0.25-0.5, b=0.001-0.2, and c=0.001-0.6, prepared by mixing molybdenum, iron, and aluminum salts with phosphoric acid, followed by aging, drying, and calcination, allows for lower reaction temperatures and improved stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the reaction temperature is raised to maintain high methanol conversion, then the catalyst activity is maintained, but the molybdenum sublimation and run-off increase causing further decline in catalyst activity
Solution Approach 1:
The patent changes the chemical composition parameters of the catalyst by introducing aluminum and phosphorus elements in specific ratios (Al/Mo=0.01-0.2, P/Mo=0.01-0.6) to modify the catalyst's thermal stability and chemical structure, thereby reducing molybdenum sublimation at high temperatures while maintaining catalytic activity
Solution Approach 2:
The patent creates a composite oxide catalyst system (Mo-Fe-Al-P-O) that combines multiple elements with complementary properties. The aluminum and phosphorus components form a stable matrix that anchors the molybdenum species, preventing their run-off while the iron component maintains the catalytic function for methanol oxidation
2Productivity
If existing iron-molybdenum catalysts are used, then methanol oxidation can be performed, but the formaldehyde selectivity is not high enough and by-products are generated
Solution Approach 1:
The patent optimizes the catalyst composition parameters by controlling the Fe/Mo ratio (0.2-0.67) and introducing specific amounts of aluminum and phosphorus, which modifies the electronic structure and surface properties of the catalyst to enhance selectivity toward formaldehyde and suppress side reactions that produce by-products
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 methanol conversion of 98.5% with high formaldehyde selectivity and stable performance over extended periods, maintaining activity and selectivity even at lower temperatures.
Implementation Method 1
A catalyst for selective oxidation of methanol to formaldehyde with low reaction temperature and steady activity
Data Source
AI summary
In a composite oxide catalyst, a preparation method therefor, and a use thereof, the catalyst has the following general formula: MoFeaAlbPcOx, wherein a=0.25-0.5, b=0.001-0.2, c=0.001-0.6, and x is a number satisfying the valence of the general formula. The catalyst has excellent low-temperature performance and thus has a long service life.