Bismuth Molybdenum Catalyst Surface Composition for Selective Oxidation
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Solution Overview
Problem
Existing catalysts for producing α,β-unsaturated aldehydes and α,β-unsaturated carboxylic acids suffer from insufficient performance and high byproduct generation, affecting selectivity.
Innovation Solution
A catalyst comprising molybdenum and bismuth with a specific bismuth composition on the surface, characterized by a B/A ratio of 1.3 to 5, is used to enhance selectivity, with a production method involving mixing raw materials, stirring, drying, and calcination to achieve the desired atomic ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional mixed oxide catalysts containing molybdenum, iron, cobalt, and/or nickel are used, then catalytic activity is achieved, but selectivity is insufficient and many byproducts are generated
Solution Approach 1:
The patent applies local quality by creating a catalyst surface with non-uniform bismuth distribution. Specifically, the bismuth atomic ratio on the surface (B/A) is controlled to be 1.3 to 5, meaning the surface composition differs from the bulk composition. This localized adjustment of bismuth concentration on the catalyst surface optimizes selectivity for target products while reducing byproducts, resolving the contradiction between catalytic activity and byproduct generation.
Solution Approach 2:
The patent changes the compositional parameter of the catalyst by controlling the bismuth-to-molybdenum atomic ratio on the surface (B/A = 1.3 to 5). This parameter adjustment transforms the catalyst performance, achieving high selectivity for α,β-unsaturated aldehydes and carboxylic acids while minimizing byproducts, thus resolving the technical contradiction.
2Reliability
If bismuth composition on catalyst surface is adjusted to achieve high selectivity, then target product selectivity improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent establishes a specific parameter range (B/A = 1.3 to 5) for bismuth composition control. This quantitative guideline transforms the manufacturing process into a controlled parameter optimization, achieving high selectivity while providing clear manufacturing targets. The parameter change principle allows for systematic control of bismuth distribution without excessive precision requirements.
Solution Approach 2:
The patent employs preliminary action through the specific manufacturing process described in embodiment 1, where bismuth-containing compound and molybdenum-containing compound are mixed in predetermined ratios before catalyst formation. This preliminary preparation ensures that the final catalyst surface achieves the desired B/A ratio, facilitating high selectivity while simplifying manufacturing control.
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 for target products, reducing byproduct formation and improving the efficiency of α,β-unsaturated aldehyde and α,β-unsaturated carboxylic acid production.
Implementation Method 1
Methods of producing α,β-unsaturated aldehydes, α,β-unsaturated carboxylic acids, and the like by gas phase oxidation reactions in the presence of metal oxide catalysts
Implementation Method 2
catalyst for synthesis of unsaturated aldehydes and unsaturated carboxylic acids with excellent catalytic activity and selectivity
Data Source
AI summary
An object of the present invention is to provide a catalyst with high selectivity for an α,β-unsaturated aldehyde, an α,β-unsaturated carboxylic acid, and the like. Problems are solved by a catalyst containing at least molybdenum and bismuth and having a B/A of 1.3 to 5 when a ratio of the amount of bismuth atoms to the amount of molybdenum atoms, calculated from ICP (inductively coupled plasma) atomic emission spectrometry is A, and a ratio of a peak area of bismuth atoms to a peak area of molybdenum atoms, measured by X-ray photoelectron spectrometry is B.