Polyoxometalate Catalyst Preparation via pH and Viscosity Control
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Solution Overview
Problem
Existing methods for preparing catalysts for producing unsaturated carboxylic acids from unsaturated aldehydes suffer from poor conversion rates and reproducibility due to structural changes caused by high drying temperatures and the difficulty in controlling the amount of catalyst poisons like ammonia, which affects the catalyst's activity and selectivity.
Innovation Solution
A method for preparing a polyoxometalate catalyst involving a metal oxide represented by Formula MOaA b V c B d C e D f Og, where A, B, C, and D are specific elements, and the catalyst is formed by adjusting pH, increasing viscosity, loading onto an inert carrier, drying, and firing, with a vanadium precursor containing vanadium in the 4+ oxidation state, to achieve improved activity and selectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high drying temperature is used to prepare the catalyst, then the drying process is efficient and quick, but the catalyst undergoes structural change which negatively affects performance and conversion rate
Solution Approach 1:
The patent changes the drying temperature parameter from high temperature to low temperature range (50-150°C) to prevent structural changes in the catalyst while maintaining drying efficiency. This parameter optimization resolves the contradiction between drying speed and structural integrity.
2Reliability
If catalyst poison ingredient is artificially added to control activity, then hot spot temperature is lowered and reaction efficiency is maintained, but the reducing substance acts as catalyst poison and greatly increases reaction temperature after long period operation
Solution Approach 1:
The patent converts the harmful effect of ammonia (catalyst poison that increases temperature) into a beneficial effect by precisely controlling its content at ultra-low levels (10-100 ppb). At this controlled level, ammonia suppresses hot spot formation and maintains reaction efficiency without causing excessive temperature increase after long operation periods.
3Ease of manufacture
If there is considerable difficulty in quantitatively controlling the amount of reducing substance in catalyst production, then the production process is simple, but the catalyst activity and selectivity cannot be precisely controlled
Solution Approach 1:
The patent implements feedback control by measuring the ammonia content in the catalyst using ion chromatography and adjusting the amount of catalyst poison ingredient accordingly. This ensures the ammonia content is precisely controlled within the range of 10-100 ppb, achieving both ease of manufacture and high manufacturing precision.
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 method results in a high-performance polyoxometalate catalyst with enhanced activity, selectivity, and reproducibility, capable of producing unsaturated carboxylic acids in high yield for an extended period, with improved control over vanadium content and ligand sublimation.
Implementation Method 1
a vanadium precursor is a compound containing vanadium with an oxidation number of 4+, and wherein the compound containing vanadium with oxidation number of 4+ is a vanadyl-containing compound
Implementation Method 2
capable of producing unsaturated carboxylic acid from unsaturated aldehyde gas by vapor-phase partial oxidation in a shell-and-tube heat exchanger
Data Source
AI summary
The present invention relates to a high-performance polyoxometalate catalyst and a method of preparing the same. More particularly, the present invention provides a high-performance polyoxometalate catalyst, the activity and selectivity of which may be improved by controlling the content of vanadium and the like and which has superior reproducibility and may unsaturated carboxylic acid from unsaturated aldehyde in a high yield for a long time, a method of preparing the same, and the like.