Palladium Catalyst Manufacturing Selectivity
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Solution Overview
Problem
Current palladium-containing catalysts for producing α,β-unsaturated carboxylic acid from olefins or α,β-unsaturated aldehydes have low selectivity, and there is a lack of catalysts that can effectively perform both hydrogen addition and oxidation reactions.
Innovation Solution
A method for manufacturing a palladium-containing supported catalyst by reducing palladium oxide supported on a carrier through heat treatment, which suppresses coagulation and particle growth, resulting in a catalyst with high selectivity for producing α,β-unsaturated carboxylic acid through liquid-phase oxidation with molecular oxygen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a palladium catalyst is manufactured by reducing a palladium salt with a reducing agent, then the catalyst can be formed for oxidation reaction, but the selectivity to α,β-unsaturated carboxylic acid is not sufficient
Solution Approach 1:
The patent applies preliminary action by pre-forming palladium oxide on the carrier surface through heat treatment before the reduction step. This preliminary oxidation step creates a specific precursor structure that, when subsequently reduced, yields catalysts with superior selectivity for α,β-unsaturated carboxylic acid production. The pre-formed PdO structure directs the reduction process to create optimal active sites.
Solution Approach 2:
The patent utilizes parameter changes by controlling the heat treatment temperature and atmosphere to form palladium oxide with specific properties. By adjusting the oxidation parameters during heat treatment and then controlling the reduction conditions, the catalyst achieves enhanced selectivity. The parameter transformation from Pd salt → PdO → Pd metal creates distinct structural characteristics.
2Manufacturing precision
If palladium atoms are maintained in a highly dispersed state, then catalyst selectivity is improved, but catalyst particle stability may be compromised
Solution Approach 1:
The preliminary heat treatment to form PdO creates a stable precursor structure that prevents direct coagulation of Pd atoms during reduction. This pre-formed oxide structure acts as a template that maintains dispersion while allowing controlled reduction to active Pd metal sites.
Solution Approach 2:
Palladium oxide serves as an intermediary substance during the catalyst preparation process. The PdO phase acts as a stable intermediate that prevents direct aggregation of Pd atoms, and its controlled reduction yields highly dispersed Pd metal particles with maintained stability. The intermediary PdO phase bridges the gap between Pd salt and active Pd metal.
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 produces α,β-unsaturated carboxylic acid with high selectivity by maintaining palladium atoms in a highly dispersed state, enhancing the catalyst's effectiveness in both olefin and aldehyde conversions.
Implementation Method 1
reducing palladium oxide contained in a catalyst precursor wherein the palladium oxide is in a state of being supported on a carrier
Implementation Method 2
forming the catalyst precursor in which at least a part of the palladium salt supported on the carrier has been changed into palladium oxide by heat treatment of the carrier
Data Source
AI summary
The present invention provides: a palladium-containing supported catalyst which is used for producing an α,β-unsaturated carboxylic acid from an olefin or an α,β-unsaturated aldehyde in high selectivity; a method for manufacturing the catalyst; and a method for producing an α,β-unsaturated carboxylic acid in high selectivity. In particular, the present invention resides in a method for manufacturing a palladium-containing supported catalyst for producing an α,β-unsaturated carboxylic acid from an olefin or an α,β-unsaturated aldehyde, comprising the step of reducing palladium oxide contained in a catalyst precursor wherein at least the palladium oxide is supported on a carrier. By using such a palladium-containing supported catalyst, an α,β-unsaturated carboxylic acid is produced through liquid-phase oxidation of an olefin or an α,β-unsaturated aldehyde with molecular oxygen.