Pt-Bi/C Catalyst Preparation for Liquid-Phase Oxidation
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Solution Overview
Problem
Conventional Pt—Bi/C catalysts exhibit decreased reaction rate and metal elution issues during liquid-phase oxidation reactions, particularly in the later stages, and require the use of alkalis to maintain activity and durability.
Innovation Solution
A method involving the preparation of a Pt—Bi/C catalyst by creating an aqueous dispersion of Pt on activated carbon and an ionic Bi solution, then combining them, which enhances the even distribution of Bi ions with Pt, forming efficient Pt—Bi complexes that improve activity and reduce metal elution without the need for alkalis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional Pt-Bi/C catalyst is used for oxidation reaction, then high initial activity is achieved, but reaction rate significantly decreases at the last stage and metal elution occurs
Solution Approach 1:
The patent applies local quality by creating a non-uniform distribution of Bi on the catalyst surface through controlled addition of Bi salt solution to Pt/C catalyst suspension. This results in Pt-Bi complexes with optimized local composition that maintain high activity while reducing metal elution, resolving the contradiction between initial activity and durability
Solution Approach 2:
The patent changes the chemical state of Bi from metallic to ionic during the preparation process, then controls the reduction and distribution of Bi species. By adjusting parameters such as Bi salt concentration, addition rate, and pH conditions, the catalyst achieves optimal Pt-Bi complex formation that simultaneously provides high reaction rate and resistance to metal elution
2Ease of manufacture
If Bi is carried on Pt/C catalyst by conventional mixing methods, then catalyst preparation is simple, but Bi distribution is uneven and metal elution increases
Solution Approach 1:
The patent applies preliminary action by pre-dispersing Pt on activated carbon to form Pt/C catalyst, then adding Bi salt solution under controlled conditions before the final reduction step. This sequential preparation ensures uniform Bi distribution on Pt sites while maintaining manufacturing simplicity, resolving the contradiction between ease of manufacture and distribution 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 catalyst with high activity and excellent durability, maintaining efficient oxidation reactions without alkali use and minimizing metal elution, thereby improving the yield and stability of the catalyst.
Implementation Method 1
uses Pt as a noble metal catalyst in combination with Bi as a promoter, causes catalytic oxidation on a hydroxy compound or an aldehyde compound
Implementation Method 2
preparing an aqueous dispersion of a catalyst carrying Pt on activated carbon; preparing an aqueous solution containing Bi in an ionic state; adding the aqueous dispersion obtained in Step 1 to the aqueous solution obtained in Step 2
Data Source
AI summary
[Problem to be Solved]To provide a method for preparing a catalyst that has high activity and exhibits high durability with reduced elution of a catalyst metal when a liquid-phase oxidation reaction is brought about without combined use of an alkali; and a method for producing an oxide highly efficiently by use of the catalyst.The method for preparing a catalyst has the following Steps 1, 2 and 3.Step 1: preparing an aqueous dispersion of a catalyst carrying Pt on activated carbon;Step 2: preparing an aqueous solution containing Bi in an ionic state; andStep 3: adding the aqueous dispersion obtained in Step 1 to the aqueous solution obtained in Step 2.