Heterogeneous Catalyst for Cyclic Carbonate Synthesis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for synthesizing cyclic carbonates using homogeneous catalysts are complex, prone to catalyst degradation, and result in byproduct formation, with heterogeneous catalysts requiring high temperatures and excess silane compounds, leading to reduced catalytic activity and increased production costs.
Innovation Solution
A heterogeneous catalyst is produced by reacting a silane compound with a silica gel having low adsorbed water content, followed by treatment with a tertiary phosphine, achieving a molar ratio of halogen to phosphorus between 0.8 and 1.6, which simplifies the production process and enhances catalytic activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a homogeneous catalyst is used for cyclic carbonate synthesis, then the catalytic activity is high, but the separation process becomes complicated and catalyst degradation occurs
Solution Approach 1:
The catalyst is extracted from the homogeneous phase and immobilized onto a solid support material, creating a heterogeneous catalyst system. This allows the catalyst to be easily separated from the reaction mixture by simple filtration, eliminating the complex distillation process required for homogeneous catalysts while maintaining catalytic activity.
Solution Approach 2:
The catalyst is localized on the surface of solid support particles, creating regions of high catalytic activity at the solid-liquid interface. The support material provides a large surface area with dispersed active sites, concentrating the catalytic function in specific locations while maintaining overall system stability and ease of separation.
2Device complexity
If a heterogeneous catalyst with quaternary phosphonium group is used, then the separation process is simplified, but high temperature and long reaction time are required for catalyst production
Solution Approach 1:
The reaction conditions for catalyst production are optimized by adjusting parameters such as temperature, reaction time, and reactant ratios. The patent identifies specific parameter ranges that achieve complete quaternary phosphonium formation while minimizing production time and energy consumption, resolving the contradiction between simplified separation and production efficiency.
3Manufacturing precision
If a large excess amount of silane compound is used to introduce sufficient haloalkyl chain, then the surface modification is complete, but condensate formation increases and catalytic activity decreases
Solution Approach 1:
Instead of using a large excess of silane compound, the patent employs a controlled, stoichiometric amount of silane reactant. This partial action approach prevents excessive condensate formation that would block active sites, while still achieving sufficient surface modification to create an effective heterogeneous catalyst with maintained catalytic activity.
4Productivity
If repeated distillation operations are performed to raise silane compound concentration, then the reaction efficiency improves, but the number of steps and system complexity increase
Solution Approach 1:
The patent performs preliminary optimization of the silane compound concentration and reaction conditions before initiating the main reaction. By pre-establishing the optimal reactant ratio and reaction parameters, the need for repeated distillation operations is eliminated, maintaining high reaction efficiency while simplifying the overall reaction system and reducing operational complexity.
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
This method allows for the efficient and cost-effective synthesis of cyclic carbonates with high conversion rates and yields, minimizing byproduct formation and improving catalytic performance.
Implementation Method 1
a silica gel in which a haloalkyl chain or a haloaryl chain is immobilized by a covalent bond
Implementation Method 2
reacting a trialkyl phosphine and a commercially available carrier in which a haloalkyl chain is immobilized to a silica gel via a covalent bond to form a quaternary phosphonium product
Implementation Method 3
A heterogeneous catalyst is produced by reacting a silane compound with a silica gel having low adsorbed water content, followed by treatment with a tertiary phosphine, achieving a molar ratio of halogen to phosphorus between 0.8 and 1.6, which simplifies the production process and enhances catalytic activity
Data Source
Figure 1A~1
AI summary
Provided are : a method for easily producing a heterogeneous catalyst having excellent catalytic activity at a low cost, said heterogeneous catalyst being used for the purpose of synthesizing a cyclic carbonate by subjecting to a reaction an epoxide and carbon dioxide; a catalyst which is obtained by this production method; and a method for synthesizing a cyclic carbonate with use of this catalyst. A method for producing a catalyst that is used for the purpose of synthesizing a cyclic carbonate by subjecting to a reaction an epoxide with carbon dioxide, said method comprising the following steps (a) and (b): (a) a step of obtaining a catalyst precursor having a haloalkyl group or a haloaryl group, by subjecting to a reaction a silane compound having a haloalkyl group or a haloaryl group and a silica gel having an amount of adsorbed water of 1% by mass or less and (b) a step of obtaining a catalyst for cyclic carbonate synthesis, by subjecting to a reaction the catalyst precursor obtained in step (a) and a tertiary phosphine, in which the molar ratio of the halogen content to the phosphorus content, namely [halogen]/[phosphorus] is from 0.8 to 1.6.