BiCl3 Silica Catalyst for CO2 to Cyclic Carbonates
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Solution Overview
Problem
Current catalyst systems are inefficient in converting CO2 into cyclic carbonates, especially when using impure or diluted CO2 sources, under mild conditions, with low catalytic activity and selectivity.
Innovation Solution
A catalyst system comprising BiCl3 supported on silica, combined with specific organic compounds such as 1-methyl-3-(3-trimethoxysilylpropyl)-1H-imidazolium iodide or N,N,N-trimethyl-3-(trimethoxysilyl)propan-1-aminium iodide, which are synthesized and loaded onto silica supports, allowing for high catalytic activity and selectivity in converting CO2 and epoxides to cyclic carbonates at moderate temperatures and pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional catalyst systems are used for CO2 conversion, then the reaction can proceed, but the catalytic activity and selectivity are low under mild conditions
Solution Approach 1:
The patent employs a composite catalyst system combining BiCl3 with ionic liquids or organocatalysts supported on silica. This composite structure integrates the high catalytic activity of bismuth chloride with the selectivity and stability of ionic liquid modifiers, achieving both high productivity and reliability in cyclic carbonate synthesis from CO2 and epoxides under mild conditions
Solution Approach 2:
The catalyst utilizes porous silica support materials with controlled pore structures that enhance reactant access to active sites while providing shape selectivity. The porous framework allows CO2 and epoxide molecules to diffuse efficiently to the BiCl3 active centers, improving catalytic activity while maintaining high selectivity for cyclic carbonate formation
2Productivity
If pure CO2 is used as substrate, then high conversion can be achieved, but the application is limited and not commercially attractive
Solution Approach 1:
The catalyst system is designed to maintain high CO2 conversion efficiency across varying CO2 purity conditions. By optimizing the BiCl3 to ionic liquid ratio and adjusting reaction parameters such as temperature and pressure, the system adapts to process impure CO2 feeds (containing N2, O2, CO, H2O) while preserving high conversion rates, enabling commercial flue gas utilization
Solution Approach 2:
The ionic liquid component acts as an intermediary that facilitates CO2 activation and transfer from impure gas streams to the epoxide substrate. The ionic liquid forms transient complexes with CO2, enhancing its reactivity even at low partial pressures in flue gas, thereby enabling high conversion from impure CO2 sources
3Productivity
If high energy input is provided to transform CO2, then conversion to cyclic carbonates can occur, but the process becomes energy-intensive and less attractive
Solution Approach 1:
The patent replaces high-energy mechanical/thermal activation methods with a chemically active catalytic system. The BiCl3-ionic liquid catalyst provides an alternative reaction pathway with lower activation energy, enabling CO2 transformation at temperatures below 100°C and atmospheric pressure, dramatically reducing energy consumption while maintaining high conversion rates
4Productivity
If complex catalyst structures are used to improve activity, then catalytic performance increases, but the preparation becomes complicated and costly
Solution Approach 1:
The catalyst preparation is segmented into simple, sequential steps: (1) impregnation of BiCl3 onto silica support, (2) modification with ionic liquid, and (3) drying/calcination. Each step uses readily available materials and standard laboratory techniques, avoiding complex multi-step syntheses while achieving high catalytic activity through the segmented functionalization of the support structure
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 system demonstrates high catalytic activity and selectivity for converting CO2 into cyclic carbonates under mild conditions, even with impure CO2 sources, while being cost-effective and recyclable, with improved yields and efficiency compared to previous systems.
Implementation Method 1
a catalyst system comprising BiCl3 supported on silica, combined with specific organic compounds such as 1-methyl-3-(3-trimethoxysilylpropyl)-1H-imidazolium iodide or N,N,N-trimethyl-3-(trimethoxysilyl)propan-1-aminium iodide, which are synthesized and loaded onto silica supports, allowing for high catalytic activity and selectivity in converting CO2 and epoxides to cyclic carbonates at moderate temperatures and pressures
Data Source
AI summary
The present invention provides a catalyst system for producing cyclic carbonates comprising:a pre-catalyst, which is BiCl3 having amounts in the range from 5 to 10% by weight of silica support;a compound having formula (I)wherein:Y is selected from bromide (Br−) or iodide (I−);R1, R2, and R3 are methyl group or R1, R2, and R3 are taken together to form a heteroaryl ring having formula (II)anda silica (SiO2) support.