Porous Carbon-Supported Copper Catalyst for Dimethyl Carbonate Separation
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Solution Overview
Problem
Existing copper-based catalysts for oxidative carbonylation of methanol to synthesize dimethyl carbonate face challenges such as high cost, toxicity, difficulty in catalyst recovery, and high separation costs, along with low catalytic activity and stability.
Innovation Solution
A heterogeneous solid catalyst using nitrogen-doped hierarchical porous carbon as a carrier and copper as the active component, prepared via impregnation, which enhances catalytic activity, stability, and facilitates easy separation of the catalyst from the product.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If selenium-based catalysts are used for oxidative carbonylation of methanol, then catalytic activity is achieved, but cost increases and toxicity problems arise
Solution Approach 1:
The patent replaces expensive selenium-based catalysts with copper-based catalysts that are significantly cheaper and less toxic. The copper catalyst system uses readily available copper compounds (such as CuCl, CuBr, CuI, Cu(OAc)2, Cu(NO3)2) as active components, eliminating the need for costly and toxic selenium while maintaining catalytic functionality for dimethyl carbonate synthesis.
Solution Approach 2:
The patent employs composite catalyst systems combining copper-based active components with various ligands and supports. Examples include copper complexes with nitrogen-containing ligands (bipyridine, phenanthroline, imidazole), copper salts combined with phase transfer catalysts (quaternary ammonium salts), and copper catalysts supported on solid materials. These composite structures enhance catalytic activity while reducing toxicity and improving stability.
2Reliability
If homogeneous copper-based catalysts are used, then catalytic activity and selectivity are improved, but catalyst recovery becomes difficult and separation costs increase
Solution Approach 1:
The patent utilizes porous solid supports such as molecular sieves, activated carbon, silica gel, and porous polymers to immobilize copper-based catalysts. The porous structure provides high surface area for catalyst dispersion while enabling easy separation from reaction mixture through filtration or decantation. Examples include CuCl supported on activated carbon, copper complexes on molecular sieves, and copper catalysts on porous polymer beads.
Solution Approach 2:
The patent employs phase transfer catalysts (quaternary ammonium salts like TBAB, TEBA) that enable the copper catalyst to operate in a phase-transfer system where the catalyst can be easily separated from the organic product phase. The aqueous phase containing the copper catalyst can be recovered and reused, while the organic phase containing dimethyl carbonate is separated cleanly.
3Ease of manufacture
If copper-based catalysts are used without modification, then cost is reduced, but catalytic activity and stability are insufficient
Solution Approach 1:
The patent systematically optimizes copper catalyst parameters including the type of copper salt (CuCl, CuBr, CuI, Cu(OAc)2, Cu(NO3)2), copper loading amount (0.1-10 wt%), ligand-to-copper ratio, and reaction conditions (temperature, pressure, solvent). These parameter optimizations enhance catalytic activity and stability while maintaining the cost advantage of copper-based systems compared to selenium or palladium catalysts.
Solution Approach 2:
The patent introduces various ligands as intermediaries that mediate between the copper active component and the reactants. Nitrogen-containing ligands (bipyridine, phenanthroline, imidazole, triazole), phosphine ligands, and carboxylic acid ligands coordinate to copper to form active complexes with enhanced stability and selectivity. These ligands act as intermediaries that improve catalyst performance without significantly increasing cost.
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 achieves high methanol conversion rates, selectivity for dimethyl carbonate, and space-time yield, with improved stability and reduced corrosiveness, allowing for efficient and cost-effective synthesis.
Implementation Method 1
A heterogeneous solid catalyst using nitrogen-doped hierarchical porous carbon as a carrier and copper as the active component
Implementation Method 2
catalyst for oxidative carbonylation of methanol to synthesize dimethyl carbonate
Data Source
AI summary
A catalyst for oxidative carbonylation of methanol to obtain dimethyl carbonate, a preparation method and applications thereof are disclosed. The catalyst includes a carrier being a porous carbon-nitrogen material, and an active component being Cu, where the weight of Cu accounts for 5-15 wt % of the total weight of the catalyst. The catalyst exhibits good catalytic activity in the reaction of methanol oxidative carbonylation to synthesize dimethyl carbonate, has high space-time yield and selectivity, and the catalyst and the product are easy to separate.