Alkali Metal Halide-Doped Bivalent Metal Fluoride Catalyst
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Solution Overview
Problem
There is a need for commercially viable methods for preparing catalyst compositions of bivalent metal fluorides doped with alkali metal halides, which are effective in converting hydrochlorofluorocarbons to fluorinated olefins with high selectivity and minimal formation of unwanted dehydrofluorination products.
Innovation Solution
A method involving the formation of a catalyst composition represented by the formula MX/M′F2, where MX is an alkali metal halide and M′F2 is a bivalent metal fluoride, by dissolving alkali metal halides and bivalent metal fluorides in a solvent, forming a slurry, and removing the solvent to create a solid mass, which is then calcined and optionally pelletized for use in dehydrochlorinating hydrochlorofluorocarbons.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If simple dry mixing method is used to prepare catalyst compositions, then manufacturing simplicity is maintained, but catalyst selectivity and performance are insufficient
Solution Approach 1:
The patent introduces a solvent as an intermediary medium to dissolve both the bivalent metal fluoride catalyst and the alkali metal halide dopant, enabling uniform distribution at the molecular level. This solution-phase mixing approach achieves superior catalyst selectivity and performance compared to dry mixing, while the solvent can be easily removed through evaporation or drying processes.
Solution Approach 2:
The patent changes the physical state parameters of the mixing process by transitioning from solid-state dry mixing to solution-phase mixing. This parameter change allows for better dispersion and interaction between catalyst components, significantly improving catalyst selectivity. The method maintains ease of manufacture by using common solvents and simple evaporation techniques.
2Productivity
If alkali metal halide loading is increased to improve catalyst activity, then dehydrofluorination products increase as unwanted side products
Solution Approach 1:
The patent changes the physical state and distribution parameter of the alkali metal halide by dissolving it in a solvent before mixing with the catalyst. This creates a uniform molecular-level dispersion rather than heterogeneous mixing, allowing the alkali metal halide to function as intended for promoting dehydrochlorination while minimizing unwanted dehydrofluorination side reactions, even at optimized loadings.
3Manufacturing precision
If conventional catalyst preparation methods are used, then commercial viability is limited, but high selectivity to 1234yf cannot be achieved
Solution Approach 1:
The patent uses a solvent as an intermediary to achieve uniform mixing of catalyst components at the molecular level, which dramatically improves selectivity to 1234yf. The method maintains commercial viability because common solvents are used, and the solvent removal step is simple through evaporation or drying, making the process suitable for scale-up in commercial settings.
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 compositions achieve higher selectivity to target products like 2,3,3,3-tetrafluoropropene with reduced formation of dehydrofluorination products, such as 1233xf, and maintain activity across varying alkali metal halide loadings, demonstrating improved performance over simple dry mixing methods.
Implementation Method 1
dissolving an amount of the alkali metal halide in an amount of solvent sufficient to substantially dissolve or solubilize the alkali metal halide to form an alkali metal halide solution
Implementation Method 2
removing substantially all of the solvent from the slurry to form a solid mass of the alkali metal halide and bi-valent metal fluoride
Data Source
AI summary
There is provided methods for making a catalyst composition represented by the formula MX/M′F2 wherein MX is an alkali metal halide; M is an alkali metal ion selected from the group consisting of Li+, Na+, K+, Rb+, and Cs+; X is a halogen ion selected from the group consisting of F−, Cl−, Br−, and I−; M′F2 is a bivalent metal fluoride; and M′ is a bivalent metal ion. There is also a method for making a fluorinated olefin.