High-Entropy Zeolitic Imidazolate Frameworks for Dynamic Hydrogen Isotope Separation.

Area of Science:

• Materials Science
• Chemical Engineering
• Nanotechnology

Background:

• Entropy is a key parameter for designing complex systems.
• Zeolitic imidazolate frameworks (ZIFs) are porous materials with tunable properties.
• Controlling pore size is crucial for gas adsorption and separation.

Purpose of the Study:

• To present a novel entropy-driven strategy for designing mixed-linker ZIFs.
• To systematically control the ratio of different pore sizes within ZIFs.
• To enhance the adsorptive properties and separation capabilities of ZIFs for hydrogen isotopes.

Main Methods:

• Synthesis of sod-ZIF-1 series with mixed linkers.
• Systematic control of configurational entropy to tune the ratio of six-membered rings (6MRs).
• Characterization of ZIFs' pore structure and adsorptive properties.

Main Results:

• Successfully synthesized sod-ZIF-1 series with tunable 6MR ratios (3.4 Å and 1.7 Å apertures).
• Demonstrated a significant improvement in H2 affinity by approximately 3 times.
• Achieved enhanced retention times in dynamic separation of hydrogen isotopes (D2/H2), even above LNG liquefaction temperatures.

Conclusions:

• Entropy-driven pore engineering is an effective strategy for designing advanced ZIF materials.
• The sod-ZIF-1 series shows great potential for efficient hydrogen isotope separation.
• This approach opens new avenues for enhancing gas adsorption and separation technologies.