Topology-Dependent Alkane Diffusion in Zirconium Metal-Organic Frameworks

Area of Science:

• Materials Science
• Chemical Engineering
• Computational Chemistry

Background:

• Metal-organic frameworks (MOFs) offer tunable pore sizes and shapes for chemical applications.
• Zirconium-based MOFs with variable node connectivity yield diverse topological nets and pore structures.
• Optimizing MOF pore structure for specific applications is challenging due to the vast material space.

Purpose of the Study:

• To investigate the effect of MOF topology on propane and isobutane diffusion across various loadings.
• To understand how MOF tuning can mitigate transport limitations in separations and catalysis.
• To elucidate the relationship between pore structure and adsorbate diffusivity.

Main Methods:

• Employed molecular dynamics simulations to study gas diffusion in MOFs.
• Utilized high-throughput simulation techniques for efficient calculation of diffusivities in 38 MOFs.
• Applied molecular siting techniques to analyze adsorbate behavior within different pore structures.

Main Results:

• MOF topologies with higher node connectivity exhibited decreased alkane diffusivities.
• Transport limitations were found to be dependent on MOF topology and adsorbate loading.
• Molecular siting revealed distinct adsorbate diffusion mechanisms influenced by pore architecture.

Conclusions:

• MOF topology significantly impacts gas diffusion, with higher node connectivity generally reducing alkane transport.
• Understanding these structure-transport relationships is crucial for designing MOFs for efficient separations and catalysis.
• Computational simulations provide a powerful tool for predicting and optimizing MOF performance.