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Published on: April 12, 2019
Diffusion of ferrocene through vanadyl phosphate by density functional theory.
Yuan Liu1, An T Ta1, R Seaton Ullberg1
1Department of Materials Science and Engineering, University of Florida, Gainesville, FL 32611, USA. sphil@mse.ufl.edu.
This study used the nudged elastic band (NEB) method to map ferrocene diffusion pathways in vanadyl phosphate (VOPO4). Ferrocene diffusion along the [100] direction has lower energy barriers than along the [110] direction.
Area of Science:
- Materials Science
- Computational Chemistry
- Solid-State Chemistry
Background:
- Vanadyl phosphate (VOPO4) is a promising material for energy storage applications.
- Understanding ion diffusion mechanisms is crucial for optimizing material performance.
- Ferrocene's complex structure presents unique challenges for diffusion pathway analysis.
Purpose of the Study:
- To investigate the diffusion pathways of ferrocene within the vanadyl phosphate (VOPO4) framework.
- To determine the energy barriers associated with different diffusion routes.
- To characterize the structural deformation of ferrocene during its diffusion process.
Main Methods:
- Employed the nudged elastic band (NEB) method for simulating diffusion pathways.
- Systematically evaluated 36 potential diffusion paths categorized by directional orientation ([110] and [100] directions).
- Established four key measures to characterize ferrocene's structural conformation during diffusion.
Main Results:
- Identified distinct diffusion pathways between V-V, V-P, and P-P sites.
- Diffusion along the [110] direction exhibited higher energy barriers (0.25–0.35 eV) compared to the [100] direction (0.11–0.20 eV).
- Quantified ferrocene's conformational changes, including axis orientation and ring dihedral angles.
Conclusions:
- The [100] direction offers more favorable diffusion pathways for ferrocene in VOPO4 due to lower energy barriers.
- Ferrocene undergoes significant structural deformation during diffusion, influenced by the host material's structure.
- This study provides fundamental insights into guest molecule diffusion in porous materials.
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