Journal
JOURNAL OF PHYSICAL CHEMISTRY C
Volume 118, Issue 47, Pages 27470-27482Publisher
AMER CHEMICAL SOC
DOI: 10.1021/jp509672c
Keywords
-
Funding
- Institut Universitaire de France
- National Key Basic Research Program of China (973) [2013CB733503]
- Natural Science Foundation of China [21136001, 21322603]
- Program for New Century Excellent Talents in University [NCET-12-0755]
- European Community [228862]
Ask authors/readers for more resources
The concentration dependence of the self-diffusivity of short-chain linear alkanes in the narrow window type metalorganic framework (MOF) UiO-66(Zr) has been studied by means of quasi-elastic neutron scattering (QENS) measurements combined with molecular dynamics (MD) simulations. These computations employ a force field to describe the host/guest interactions which was preliminarily validated on the adsorption data obtained for the system of interest via gravimetry and microcalorimetry measurements. The QENS-measured self-diffusivity profile presents a nonmonotonic tendency as the alkane loading increases, with the existence of a maximum that depends on the size of the alkane. The comparison with the simulated results obtained using either a flexible or a rigid framework highlights that the consideration of the flexibility is of prime importance when exploring the diffusion of ethane molecules in porous materials. The self-diffusivities subsequently calculated for propane and n-butane corroborate the results obtained for ethane, leading to a similar form for the plots of self-diffusion coefficient vs loading. The global microscopic diffusion mechanism is further shown to involve a combination of intracage motions and jump sequences between the tetrahedral and octahedral cages of the framework. The self-diffusion coefficients which decrease with increasing molecular size, and thus increasing confinement, are further compared to the values previously reported for MOFs with pore networks of different dimensions.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available