Role of Structural Defects in the Adsorption and Separation of C3 Hydrocarbons in Zr-Fumarate-MOF (MOF-801)

28 May 2019, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


An effective separation of propylene/propane mixtures is one of the most important processes in the petrochemical industry. Incidentally this separation is challenging due to the extensive similarities between both gases in terms of physicochemical properties such as, but not only limited to, boiling point, kinetic diameter and molecular weight. A drive to switch to less energy consuming processes, like adsorption or membrane separation, has highlighted several microporous metal organic frameworks as promising materials. In this work, we present a combined numerical and experimental investigation on propane and propylene adsorption in Zr-fumarate-MOF (also known as MOF-801), a small pore isoreticular analogue of UiO-66. Here, we demonstrate how the presence of structural defects can completely change the sorptive properties and separation performance of the Zr-fumarate-MOF, with enhanced capacity and gas diffusion rates for C3-sized hydrocarbons at the cost of kinetic selectivity. Extensive GCMC simulations performed on mixed defective supercells show that a percentage of missing cluster defects of around 1/8th can best account for the experimental results. Furthermore, analysis of low-frequency phonon spectra is used to explain gaseous diffusion in the original pristine material. A slight preference for propane over propylene is highlighted in the defective sample, and confirmed through column breakthrough experiments, suggesting the potential applicability of the Zr-fumarate-MOF in this challenging separation.


metal-organic frameworks
gas adsorption
paraffin-olefin separation
defect engineering

Supplementary materials



Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.