Pore-filling contamination in metal–organic frameworks

Glover, Joseph; Besley, Elena

Abstract

Tuneable pore sizes, ordered crystal structures, and large surface areas are some of the main attractive features of metal–organic frameworks (MOFs). To fully understand the structure–property relationships of these materials, accurate characterisation of their structural features is essential. The surface areas of MOFs are routinely estimated from the physical adsorption of gases. By applying the Brunauer, Emmett & Teller (BET) theory to an adsorption isotherm, the surface area is calculated from the amount of gas that forms a monolayer on the pore surface. While this technique is used ubiquitously within the porous solid community, its accuracy can be greatly affected by pore-filling contamination. This process causes an overestimation of the BET surface area from the overlap of surface and pore-filling adsorption as molecules that are not in contact with the surface are erroneously included into the surface area calculation. Experimentally, it is rather challenging to examine the effects of pore-filling contamination, which typically rely on accurate atomistic simulations to provide insight. In this work, we employ grand canonical Monte Carlo simulations and other theoretical approaches to assess the impact of pore-filling contamination on MOF surface areas. With a focus on the rht and nbo topologies, we show how experimental studies that suggest MOF surface areas can be increased by replacing phenyl rings for alkynes are largely influenced by the pore-filling contamination effect.

Citation

Glover, J., & Besley, E. (2018). Pore-filling contamination in metal–organic frameworks. Physical Chemistry Chemical Physics, 20(36), 23616-23624. https://doi.org/10.1039/c8cp04769c

• Journal Article Type: Article
• Acceptance Date: Aug 29, 2018
• Online Publication Date: Aug 29, 2018
• Publication Date: Aug 29, 2018
• Deposit Date: Nov 26, 2018
• Publicly Available Date: Aug 30, 2019
• Journal: Physical Chemistry Chemical Physics
• Print ISSN: 1463-9076
• Electronic ISSN: 1463-9084
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 20
• Issue: 36
• Pages: 23616-23624
• DOI: https://doi.org/10.1039/c8cp04769c
• Keywords: Physical and Theoretical Chemistry; General Physics and Astronomy
• Public URL: https://nottingham-repository.worktribe.com/output/1307376
• Additional Information: : This document is Similarity Check deposited; : Supplementary Information; : Joseph Glover (ORCID); : Elena Besley (ORCID); : Single-blind; : Received 26 July 2018; Accepted 29 August 2018; Accepted Manuscript published 29 August 2018; Advance Article published 7 September 2018; Version of Record published 19 September 2018
• Contract Date: Nov 26, 2018