TU Darmstadt / ULB / TUprints

Water and small organic molecules as probes for geometric confinement in well-ordered mesoporous carbon materials

Xu, Yeping ; Watermann, Tobias ; Limbach, Hans-Heinrich ; Gutmann, Torsten ; Sebastiani, Daniel ; Buntkowsky, Gerd (2021):
Water and small organic molecules as probes for geometric confinement in well-ordered mesoporous carbon materials. (Publisher's Version)
In: Physical Chemistry Chemical Physics (PCCP), 16 (20), pp. 9327-9336. Royal Society of Chemistry (RSC), ISSN 1463-9076, e-ISSN 1463-9084,
DOI: 10.26083/tuprints-00018898,
[Article]

[img]
Preview
Text
c4cp00808a.pdf
Available under CC-BY-NC 3.0 International - Creative Commons, Attribution Non-commercial.

Download (1MB) | Preview
Item Type: Article
Origin: Secondary publication service
Status: Publisher's Version
Title: Water and small organic molecules as probes for geometric confinement in well-ordered mesoporous carbon materials
Language: English
Abstract:

Mesoporous carbon materials were synthesized employing polymers and silica gels as structure directing templates. The basic physico-chemical properties of the synthetic mesoporous materials were characterized by ¹H and ¹³C MAS solid-state NMR, X-ray diffraction, transmission electron microscopy (TEM) and nitrogen adsorption measurements. The confinement effects on small guest molecules such as water, benzene and pyridine and their interactions with the pore surface were probed by a combination of variable temperature ¹H-MAS NMR and quantum chemical calculations of the magnetic shielding effect of the surface on the solvent molecules. The interactions of the guest molecules depend strongly on the carbonization temperature and the pathway of the synthesis. All the guest-molecules, water, benzene and pyridine, exhibited high-field shifts by the interaction with the surface of carbon materials. The geometric confinement imposed by the surface causes a strong depression of the melting point of the surface phase of water and benzene. The theoretical calculation of ¹H NICS maps shows that the observed proton chemical shifts towards high-field values can be explained as the result of electronic ring currents localized in aromatic groups on the surface. The dependence on the distance between the proton and the aromatic surface can be exploited to estimate the average diameter of the confinement structures.

Journal or Publication Title: Physical Chemistry Chemical Physics (PCCP)
Journal volume: 16
Number: 20
Publisher: Royal Society of Chemistry (RSC)
Collation: 10 Seiten
Classification DDC: 500 Naturwissenschaften und Mathematik > 530 Physik
500 Naturwissenschaften und Mathematik > 540 Chemie
Divisions: 07 Department of Chemistry > Physical Chemistry
Date Deposited: 02 Jul 2021 12:39
Last Modified: 02 Jul 2021 12:40
DOI: 10.26083/tuprints-00018898
Corresponding Links:
URN: urn:nbn:de:tuda-tuprints-188983
URI: https://tuprints.ulb.tu-darmstadt.de/id/eprint/18898
Export:
Actions (login required)
View Item View Item