Water Adsorption in Nanoporous Carbon Characterized by in Situ NMR: Measurements of Pore Size and Pore Size Distribution

Autor:	Alfred Kleinhammes, Yue Wu, Jie Liu, Haijing Wang, Thomas P. McNicholas
Rok vydání:	2014
Předmět:	Chemistry Vapor pressure Analytical chemistry Surfaces Coatings and Films Electronic Optical and Magnetic Materials NMR spectra database Nanopore General Energy Adsorption medicine Proton NMR Nanometre Water cluster Physical and Theoretical Chemistry Activated carbon medicine.drug
Zdroj:	The Journal of Physical Chemistry C. 118:8474-8480
ISSN:	1932-7455 1932-7447
Popis:	We report an in situ nuclear magnetic resonance (NMR) study of water adsorption in a series of activated carbon samples with pore sizes of a few nanometers down to the subnanometer scale (nanoporous carbon). Water adsorption exhibits S-shaped type V isotherms with a steep increase near a certain vapor pressure. Using a previously proposed water isotherm model, pore size and pore size distribution are derived from the in situ NMR data, and they are shown to be in good agreement with results derived from N2 adsorption. The change of 1H NMR spin–lattice relaxation time of adsorbed H2O with vapor pressure is consistent with the mechanism of water cluster formation at surface groups preceding the occurrence of pore filling. NMR spectra of high pressure H2 gas in nanoporous carbon with preadsorbed D2O proves unambiguously that water preferentially fills the smaller nanopores. These results suggest that water adsorption can potentially be used for the characterization of pore structures of nanoporous carbon, and...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::39f9e93279407e33e9a3b5287c49a562 https://doi.org/10.1021/jp501518f Zobrazit plný text záznamu