Fizika Nizkikh Temperatur: Volume 44, Number 2 (February 2018), p. 191-196 ( to contents , go back )
Sorption of hydrogen by silica aerogel at low temperatures
A.V. Dolbin, M.V. Khlistyuck, V.B. Esel’son, V.G. Gavrilko, N.A.Vinnikov, R.M. Basnukaeva
B. Verkin Institute for Low Temperature Physics and Engineering of the National Academy of Sciences of Ukraine 47 Nauky Ave., Kharkiv 61103, Ukraine
V.E. Martsenuk, N.V. Veselova, I.A. Kaliuzhnyi
National Technical University “Kharkiv Polytechnic Institute”, 21 Bahaliy Str., Kharkov 61002, Ukraine
V. Karazin Kharkov National University, 4 Svobody Sq., Kharkov 61107, Ukraine
Received Jule 10, 2017
By the TPD desorption method in the temperature interval of 7–95 K the sorption and subsequent desorption of hydrogen by sample of silicate aerogel was investigated. In all temperature range of investigations only physical adsorption of hydrogen by the sample was observed. The sorption processes were caused by van der Waals interaction of the hydrogen molecules with silicate walls of sample’s pores. Total hydrogen capacity of the aerogel sample were ~1.5 wt.%. Was observed, that with decrease of the temperature of sample (from 95 to 60 K) the characteristic times of hydrogen sorption were increased, which is indicative for thermal activated diffusion (Еа ≈ 408 K). In the temperature range of 15–45 K the characteristic times of Н2 sorption was weakly dependant on the temperature, which is, presumably for predominance of tunnel mechanism of diffusion over thermoactivation. Below 15 K the characteristic times of diffusion were slightly increased with lowering temperature, which could be explained by formation of Н2 molecular monolayer on the aerogel’s granules surface.
PACS: 61.43.Gt Powders, porous materials;
Key words: silica aerogel, sorption capacity, hydrogen storage, adsorption.
Published online: December 26, 2017