2024-03-29T14:32:44Zhttps://riubu.ubu.es/oai/requestoai:riubu.ubu.es:10259/57792023-03-31T11:54:55Zcom_10259_4759com_10259_2604col_10259_4760
Valentoni, Antonio
Mulas, Gabriele
Enzo, Stefano
Garroni, Sebastiano
2021-05-24T09:40:47Z
2021-05-24T09:40:47Z
2018-02
1463-9076
http://hdl.handle.net/10259/5779
10.1039/c7cp07157d
1463-9084
The present work concerns the catalytic effect of VNbO5, a ternary oxide prepared via a solid-state
route, on the sorption performance of MgH2. Three doped systems, namely 5, 10 and 15 wt% VNbO5–
MgH2 have been prepared by ball milling and thoroughly characterized. Hydrogen sorption, evaluated by
temperature programmed desorption experiments, revealed a significant reduction of the desorption
temperature from 330 1C for the un-doped sample (prepared and tested for comparison) to 235 1C for
the VNbO5-doped sample. Furthermore, more than 5 wt% of hydrogen can be absorbed in 5 minutes at
160 1C under 20 bar of hydrogen, which is remarkable compared to the 0.7 wt% achieved for the
un-doped system. The sample doped with 15 wt% of additive, showed good reversibility: over 5 wt% of
hydrogen with negligible degradation even after 70 consecutive cycles at 275 1C and 50 cycles at
300 1C. The kinetics analysis carried out by Kissinger’s method exhibited a considerable reduction of the
activation energy for the desorption process. Finally, pressure-composition-isotherm experiments
conducted at three different temperatures allowed estimating the thermodynamic stability of the system
and shed light on the additive role of VNbO5.
application/pdf
eng
Royal Society of Chemistry
Physical Chemistry Chemical Physics. 2018, V. 20, n. 6, p. 4100-4108
https://doi.org/10.1039/C7CP07157D
Química física
Chemistry, Physical and theoretical
Remarkable hydrogen storage properties of MgH2 doped with VNbO5
info:eu-repo/semantics/article
info:eu-repo/semantics/acceptedVersion
info:eu-repo/semantics/openAccess
Physical Chemistry Chemical Physics
20
6
4100
4108