Jump to main content
Jump to site search

Issue 48, 2016
Previous Article Next Article

Enhanced hydrogen storage properties of MgH2 co-catalyzed with K2NiF6 and CNTs

Author affiliations

Abstract

The composite of MgH2/K2NiF6/carbon nanotubes (CNTs) is prepared by ball milling, and its hydrogenation properties are studied for the first time. MgH2 co-catalyzed with K2NiF6 and CNTs exhibited an improvement in the onset dehydrogenation temperature and isothermal de/rehydrogenation kinetics compared with the MgH2–K2NiF6 composite. The onset dehydrogenation temperature of MgH2 doped with 10 wt% K2NiF6 and 5 wt% CNTs is 245 °C, which demonstrated a reduction of 25 °C compared with the MgH2 + 10 wt% K2NiF6 composite. In terms of rehydrogenation kinetics, MgH2 doped with 10 wt% K2NiF6 and 5 wt% CNTs samples absorbed 3.4 wt% of hydrogen in 1 min at 320 °C, whereas the MgH2 + 10 wt% K2NiF6 sample absorbed 2.6 wt% of hydrogen under the same conditions. For dehydrogenation kinetics at 320 °C, the MgH2 + 10 wt% K2NiF6 + 5 wt% CNTs sample released 3.3 wt% hydrogen after 5 min of dehydrogenation. By contrast, MgH2 doped with 10 wt% K2NiF6 released 3.0 wt% hydrogen in the same time period. The apparent activation energy, Ea, for the dehydrogenation of MgH2 doped with 10 wt% K2NiF6 reduced from 100.0 kJ mol−1 to 70.0 kJ mol−1 after MgH2 was co-doped with 10 wt% K2NiF6 and 5 wt% CNTs. Based on the experimental results, the hydrogen storage properties of the MgH2/K2NiF6/CNTs composite is enhanced because of the catalytic effects of the active species of KF, KH and Mg2Ni that are formed in situ during dehydrogenation, as well as the unique structure of CNTs.

Graphical abstract: Enhanced hydrogen storage properties of MgH2 co-catalyzed with K2NiF6 and CNTs

Back to tab navigation

Publication details

The article was received on 20 Sep 2016, accepted on 05 Nov 2016 and first published on 07 Nov 2016


Article type: Paper
DOI: 10.1039/C6DT03646E
Dalton Trans., 2016,45, 19380-19388

  •   Request permissions

    Enhanced hydrogen storage properties of MgH2 co-catalyzed with K2NiF6 and CNTs

    N. N. Sulaiman and M. Ismail, Dalton Trans., 2016, 45, 19380
    DOI: 10.1039/C6DT03646E

Search articles by author

Spotlight

Advertisements