Inclusion of CoTiO 3 to ameliorate the re/dehydrogenation properties of the Mg-Na-Al system

For the first time, the MgH 2 -NaAlH 4 (ratio 4:1) destabilized system with CoTiO 3 addition has been explored. The CoTiO 3 -doped MgH 2 - NaAlH 4 sample begins to dehydrogenate at 130 degrees C, which is declined by 40 degrees C compared to the undoped MgH 2 -NaAlH 4 . Moreover, the de/rehydrogenation kinetics characteristics of the CoTiO 3 -doped MgH 2 -NaAlH 4 were greatly ameliorated. With the inclusion of CoTiO 3 , the MgH 2 -NaAlH 4 composite absorbed 5.2 wt.% H 2 , higher than undoped MgH 2 -NaAlH 4 . In the context of dehydrogenation, the CoTiO 3 -doped MgH 2 -NaAlH 4 sample desorbed 2.6 wt.% H 2 , almost doubled compared to the amount of hydrogen desorbed from the undoped MgH 2 - NaAlH 4 sample. The activation energy obtained by the Kissinger analysis for MgH 2 decomposition was significantly lower by 35.9 kJ/mol than the undoped MgH 2 -NaAlH 4 sample. The reaction mechanism demonstrated that new phases of MgCo and AlTi 3 were generated in situ during the heating process and are likely to play a substantial catalytic function and be useful in ameliorating the de/rehydrogenation properties of the destabilized MgH 2 -NaAlH 4 system with the inclusion of CoTiO 3 . (c) 2024 Chongqing University. Publishing services provided by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY -NC -ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ) Peer review under responsibility of Chongqing University