The catalytic effect of Nb, NbO and Nb2O5 with different surface planes on dehydrogenation in MgH2: Density functional theory study

► Dehydrogenation of MgH2 cluster on (1 0 0)(1 1 0)(1 1 1) of Nb, NbO and Nb2O5. ► NbO(1 1 1) shows very high adsorption energy. ► MgO forms on all of Nb2O5 planes. ► Density of state reveals that dehydrogenated Mg on NbO(1 1 1) is unstable and may be easy to rehydrogenate.