The influences of Nb-containing oxides and ternary compound in hydrogen sorption performance were investigated. As faster desorption kinetic and lower activation energy were reported by addition of a ternary compound catalyst such as K2NiF6, the influence of KNbO3 on hydrogen storage properties of MgH2 has been investigated for the first time. The MgH2 - KNbO3 composite desorbed 3.9 wt% of hydrogen within 10 min, while MgH2 and MgH2-Nb2O5 composites desorbed 0.66 wt% and 3.2 wt% respectively under similar condition. For MgH2 with other Nb-contained catalysts such as Nb, NbO and Nb2O3, the desorption rate was almost the same as the one registered for as-milled MgH2. The analysis of differential scanning calorimetry (DSC) showed that MgH2-KNbO3 composite started to release hydrogen at similar to 335 degrees C which is 50 degrees C lower compared to as-milled MgH2 without any additives. The activation energy for the hydrogen desorption was estimated to be about 104 +/- 6.8 kJ mol(-1) for this material, while for the as-milled MgH2 was about 165 +/- 2.0 kJ mol(-1). It is believed that Nb-ternary oxide catalyst (KNbO3) showed a good catalytic effect and enhance the sorption kinetics of MgH2. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.