Chloride catalytic effect on hydrogen desorption in NaAlH4

Abstract Hydrogen is considered as an environmental friendly energy carrier because it generates no pollution. Chlorides are promising catalyst for the hydrogen desorption in sodium alanate. All reactions and operations were performed under argon atmosphere in glove box. Crystalline NaAlH 4 and catalyst TiCl 3 , Nb 2 O 5 PbCl 2 and CeCl 3 were mixed in a ratio of (1, 2) wt%. Due to the air sensitivity of the samples they were covered with a kapton tape layer to minimize any contamination for characterization purpose. Structural characterizations and phase compositions of the samples were studied by XRD. The hydrogen storage capacity is measured by seivert type apparatus. Amount of desorbed hydrogen was found to be 3.6 wt % to 5.5 wt% at 250 °C with different type of catalyst. In the present work effect of doping of TiCl 3 , Nb 2 O 5 PbCl 2 and CeCl 3 catalysis in NaAlH 4 are investigated to understand the hydrogen desorption kinetics. It is concluded that enhanced storage capacity of NaAlH 4 can be achieved due to various catalysts with reduction in temperature 285 °C–250 °C for desorption.