Chloride catalytic effect on hydrogen desorption in NaAlH4

• Chlorides are promising catalyst for the hydrogen desorption from sodium alanate.
• CeCl3 doped NaAlH4 desorbed 5.4% hydrogen almost equals theoretical capacity of 5.6%.
• In the present case NaAlH4 decomposes and released almost all hydrogen.
• CeCl3 is found to be a good catalyst for supplying hydrogen for various applications.
• Chloride catalysts reduced hydrogen desorption temperature from 285 °C to 250 °C.

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 NaAlH4 and catalyst TiCl3, Nb2O5 PbCl2 and CeCl3 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 TiCl3, Nb2O5 PbCl2 and CeCl3 catalysis in NaAlH4 are investigated to understand the hydrogen desorption kinetics. It is concluded that enhanced storage capacity of NaAlH4 can be achieved due to various catalysts with reduction in temperature 285 °C–250 °C for desorption.