Effect of Pore Confinement of LiNH2 on Ammonia Decomposition Catalysis and the Storage of Hydrogen and Ammonia

LiNH 2 is of interest to several aspects of energy storage such as reversible hydrogen storage, battery technology, catalysis, and ammonia capture/storage. We investigated the impact of nanoconfinement in carbon scaffolds on the hydrogen and ammonia release properties of LiNH 2 and its catalytic activity in NH 3 decomposition. Ammonia release from macrocrystalline LiNH 2 begins at 350 °C, while confined LiNH 2 releases ammonia from below 100 °C under helium flow. This ammonia release consisted of 30.5 wt % ammonia in the first cycle and was found to be partially reversible. Above 300 °C, hydrogen is also released due to an irreversible reaction between LiNH 2 and the carbon support to form Li 2 NCN. Ni-doped LiNH 2 /C nanocomposites were active in the catalytic decomposition of ammonia into N 2 and H 2 with 53% conversion at 400 °C and a gas hourly space velocity of 13000 h –1 . This is comparable to the performance of a commercial-type Ru-based catalyst where 79% conversion is observed under the same conditions. This work demonstrates that nanoconfinement is effective for improving the functionality of LiNH 2 . The versatility of this system offers promise in a number of different areas including hydrogen/ammonia storage and ammonia decomposition catalysis.