Na-ZSM-5 Zeolite Nanocrystals Supported Nickel Nanoparticles for Efficient Hydrogen Production from Ammonia Decomposition

Graphical Ammonia decomposition : Ni nanoparticles with a mean size of ∼2.3 nm anchored on Na-ZSM-5 nanocrystals were prepared as a catalyst to effectively crack ammonia for CO x -free H 2 production. Ammonia has been increasingly recognised as an effective hydrogen carrier to produce clean hydrogen free of CO x emissions. This study reports the development of Ni-based catalysts to efficiently crack ammonia into hydrogen and nitrogen. A series of catalysts with different Ni loadings supported on Na-ZSM-5 zeolite nanocrystals were prepared with the assistance of 1,10-phenanthroline ligand. The coordination of Ni and the ligand led to the formation of uniform Ni nanoparticles with a mean size of ∼2.3 nm. These small Ni nanoparticles of the catalyst enabled a high activity in ammonia decomposition evaluated using a fixed-bed reactor. Using the zeolite support in its pristine sodium form provided the catalyst with desired basicity. This promotes a strong metal-support interaction, leading the catalyst to have high stability. The catalyst with 5 wt% Ni loading exhibited a high TOF of 3.51 s −1 with no performance degradation at 650 °C for 50 h.