A noble-metal-free nanocatalyst for highly efficient and complete hydrogen evolution from N2H4BH3

Abstract

Hydrazine borane (N₂H₄BH₃, 15.4 wt% H) has been considered as a highly promising hydrogen storage material because of its inherent advantages such as high hydrogen content and high stability in the solid state. However, the practical application of N₂H₄BH₃ for the generation of hydrogen is strongly inhibited by the need for expensive noble metal-based catalysts. To overcome this challenge, noble-metal-free CuNiMo nanocatalysts were prepared using a facile chemical reduction approach under an ambient atmosphere at room temperature. Unexpectedly, the resultant CuNiMo catalyst exhibits excellent catalytic activity, and 100% H₂ selectivity toward hydrogen generation from N₂H₄BH₃via its BH₃ group hydrolysis and N₂H₄ moiety decomposition at 323 K. To the best of our knowledge, this is the first report of a noble-metal-free catalyst achieving a complete conversion of N₂H₄BH₃ to H₂. In addition, CuNiMo can achieve a complete dehydrogenation of hydrous hydrazine (N₂H₄·H₂O). The excellent catalytic performance of the Cu_0.4Ni_0.6Mo catalyst may be attributed to the electronic modification among Cu, Ni and Mo, and may also be related to the strong basic sites of Cu_0.4Ni_0.6Mo. The present simple, low cost, highly efficient, and highly selective catalyst may promote the practical application of N₂H₄BH₃ as an effective hydrogen storage material.