Noble-Metal-Free NiO-MoO2-CeOx/N-C Catalysts for Enhanced Catalytic Dehydrogenation of Hydrous Hydrazine

Abstract

Efficient hydrogen generation from the dehydrogenation of hydrazine hydrate, a novel hydrogen storage material with high hydrogen content (8 wt.%), is a key challenge for a fuel-cell-based hydrogen economy. However, even using the noble metal catalysts for hydrazine hydrate dehydrogenation, the activities are still far from satisfying, to say nothing of non-noble-metal catalysts. Herein, noble-metal-free NiO-MoO2-CeOx nanoparticles without any surfactant are successfully immobilized on an N-C support derived from ZIF-8 by a facile wet-chemical strategy. Remarkably, the resultant NiO-MoO2-CeOx/N-C catalyst exhibits outstanding performance in the hydrazine hydrate dehydrogenation reaction, with an initial turnover frequency of 45.3 mol H2 mol cat.−1 h−1 and a low apparent activation energy of 39.2 kJ mol−1, outperforming most reported non-noble metal catalysts and rivaling some noble-metal systems. The excellent activity is attributed to the synergistic electronic interaction among Ni, Mo, and Ce, as well as the good dispersion and uniform particle size of the NiO-MoO2-CeOx nanoparticles due to steric restrictions effect of the N-C support. The development of high-performance and low-cost catalysts is a critical step towards promoting hydrous hydrazine for practical hydrogen storage applications.