Complete dehydrogenation of hydrazine borane and hydrazine catalyzed by MIL-101 supported NiFePd nanoparticles

Highlights: • NiFePd/MIL-101 catalyst was synthesized via a simple impregnation method. • The complete hydrogen release from N₂H₄ or N₂H₄BH₃ was achieved. • A TOF value of 60 and 40.8 h⁻¹ for dehydrogenation of N₂H₄BH₃ and N₂H₄ is obtained at 323 K respectively. • This catalyst shows good durability. Trimetallic NiFePd nanoparticles (NPs) anchored on metal-organic framework (MOF) MIL-101 have been facilely prepared via a simple impregnation method. The as-prepared NiFePd/MIL-101 catalysts have been characterized by powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) equipped with energy dispersed X-ray detector (EDX) and selected area electron diffraction (SAED), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), N₂ adsorption/desorption isotherms and X-ray photoelectron spectroscopy (XPS) techniques. And the as-synthesized catalysts have been applied for hydrogen generation from aqueous alkaline solution of hydrazine borane (HB, N₂H₄BH₃). Compared to the pure Ni_0.36Fe_0.24Pd_0.4 NPs, MIL-101 supported mono- and bi-metallic counterparts, the Ni_0.36Fe_0.24Pd_0.4/MIL-101 catalyst exhibits much higher catalytic performance for complete conversion of N₂H₄BH₃ to H₂ with 100% selectivity at 323 K. The turnover frequency (TOF) value for the dehydrogenation of N₂H₄BH₃ in the presence of Ni_0.36Fe_0.24Pd_0.4/MIL-101 catalyst reaches 60 h⁻¹. Remarkably, the Ni_0.36Fe_0.24Pd_0.4/MIL-101 catalyst also shows high catalytic activity and 100% selectivity towards hydrogen generation from hydrous hydrazine (N₂H₄·H₂O) at 323 K with a TOF value of 40.8 h⁻¹. In addition, the durability tests exhibit that the Ni_0.36Fe_0.24Pd_0.4/MIL-101 catalyst is still highly active in the complete dehydrogenation of N₂H₄BH₃ and decomposition of N₂H₄·H₂O with 100% hydrogen selectivity even after five recycles.