Modified Nimo Nanoparticles for Efficient Catalytic Hydrogen Generation from Hydrous Hydrazine

• Main Authors: Ying Liu, Huan Zhang, Cong Ma, Nan Sun
• Format: Article
• Language: English
• Published: MDPI AG 2019-07-01
• Series: Catalysts
• Subjects: NiMoM (M = Pr₂O₃, Cu₂O) catalysts; hydrous hydrazine; hydrogen production
• Online Access: https://www.mdpi.com/2073-4344/9/7/596

Precious metal-free NiMoM (M = Pr₂O₃, Cu₂O) catalysts have been synthesized through a simple coreduction method, without any surfactant or support material, and characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The resultant Pr₂O₃- or Cu₂O-modified NiMo catalysts exhibit different structures, which is due to a difference in the synergistic effects of NiMo and the modifying elements. NiMoPr₂O₃ has an amorphous structure, with low crystallinity and uniform particle dispersion, while NiMo@Cu₂O adopts the core−shell structure, where the core and shell are synergistic with each other to promote electron transfer efficiency. The support material-free nanocatalysts Ni₉Mo₁(Pr₂O₃)_0.375 and Ni₄Mo@Cu₂O are both highly efficient compared with bimetallic NiMo catalysts, in terms of hydrogen generation from hydrous hydrazine (N₂H₄·H₂O) at 343 K, with total turnover frequencies (TOFs) of 62 h^−1 and 71.4 h^−1, respectively. Their corresponding activation energies (Ea) were determined to be 43.24 kJ mol^−1 and 46.47 kJ mol^−1, respectively. This is the first report on the use of Pr-modified NiMo and core−shell NiMo@Cu₂O catalysts, and these results may be used to promote the effective application of noble metal-free nanocatalysts for hydrogen production from hydrous hydrazine.