A safe, efficient, and responsive online hydrogen source is critical for the commercial application of proton exchange membrane fuel cells (PEMFCs). Catalysts play an important role in accelerating the development of hydrous hydrazine as a promising online hydrogen source, and the development of hydrous hydrazine (N₂H₄·H₂O) as a promising online hydrogen source for PEMFCs requires superior catalysts with low cost and high activity. Herein, we report the synthesis of a supported amorphous catalyst NiMo/TiO₂ using a combination of impregnation and coreduction methods. The NiMo/TiO₂ catalyst can be responsive and completely decompose hydrous hydrazine to produce hydrogen in 1.5 min with a H₂ selectivity of 100% and a turnover frequency (TOF) value of 484 h^–1 under alkaline conditions at 343 K, outperforming most non-noble metal catalysts. Moreover, H₂ selectivity has no decline after 10 cycles. The excellent catalytic properties can be attributed to the strong synergistic interaction between the support TiO₂ and NiMo nanoparticles, as well as the amorphous NiMo nanoparticles possessing a high concentration of coordinated unsaturated sites. In addition, the doping of Mo leads to the modification of the electronic and geometric structures of the NiMo/TiO₂ surface, which results in an easier cleavage of the N–H bond and desorption of reaction intermediates.

中文翻译：

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锐钛矿型 TiO2 改性无定形 NiMo 纳米粒子对水合肼脱氢具有优异的催化性能

安全、高效和响应迅速的在线氢源对于质子交换膜燃料电池 (PEMFC) 的商业应用至关重要。催化剂在加速水合肼作为一种有前景的在线氢源的发展中发挥着重要作用，而水合肼（N ₂ H ₄ ·H ₂ O）作为一种有前景的PEMFCs在线氢源的开发需要具有成本低且性能优良的催化剂。高活性。在此，我们报告了使用浸渍和核还原方法相结合的负载型非晶催化剂 NiMo/TiO _{2的合成。}NiMo/TiO ₂催化剂具有响应性，可在 1.5 min 内将水合肼完全分解生成氢气，H ₂在 343 K 的碱性条件下，选择性为 100%，转换频率 (TOF) 值为 484 h ^–1，优于大多数非贵金属催化剂。而且，H ₂选择性在10个循环后没有下降。优异的催化性能可归因于载体TiO ₂和NiMo纳米颗粒之间的强协同相互作用，以及具有高浓度配位不饱和位点的无定形NiMo纳米颗粒。此外，Mo的掺杂导致NiMo/TiO ₂表面的电子和几何结构发生改变，这导致N-H键更容易断裂和反应中间体的解吸。