Hydrazine borane (HB) has great potential as a safe and convenient hydrogen carrier material due to its high hydrogen capacity (15.4 wt%) and good stability under ambient conditions. However, efficient hydrogen production through complete decomposition of hydrazine borane at low temperatures (<373 K) constitutes a major challenge. Herein, we report the successful immobilization of monodisperse Rh nanoparticles on MgO solid support, leading to the formation of the Rh@MgO catalyst. This developed catalyst exhibits outstanding catalytic performance in the dehydrogenation of HB, achieving a remarkable turnover frequency (TOF) of 2005.34 h⁻¹ at 50 °C with 100% H₂ selectivity, despite containing only 2 wt% Rh. Comparative experiments with Rh on various metal–oxide nanoparticles, other transition metal catalysts on MgO, and Ni grown on MgO in both single-phase and bimetallic forms reveal that Rh@MgO consistently outperforms these alternatives. The exceptional catalytic activity is attributed to the synergistic interaction between Rh and MgO, which involves several key factors: the homogeneous dispersion of ultrafine, monodisperse Rh particles enhances catalytic efficiency; the proximity of the work functions of Rh and MgO results in a low-energy Schottky barrier that facilitates electron transfer; and the localization of electrons in surface defects of MgO aligns with the Fermi level of Rh, further promoting electron transfer through Fermi level pinning (FLP). The combination of low Rh content and cost-effective MgO support presents a promising pathway for both laboratory-scale research and practical industrial applications, highlighting the potential of the Rh@MgO catalyst as an efficient and economically viable solution for catalytic processes.

中文翻译：

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用于肼硼烷完全脱氢的高性能 Rh@MgO 催化剂：比较研究


肼硼烷 （HB） 由于其高氢容量 （15.4 wt%） 和环境条件下的良好稳定性，作为一种安全便捷的氢载体材料具有巨大潜力。然而，通过在低温 （<373 K） 下完全分解肼硼烷来高效制氢是一项重大挑战。在此，我们报道了单分散 Rh 纳米颗粒成功固定在 MgO 固体载体上，导致 Rh@MgO 催化剂的形成。这种开发的催化剂在 HB 脱氢中表现出出色的催化性能，在 50 °C 下实现了 2005.34 ^h-1 的显着周转频率 （TOF），具有 100% 的 H₂ 选择性，尽管仅包含 2 wt% Rh。在各种金属氧化物纳米颗粒上使用 Rh、在 MgO 上使用其他过渡金属催化剂以及在 MgO 上以单相和双金属形式生长的 Ni 的比较实验表明，Rh@MgO 的性能始终优于这些替代方案。卓越的催化活性归因于 Rh 和 MgO 之间的协同相互作用，这涉及几个关键因素：超细单分散 Rh 颗粒的均匀分散提高了催化效率;Rh 和 MgO 的功函数接近导致低能肖特基势垒，促进电子转移;电子在 MgO 表面缺陷中的定位与 Rh 的费米能级一致，进一步促进通过费米能级固定 （FLP） 的电子转移。 低 Rh 含量和具有成本效益的 MgO 载体相结合，为实验室规模的研究和实际工业应用提供了一条有前途的途径，突出了 Rh@MgO 催化剂作为高效且经济可行的催化工艺解决方案的潜力。