Atomically dispersed oxide-on-metal inverse nanocatalysts provide a blueprint to amplify the strong oxide–metal interactions for heterocatalysis but remain a grand challenge in fabrication. Here we report a 2D inverse nanocatalyst, RuO_x-on-Pd nanosheets, by in situ creating atomically dispersed RuO_x/Pd interfaces densely on ultrathin Pd nanosheets via a one-pot synthesis. The product displays unexpected performance toward the oxygen reduction reaction (ORR) in alkaline medium, which represents 8.0- and 22.4-fold enhancement in mass activity compared to the state-of-the-art Pt/C and Pd/C catalysts, respectively, showcasing an excellent Pt-alternative cathode electrocatalyst for fuel cells and metal–air batteries. Density functional theory calculations validate that the RuO_x/Pd interface can accumulate partial charge from the 2D Pd host and subtly change the adsorption configuration of O₂ to facilitate the O−O bond cleavage. Meanwhile, the d-band center of Pd nanosubstrates is effectively downshifted, realizing weakened oxygen binding strength.

中文翻译：

---

用于高性能氧还原的原子分散 RuOx-on-Pd 二维逆纳米催化剂中的放大界面效应

原子分散的氧化物-金属反相纳米催化剂提供了一个蓝图，可以放大异质催化的强氧化物-金属相互作用，但在制造中仍然是一个巨大的挑战。在这里，我们报告了一种二维反向纳米催化剂，RuO _x -on-Pd 纳米片，通过一锅法在超薄 Pd 纳米片上原位创建原子分散的 RuO _x /Pd 界面。该产品对碱性介质中的氧还原反应 (ORR) 显示出意想不到的性能，与最先进的 Pt/C 和 Pd/C 催化剂相比，其质量活性分别提高了 8.0 倍和 22.4 倍，展示了用于燃料电池和金属-空气电池的出色的 Pt 替代阴极电催化剂。密度泛函理论计算验证了 RuO_x /Pd 界面可以从 2D Pd 主体中积累部分电荷，并巧妙地改变 O ₂的吸附构型以促进 O-O 键的断裂。同时，Pd纳米衬底的d带中心被有效地下移，实现了氧结合强度的减弱。