State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
Nat Commun. 2023 Mar 30;14(1):1761. doi: 10.1038/s41467-023-37406-y.
Metastable phase two-dimensional catalysts provide great flexibility for modifying their chemical, physical, and electronic properties. However, the synthesis of ultrathin metastable phase two-dimensional metallic nanomaterials is highly challenging, mainly due to the anisotropic nature of metallic materials and their thermodynamically unstable ground-state. Here, we report free-standing RhMo nanosheets with atomic thickness and a unique core/shell (metastable phase/stable phase) structure. The polymorphic interface between the core region and shell region stabilizes and activates metastable phase catalysts; the RhMo Nanosheets/C shows excellent hydrogen oxidation activity and stability. Specifically, the mass activities of RhMo Nanosheets/C is 6.96 A mg; this is 21.09 times higher than that of commercial Pt/C (0.33 A mg). Density functional theory calculations suggest that the interface aids in the dissociation of H and the H species can then spillover to weak H binding sites for desorption, providing excellent hydrogen oxidation activity for RhMo nanosheets. This work advances the highly controlled synthesis of two-dimensional metastable phase noble metals and provides great directions for the design of high-performance catalysts for fuel cells and beyond.
亚稳相二维催化剂为修饰其化学、物理和电子特性提供了极大的灵活性。然而，超薄亚稳相二维金属纳米材料的合成极具挑战性，主要是由于金属材料的各向异性及其热力学不稳定的基态。在这里，我们报道了具有原子厚度和独特核/壳（亚稳相/稳定相）结构的游离 RhMo 纳米片。核区和壳区之间的多晶界面稳定并激活了亚稳相催化剂；RhMo 纳米片/C 表现出优异的氧化氢活性和稳定性。具体而言，RhMo 纳米片/C 的质量活性为 6.96 A mg; 这比商业 Pt/C（0.33 A mg）高 21.09 倍。密度泛函理论计算表明，界面有助于 H 的离解，然后 H 物种可以溢出到弱 H 结合位点进行解吸，为 RhMo 纳米片提供了优异的氧化氢活性。这项工作推进了二维亚稳相贵金属的高度可控合成，并为燃料电池等领域高性能催化剂的设计提供了重要方向。
