Atomic-thick metastable phase RhMo nanosheets for hydrogen oxidation catalysis.
Juntao Zhang1, Xiaozhi Liu2, Yujin Ji3
1State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
Nature Communications
|March 30, 2023
Summary
Researchers developed ultrathin RhMo nanosheets with a unique core/shell structure. These metastable phase catalysts exhibit superior hydrogen oxidation activity, significantly outperforming commercial platinum catalysts for fuel cell applications.
Area of Science:
- Materials Science
- Catalysis
- Nanotechnology
Background:
- Two-dimensional (2D) metastable phase catalysts offer tunable properties but are difficult to synthesize.
- Metallic nanomaterials present synthesis challenges due to their inherent anisotropy and thermodynamic instability.
Purpose of the Study:
- To develop a synthesis method for ultrathin, metastable phase 2D metallic nanomaterials.
- To investigate the catalytic activity of novel RhMo nanosheets for hydrogen oxidation.
Main Methods:
- Synthesis of free-standing RhMo nanosheets with atomic thickness and a core/shell structure.
- Characterization of the nanosheets' structure and composition.
- Electrochemical testing of RhMo nanosheets/carbon (C) for hydrogen oxidation.
- Density functional theory (DFT) calculations to elucidate the catalytic mechanism.
Main Results:
- Successfully synthesized RhMo nanosheets with a metastable/stable phase core/shell structure.
- RhMo Nanosheets/C demonstrated significantly higher mass activity (6.96 A mgRh-1) for hydrogen oxidation compared to commercial Pt/C (0.33 A mgPt-1).
- DFT calculations indicated that the interface facilitates H2 dissociation and desorption, enhancing catalytic performance.
Conclusions:
- The polymorphic interface in RhMo nanosheets stabilizes and activates the metastable phase.
- These 2D metastable phase catalysts show exceptional activity and stability for hydrogen oxidation.
- This work provides a pathway for controlled synthesis of 2D metastable noble metals for advanced catalyst design.
