Single-atom cobalt array bound to distorted 1T MoS₂ with ensemble effect for hydrogen evolution catalysis

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Atomically dispersed metallic catalysts face challenges with low metal loading, localization, and support interactions, limiting catalytic performance.
• Developing efficient single-atom catalysts requires precise control over metal-support interfaces.

Purpose of the Study:

• To engineer an interface catalyst with high metal-atom loading density and controllable localization.
• To investigate the role of support phase transformation in single-atom catalyst activity.
• To achieve platinum-like activity and stability for the hydrogen evolution reaction (HER).

Main Methods:

• Synthesis of single-atom cobalt array covalently bound to distorted 1T MoS₂ nanosheets (SA Co-D 1T MoS₂).
• Induction of MoS₂ phase transformation from 2H to D-1T via strain and Co-S covalent bonding.
• Characterization using advanced techniques and density functional theory (DFT) calculations.
• Evaluation of catalytic activity and stability for HER using active-site blocking experiments.

Main Results:

• Achieved an atomically dispersed cobalt array on distorted 1T MoS₂ (SA Co-D 1T MoS₂).
• Demonstrated Pt-like activity and high long-term stability for the hydrogen evolution reaction (HER).
• DFT calculations and experiments revealed synergistic effects between Co adatoms and the D-1T MoS₂ support.

Conclusions:

• The phase transformation of MoS₂ to D-1T is crucial for forming highly active single-atom array catalysts.
• The interface catalyst exhibits superior HER performance due to an ensemble effect and tuned hydrogen binding.
• This work provides a new strategy for designing high-performance single-atom catalysts.