Resolving the Nanostructure of Carbon Nitride-Supported Single-Atom Catalysts

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Single-atom catalysts (SACs) offer high selectivity and uniform active sites.
• The precise atomic structure of SACs is often ambiguous, hindering mechanistic understanding.
• Elucidating the coordination environment is key to optimizing catalytic performance.

Purpose of the Study:

• To comprehensively investigate the local atomic structure of nickel active centers in carbon nitride (CNx)-supported SACs.
• To challenge existing structural models and propose a novel architecture for nickel SACs.
• To provide a foundation for rational catalyst design and development.

Main Methods:

• Synthesis of CNx-supported single-atom catalysts with isolated nickel atoms.
• Characterization using Fourier-transform infrared spectroscopy and X-ray absorption spectroscopy (XAS).
• Theoretical analysis through density functional theory (DFT) calculations.

Main Results:

• Experimental and computational data reveal a unique coordination environment for nickel active centers.
• The findings challenge conventional structural models for nickel SACs on CNx.
• A new structural model is proposed that better fits the experimental evidence.

Conclusions:

• The proposed atomic structure provides a more accurate representation of nickel SACs in CNx.
• This structural elucidation is crucial for understanding catalytic activity and selectivity.
• The study facilitates a rational design approach for advanced single-atom catalysts.