General negative pressure annealing approach for creating ultra-high-loading single atom catalyst libraries.

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• High-density single-atom catalysts (SACs) are vital for enhancing catalytic performance but achieving high metal loadings (>10 wt%) is challenging.
• Existing methods struggle to create SACs with industrially relevant metal content.

Purpose of the Study:

• To develop a general strategy for fabricating ultrahigh-loading SACs.
• To explore the synthesis of high-entropy single-atom catalysts (HESACs).
• To investigate the catalytic activity of these novel SACs.

Main Methods:

• A novel negative pressure annealing strategy was employed.
• Fabrication of SACs with 13 different metals on a carbon nitride matrix.
• Characterization using in-situ aberration-corrected scanning transmission electron microscopy (AC-STEM) and X-ray absorption fine structure (XAFS).

Main Results:

• Achieved ultrahigh metal loadings (27.3–44.8 wt%) for 13 metals.
• Successfully synthesized high-entropy single-atom catalysts (HESACs).
• Demonstrated enhanced propane oxidation activity with a 41.8 wt% Pt SAC.

Conclusions:

• The negative pressure annealing method is a straightforward and universal approach for producing high-density SACs.
• This method significantly boosts metal-nitrogen coordination and catalytic efficiency.
• The developed SACs show promise for various efficient catalytic transformations.