Ultralow loading atomically dispersed Fe on N-doped carbon hollow shells for efficient CO₂ cycloaddition

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Developing highly efficient single-atom catalysts (SACs) with optimal active-site utilization is crucial but challenging.
• Iron single atoms supported on nitrogen-doped carbon (Fe/NC) are promising catalysts for CO2 conversion.

Purpose of the Study:

• To synthesize a novel hollow macroporous-mesoporous Fe/NC catalyst for CO2 cycloaddition.
• To evaluate the catalytic performance, stability, and substrate compatibility of the synthesized Fe/NC catalyst.

Main Methods:

• Utilized silica microspheres as a sacrificial template for catalyst synthesis.
• Employed dopamine hydrochloride as a bifunctional C/N source and iron-anchoring ligand.
• Investigated the CO2 cycloaddition reaction of styrene oxide with CO2 using the Fe/NC catalyst.

Main Results:

• Achieved a high yield of 97.45 ± 0.33% for CO2 cycloaddition with a low iron loading (1.36 ± 0.01 wt%).
• Demonstrated exceptional catalytic activity (turnover frequency = 38.19 h-1) attributed to FeN4 active sites and the unique porous structure.
• Exhibited excellent cycling stability, maintaining 93.26 ± 0.52% conversion after five cycles, and broad substrate compatibility.

Conclusions:

• The synthesized hollow macroporous-mesoporous Fe/NC catalyst offers superior performance in CO2 cycloaddition.
• The catalyst's structure effectively anchors iron atoms, enhances substrate/product diffusion, and improves catalytic efficiency.
• This study provides a foundation for designing advanced porous carbon materials with single-atom loading for efficient CO2 catalytic conversion.