Graphitized Carbon-Supported Co@Co₃O₄ for Ozone Decomposition over the Entire Humidity Range

Area of Science:

• Environmental Chemistry
• Materials Science
• Catalysis

Background:

• Ground-level ozone (O3) pollution poses significant risks to human health and ecosystems.
• Catalytic removal is an efficient and cost-effective method for O3 abatement.
• Current catalysts struggle with consistent performance across varying humidity levels.

Purpose of the Study:

• To develop a novel catalyst with sustained O3 decomposition efficiency across the entire humidity range.
• To investigate the mechanism behind the enhanced catalytic activity and humidity tolerance.
• To fabricate practical O3 decomposition catalysts using 3D printing technology.

Main Methods:

• Synthesis of graphitized carbon-loaded core-shell cobalt catalysts (Co@Co3O4-C) via pyrolysis.
• Comprehensive physicochemical characterization of the synthesized catalysts.
• Density functional theory (DFT) calculations to elucidate reaction mechanisms.
• Fabrication of monolithic catalysts using 3D printing.

Main Results:

• The Co@Co3O4-C catalyst achieved nearly 100% working efficiency for O3 decomposition across all humidity levels.
• Dual active sites (metallic Co and interface carbon) were identified as key to enhanced reactivity and water tolerance.
• The catalyst design mitigates water interference by directing H2O adsorption to the cobalt oxide layer.
• 3D printed monolithic catalysts exhibited low pressure drop and high mechanical strength.

Conclusions:

• The proposed
• dual active site
• strategy enables highly efficient O3 catalytic decomposition irrespective of humidity.
• The encapsulated metallic cobalt core enhances the cobalt oxide shell's reactivity, while interface carbon acts as a secondary active site.
• This approach provides a robust solution for practical O3 abatement applications, with 3D printing enabling scalable catalyst fabrication.