Metal-organic framework-confined Co₃O₄ for humidity-immune ozone decomposition

Area of Science:

• Materials Science
• Environmental Chemistry
• Catalysis

Background:

• Ground-level ozone (O3) is a significant air pollutant.
• Catalytic decomposition is a key strategy for O3 removal.
• Maintaining catalyst efficiency in humid environments is challenging.

Purpose of the Study:

• To design and synthesize a humidity-immune catalyst for efficient O3 decomposition.
• To investigate the mechanism behind the catalyst's performance under varying humidity levels.

Main Methods:

• Encapsulation of ultrafine metal oxides (Co3O4, NiO) within a metal-organic framework (PCN-333(Fe)).
• Testing catalytic O3 decomposition efficiency under high space velocity and broad humidity range (10-90% RH).
• Utilizing in situ DRIFTS and Raman spectroscopy for mechanistic studies.

Main Results:

• The optimized Co3O4@PCN-333(Fe) catalyst achieved 100% O3 conversion for over 120 hours.
• Sustained high performance was observed across a wide humidity range.
• An interfacial hydrogen-atom transfer mechanism was identified as crucial for the catalyst's stability and efficiency.

Conclusions:

• A novel catalytic interface design principle for humidity-immune metal oxide catalysts was established.
• The developed catalyst offers a practical foundation for sustainable control of O3 pollution in diverse environmental conditions.