Formaldehyde Decomposition from -20 °C to Room Temperature on a Mn-Mullite YMn₂O₅ Catalyst

Area of Science:

• Environmental Chemistry
• Materials Science
• Catalysis

Background:

• Indoor formaldehyde pollution poses significant health risks.
• Conventional air purification methods struggle with large ambient temperature fluctuations (-20°C to 25°C).

Purpose of the Study:

• To develop an efficient formaldehyde removal strategy effective across a broad temperature range.
• To investigate a manganese-based mullite catalyst (YMn2O5) combined with ozone for formaldehyde degradation.

Main Methods:

• Utilized a YMn2O5 mullite catalyst with ozone for formaldehyde oxidation.
• Employed low temperature-programmed desorption and in situ infrared spectroscopy to analyze reaction mechanisms.
• Tested performance across temperatures from -20°C to 25°C.
• Constructed and evaluated a prototype air purifier.

Main Results:

• Achieved 62% formaldehyde removal efficiency at -20°C and 60,000 mL gcat⁻¹ h⁻¹.
• Complete conversion of formaldehyde and ozone to CO2, H2O, and O2 at -5°C.
• Identified highly reactive oxygen species and carboxyl groups as key to performance.
• Demonstrated effective formaldehyde decomposition (150 m³ h⁻¹) in a prototype purifier at 25°C and 30% RH without secondary pollutants.

Conclusions:

• The YMn2O5 + ozone system offers a robust solution for formaldehyde removal in variable temperature environments.
• This catalytic strategy provides a consumable-free and efficient air purification route.
• The findings pave the way for advanced indoor air quality management systems.