Mitigation of Indoor Air Pollution from Air Cleaners Using a Catalyst

The COVID-19 pandemic highlighted the importance of indoor air quality and the role of airborne transmission in the disease spread. Heightened public awareness led to an increase in the commercialization and use of air cleaners. While several of these devices effectively disinfect the air, some also initiate chemical reactions that can worsen indoor air quality by generating ozone (O₃) and other harmful air pollutants. Here we demonstrate the use of a MnO_x-based catalyst to mitigate both air cleaner-generated and ambient pollution in a university office. We deployed two real-time chemical ionization mass spectrometers alongside a suite of air quality analyzers to measure a wide range of volatile organic compounds (VOCs), other trace gases, and particles. We show the reduction of many indoor pollutants in a combination of real indoor environment and atmospheric chamber experiments, including O₃, nitrogen oxides, formaldehyde, and other oxidized VOCs. We observed an increase in the concentrations of more reduced VOCs with catalyst use. We demonstrate that over 24 weeks of continuous operation, the clean air delivery rate of the catalyst for O₃ pollution declined linearly by 20%. These findings suggest that employing a dedicated catalyst could reduce indoor air pollution and enhance the human health benefits of air cleaners by minimizing the associated indoor air quality risks.

This paper reports on the mitigation of ambient and air cleaner-generated indoor air pollution using a dedicated catalyst.