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 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 catalyst to mitigate both air cleaner-generated and ambient pollution in a real indoor environment. 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, including O3, nitrogen oxides, formaldehyde, and other oxidized VOCs. We observe an increase in the concentrations of more reduced VOCs with catalyst use. We demonstrate that over 16 weeks of continuous operation, the clean air delivery rate of the catalyst for O3 pollution declined linearly by 12.5%. 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.