Removing volatile organic compounds (VOCs) and particles can improve indoor air quality and enable ventilation energy savings. Different methods can be used to remove pollutants from indoor air, including mature technologies relying on adsorption or chemisorption and emerging technologies based on room-temperature catalysis and photocatalysis. The Indoor Environment Group carries out research to evaluate and optimize the performance of novel air cleaning technologies that remove indoor VOCs. We develop methods to test air cleaning devices under realistic conditions.
Photocatalytic oxidation (PCO) relies on a high-surface substrate coated with titanium dioxide (TiO2) nanoparticles and irradiated with ultraviolet light. VOCs adsorb reversibly to the photocatalyst and can be photooxidized, yielding intermediate partially oxidized species and final byproducts such as CO2 and water. The complete oxidation to inorganic products (mineralization), is the ultimate goal of the air cleaning process.We developed methods to evaluate the performance of active and passive PCO systems under realistic conditions using multi-component VOC mixtures at low concentrations (<10 ppb) and short contact times (milliseconds) using room-sized chambers.
Some of our projects involve also the synthesis and characterization of supported catalysts that react with indoor pollutants at room temperature without requiring photoactivation. We synthesized and characterized a manganese oxide catalyst with high surface area that shows remarkably high formaldehyde removal efficiencies and quantitative mineralization to CO2. The catalyst showed a promising performance both in laboratory and field demonstrations.