Destruction mechanisms for formaldehyde in atmospheric pressure low temperature plasmas

Abstract

Formaldehyde (CH₂O) is a common pollutant of indoor air in residences and commercial buildings. The removal of CH₂O from atmospheric pressure gas streams (N₂/O₂/H₂O/CH₂O) using plasmas generated by a dielectric barrier discharge has been theoretically investigated with the goal of cleansing indoor air. The model consists of a full accounting of the electron, ion, and neutral chemical kinetics in contaminated humid air. We find that the destruction of CH₂O results dominantly from chemical attack by OH and O radicals, with the primary end products being CO and H₂O. The predicted destruction rates for CH₂O are typically 2–8 ppm/(mJ cm⁻³) (parts per million of CH₂O in air/energy deposition). The elimination of the unwanted byproducts, CO and NO, using a platinum catalyst is discussed.