A review on gaseous pollutants purification using H2O2-based Fenton-like reactions

Hydrogen peroxide (H2O2) is an environmentally friendly chemical reagent in various environmental pollution treatment processes. However, a critical review of gaseous pollutant treatment using H2O2-based Fenton-like reactions is unavailable. This article reviews the treatment of gaseous pollutants with H2O2, including H2O2 activation, H2O2 detection, pollutant removal performance, and relevant mechanism. Energy excitation and catalysis for H2O2 activation are outlined and elucidated in detail. Liquid and gaseous H2O2 detection methods are presented, such as titration, optical measurement, and electrochemical processes. The removal of inorganic and organic pollutants with H2O2 solution or vapor is presented, such as NO, Hg0, As2O3, H2S, CO, BTEX (benzene, toluene, ethylbenzene, and xylene), sulfur volatile organic compounds (SVOC) and chlorinated volatile organic compounds (CVOC). The effects of operating parameters on purification efficiency are discussed in detail to provide some consensus phenomena. Finally, mechanism studies are provided regarding reaction pathways and the structure-activity relationship of catalysts.