Porous graphitized carbon-supported FeOCl as a bifunctional adsorbent-catalyst for the wet peroxide oxidation of chlorinated volatile organic compounds: Effect of mesopores and mechanistic study

Abstract

Wet scrubbing coupled with adsorption-enhanced heterogeneous advanced oxidation processes (AOPs) are promising approaches to the treatment of chlorinated volatile organic compounds (CVOCs). However, microporous activated carbon-based adsorbents and catalyst supports have the disadvantage of difficult molecule diffusion. Herein, we have demonstrated that porous graphitized carbon (PGC) allowed faster intra-particle diffusion of organic molecules due to its well-developed mesoporous structure. Therefore, a wet scrubbing system containing H2O2 and a PGC-supported FeOCl catalyst has been developed to effectively remove gaseous dichloroethane, trichloroethylene, dichloromethane and chlorobenzene. The scrubber performed well at pH 3.0 using a FeOCl/PGC dosage of 0.2 g/L and initial H2O2 concentration of 40 mM. Its good long-term performance was achieved by replenishing H2O2 to maintain a suitable concentration. The degradation pathways of dichloroethane have been proposed using a combination of intermediate analysis and density functional theory calculations. PGC-supported catalysts may be desirable bifunctional adsorbent-catalyst materials for wet scrubbing of CVOCs.