Catalytic deep degradation of Cl-VOCs with the assistance of ozone at low temperature over MnO2 catalysts

Abstract

This paper conducted catalytic ozonation and oxidation of chlorobenzene (CB) and dichloroethane (DCE) over three synthesized MnO2 catalysts with different properties. Catalytic ozonation exhibited high efficiency with less catalyst dosage at low temperature, ca. 30 ~ 120 °C, excellent stability, and less byproducts formation for both CB and DCE conversion. MnO2–I exhibited the best performance for all experiments, attributing to its abundant oxygen vacancies, more acid sites, and excellent CO2 desorption properties. Catalytic ozonation exhibited excellent stability with much fewer organic byproducts in effluent gas at 120 °C·H2O had no effect on catalytic ozonation but recovered catalytic oxidation performance. Besides, O3 existence attained high activity over deactivated catalyst by Cl poisoning. In–situ DRIFTs measurements validated facilitated transformation of intermediates during catalytic ozonation. These findings comprehensively verify the superiority of catalytic ozonation to attain highly stable and complete degradation of chlorinated volitile organic compounds (Cl–VOCs) at mild conditions.