CaO-Promoted Lattice Oxygen Activation and Antichlorine Poisoning over Mullite for Catalytic Chlorobenzene Combustion

Abstract

The degradation of chlorine-containing volatile organic compounds (Cl–VOCs) utilizing catalytic combustion technology is subject to the paradox of toxic byproduct formation and catalyst chlorine poisoning. Herein, a CaO-assisted strategy is proposed to resolve the awkward stuff for improving the catalytic combustion performance of chlorobenzene on SmMn 2 O 5 . The CaO-collaborated SmMn 2 O 5 exhibits a significant decrease in T 90 by 142 and 125 °C compared with unmodified and inert SiO 2 -composited SmMn 2 O 5, respectively. The integrated characterization results confirm that CaO collaboration causes electron transfer from CaO to SmMn 2 O 5, resulting in a reduction of the orbital overlap between Mn and O atoms to activate lattice oxygen (O latt ). The activated O latt enables chlorobenzene to combust completely at a lower temperature of 275 °C at which toxic byproducts are not generated. Furthermore, the switching of the dechlorination site from SmMn 2 O 5 to CaO avoids chlorine poisoning of active sites on SmMn 2 O 5 and thus endows CaO-collaborated SmMn 2 O 5 with prominent stability.