Enhancing C[sbnd]Cl bond cleavage and ozone conversion: Optimizing surface Co3+ and chemosorbed oxygen through polystyrene and dodecylamine modification

Abstract

The activation of CCl bonds and the conversion of O3 are crucial for the degradation of chlorinated hydrocarbons through catalytic ozonation. This work constructed the surface active sites of Co3O4 with polystyrene (PS) and dodecylamine to enhance dichloromethane (DCM) removal and O3 conversion in photo-ozone catalysis simultaneously. The dodecylamine created active Co3+ on the catalyst surface, and the PS prevented the elimination of active Co3+ during calcination by forming CCoO. The O3 pre-treatment removed the deposited carbon to expose the active Co3+ and the chemisorbed oxygen. The surface Co3+ played a crucial role in cleaving the CCl bonds of DCM, and the chemosorbed oxygen facilitated the conversion of O3 into O. Moreover, the photogenerated holes oxidized the intermediates formed after the DCM dechlorination. The removal rate of DCM for the sample co-modified by PS and dodecylamine was 80.8 mg/(g‧h) under one sun irradiation, which was 2.2 times higher than that by Co3O4.