Enhanced catalytic performance and antichlorine poisoning over Cu-doped cobalt oxide nanosheets for chlorobenzene oxidation

Abstract

The degradation of Chlorinated volatile organic compounds (CVOCs) by catalytic oxidation forms toxic products, and catalysts may be poisoned by chlorine at low temperatures. To address this, a Cu-assisted strategy is proposed for enhancing the catalytic degradation of chlorobenzene (CB) over cobalt oxide nanosheets. The Cu-doped Co3O4 catalysts exhibited lower T90 values (temperatures with 90 % conversion) and improved stability compared to the unmodified catalyst. These results were attributed to strong metal-metal interactions between Cu species and cobalt oxide nanosheets, which showed a high specific surface area, reduced binding energy of lattice oxygen, higher surface oxygen concentration, and more surface Co3+ species. These properties promoted low-temperature catalytic activity. In addition, the disappearance of Cu2+ satellite peak after the catalyst is used, indicating that the Cu2+ also contributes to the catalytic activity. Furthermore, the in situ FTIR spectra provided details about the reaction mechanism of CB degradation over Cu-doped cobalt oxide nanosheets. The oxygen vacancy generation and the surface absorption of chlorine-containing intermediates were calculated using density functional theory calculations. This study provides new insight into novel pathways for catalyst design aimed at CB degradation.