Non-thermal plasma catalysis for chlorobenzene removal over CoMn/TiO2 and CeMn/TiO2: Synergistic effect of chemical catalysis and dielectric constant

Abstract

The decomposition of chlorobenzene (CB) in a non-thermal plasma (NTP) catalysis combined reactor was investigated. CoMn/TiO2 and CeMn/TiO2 were prepared using a deposition–precipitation method. CB decomposition, carbon balance, selectivity of CO2, and the byproducts of NOx and O3 were investigated. NTP catalysis provided significantly better CB removal efficiency and CO2 selectivity than did the plasma alone. CoMn/TiO2 exhibited better removal efficiency than CeMn/TiO2 in the NTP-catalysis reactor, but the performance of the catalysts during the thermal catalytic oxidation was reversed without the NTP. To reveal the activity difference with CB decomposition in the NTP-catalysis hybrid system, the dielectric constant and the physicochemical properties of CoMn/TiO2 and CeMn/TiO2 were analyzed. The plasma, which was affected by the dielectric constant, played a dominant role in this hybrid system. The reducibility of the catalysts promoted the CO2 selectivity and O3 decomposition. The CoMn/TiO2 was remarkably stable in the NTP-catalysis hybrid system during extended testing.