Post plasma-catalysis for trichloroethylene decomposition over CeO2 catalyst: Synergistic effect and stability test

Abstract

This study is devoted to investigate the opportunities of a plasma-catalytic system with CeO2 downstream (i.e. PPC-Post Plasma-catalysis) for the abatement of trichloroethylene (TCE), a typical chlorinated VOC, from dry air. A multi-pin-to-plate negative DC corona/glow discharge is used and showed poor COx selectivity despite having high abatement efficiency due to the formation of oxygenated intermediates such as phosgene, dichloroacetylchloride (DCAC) and trichloroacetaldehyde (TCAA), when operated alone. Nonetheless, NTP enables catalyst activation at lower temperature. As a result, suppression of unwanted chlorinated by-products as well as high COx selectivity at lower energy cost have been achieved, proving that this plasma-catalysis route shows great potential as air pollution control technology for low concentrated VOC air streams. Special attention is given to the effect of catalyst temperature, the role of ozone in the plasma–catalytic TCE abatement and the possible synergy between NTP and catalysis. Also, a long term test to evaluate the stability of CeO2 catalyst has also been successfully performed.