Plasma-enhanced catalytic activation of CO2 in a modified gliding arc reactor

For the first time, this paper demonstrates a synergistic effect from the combination of a gliding arc discharge plasma with a photocatalyst TiO2 for CO2 dissociation. The effects of adding a tray downstream the discharge and the combination of the catalyst with plasma have been investigated. Two different combination modes of plasma catalysis, i.e., in-plasma catalysis and post-plasma catalysis, have been evaluated with the emphasis on the analysis of potential mechanisms. The results show that modifying the gliding arc reactor by the addition of a tray can enhance the fraction of gas treated by plasma, thus improving the reaction performance. An exceptional synergistic effect of combining the gliding arc discharge with TiO2 for CO2 activation forms in the in-plasma catalysis mode. The presence of TiO2 significantly enhances the CO2 conversion by 138% and the energy efficiency by 133% at a flow rate of 2 L/min. The plasma activation effect, which produces energetic electrons that can create the electron-hole pairs on the catalyst surface, is believed to be the major contributor to the generation of the plasma catalysis synergy. This mechanism has been further evidenced by the negligible influence of the post-plasma catalysis on the reaction performance.