Combination of atmospheric pressure dielectric barrier discharge and photocatalysis for C$_{2}$H$_{2}$ oxidation

Non-thermal plasma and photocatalysis have attracted attention as energy-saving methods for VOCs destruction. TiO$_{2}$ photocatalysts are porous semiconductors activated by UV radiations. They are known for their ability to oxidize organic molecules with high CO$_{2}$ selectivity. It was shown recently that the coupling of dielectric barrier discharges (DBD) with photocatalysis improves oxidation efficiency and reduces undesirable by-products. Experiments were carried out in a closed DBD reactor containing photocatalytic surface, with C$_{2}$H$_{2}$ as a test molecule. First, TiO$_{2}$ influence on DBD deposited energy was investigated, as well as ageing of TiO$_{2}$ under DBD conditions. Then, air cleaning efficiency of coupling was investigated. Introduction of higher specific energy and addition of UV radiations increase the synergistic effect. Selectivity is clearly enhanced. The CO amount is reduced in presence of TiO$_ {2}$. CO$_{2}$ formation is improved. Experimental data were fitted by kinetics models. Constants were calculated and reaction mechanisms are reported. Understanding of plasma-TiO$_{2}$ synergy has been improved by in situ and time resolved laser absorption experiment in the mid infrared region