Acetaldehyde removal using a diphasic process coupling a silver-based nano-structured catalyst and a plasma at atmospheric pressure

The efficiency of the process coupling a dielectric barrier discharge and a fluidized nanostructured silver-based bed for the degradation of a model pollutant (acetaldehyde CH3CHO) is presented. The deposition of silver nanoparticles has been realized by photocatalytic reduction of Ag+ ions in aqueous solution of silver nitrate salt on TiO2 nanoparticles deposited on SiO2 beads. In the first part, the efficiency of the plasma alone process is discussed, in terms of pollutant removal and CO and CO2 production. The main pathways of pollutant degradation and COx production are discussed. In the second part, CH3CHO removal as well as COx production is studied as a function of the photocatalytic reduction time of Ag+ ions, which is related to the deposited silver mass. Finally, pollutant removal pathways, including homogeneous chemistry in the plasma phase and heterogeneous chemistry on the surface, are discussed.