Non-thermal plasma-catalytic decomposition of volatile organic compounds using alumina supported metal oxide nanoparticles

This work investigated the performance of ethylene and butane decomposition in a dielectric barrier discharge (DBD) plasma reactor packed with nanoparticle-coated γ-alumina at 150 °C. The effects of input power and type of metal oxide nanoparticle (TiO2 and ZrO2 coated on γ-alumina) on the decomposition efficiency and the distribution of by-products were examined and discussed. The decomposition efficiencies of ethylene and butane obtained with the nanoparticle-coated γ-alumina were higher than those with the bare γ-alumina. The main decomposition by-products were found to be carbon oxides. Nitrogen-containing by-products such as nitrous oxide and nitrogen dioxide were also detected with both ethylene and butane. Besides, some partially oxidized by-products like formaldehyde and acetaldehyde and lower molecular weight by-products like acetylene and methane were identified during the decomposition of ethylene and butane. The formations of such unwanted by-products were completely avoided and high selectivity towards carbon oxides was achieved when the ZrO2 nanoparticle-coated γ-alumina was used as the packing material. The emission spectra of the DBD plasma showed various oxygen and nitrogen reactive species that are responsible for the decomposition of ethylene and butane.