Journal of Industrial and Engineering Chemistry, Vol.95, 215-223, March, 2021
Two-component zeolite-alumina system for toluene trapping with subsequent nonthermal plasma mineralization
Two-component zeolite-alumina packed dielectric barrier discharge plasma was developed to deeply mineralize toluene. Compared with packing ZSM-5 and γ-Al2O3 separately in layers, uniform mixing of ZSM-5 and γ-Al2O3 was more conducive to the mineralization of adsorbed toluene in nonthermal plasma. When the mixing ratio of ZSM-5 to γ-Al2O3 was 1:2, the mineralization rate reached 80% after discharging for 120 min. Ag supported on the catalyst surface significantly improved the selectivity of CO2. Increased relative humidity had little effect on the mineralization of adsorbed toluene, but significantly reduced the byproducts O3 and N2O. The adsorption and plasma mineralization performance of Ag/ZSM-5-γ-Al2O3 during five cycles of toluene adsorption was stable with only the peak concentration of CO showing a slight upward trend. GC.MS, TG, and XPS characterization of fresh and used catalysts revealed deactivation of Ag/ZSM-5-γ-Al2O3 in terms of CO oxidation due to intermediate organic residues and decreased amounts of Ag+ and lattice oxygen on the support ZSM-5 instead of γ-Al2O3.
Keywords:Toluene;Adsorption with subsequent;Nonthermal;Plasma catalysis;Zeolite-alumina;Mineralization