Byproducts and pathways of toluene destruction via plasma-catalysis

To improve toluene removal efficiency and reduce byproducts, a TiO2/γ-Al2O3/nickel foam catalyst was combined in and after the non-thermal plasma (NTP), leading to a plasma-driven catalysis (PDC) and plasma-assisted catalysis (PAC) process, respectively. The addition of catalysis could significantly enhance the toluene destruction with an increased CO2 selectivity and carbon balance while the byproducts, such as O3 and organic compounds, were dramatically reduced. The PAC exhibited the highest efficiency in toluene destruction due to the formation of more atomic oxygen and hydroxyl radicals from O3 catalytic decomposition. The pathways of toluene destruction by NTP and plasma-catalysis were proposed according to the identified intermediates.

Graphical abstractThe pathways of toluene destruction by energetic electrons are greatly different to that by O/OH, which accounts for much less byproducts in the plasma-catalysis process.Figure optionsDownload full-size imageDownload high-quality image (109 K)Download as PowerPoint slideResearch highlights▶ The catalyst could significantly enhance the toluene destruction and reduce byproducts. ▶ The PAC process exhibited the highest efficiency in both toluene and O3 destruction. ▶ More reactive species from O3 catalytic decomposition is responsible for the increased activity. ▶ The pathways of toluene destruction in plasma-catalysis are greatly different to that in the NTP alone.