Gaseous toluene heterogeneous oxidative degradation by iron-based hypercrosslinked polymeric resin LXQ-10

Abstract

Heterogeneous Fenton-like reaction for gaseous toluene removal was enhanced by loading an amount of iron elements onto the hypercrosslinked polymeric resin (LXQ-10) as a novel catalyst. Characterization and experiment results confirmed that Fe/LXQ-10 with great catalytic and stability performance were successfully synthesized. The effects of several key running parameters such as iron loading amount, initial toluene concentration, H2O2 concentration, and reaction temperature were investigated. Under the optimal conditions for a Fenton-like reaction (gaseous toluene concentration, 200 mg/m3; H2O2 concentration, 0.15 mol/L; reaction temperature, 303 K), 3-Fe/LXQ-10 was identified to produce OH radical and the toluene removal efficiency reached 93.56%. Gas chromatography-mass spectrometry (GC–MS) was employed to detect the byproducts in the toluene removal process, and the possible degradation pathway of toluene was explored. Radical quenching tests and EPR investigation were carried out to clarify the contribution of OH radical in the Fenton-like process. Physical adsorption and OH oxidation were the possible mechanisms of toluene removal. In addition, the catalyst maintained its activity after the six cycles. suggesting strong stability and reusability. All the results demonstrated that Fe/LXQ-10 showed high potential and economic feasibility to remove gaseous toluene through adsorption and Fenton-like oxidation. This research not only presents a promising alternative for the effective removal of gaseous VOCs but also provides a theoretical basis in the field of VOCs control.