Three manganese oxide catalysts (MnO x ) were synthesized via a simple method, and then they were introduced into the non-thermal plasma (NTP) system for benzene removal. The XRD and EXAFS results showed the MnO x were mainly in the Mn 3 O 4 phase, and from the analysis of N 2 adsorption/desorption isotherms, we knew the MnO x calcined at 250 °C (Mn250) had the largest surface area of 274.5 m 2 g −1 . Besides, Mn250 also exerted higher benzene adsorption capacity (0.430 mmol g −1 ) according to C 6 H 6 -TPD. O 2 -TPD indicated that Mn250 showed better oxygen mobility than Mn300. Moreover, by analyzing XPS results, it revealed that Mn250 exhibited rich abundant of surface adsorbed oxygen species (O ads ) and moderate ratio of Mn 4+ /Mn 3+ , and the reducibility temperature was also the lowest among all the MnO x catalysts drawn by H 2 -TPR profiles. As a result, Mn250 combined with NTP could remove 96.9% of benzene at a low input power of 3 W (benzene concentration 200 ppm, and GHSV 60,000 mL g cat. −1 h −1 ), performing the best catalytic activity among the three catalysts and plasma only. Furthermore, the “NTP + Mn250” system also produced the highest CO 2 concentration and lowest CO concentration in downstream, and the residual O 3 after catalytic reaction was also the lowest, that is to say, the synergistic effect between NTP and Mn250 was more effective than other catalysts in benzene removal. [Figure not available: see fulltext.].
All Science Journal Classification (ASJC) codes
- Environmental Chemistry
- Health, Toxicology and Mutagenesis