Plasma-enhanced catalytic oxidation of ethylene oxide over Fe-Mn based ternary catalysts

In this work, Fe-Mn based ternary catalysts (Fe-Mn-X, X = Ce, Co and Cu) were evaluated in the plasma-catalytic oxidation of ethylene oxide (EO) using a cylindrical dielectric barrier discharge (DBD) reactor. The addition of transition metal dopants to the Fe-Mn catalyst significantly improved the performance of plasma-catalyzed EO oxidation compared to the reaction using plasma only and the Fe-Mn catalyst. The highest EO conversion (91.9%) and CO2 selectivity (78.9%) were obtained over the Fe-Mn-Co catalyst at a specific energy input (SEI) of 730.2 J l- 1. Moreover, the presence of water vapor improved EO conversion and CO2 selectivity in the relative humidity (RH) range of 0-60%, while further increasing the RH to 80% reduced EO conversion. The interactions between Fe, Mn and dopants increased the specific surface area and pore volume of the Fe-Mn-X catalyst, while maintaining the crystalline structure of the catalysts. The presence of the dopants enhanced the reducibility of the Fe-Mn-X catalysts and produced more surface adsorbed oxygen (Oads) on the catalyst surfaces. Moreover, the interactive effects among the Fe, Mn and dopants facilitated the plasma-catalytic oxidation reactions via enhanced surface reactions. The coupling of plasma with the Fe-Mn-Co catalyst reduced the formation of organic by-products in the plasma-catalyzed oxidation of EO.

Automated summary

In this study, Fe-Mn based ternary catalysts were evaluated for the plasma-catalytic oxidation of ethylene oxide. The addition of transition metal dopants significantly improved the catalyst performance. The presence of water vapor improved the reaction performance, but high humidity reduced the performance.