Plasma Catalytic Removal of Hexanal over Co–Mn Solid Solution: Effect of Preparation Method and Synergistic Reaction of Ozone

Abstract

Removal of hexanal via a post-plasma catalysis system over a Co–Mn solid solution at ambient temperature and pressure was investigated in this study. Results showed that CoMn(9/1) prepared by a citric acid method exhibited the best catalytic activity, which could be ascribed to the higher redox property. Moreover, the coprecipitation method was applied and improved CO2 selectivity significantly, which could be due to smaller grain size, larger surface area, and higher oxygen storage capacity. The reaction pathway and intermediates were analyzed by in situ Fourier transfrom infrared spectroscopy. In addition, results indicated that the removal of hexanal included direct decomposition by plasma and further oxidation of intermediates on the catalyst surface. Furthermore, it could be inferred that the intermediates were further oxidized by the synergistic effect between active oxygen species and catalyst and that the utilization of ozone was the key point in the process.