Competitive Adsorption of O2 and Toluene on the Surface of FeOx/SBA-15 Catalyst

Abstract

The adsorption of volatile organic compounds (VOCs) and O 2 on the surface of the catalyst was one of the vital progresses in the plasma-catalytic oxidation of VOCs. In this work the breakthrough curves of toluene adsorption on the 3%FeO x /SBA-15 were measured under the various O 2 concentrations. The results showed that the breakthrough time of toluene reduced with increasing O 2 . Competitive adsorption was observed on the catalyst surface between O 2 and toluene. The catalysts adsorbed the toluene under the various O 2 concentrations were characterized by O 2 temperature-programmed desorption (O 2 -TPD), and X-ray photoelectron spectroscopy (XPS). The desorption amounts of O 2 -and the Fe percentage on the catalyst surface were dependent on the O 2 concentration during toluene adsorption. The experimental results of pure SBA-15 and 5%MnO x /SBA-15 indicated the competitive adsorption site of O 2 and toluene was FeO x . In situ FTIR data of toluene adsorption on the catalyst surface indicated that the adsorption state of toluene could not be impacted by the competitive adsorption of O 2 , and the O 2 adsorbed on the catalyst could oxidize toluene.