Microwave-assisted heterogeneous photocatalytic oxidation of ethylene

Porous TiO2 and SO42-/TiO2 catalysts were prepared by sol-gel method and charaterized by XRD, N-2 sorption analysis applying BET method, and microwave absorption spectrum. Photocatalytic oxidation of C2H4 in air stream was studied. The results showed that the photocatalytic activity of both SO42-/TiO2 and TiO2 catalysts was obviously increased under the reaction condition of ultraviolet combined with microwave. The conversions of ethylene over TiO2 and SO42-/TiO2 were enhanced from 20% and 41% (UV) to 27% and 62%(UV+MW), respectively. The effect of MW on SO42-/TiO2 catalyst was more notable, The improvement on photocatalytic activity was attributed to the polarization effect of the highly defected catalysts in microwave field, which increased the transition probability of photon-generated electrons and decreased the electron-hole recombination on semiconductor surface.