Efficient degradation of gaseous benzene by VUV photolysis combined with ozone-assisted catalytic oxidation: Performance and mechanism

• VUV photolysis was firstly combined with an efficient Mn/ZSM-5 catalyst.
• Both benzene and O3 were completely removed by VUV-OZCO.
• O3 can be used to enhance benzene degradation through OZCO.
• The pathways and mechanism of benzene degradation was proposed.

Vacuum ultraviolet (VUV) photolysis is a simple way to destroy volatile organic compounds (VOCs). However, its application is greatly limited by the formation of O3 byproduct and the low degradation capacity. In this study, we are the first combining an efficient Mn/ZSM-5 catalyst with VUV photolysis to eliminate O3 and improve VOC degradation efficiency via ozone-assisted catalytic oxidation (OZCO). Results indicate that the benzene removal efficiency is only 48% with 83 ppm residual O3 in the VUV photolysis process. However, both benzene and O3 were completely removed after the adoption of the Mn/ZSM-5 catalyst. O3 can be efficiently decomposed by Mn/ZSM-5 and used for benzene degradation through the OZCO. The possible degradation pathways and mechanism in such a novel VUV-OZCO process was proposed according to the identified products and intermediates. This study provides an efficient and promising process and unique insights for the degradation of VOCs.

O3 can be efficiently decomposed by MnO2/ZSM-5 and used for benzene degradation through the OZCO.Figure optionsDownload as PowerPoint slide