By-product reduction for the non-thermal plasma removal of toluene using an α-MnO2/Cordierite honeycomb monolithic catalyst in a honeycomb structure

The practical implementation of non-thermal plasma (NTP) combined with catalysts still faces challenges due to the by-products, such as O3 and nanoparticles. In this study, α-MnO2/Cordierite honeycomb monolithic (CHM) catalyst was used to reduce the by-products for NTP degradation of toluene. The by-products analysis shows that using the α-MnO2/CHM catalyst not only improves the degradation efficiency up to 98% and COX selectivity to 50%, but also simultaneously and greatly reduces the release of three types of hazardous by-products, organic components, ozone, and particles. The mechanisms of toluene degradation and by-product formation were investigated through online monitoring which can be summarized in two ways: direct degradation by energetic electrons and reactive radicals in the discharge region, and deep oxidation by active oxygen species on the catalyst surface. This investigation can improve our understanding of VOC degradation by combining monolithic catalysts with plasma, and accelerate the implementation of plasma-catalyzed technology in real-world.