Plasma-catalyst hybrid reactor with CeO 2 /γ-Al 2 O 3 for benzene decomposition with synergetic effect and nano particle by-product reduction.

A dielectric barrier discharge (DBD) catalyst hybrid reactor with CeO2 /γ-Al2 O3 catalyst balls was investigated for benzene decomposition at atmospheric pressure and 30 °C. At an energy density of 37-40 J/L, benzene decomposition was as high as 92.5% when using the hybrid reactor with 5.0wt%CeO2 /γ-Al2 O3 ; while it was 10%-20% when using a normal DBD reactor without a catalyst. Benzene decomposition using the hybrid reactor was almost the same as that using an O3 catalyst reactor with the same CeO2 /γ-Al2 O3 catalyst, indicating that O3 plays a key role in the benzene decomposition. Fourier transform infrared spectroscopy analysis showed that O3 adsorption on CeO2 /γ-Al2 O3 promotes the production of adsorbed O2 - and O2 2‒ , which contribute benzene decomposition over heterogeneous catalysts. Nano particles as by-products (phenol and 1,4-benzoquinone) from benzene decomposition can be significantly reduced using the CeO2 /γ-Al2 O3 catalyst. H2 O inhibits benzene decomposition; however, it improves CO2 selectivity. The deactivated CeO2 /γ-Al2 O3 catalyst can be regenerated by performing discharges at 100 °C and 192-204 J/L. The decomposition mechanism of benzene over CeO2 /γ-Al2 O3 catalyst was proposed.