High ratio of Ce/(Ce+Ce) enhanced the plasma catalytic degradation of n-undecane on CeO/γ-AlO.

n-Undecane (C11) is the main component of volatile organic compounds (VOCs) emitted from the printing industry, and its emission to the atmosphere should be controlled. In this study, a dielectric barrier discharge reactor coupled with CeO/γ-AlO catalysts was used to degrade C11. The effect of the chemical state of CeO on C11 degradation was evaluated by varying the CeO loading on γ-AlO. The C11 conversion and COx selectivity were as high as 92% and 80%, respectively, under mild reaction conditions of energy density 34 J/L and 423 K to degrade 134 mg/m C11 in a simulated air using 10 wt%CeO impregnated on γ-AlO. After analyses using in-situ plasma diffuse reflectance Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry, it was found that most of C11 were degraded to CO, and the main by-products on catalyst surfaces were alcohols and ketones. It was concluded from X-ray photoemission spectroscopy that the good performance of the 10 wt%CeO/γ-AlO catalyst was due to its high Ce/(Ce+Ce) ratio as well as the oxygen vacancies. The Ce/(Ce+Ce) ratio of CeO on γ-AlO is crucial for the degradation of C11, providing a further roadmap for the plasma catalytic oxidation of alkanes.