Catalytic Ozonation of Atrazine Enhanced by Mesoporous CeO2: Morphology, Performance and Intermediates

Abstract

Heterogeneous catalytic ozonation is an alternative approach for the removal of refractory pollutants from water, and the fabrication of mesoporous materials with high dispersibility would enhance the catalytic efficiency. A mesoporous CeO2 was prepared by the nanocasting method with SBA-15 as a hard template, and was investigated in the catalytic ozonation of atrazine. The synthetical CeO2 nanorods have a specific surface area of 95.08 m2/g, a diameter of 10.16 nm, and a spacing of 2.18 nm. The removal rate of atrazine was 85.5%, 64.8%, and 46.4% in the order of catalytic ozonation by synthetical CeO2 > single ozonation > catalytic ozonation by commercial CeO2, respectively. The superior activity of the synthetical CeO2 could be attributed to the well-ordered mesoporous structure, the high surface area, and the redox Ce3+/Ce4+ cycling. Moreover, eight organic intermediates were identified after one minute of catalytic ozonation of atrazine, and the cleavage of the ethylamino group was proposed as the main pathway of atrazine degradation.