Synthesis of flower-like Co3O4–CeO2 composite oxide and its application to catalytic degradation of 1,2,4-trichlorobenzene

A micrometer-sized, nanostructured, flower-like Co3O4–CeO2 composite oxide was synthesized by an ethylene-glycol-mediated process. The composite oxide was an assembly of polycrystalline nanoparticles, with a typical mesoporous structure. The composite's catalytic activity in 1,2,4-trichlorobenzene degradation was evaluated using a pulsed-flow microreactor–gas chromatography system, and compared with that of quartz sand, commercial CeO2, commercial Co3O4, and a Co3O4/CeO2 equimass mixture. The composite oxide was a promising catalyst for 1,2,4-trichlorobenzene degradation. This is attributed to the structural features of the composite oxide with a high specific surface area and a high total pore volume, and the synergistic effect between the two composite phases. The easy creation of high-mobility active oxygen on CeO2 and the easy cleavage of CoO bonds at the interface of the two components promote reactivity of Co3O4 in 1,2,4-trichlorobenzene degradation. Pulsed catalytic theory suggests a first-order reaction between the composite oxide and 1,2,4-trichlorobenzene, with an apparent activation energy of about 27 kJ/mol, and degradation on the Co3O4–CeO2 composite oxide would occur easily.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights▸ A flower-like Co3O4–CeO2 composite oxide was synthesized to degrade 1,2,4-trichlorobenzene. ▸ The Co3O4–CeO2 composite oxide showed the best catalytic performance in the degradation of 1,2,4-trichlorobenzene, with an apparent activation energy of 27 kJ/mol under pulsed conditions. ▸ The high activity was attributed to the composite oxide's structural features and synergistic catalytic effects between the two phases of the composite.