Promoted chlorobenzene deep oxidation over CeCo₁₀O_x-P nanosheet catalyst via acid site and oxygen vacancy rational construction

Developing economically efficient catalysts with excellent deep oxidation performance and rapid dechlorination capability to inhibit the formation of by-products is crucial for the purification of chlorinated volatile organic compounds (CVOCs). Herein, a phosphate-modified spinel phase CeCo₁₀O_x-P nanosheet catalyst with reasonably regulated surface acidity and redox capacity was synthesized for catalytic oxidation of chlorobenzene (CB). Compared with the Co₃O₄ catalyst, Ce doping and phosphate acid modification separately increase the active O_latt and Co³⁺ species by 4 % and 33 %, achieving 90 % conversion of 500 ppm CB at 275 °C. Additionally, the CeCo₁₀O_x-P catalyst with abundant acidic hydroxyl groups created by phosphate modification can accelerate the degradation of phenol (initial product of CB oxidation) into quinone or carboxylic acid compounds, and therefore promotes the deep oxidation reaction. Meanwhile, the introduced hydroxyl groups as the important proton-giving sites facilitate the desorption of Cl species, efficiently inhibiting the generation of 13 by-products and avoiding the formation of m-dichlorobenzene, p-dichlorobenzene and 1,2-dichloroethane. This work provides a feasible and promising strategy for engineering efficient catalysts for industrial CVOC destruction.