Synthesis and Optimization of Foam Copper-Based CoMnO_<i>x</i>@Co₃O₄/CF Catalyst: Achieving Efficient Catalytic Oxidation of Paraxylene

This study successfully developed a foam copper (CF)-based CoMnO_<i>x</i>@Co₃O₄/CF composite catalyst, achieving efficient thermal catalytic oxidation of paraxylene through multifactor optimization of synthesis conditions. At a Co:Mn molar ratio of 2:1 and a calcination temperature of 450 °C, the catalyst exhibited outstanding catalytic performance, with a <i>T</i>₉₀ temperature as low as 246 °C, significantly lower than that of catalysts synthesized under other conditions. Additionally, BET, XPS, Raman, EPR, and H₂-TPR test results indicate that the catalyst possesses a high specific surface area, abundant oxygen vacancies, a distribution of multivalent Co and Mn species, and a lower hydrogen reduction temperature, all of which contribute to the high catalytic activity of CoMnO_<i>x</i>@Co₃O₄/CF. Furthermore, <i>in situ</i> DRIFTS confirmed that the oxidation of paraxylene on CoMnO_<i>x</i>@Co₃O₄/CF follows the Mars-Van Krevelen (MvK) mechanism. The proposed reaction pathway begins with the oxidation of the methyl group on paraxylene, followed by the opening of the benzene ring and further oxidation to CO₂ and H₂O. The innovative structural design and excellent catalytic performance of this catalyst provide new insights and solutions for the industrial treatment of VOCs.