Stability in catalytic oxidation of styrene over Co₃O₄/Al₂O₃

The application of metal oxides in catalytic oxidation of organic pollutants has gained high interest due to their high efficiency and eco-friendly character. In this study, styrene was catalytically oxidized by coating Co and Ni oxides on Al₂O₃, SiO₂, and Al₂SiO₅ support materials. Combination of 30 wt% Co oxide and Al₂O₃ presented the best styrene catalytic oxidation with detection of Co₃O₄ structure. The impact of different operating conditions on 30 wt% Co₃O₄/Al₂O₃ was also investigated. Higher initial concentration of styrene reduced the active site number and led to lower conversion. Likewise, decline of catalytic performance was also seen in the presence of higher space velocity and the absence of O₂ in the system. In the deactivation test, deposited carbon was found through tests of catalyst characteristic. Moreover, the Langmuir-Hinshelwood and Mars van Krevelen kinetics modeling well fitted the data to describe the reaction kinetics of the study.