A highly active bimetallic oxide catalyst supported on γ-Al2O3/TiO2 for catalytic wet peroxide oxidation of quinoline solutions under microwave irradiation

A new heterogeneous wet oxidation catalyst, Cu-Ni bimetallic oxides supported on gamma-Al2O3/TiO2, was synthesized using a wet impregnation method. The physicochemical characteristics of the as-synthesized catalyst were assessed using various modern methods such as scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), N-2 adsorption-desorption, and X-ray photoelectron spectroscopy (XPS). Compared with monometallic Cu or Ni oxide catalysts, this new supported Cu-Ni bimetallic oxide catalyst presented a higher activity and stability in quinoline mineralization. The impact of the microwave (MW) power, temperature, pH and H2O2 dosage was studied on the basis of the TOC mineralization. At a MW power of 500 W, pH 7, 333 K and a 22.75 mmol L-1 H2O2 dosage, an 81% abatement of the TOC was reached. Based on the results of metal leaching and XPS analysis, the stability of the Cu-Ni bimetallic supported catalyst, along with the role of the copper and nickel, is discussed.