Low-Pressure Catalytic Wet Air Oxidation of Aniline Over Co3O4/CeO2

Low-pressure catalytic wet air oxidation of aniline was investigated in a bubble reactor over Co3O4 (10% wt)/CeO2. The catalyst was prepared by sol-gel technology and characterized by using scanning electron microscope, X-ray diffraction, nitrogen adsorption, and thermogravimetric analysis techniques. The aim was to search for the conditions to destroy the aniline content by avoiding production of byproducts such as ammonium, nitrate, and nitrite ions. The reaction was optimized at 0.5 g/L catalyst loading at 150 degrees C with a pressure of 4 atm, in 2 h with an air flow rate of 1.36 L/min. A 35.15% amount of aniline was removed, and 14% of the input nitrogen was converted into N-2 gas. To evaluate the stability of the catalyst, two consecutive runs were performed by reusing the catalyst recovered. The highest removal with the reused catalyst was found as 34.94%, showing that Co3O4/CeO2 is a stable catalyst.