(6br) Environmental Applications of Al/Zr Pillared Clay As Efficient Heterogeneous Catalyst for Catalytic Wet Oxidation of Phenol

Natural bentonite clay was used in the synthesis of single and mixed oxide Al/Zr pillared clay catalysts by means of ultrasonic treatment during the aging and intercalation steps. The raw bentonite and pillared clay catalysts were characterized using high resolution scanning electron microscopy with energy dispersive system (HRSEM-EDS), powder X-ray diffraction (PXRD), N₂ adsorption/desorption, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), cation exchange capacity (CEC), zeta potential and all the catalysts evaluated in the catalytic wet air oxidation (CWAO) of phenol. Calcination of the synthesized Al/Zr-PILC at 500 °C for 120 minutes yielded optimum physical properties with BET surface area of 230 m²/g, pore volume of 0.115 cm³/g and basal spacing of 1.92 nm and with good thermal stability. Complete oxidation of phenol in aqueous solution using the Al/Zr-PILC catalyst under mild reaction conditions of 100 °C and 10 bars occurred after 120 minutes reaction time. The process obeyed the first-order kinetics by assuming a constant concentration of oxygen. Catalyst reusability studies showed that the Al/Zr-PILC catalyst demonstrated excellent chemical and structural stability with insignificant leaching of Zr⁴⁺ after six consecutive catalytic runs. The Al/Zr-PILC catalyst therefore demonstrated excellent catalytic properties in the CWAO of phenol in aqueous solution.

Teaching Interests: Material Science and Environmental Catalysis