Delafossite-alumina nanocomposite for enhanced catalytic wet peroxide oxidation of anionic pollutants

Abstract

Mass transfer efficiency and catalytic reactivity are the two major hurdles for heterogeneous catalytic wet peroxide oxidation (CWPO) technologies. To address these issues, nanocomposite CuFeO2/Al2O3 was synthesized and assessed as a novel catalyst for enhanced adsorption and oxidation of anionic pollutants (catechol and reactive red 195 (RR195)) in waters. With a positive charge on the nanocomposite by introducing Al2O3, the adsorption of anionic pollutants was promoted. The surface complexation reaction on CuFeO2/Al2O3, which fits well to the Langmuir isotherm, has engined the mass transfer of pollutants to the nanocatalyst that demonstrated 96.46% and 99.75% removal of catechol and RR195 at pH 3, respectively. CuFeO2/Al2O3 also showed good performance in various reaction media including binary pollutants system and real wastewaters. The hydroxyl radical in aqueous solution played a major role in the pollutants degradation. The CWPO, which followed the Haber-Weiss mechanism, has been accelerated by the Cu and Fe redox cycles. The robustness of the catalyst was verified by negligible amount of metal leaching from the catalysts along with stable catalytic performance after five cycles. Upon the observed results, CuFeO2/Al2O3 with the synergistic effect has shown to be a promising catalyst for removal and degradation of anionic pollutants in CWPO.