Catalytic wet air oxidation of phenol over nano mesoporous lanthanum oxide synthesized by chitosan template method

Abstract

The study investigates the effectiveness of nano mesoporous lanthanum oxide (La2O3), synthesized by the chitosan template method, as a catalyst for the wet air oxidation of phenol (WAO). To relate the performance of the synthesized La2O3 to its chemical and textural characteristics, it was subjected to a thorough characterization using various analytical techniques, including TG-DTG, XRD, FTIR, BET, TEM, TPD-CO2, TPD-NH3, and H2-TPR. Nanomesoporous La2O3 displayed remarkable efficiency in removing phenol and total organic carbon (TOC) while exhibiting a greater preference towards non-organic compounds. Significant improvement in removal efficiency and selectivity when compared to non-catalytic wet air oxidation is observed for the catalyst. The study investigated the impact of temperature, catalyst dosage, airflow, and phenol pumping rate on the catalytic wet air oxidation (CWAO) of phenol. Even after 6 h of continuous reaction, La2O3 exhibited exceptional catalytic stability. The mesoporous nature and presence of Lewis basic sites in nano-La2O3 may be crucial in facilitating the degradation of phenol and enhancing the efficiency of TOC removal. The study concludes that the chitosan template method is an effective approach for synthesizing nano mesoporous lanthanum oxide, which could be used as a promising catalyst for the treatment of phenol-containing wastewater.