The Role of Mn Doping on Ce-Based γ-Al2O3 Catalysts for Phenol Degradation

In this article, Mn doping on Ce-based γ-Al2O3 (i.e., Mn-Ce-γ-Al2O3) was synthesized and then employed as catalysts to study the removal of phenol from aqueous solutions through catalytic ozonation process. The results showed that the phenol removal was remarkably increased to 97.50% if Mn-Ce-γ-Al2O3 was adopted as the catalyst. In addition, the kinetic rate of the reaction was increased, approximately, about 1.49 times when using Ce-γ-Al2O3 catalyst with Mn doping. Moreover, X-ray diffraction, transmission electron microscopy, Brunner-Emmet-Teller measurements, and X-ray photoelectron spectroscopy techniques were used to comprehensively characterize the physicochemical properties of the synthesized Mn-Ce-γ-Al2O3 catalyst, including the phases, morphologies, textural properties, and dispersity of the surface active species. More uniform channel mesoporous structures were obtained after Mn doping on Ce-γ-Al2O3, which could enhance the gas-liquid mass transfer rate, surface hydroxyl groups, Ce3+/Ce4+ ratio, and the formation of Mn-Ce solid solution. In this study, the effects of Mn doping on Ce-based γ-Al2O3 on phenol degradation were investigated and the removal mechanisms were suggested for a better understanding of the improved removal efficiency.