Exposed ternary metal active sites on mesoporous channels: A promising catalyst for low-temperature selective catalytic oxidization of phenol with H₂O₂

Multi-components-bearing mesoporous silica pays the way to the controlling of catalytic selective oxidation by virtue of the synergy of several functional active species in the catalyst, but still faces huge challenge in design and preparation of this functional catalyst. Herein, we rationally constructed a steady ternary-component catalyst (FAM-MS) by incorporating three kinds of catalytically active centers Fe, Al and Mn into the skeleton of mesoporous silica, which reveals a potential industrial application prospect. These resultant catalyst samples were investigated thoroughly by various means, which include XRD, HRTEM, N₂-isotherms, UV–vis, and XPS. The present results indicated that the FAM-MS catalyst affords narrow pore size distribution (2.71 nm), 2D hexagonal mesostructure and huge specific surface area (918 m²·g⁻¹) which accordingly contributes to a capacious catalytic reaction space. In addition, the synergy of tri-active components shows greater ability to improve the selectivity of DHB, compared to single-active component and dual-active components ones. As a result, the catalyst FAM-MS shows an optimal catalytic activity (22.8% conversion & 93.1% selectivity DHB) under the optimal reaction conditions for selective oxidization of high concentration of phenol solution (ca. 30%) with H₂O₂ by virtue of the solubilizing effect of lauryl sodium sulfate in the reaction system. More importantly, the resulted catalyst reveals a durable catalytic activity with puny activity-loss (20% conversion & 90% selectivity DHB) during the fifteen recycling, which exhibits potential industrial application prospect.