华东理工大学王丽副教授
https://doi.org/10.1016/j.chemosphere.2022.135861
Abstract
Supported Pt catalysts usually produce chlorinated byproducts during chlorinated volatile organic compounds (CVOCs) combustion, the removal of formed surface chlorine species is the key to improve the activity, selectivity and stability. In this paper, the Pt chemical state is adjusted by the interaction between Pt and CeO2 through controlling the morphology of CeO2, which further affects the catalytic performance of VC combustion. For Pt/CeO2-octahedron, the weak interaction between Pt and CeO2 results in the formation of PtO2, facilities VC adsorption and C–Cl bonds cleavage and becomes a key active site to accommodate the dissociated Cl species. While the strong interaction leads to the formation of PtxCe1-xO2-σ solid solution on Pt/CeO2-rod has relative lower ability in Cl species removal compared with PtO2. Density functional theory (DFT) calculations also confirms that the introduced Pt species reduces the concentration of Cl species on the surface as well as the chlorinated-byproducts. Hence, Pt/CeO2-octahedron outperformed Pt/CeO2-rod and Pt/CeO2-cube with 90% VC conversion at 280 °C. Furthermore, under the same VC conversion (90%), the concentration of chlorinated byproducts on Pt/CeO2-octahedron was only 4% than that of Pt/CeO2-rod.
武汉科技大学王钰
https://doi.org/10.1016/j.apcata.2022.118809
Abstract
FMO was doped with nickel (NFMO) and lanthanum (LFMO) and compared for catalytic oxidation of chlorobenzene (CB), with NFMO showing superior activity (T90 = 192 ℃, 600 ppm CB/dry air, GHSV=20,000 h−1), CO2 selectivity and durability. And great water-resistance with T90 = 195 °C in humid air (H2O = 1.6 wt%), which is critical for real-world applications. The strong interaction between Ni and FMO enhances the contents of both reactive oxygen species (ROS) and surface Mn4+ species, which elevate the low temperature reactivity of NFMO. Both total acid content and Lewis/Brønsted acid ratio were enhanced during the nickel doping process. The stronger and more Lewis acid sites facilitated the dechlorination reaction and C-C band cleavage, further improving the catalytic performance at lower temperature. Oppositely, the addition of lanthanum reduced the total acid content and Lewis/Brønsted acid ratio, resulting in the Cl species accumulation at La-Fe or La-Mn interfaces and deactivation of LFMO.
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