Title: | Synthesis of xCe-MnO(2) with three-dimensional ultra-thin nanosheet structure and its excellent low-temperature reducibility for toluene catalysis |
Address: | "School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China. School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China. mlfu@scut.edu.cn. Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, Guangzhou, 510006, China. mlfu@scut.edu.cn. National Engineering Laboratory of Volatile Organic Compounds Pollution Control Technology and Equipment, Guangzhou, 510006, China. mlfu@scut.edu.cn" |
Journal Title: | Environ Sci Pollut Res Int |
DOI: | 10.1007/s11356-023-28715-2 |
ISSN/ISBN: | 1614-7499 (Electronic) 0944-1344 (Linking) |
Abstract: | "A series of xCe-MnO(2) (x = 0-1) catalysts were synthesized using ammonium oxalate as a precipitator via the redox precipitation method and hydrothermal synthesis method. The results indicate that 0.25Ce-MnO(2) exhibited the highest catalytic activity for toluene oxidation, with the T(99) of 240 degrees C. Characterization results from XRD, Raman, SEM, TEM, EDS-mapping, BET, and other techniques reveal that the 0.25Ce-MnO(2) catalyst exhibited a three-dimensional multistage ultrathin nanosheet structure by adjusting the introduction amount of Ce, with abundant active sites, and effectively formed Ce-Mn homogeneous dispersion. The larger pore size and volume of 0.25Ce-MnO(2) catalyst lead to it excellent toluene transfer ability. Furthermore, compared with MnO(2), the crystal pattern of 0.25Ce-MnO(2) shifted to the tetragonal cryptomelane type alpha-MnO(2) phase and exposed more crystal planes which are beneficial to catalyze toluene. H(2)-TPR, O(2)-TPD, and XPS characterization further confirmed the strong interaction between Ce and Mn oxides, which exhibited better low-temperature reducibility and oxygen migration, along with abundant Ce(3+) and Mn(3+) species, where lattice oxygen played a major role. Moreover, in situ DRIFTS revealed that the 0.25Ce-MnO(2) catalyst showed higher adsorption and desorption capacity for toluene than the MnO(2) catalyst, and benzoate species were the key intermediates for catalytic oxidation. Additionally, benzoate and surface phenolic species were the key intermediates for catalytic oxidation of MnO(2). Because 0.25Ce-MnO(2) possesses better ability of converting toluene to benzoate species, it exhibits better activity" |
Keywords: | *Oxides/chemistry *Toluene/chemistry Temperature Manganese Compounds/chemistry Oxidation-Reduction Catalysis Oxygen/chemistry Ammonium oxalate Crystal faces In situ DRIFTS Low temperature reduction Toluene oxidation xCe-MnO2; |
Notes: | "MedlineLi, Zhi Su, Chunjing Yan, Ying Fu, Mingli eng 518708079/the National Natural Science Foundation of China/ 2018YFB0605200/the National Key Research and Development Plan/ 2020M682715/China Postdoctoral Science Foundation/ Germany 2023/07/25 Environ Sci Pollut Res Int. 2023 Aug; 30(40):92238-92254. doi: 10.1007/s11356-023-28715-2. Epub 2023 Jul 24" |