فهرست مطالب xianxian wei

In this study, a series of LaCoO3 perovskite catalysts with varying calcination temperatures were synthesized hydrothermally, and their structure, morphology, and optical properties were investigated using X-Ray powder Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray electron spectroscopy analysis (XPS), Magnetic Property Measurement System (MPMS), and other characterization techniques. Using phenol as the target degradation product, the photocatalytic degradation reaction was carried out in the presence of visible light. In addition, the photocatalytic mechanism of LaCoO3 perovskite was also discussed. The experimental results showed that the LaCoO3 perovskite catalyst has been prepared with good crystallization. The particle size of the catalysts ranged from 10 to 40 nm, and the specific surface area decreased with calcination depth. Moreover, all the LaCoO3 catalysts showed strong paramagnetism, and the particles were regularly agglomerated under the action of magnetic force. LaCoO3 catalyst (the calcination temperature of 750 °C) exhibited high photocatalytic activity. In addition, the study of photocatalytic mechanisms revealed three degradation pathways for degrading phenol into inorganic small molecules such as CO2 and H2O via highly active HO•, HO2•, and h+ radicals.

The Al, Zr, and Ti modified MCM-41 materials were prepared by the post-synthesis method, and then the Ni-W species were introduced on them by using the co-impregnation method in order to obtain high-performance hydrodenitrogenation (HDN) catalysts. The activity of the catalysts was evaluated by the HDN reaction of quinoline. The optimum HDN activity was observed on the catalyst supported on the Al modified MCM-41. The high performance of the NiW/Al catalyst was due to the higher dispersion of Ni, W species, the more density of acid sites, the more appropriate nature of W species, and the lower reduction temperature of W species. Moreover, the catalysts prepared by co-impregnation method showed better performance than the catalysts prepared by the sequential impregnation method in the HDN of quinoline.