| Summary: | 碩士 === 國立中正大學 === 化學工程所 === 96 === The goal of this study is to understand the effects of the structures of VOx-Al2O3 and VOx-SiO2 on the oxidation reaction. Catalysts are prepared by impregnation methods with TiO2-grafted, and calcination temperature as operating parameters. The efficacy of the catalyst was examined by oxidation reaction of 1,2-dichlorobenzene . The oxidation tests were carried out at a fixed bed reaction system under 1 atm and temperature ranged from 200 to 550˚C. The structures of catalysts were characterized by FT-IR (Fourier transform-Infrared spectroscopy), synchrotron XRD (X-ray diffraction), and XAS (X-ray adsorption spectroscopy). Correlation between catalysts and oxidation performance, we conclude：
1. Grafted TiO2 on silica promote V2O5 dispersion, thereby increasing conversion and CO2 selectivity.
2. Alumina support enhances V2O5 dispersion, whereas the catalytic performance can not be enhanced as well.
3. Inferred from in-situ XAS and TPR results, we suggest the 1,2-dichlorobenzene oxidation reaction is dominated by reductive decomposition of V2O5. Based on the inference, we suggest the un-expected results for the V2O5 /alumina samples are due to strong V2O5 -alumina interactions; V2O5 on alumina is harder to be reduced than that on TiO2/SiO2.
4. For industry application, reaction temperature of 250˚C or higher is suggested, because at this temperature no secondary VOC emission resulting from oxidative fragmentation of 1,2-dichlorobenzene being observed.
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