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付贤智, XIAN ZHIFU, LOU ISA. CLARK, QING YANG, MARCA . AND ERSON
Environ. Sci. Technol. 1996, 30, 647-653,-0001,():
-1年11月30日
Sol-gel prepared mixtures of silica or zirconia with titania are shown to have significantly higher activities than pure titania for the complete photocatalytic oxidation of ethylene. These higher activities are only apparentwhen the respective catalysts are stabilized by sintering. The differences become even more pronounced when the catalysts are used in a tubular reactor. Optimum mixture concentrations are found to be 12 wt % zirconia and 16 wt % silica in titania. Both catalyst types exhibit activity maxima with respect to sintering temperature. It is hypothesized that the maxima arise from opposing effects of densification and phase transformation versus beneficial sintering. A comparison of our catalyst compositions with literature in this area suggests that the increase in activity due to the addition of silica or zirconia may be a result of higher surface acidity. However, isoelectric point measurements employing the unsintered and sintered catalysts show no conclusive increase in surface acidity. The effects of sintering temperature on the surface area, porosity, and crystal structure of the catalysts are also presented.
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【期刊论文】The gas-phase photocatalytic mineralization benzene on porous titania-based catalysts
付贤智, Xianzhi Fu, Walter A. Zeltner , Marc A. Anderson
X. Fu et al. Applied Catalysis B: Environmental 6 (1995) 209-224,-0001,():
-1年11月30日
Photocatalytic degradation of benzene in oxygen-containing gaseous feed streams was investigated using titania and platinized (0.1 wt.-%) titania photocatalysts. The titania catalyst was synthesized using sol-gel techniques. Results of this study indicate that, when using this particular photocatalyst, benzene was oxidized to carbon dioxide and water without forming any detectable organic reaction products in the reactor effluent, although only some of the benzene reacted. Both the overall conversion of benzene and its mineralization were improved by platinizing the titania. When the titania catalyst was platinized, both photocatalytic and thermocatalytic reactions were promoted. Rates of photocatalytic reactions were significantly enhanced at reaction temperatures between 70 and 90
hotocatalysis, Photocatalytic oxidation, Thermocatalytic oxidation, Titania, Platinized titania, Solgel process, Benzene, Environmental remediation, Mineralization
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【期刊论文】Template Synthesis of Hollow Metal Oxide Fibers with Hierarchical Architecture
付贤智, Rusheng Yuan, Xianzhi Fu, * Xinchen Wang, Ping Liu, Ling Wu, Yiming Xu, Xuxu Wang, Zhanyi Wang
Template Synthesis of TiO2 and Fe2O3 Fibers Chem. Mater., Vol. 18, No. 19, 2006,-0001,():
-1年11月30日
Hollow metal oxide fibers [TiO2 and Fe2O3] have been prepared by using activated carbon fibers [ACFs] as the templates, through a simple impregnation and heat treatment. The resulting products, as compared to ACFs, possessed not only a similar morphological feature upward to the micrometer scale but also different surface nanostructures with unique morphology. The TiO2 fibers displayed overlapped “wormlike” surface and a hierarchical structure with two distinguishable layers, the inner layer and the outer layer, which were composed of the particles of 7 and 15 nm, respectively. It was also found that the reaction temperature had a significant effect on the TiO2 surface morphology. The Fe2O3 fibers exhibited a rough and crinkle-like surface and were also composed of hierarchical particles. Both TiO2 and Fe2O3 fibers possessed the hierarchical pore structure with mesopores in the walls of the large hollow channel. Such porous architecture favored the resultant TiO2 with better apparent photoactivity than P25 titania for degradation of gaseous acetone and would also make the materials useful for further application in other fields.
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付贤智, Xianzhi Fu, Walter A. Zeltner, Qing Yang, and Marc A. Anderson
JOURNAL OF CATALYSIS 168, 482-490 (1997),-0001,():
-1年11月30日
Catalytic hydrolysis of dichlorodifluoromethane (CFC-12) in a humid air stream was studied over pure and sulfate promoted TiO2 catalysts which were prepared by sol-gel methods. The results showed that complete conversion of CFC-12 on unmodified TiO2 was achieved at reaction temperatures higher than 340±C under the employed reaction conditions. The selectivity to CO2 ([CO2]produced/[CFC-12]converted) varied from 0.5 to 0.88 over the range of 250–350±C and CClF3 (CFC-13) was detected as the main by-product. Surface fluorination of the TiO2 catalyst during the reaction improved its activity, induced the formation of the fluorinated by-product CFC-13, and changed such properties of the catalyst as its specific surface area, pore size distribution, and crystal size. It was found that the catalytic and structural properties of TiO2 were greatly improved by sulfation. The sulfated TiO2 (TiO2/SO42-) exhibited excellent reaction activity and selectivity for CFC-12 catalytic decomposition at low reaction temperatures (190–250±C) while retaining a stable structure. Complete decomposition of CFC-12 with stoichiometric production of CO2 was observed over the TiO2/SO42- catalyst at 250±C under otherwise identical reaction conditions as used for pure TiO2. Results of catalyst characterization by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and N2 sorption analysis indicated that surface sulfate species formed on the sulfated TiO2. When compared to unmodified TiO2, the sulfated TiO2 exhibited higher resistance to crystal phase transformation from anatase to rutile, higher resistance to the deleterious effects of fluorination of the catalyst, and higher specific surface area. Fluorination of the catalyst did not improve the activity of sulfated TiO2 and no CFC-13 was detected as a by-product, indicating that fluorine was not involved in the formation of reaction sites over the sulfated TiO2 catalysts. °c 1997 Academic Press.
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付贤智, Xianzhi Fu, Louis A. Clark, Walter A. Zeltner, Marc A. Anderson
X. Fu et al. Journal of Photochemistry and Photobiology A: Chemistry 97 (1996) 181-186,-0001,():
-1年11月30日
The photocatalytic degradation of ethylene in airstreams has been studied over the temperature range 30-110
Photocatalysis, Photocatalytic oxidation, Ethylene, Water vapour, Titania, Heterogeneous catalysis
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