A series of catalysts were prepared by doping different loadings of CeO2 over TiO2-SiO2-WO3 and used for the selective catalytic reduction of NOx by NH3. The experimental results showed that the selective catalytic re...A series of catalysts were prepared by doping different loadings of CeO2 over TiO2-SiO2-WO3 and used for the selective catalytic reduction of NOx by NH3. The experimental results showed that the selective catalytic reduction（SCR） performance and SO2-resistant ability of TiO2-SiO2-WO3 were greatly enhanced by the introduction of cerium. The catalyst containing 10% CeO2 showed the highest NO conversion in a wide temperature range and good N2 selectivity with broad operation temperature window at the gas hourly space velocity（GHSV） of 30000 h–1, which was a very promising catalyst for NOx abatement from diesel engine exhaust. The catalysts were characterized by X-ray diffraction（XRD）, scanning electron microscopy with energy dispersive X-ray spectroscopy（SEM-EDS）, N2 adsorption-desorption（BET） and X-ray photoelectron spectroscopy（XPS）. The characterization results showed that the bigger pore radius, higher surface atomic concentration and dispersion of Ce and the abundant adsorbed oxygen on the surface of catalyst contributed to the best NH3-SCR performance of CeO2/TiO2-SiO2-WO3 catalyst containing 10% CeO2.展开更多
A series of CeO2-ZrO2-WO3 catalysts for the selective catalytic reduction （SCR） of NO with NH3 were prepared by hydrothermal method. The influence of calcination temperature on the catalytic activity, microstructure...A series of CeO2-ZrO2-WO3 catalysts for the selective catalytic reduction （SCR） of NO with NH3 were prepared by hydrothermal method. The influence of calcination temperature on the catalytic activity, microstructure, surface acidity and redox behavior of CeO2-ZrO2-WO3 catalyst was investigated using various characterization methods. It was found that the CeO2-ZrO2-WO3 catalyst calcined at 600 ℃ showed the best catalytic performance and excellent N2 selectivity, and yielded more than 90% NO conversion in a wide temperature range of 250-500 ℃ with a space velocity （GHSV） of 60000 131. As the calcination temperature was increased from 400 to 600 ℃, the NO conversion obviously increased, but decreased at higher calcination temperature. The results implied that the higher surface area, the strongest synergistic interaction, the superior redox property and the highly dispersed or amorphous WO3 species contributed to the excellent SCR activity of the CeO2-ZrO2-WO3 catalyst calcined at 600℃.展开更多
采用静电纺丝法成功制备了TiO2-WO3纳米纤维,利用X-射线衍射(X-ray diffraction,XRD)、扫描电子显微镜(scanning electron microscopy,SEM)、紫外可见吸收光谱(ultraviolet-visible,UV-Vis)及比表面积及孔径分析仪(Brunauer-Emmett-Tell...采用静电纺丝法成功制备了TiO2-WO3纳米纤维,利用X-射线衍射(X-ray diffraction,XRD)、扫描电子显微镜(scanning electron microscopy,SEM)、紫外可见吸收光谱(ultraviolet-visible,UV-Vis)及比表面积及孔径分析仪(Brunauer-Emmett-Teller,BET)对其进行表征。使用制备的纤维脱除模拟烟气中的元素汞,研究了TiO2-WO3分别在无光、紫外光和可见光下的脱汞率;考察了WO3的最佳掺杂比;并分析了TiO2-WO3光催化脱汞的机制。结果表明TiO2-WO3纤维中TiO2以锐钛矿相形态存在,纤维的直径约为200nm;当WO3的掺杂含量为7%时,TiO2-WO3在紫外光下的汞脱除率可达到100%;TiO2-WO3脱汞效率的稳定性好,在420 min时紫外光下的脱汞率仍保持在100%。表面酸性和有效的电荷转移是TiO2-WO3纳米纤维光催化活性提高的主要原因。展开更多
基金supported by the National Natural Science Foundation of China(21173153)the National High Technology Research and Development Program of China(863 project)(2013AA065304)
文摘A series of catalysts were prepared by doping different loadings of CeO2 over TiO2-SiO2-WO3 and used for the selective catalytic reduction of NOx by NH3. The experimental results showed that the selective catalytic reduction（SCR） performance and SO2-resistant ability of TiO2-SiO2-WO3 were greatly enhanced by the introduction of cerium. The catalyst containing 10% CeO2 showed the highest NO conversion in a wide temperature range and good N2 selectivity with broad operation temperature window at the gas hourly space velocity（GHSV） of 30000 h–1, which was a very promising catalyst for NOx abatement from diesel engine exhaust. The catalysts were characterized by X-ray diffraction（XRD）, scanning electron microscopy with energy dispersive X-ray spectroscopy（SEM-EDS）, N2 adsorption-desorption（BET） and X-ray photoelectron spectroscopy（XPS）. The characterization results showed that the bigger pore radius, higher surface atomic concentration and dispersion of Ce and the abundant adsorbed oxygen on the surface of catalyst contributed to the best NH3-SCR performance of CeO2/TiO2-SiO2-WO3 catalyst containing 10% CeO2.
基金Project supported by the National Natural Science Foundation of China(21377048,21307047)the Opening Project of Key Laboratory of Green Catalysis of Sichuan Institutes of High Education(LYJ1309)
文摘A series of CeO2-ZrO2-WO3 catalysts for the selective catalytic reduction （SCR） of NO with NH3 were prepared by hydrothermal method. The influence of calcination temperature on the catalytic activity, microstructure, surface acidity and redox behavior of CeO2-ZrO2-WO3 catalyst was investigated using various characterization methods. It was found that the CeO2-ZrO2-WO3 catalyst calcined at 600 ℃ showed the best catalytic performance and excellent N2 selectivity, and yielded more than 90% NO conversion in a wide temperature range of 250-500 ℃ with a space velocity （GHSV） of 60000 131. As the calcination temperature was increased from 400 to 600 ℃, the NO conversion obviously increased, but decreased at higher calcination temperature. The results implied that the higher surface area, the strongest synergistic interaction, the superior redox property and the highly dispersed or amorphous WO3 species contributed to the excellent SCR activity of the CeO2-ZrO2-WO3 catalyst calcined at 600℃.
基金Supported by Fundamental Research Funds for Central Universities(HEUCF201403002)Advanced Technique Project Funds of the Manufacture and Information Ministry
文摘采用静电纺丝法成功制备了TiO2-WO3纳米纤维,利用X-射线衍射(X-ray diffraction,XRD)、扫描电子显微镜(scanning electron microscopy,SEM)、紫外可见吸收光谱(ultraviolet-visible,UV-Vis)及比表面积及孔径分析仪(Brunauer-Emmett-Teller,BET)对其进行表征。使用制备的纤维脱除模拟烟气中的元素汞,研究了TiO2-WO3分别在无光、紫外光和可见光下的脱汞率;考察了WO3的最佳掺杂比;并分析了TiO2-WO3光催化脱汞的机制。结果表明TiO2-WO3纤维中TiO2以锐钛矿相形态存在,纤维的直径约为200nm;当WO3的掺杂含量为7%时,TiO2-WO3在紫外光下的汞脱除率可达到100%;TiO2-WO3脱汞效率的稳定性好,在420 min时紫外光下的脱汞率仍保持在100%。表面酸性和有效的电荷转移是TiO2-WO3纳米纤维光催化活性提高的主要原因。
