A series of praseodymium added CeO2（ZrO2）/TiO2 catalysts separately prepared by methods of sol-gel and impregnation were tested for selective catalytic reduction of NO, and characterized by X-ray diffraction （XRD）...A series of praseodymium added CeO2（ZrO2）/TiO2 catalysts separately prepared by methods of sol-gel and impregnation were tested for selective catalytic reduction of NO, and characterized by X-ray diffraction （XRD）, N2-brumauer-emmett-teller （N2-BET）, NH3-temperature programmed desorption （NH3-TPD）, H2-temperature programmed reduction （H2-TPR）, PL spectra, Ra-man spectra, electron paramagnetic resonance （EPR） and X-ray photoelectron spectroscopy （XPS）, respectively. Influence of prepara-tion method on catalytic performance was studied. Results showed that the influence of Pr addition on catalytic performance of the CeO2（ZrO2）/TiO2 catalysts was different between the sol-gel method and the impregnation method. The Pr addition tended to interact with TiO2 and formed the structure of Ti-O-Pr in the sol-gel method while it was more likely to interact with CeO2 forming the struc-ture of Ce-O-Pr in the impregnation method. The total acid amount and redox properties of the catalysts prepared by sol-gel method decreased with the addition of Pr element, which resulted in decrease of catalytic activity. In contrast, the Pr-added catalyst prepared by impregnation method was found to possess easier reducibility, more total acid amount and higher proportion of Ce3＋ species, which was favourable for higher catalytic activity.展开更多
The RuCoB/ZrO2 catalyst was prepared by chemical reduction method,in which Ru was an active component,Co was a promoter and ZrO2 was a dispersant.The influences of the different contents of Co and ZrO2 and t...The RuCoB/ZrO2 catalyst was prepared by chemical reduction method,in which Ru was an active component,Co was a promoter and ZrO2 was a dispersant.The influences of the different contents of Co and ZrO2 and the different reducing agents on the catalytic characteristics were studied.The results indicated that the characteristics of the catalysts reduced by KBH4 were better than that by formaldehyde.When Co/Ru ratio was 2% and Ru/ZrO2 ratio was 13%,the snythetically catalytic characteristics of RuCoB/ZrO2 was the best, and γ40 and S40 reached 14239h-1 and 758%, respectively.展开更多
A series of Cu-SSZ-13 catalysts with the same Cu loading were prepared by different methods of incipient wetness impregnation [Cu-SSZ-13(IWI)], ion exchange[Cu-SSZ-13(IE)] and hydro-thermal synthesis [Cu-SSZ-13(HTS)]....A series of Cu-SSZ-13 catalysts with the same Cu loading were prepared by different methods of incipient wetness impregnation [Cu-SSZ-13(IWI)], ion exchange[Cu-SSZ-13(IE)] and hydro-thermal synthesis [Cu-SSZ-13(HTS)]. Their activity for selective catalytic reduction of nitrogen oxides(NO_x) with NH3 was determined. The results show that the Cu-SSZ-13(HTS) catalyst exhibits a better ammonia selective catalytic reduction(NH3-SCR)activity compared with the other two catalysts, over which more than 90% NO conversion is obtained at 215-600℃under the space velocity of 180,000 h^(-1). The characterization results reveal that the Cu-SSZ-13(HTS) catalyst possesses more amount of stable Cu^(2+) in the six-membered ring and high ability for NH3 and NO adsorption, leading to its high NH3-SCR activity, although this catalyst has low surface area. On the other hand, the activity of Cu-SSZ-13(IE) catalyst is almost the same as that of Cu-SSZ-13(IWI) catalyst at the temperature lower than 400 ℃, but the activity of the former is much higher than that of the latter at > 400 ℃ due to the high activity of Cu-SSZ-13(IWI) catalyst for NH3 oxidation.展开更多
Hollow-ZSM-5 was synthesized by a traditional hydrothermal method without alcohol, and a novel nano-sized Ce-Cu/hollow ZSM-5 sample was prepared by conventional incipient wetness impreganation. The catalysts were char...Hollow-ZSM-5 was synthesized by a traditional hydrothermal method without alcohol, and a novel nano-sized Ce-Cu/hollow ZSM-5 sample was prepared by conventional incipient wetness impreganation. The catalysts were characterized by TEM, SEM, XRD, NMR and N2 adsorption-desorption. The results indicate that the hollow-ZSM-5 has a good MFI structure with large surface area. The synthesized CeO2-CuO/hollow ZSM-5 showed an excellent catalytic activity for NOx conversion（90% NOx conversion were obtained） in the temperature range of 340-550℃ under GHSV=480000 mL. g^-1.h^-1 due to its appropriate redox ability and acidity.展开更多
Transition metals doped Mn-based catalysts were prepared via ultrasonic immersing method for the selective catalytic reduction (SCR) of NOx from fuel gas. The Catalysts’ DeNOx efficiency and tolerance to sulfur were ...Transition metals doped Mn-based catalysts were prepared via ultrasonic immersing method for the selective catalytic reduction (SCR) of NOx from fuel gas. The Catalysts’ DeNOx efficiency and tolerance to sulfur were investigated in the paper. XRD results demonstrate high dispersion of Mn, Ce and M (Pr, Y, Zr, W) elements on TiO2 carrier, which is favor for reduction of active materials content. Mn-Ce-W catalyst presents uniform particle size about 500 nm to 800 nm from SEM pictures and shows the best NOx conversion of 93.2% at 200°C and 98.4% at 250°C, respectively. Sulfur tolerance analysis indicated that transition metals M can improve the catalysts’ performance when 0.01% SO2 exists in the fuel gas, because metal doping into the Mn-Ce catalyst can inhibit the sulfate deposition, especially metal sulfate, on the catalyst, which can be seen from the Fourier infrared spectrum.展开更多
基金supported by National Key Research and Development Program of China(2016YFC0205500)National Natural Science Foundation of China(51272105)+1 种基金Jiangsu Provincial Science and Technology Supporting Program(BE2013718)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘A series of praseodymium added CeO2（ZrO2）/TiO2 catalysts separately prepared by methods of sol-gel and impregnation were tested for selective catalytic reduction of NO, and characterized by X-ray diffraction （XRD）, N2-brumauer-emmett-teller （N2-BET）, NH3-temperature programmed desorption （NH3-TPD）, H2-temperature programmed reduction （H2-TPR）, PL spectra, Ra-man spectra, electron paramagnetic resonance （EPR） and X-ray photoelectron spectroscopy （XPS）, respectively. Influence of prepara-tion method on catalytic performance was studied. Results showed that the influence of Pr addition on catalytic performance of the CeO2（ZrO2）/TiO2 catalysts was different between the sol-gel method and the impregnation method. The Pr addition tended to interact with TiO2 and formed the structure of Ti-O-Pr in the sol-gel method while it was more likely to interact with CeO2 forming the struc-ture of Ce-O-Pr in the impregnation method. The total acid amount and redox properties of the catalysts prepared by sol-gel method decreased with the addition of Pr element, which resulted in decrease of catalytic activity. In contrast, the Pr-added catalyst prepared by impregnation method was found to possess easier reducibility, more total acid amount and higher proportion of Ce3＋ species, which was favourable for higher catalytic activity.
文摘The RuCoB/ZrO2 catalyst was prepared by chemical reduction method,in which Ru was an active component,Co was a promoter and ZrO2 was a dispersant.The influences of the different contents of Co and ZrO2 and the different reducing agents on the catalytic characteristics were studied.The results indicated that the characteristics of the catalysts reduced by KBH4 were better than that by formaldehyde.When Co/Ru ratio was 2% and Ru/ZrO2 ratio was 13%,the snythetically catalytic characteristics of RuCoB/ZrO2 was the best, and γ40 and S40 reached 14239h-1 and 758%, respectively.
基金financially supported by the National Key Research and Development Program of China (No. 2016YFC0204300)the National Natural Science Foundation of China (Nos. 21577034 and 21333003)the Science and Technology Commission of Shanghai Municipality (No. 16ZR1407900)
文摘A series of Cu-SSZ-13 catalysts with the same Cu loading were prepared by different methods of incipient wetness impregnation [Cu-SSZ-13(IWI)], ion exchange[Cu-SSZ-13(IE)] and hydro-thermal synthesis [Cu-SSZ-13(HTS)]. Their activity for selective catalytic reduction of nitrogen oxides(NO_x) with NH3 was determined. The results show that the Cu-SSZ-13(HTS) catalyst exhibits a better ammonia selective catalytic reduction(NH3-SCR)activity compared with the other two catalysts, over which more than 90% NO conversion is obtained at 215-600℃under the space velocity of 180,000 h^(-1). The characterization results reveal that the Cu-SSZ-13(HTS) catalyst possesses more amount of stable Cu^(2+) in the six-membered ring and high ability for NH3 and NO adsorption, leading to its high NH3-SCR activity, although this catalyst has low surface area. On the other hand, the activity of Cu-SSZ-13(IE) catalyst is almost the same as that of Cu-SSZ-13(IWI) catalyst at the temperature lower than 400 ℃, but the activity of the former is much higher than that of the latter at > 400 ℃ due to the high activity of Cu-SSZ-13(IWI) catalyst for NH3 oxidation.
基金Supported by the National Natural Science Foundation of China（Nos.21603213, 21677139）, the Fund of the Changchun Science and Technology Bureau, China（No.17DY004）, the Fund of the Youth Innovation Promotion Association of Chinese Academy of Sciences （No.2018263） and the Development Program of the Science and Technology Department of Jilin Province, China （No.20180201088GX）.
文摘Hollow-ZSM-5 was synthesized by a traditional hydrothermal method without alcohol, and a novel nano-sized Ce-Cu/hollow ZSM-5 sample was prepared by conventional incipient wetness impreganation. The catalysts were characterized by TEM, SEM, XRD, NMR and N2 adsorption-desorption. The results indicate that the hollow-ZSM-5 has a good MFI structure with large surface area. The synthesized CeO2-CuO/hollow ZSM-5 showed an excellent catalytic activity for NOx conversion（90% NOx conversion were obtained） in the temperature range of 340-550℃ under GHSV=480000 mL. g^-1.h^-1 due to its appropriate redox ability and acidity.
文摘Transition metals doped Mn-based catalysts were prepared via ultrasonic immersing method for the selective catalytic reduction (SCR) of NOx from fuel gas. The Catalysts’ DeNOx efficiency and tolerance to sulfur were investigated in the paper. XRD results demonstrate high dispersion of Mn, Ce and M (Pr, Y, Zr, W) elements on TiO2 carrier, which is favor for reduction of active materials content. Mn-Ce-W catalyst presents uniform particle size about 500 nm to 800 nm from SEM pictures and shows the best NOx conversion of 93.2% at 200°C and 98.4% at 250°C, respectively. Sulfur tolerance analysis indicated that transition metals M can improve the catalysts’ performance when 0.01% SO2 exists in the fuel gas, because metal doping into the Mn-Ce catalyst can inhibit the sulfate deposition, especially metal sulfate, on the catalyst, which can be seen from the Fourier infrared spectrum.
基金supported by the National Natural Science Foundation of China(21273043,21077026)Science and Technology Commission of Shanghai Municipality,China(13DZ2275200)~~
