A porous NiO/yttria-stabilized zirconia was prepared by gel casting technique. anode substrate for tubular solid oxide fuel cells Nano-scale samaria-doped ceria （SDC） particles were formed onto the anode substrate t...A porous NiO/yttria-stabilized zirconia was prepared by gel casting technique. anode substrate for tubular solid oxide fuel cells Nano-scale samaria-doped ceria （SDC） particles were formed onto the anode substrate to modify the anode microstructure by the impregnation of solution of Sm（NO3）3 and Ce（NO3）3. Electrochemical impedance spectroscopy, current-voltage and current-powder curves of the cells were measured using an electrochemical workstation. Scanning electron microcopy was used to observe the microstructure. The results indicate that the stability of the performance of the cell operated on humidified methane can be significantly improved by incorporating the nano-structured SDC particles, compared with the unmodified cell. This verifies that the coated SDC electrodes are very effective in suppressing catalytic carbon formation by blocking methane from approaching the Ni, which is catalytically active towards methane pyrolysis. In addition, it was found that a small amount of deposited carbon is beneficial to the performance of the anode. The cell showed a peak power density of 225 mW/cm^2 when it was fed with H2 fuel at 700 ℃, but the power density increased to 400 mW/cm^2 when the fuel was switched from hydrogen to methane at the same flow rate. Methane conversion achieved about 90%, measured by gas chromatogram with a 10.0 mL/min flow rate of fuel at 700 ℃. Although the carbon deposition was not suppressed absolutely, some deposited carbon was beneficial for performance improvement.展开更多
In the methanolic solution, the selectivity of rhodamine hydrazide （RhH） was simply switched from Cu2＋ to Hg2＋ ions. For the optimal absorption of RhH onto a solid-phase membrane, pure methanol was used to dissolv...In the methanolic solution, the selectivity of rhodamine hydrazide （RhH） was simply switched from Cu2＋ to Hg2＋ ions. For the optimal absorption of RhH onto a solid-phase membrane, pure methanol was used to dissolve RhH prior to the impregnation. Of solid-phase membranes tested, the filter paper was chosen due to its cost-effectiveness and good detection limit of Hg2＋ ion. The detection limit of the RhH impregnated filter paper for the detection of Hg2＋ ion was determined to be under 2 ppm both fluorescent and colorimetric detection.展开更多
In this study, MWNT and alumina nanopowder were used as a ruthenium catalyst support for the conversion of carbon monoxide to methane. Metal foam structures were employed to support such catalytic systems, offering in...In this study, MWNT and alumina nanopowder were used as a ruthenium catalyst support for the conversion of carbon monoxide to methane. Metal foam structures were employed to support such catalytic systems, offering interesting possibilities for commercial applications due to low-pressure drop; excellent flow characteristic and heat transfer properties. Prior to the ruthenium impregnation, the MWNT surface was initially modified by means of metal cation activation and surface adsorption of anionic surfactant. The decoration processes using both surface modifications promoted the deposition of ruthenium with a mean 2 nm diameter. The use of nickel as a nucleating center enhanced the Ru nanoparticle density on the CNT surface compared to the Ru/CNT catalyst prepared by excess solution impregnation. As a reducing agent, ethylene glycol completely converted Ru2＋ to Ru0as confirmed by an EDS/TEM analysis. Among the prepared catalysts, Ru/AI203-CNTs prepared by Ni2＋ activation showed the best performance for the hydrogenation reaction. This is interpreted in terms of the higher ruthenium nanoparticle exposure on the nanostructured catalyst, as a result of the better MWNT dispersion in the MWNT/Al2O3 mixture.展开更多
This review summarizes the preparation methods of support ionic liquids （SILs） and their applications in rare metals separation The rare metals separation includes the recovery of high value metal ions and the remov...This review summarizes the preparation methods of support ionic liquids （SILs） and their applications in rare metals separation The rare metals separation includes the recovery of high value metal ions and the removal of heavy metal ions from wastewater. SILs can be used as a kind of highly efficient multifunctional separation materials. The preparation methods of SILs include chemical immobilization technique in which ILs moieties are supported on solid supports via covalent bonds and physical immobilization techniques in which ILs are immobilized on solid supports via physical method such as simple im- pregnation, sol-gel method. According to the difference of solid supports, this review summarizes the application of polymer supported ionic liquids （P-SILs）, silica based material supported ionic liquids （SM-SILs） and membrane supported ionic liq- uids （M-SILs） in rare metals separation, P-SILs and SM-SILs prepared by chemical method with N-methylimidazolium group can be used as highly efficient anion exchangers with high thermal stability and good chemical stability for adsorption of Cr（Ⅵ）, Re（Ⅶ）, Ce（Ⅳ）. P-SILs prepared via simple impregnation afforded IL functionalized solvent impregnated resins （SIRs） which showed high separation efficiency and selectivity in the separation of rare earths（Ⅲ） （REs（Ⅲ））. SM-SILs prepared via sol-gel method with IL doped in the support as porogens or extractant show high removal efficiencies and excellent stability for the separation of RE（Ⅲ）, Cr（Ⅲ） and Cr（Ⅵ）. M-SILs with IL as plasticizer or carrier show improved stability, high perme- ability coefficient and good selectivity for Cr（VI） transport. Different supports and different supporting methods were suffi- ciently compared. Based on the different practical application, different forms of SILs can be prepared for separation of rare metals with high separation efficiency and selectivity.展开更多
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.20871110 and No.50730002）. The authors express their appreciation to Xin-bo Lii, Qingdao Tianhe Graphite Co. Ltd. for supporting appropriate pore former graphite.
文摘A porous NiO/yttria-stabilized zirconia was prepared by gel casting technique. anode substrate for tubular solid oxide fuel cells Nano-scale samaria-doped ceria （SDC） particles were formed onto the anode substrate to modify the anode microstructure by the impregnation of solution of Sm（NO3）3 and Ce（NO3）3. Electrochemical impedance spectroscopy, current-voltage and current-powder curves of the cells were measured using an electrochemical workstation. Scanning electron microcopy was used to observe the microstructure. The results indicate that the stability of the performance of the cell operated on humidified methane can be significantly improved by incorporating the nano-structured SDC particles, compared with the unmodified cell. This verifies that the coated SDC electrodes are very effective in suppressing catalytic carbon formation by blocking methane from approaching the Ni, which is catalytically active towards methane pyrolysis. In addition, it was found that a small amount of deposited carbon is beneficial to the performance of the anode. The cell showed a peak power density of 225 mW/cm^2 when it was fed with H2 fuel at 700 ℃, but the power density increased to 400 mW/cm^2 when the fuel was switched from hydrogen to methane at the same flow rate. Methane conversion achieved about 90%, measured by gas chromatogram with a 10.0 mL/min flow rate of fuel at 700 ℃. Although the carbon deposition was not suppressed absolutely, some deposited carbon was beneficial for performance improvement.
文摘In the methanolic solution, the selectivity of rhodamine hydrazide （RhH） was simply switched from Cu2＋ to Hg2＋ ions. For the optimal absorption of RhH onto a solid-phase membrane, pure methanol was used to dissolve RhH prior to the impregnation. Of solid-phase membranes tested, the filter paper was chosen due to its cost-effectiveness and good detection limit of Hg2＋ ion. The detection limit of the RhH impregnated filter paper for the detection of Hg2＋ ion was determined to be under 2 ppm both fluorescent and colorimetric detection.
文摘In this study, MWNT and alumina nanopowder were used as a ruthenium catalyst support for the conversion of carbon monoxide to methane. Metal foam structures were employed to support such catalytic systems, offering interesting possibilities for commercial applications due to low-pressure drop; excellent flow characteristic and heat transfer properties. Prior to the ruthenium impregnation, the MWNT surface was initially modified by means of metal cation activation and surface adsorption of anionic surfactant. The decoration processes using both surface modifications promoted the deposition of ruthenium with a mean 2 nm diameter. The use of nickel as a nucleating center enhanced the Ru nanoparticle density on the CNT surface compared to the Ru/CNT catalyst prepared by excess solution impregnation. As a reducing agent, ethylene glycol completely converted Ru2＋ to Ru0as confirmed by an EDS/TEM analysis. Among the prepared catalysts, Ru/AI203-CNTs prepared by Ni2＋ activation showed the best performance for the hydrogenation reaction. This is interpreted in terms of the higher ruthenium nanoparticle exposure on the nanostructured catalyst, as a result of the better MWNT dispersion in the MWNT/Al2O3 mixture.
基金supported by the National Natural Science Foundation of China (51174184)National Basic Research Program of China(2012CBA01202)SRF for ROCS, Ministry of Education of China
文摘This review summarizes the preparation methods of support ionic liquids （SILs） and their applications in rare metals separation The rare metals separation includes the recovery of high value metal ions and the removal of heavy metal ions from wastewater. SILs can be used as a kind of highly efficient multifunctional separation materials. The preparation methods of SILs include chemical immobilization technique in which ILs moieties are supported on solid supports via covalent bonds and physical immobilization techniques in which ILs are immobilized on solid supports via physical method such as simple im- pregnation, sol-gel method. According to the difference of solid supports, this review summarizes the application of polymer supported ionic liquids （P-SILs）, silica based material supported ionic liquids （SM-SILs） and membrane supported ionic liq- uids （M-SILs） in rare metals separation, P-SILs and SM-SILs prepared by chemical method with N-methylimidazolium group can be used as highly efficient anion exchangers with high thermal stability and good chemical stability for adsorption of Cr（Ⅵ）, Re（Ⅶ）, Ce（Ⅳ）. P-SILs prepared via simple impregnation afforded IL functionalized solvent impregnated resins （SIRs） which showed high separation efficiency and selectivity in the separation of rare earths（Ⅲ） （REs（Ⅲ））. SM-SILs prepared via sol-gel method with IL doped in the support as porogens or extractant show high removal efficiencies and excellent stability for the separation of RE（Ⅲ）, Cr（Ⅲ） and Cr（Ⅵ）. M-SILs with IL as plasticizer or carrier show improved stability, high perme- ability coefficient and good selectivity for Cr（VI） transport. Different supports and different supporting methods were suffi- ciently compared. Based on the different practical application, different forms of SILs can be prepared for separation of rare metals with high separation efficiency and selectivity.
