This work presents an electrochemical extraction of cerium and synthesization of Al–Ce alloy in LiCl–KCl melts on Mo and Al electrodes by chlorination of CeO2 using AlCl3 at 873 K. The cyclic voltammogram on Mo elec...This work presents an electrochemical extraction of cerium and synthesization of Al–Ce alloy in LiCl–KCl melts on Mo and Al electrodes by chlorination of CeO2 using AlCl3 at 873 K. The cyclic voltammogram on Mo electrodes in LiCl–KCl–CeO2 melt showed no obvious reduction wave other than the reduction of Li(I). After the addition of AlCl3, the signals of the reaction of Ce(ⅡI)/Ce(0) and the synthesization of Al–Ce and Al–Li alloys were investigated by cyclic voltammetry, square-wave voltammetry, open-circuit chronopotentiometry and chronopotentiometry. These results indicated that AlCl3 can chloridize CeO2 and that it is possible to extract cerium and form Al–Ce and Al–Li–Ce alloys in LiCl–KCl–CeO2–AlCl3 melts. According to potentiostatic electrolysis, only the Al4 Ce layer coated the Al electrodes. According to galvanostatic electrolysis, Al–Ce(Al4Ce, Al3 Ce, and Al92Ce8), Al2Li3, and Al phases were formed on Mo electrodes, and the content of cerium in the Al–Li–Ce alloys was more than 17 wt%.展开更多
In this study, Co3O4@CeO2 core@shell nanowires were successfully prepared via thermal decomposition of Co（CO3）0.5（OH）.0.11H2O@CeO2 core@shell nanowire precursors. As a CO oxidation catalyst, Co3O4@CeO2 shows remar...In this study, Co3O4@CeO2 core@shell nanowires were successfully prepared via thermal decomposition of Co（CO3）0.5（OH）.0.11H2O@CeO2 core@shell nanowire precursors. As a CO oxidation catalyst, Co3O4@CeO2 shows remarkably enhanced catalytic performance compared to Co3O4 nanowires and CeO2 nanoparticles （NPs）, indicating obvious synergistic effects between the two components. It also suggests that the CeO2 shell coating can effectively prevent Co3O4 nanowires from agglomerating, hence effecting a substantial improvement in the structural stability of the Co3O4 catalyst. Furthermore, the fabrication of the welbdisperse4 core@shell structure results in a maximized interface area between Co3O4 and CeO2, as well as a reduced Co3O4 size, which may be responsible for the enhanced catalytic activity of Co3O4@CeO2. Further examination revealed that CO oxidation may occur at the interface of Co3O4 and CeO2. The influence of calcination temperatures and the component ratio between Co3O4 and CeO2 were then investigated in detail to determine the catalytic performance of Co3O4@CeO2 core@shell nanowires, the best of which was obtained by calcination at 250 ℃ for 3 h with a Ce molar concentration of about 38.5%. This sample achieved 100% CO conversion at a reduced temperature of 160 ℃. More importantly, more than 2.5 g of the Co3O4@CeO2 core@shell nanowires were produced in one pot by this simple process, which may be beneficial for practical applications as automobile-exhaust gas-treatment catalysts.展开更多
Herein, we report a versatile strategy to fabri- cate three-dimensional melamine sponge （MS）-Au/ceria nanowire （NW） networks to realize in situ continuous reduction of p-nitrophenol in a consecutive flow system. T...Herein, we report a versatile strategy to fabri- cate three-dimensional melamine sponge （MS）-Au/ceria nanowire （NW） networks to realize in situ continuous reduction of p-nitrophenol in a consecutive flow system. This system has proven to be high activity and stability. The ceria NW networks with large surface area can stabi- lize tiny Au nanoparticles dispersed on the ceria NWs, which are loaded on the framework of MS by dip-coating, and enhance the synergistic effect between ceria NWs networks and Au nanoparticles, leading to extremely high activity and good stability for catalytic application. The low-cost raw materials and catalyst with high activity and stability may make this three-dimensional MS-Au/ceria NWs composite material promising for continuous cat- alytic reaction application in industry or other fields.展开更多
基金supported by the High Technology Research and Development Program of China(2011AA03A409)the National Natural Science Foundation of China(51104050,91326113,21271054,21173060)+6 种基金the Natural Science Foundation of Heilongjiang Province(E201413)China Postdoctoral Science Foundation(20110491029)the HeilongJiang Postdoctoral Fund(LBH-Z10208)the Heilongjiang Educational Commission Foundation(12513045)the Fundamental Research Funds for the Central Universities(HEUCFD1415)the Scientific Technology Bureau of Harbin(2012RFQXS102)the Basic Research Foundation of Harbin Engineering University(HEUFT08031)
文摘This work presents an electrochemical extraction of cerium and synthesization of Al–Ce alloy in LiCl–KCl melts on Mo and Al electrodes by chlorination of CeO2 using AlCl3 at 873 K. The cyclic voltammogram on Mo electrodes in LiCl–KCl–CeO2 melt showed no obvious reduction wave other than the reduction of Li(I). After the addition of AlCl3, the signals of the reaction of Ce(ⅡI)/Ce(0) and the synthesization of Al–Ce and Al–Li alloys were investigated by cyclic voltammetry, square-wave voltammetry, open-circuit chronopotentiometry and chronopotentiometry. These results indicated that AlCl3 can chloridize CeO2 and that it is possible to extract cerium and form Al–Ce and Al–Li–Ce alloys in LiCl–KCl–CeO2–AlCl3 melts. According to potentiostatic electrolysis, only the Al4 Ce layer coated the Al electrodes. According to galvanostatic electrolysis, Al–Ce(Al4Ce, Al3 Ce, and Al92Ce8), Al2Li3, and Al phases were formed on Mo electrodes, and the content of cerium in the Al–Li–Ce alloys was more than 17 wt%.
基金This work was supported by the financial aid from the National Natural Science Foundation of China （Nos. 91122030, 51272249, 21210001, 21221061 and 21401186）, and the National Key Basic Research Program of China （No. 2014CB643802）.
文摘In this study, Co3O4@CeO2 core@shell nanowires were successfully prepared via thermal decomposition of Co（CO3）0.5（OH）.0.11H2O@CeO2 core@shell nanowire precursors. As a CO oxidation catalyst, Co3O4@CeO2 shows remarkably enhanced catalytic performance compared to Co3O4 nanowires and CeO2 nanoparticles （NPs）, indicating obvious synergistic effects between the two components. It also suggests that the CeO2 shell coating can effectively prevent Co3O4 nanowires from agglomerating, hence effecting a substantial improvement in the structural stability of the Co3O4 catalyst. Furthermore, the fabrication of the welbdisperse4 core@shell structure results in a maximized interface area between Co3O4 and CeO2, as well as a reduced Co3O4 size, which may be responsible for the enhanced catalytic activity of Co3O4@CeO2. Further examination revealed that CO oxidation may occur at the interface of Co3O4 and CeO2. The influence of calcination temperatures and the component ratio between Co3O4 and CeO2 were then investigated in detail to determine the catalytic performance of Co3O4@CeO2 core@shell nanowires, the best of which was obtained by calcination at 250 ℃ for 3 h with a Ce molar concentration of about 38.5%. This sample achieved 100% CO conversion at a reduced temperature of 160 ℃. More importantly, more than 2.5 g of the Co3O4@CeO2 core@shell nanowires were produced in one pot by this simple process, which may be beneficial for practical applications as automobile-exhaust gas-treatment catalysts.
基金the funding support from the National Natural Science Foundation of China(2143100621521001)+8 种基金the National Basic Research Program of China(2014CB9318002013CB931800)the Users with ExcellenceGrant of Hefei Science Center of Chinese Academy of Sciences(2015HSC-UE007)the Chinese Academy of Sciences(KJZDEW-M01-1)the National Natural Science Foundation of China(5147115721401183)Youth Innovation Promotion Association of Chinese Academy of Sciences(2014298)Anhui Provincial Natural Science Foundation(1508085QB28)the Fundamental Research Funds for the Central Universities(WK2060190026)
文摘Herein, we report a versatile strategy to fabri- cate three-dimensional melamine sponge （MS）-Au/ceria nanowire （NW） networks to realize in situ continuous reduction of p-nitrophenol in a consecutive flow system. This system has proven to be high activity and stability. The ceria NW networks with large surface area can stabi- lize tiny Au nanoparticles dispersed on the ceria NWs, which are loaded on the framework of MS by dip-coating, and enhance the synergistic effect between ceria NWs networks and Au nanoparticles, leading to extremely high activity and good stability for catalytic application. The low-cost raw materials and catalyst with high activity and stability may make this three-dimensional MS-Au/ceria NWs composite material promising for continuous cat- alytic reaction application in industry or other fields.
