In this work,to study the phase structure effect,three groups of Cu/REO catalysts were prepared with cubic and monoclinic Gd_(2)O_(3),Eu_(2)O_(3)and Sm_(2)O_(3) supports for MSR reaction to produce H_(2).Based on CH3O...In this work,to study the phase structure effect,three groups of Cu/REO catalysts were prepared with cubic and monoclinic Gd_(2)O_(3),Eu_(2)O_(3)and Sm_(2)O_(3) supports for MSR reaction to produce H_(2).Based on CH3OH conversion and H_(2)yield,the reaction perfo rmance of the catalysts ranks as Cu/Sm_(2)O_(3)-M>Cu/Sm_(2)O_(3)-C>Cu/Gd_(2)O_(3)-M>Cu/Gd_(2)O_(3)-C>Cu/Eu_(2)O_(3)-M>Cu/Eu_(2)O_(3)-C.For the same kind of REO,Cu supported on the monoclinic support shows better performance than on the cubic one.Despite the phase structure difference,Sm_(2)O_(3) is the best support among all the three kinds of REOs.Compared with Cu/REO catalysts prepared with cubic supports,the corresponding catalysts prepared with monoclinic supports generally possess mo re surface oxygen vacancies,which can generate mo re surface active oxygen(O_(2)^(-)) and moderate basic sites.Moreover,the contents of Cu^(+) on the catalysts follow the same sequence.The reaction performance is positively related to the amount of these three types of surface sites.But metallic Cuo species is necessary to maintain the Cu^(+)■Cu^(0) redox cycle.Furthe rmore,on a catalyst with good perfo rmance,those vital surface reaction intermediates can be stabilized during the reaction.Cu/Sm_(2)O_(3)-M possesses the largest quantities of these surface sites,and has the appropriate amount of Cu^(+) and Cu^(0) after reduction,thereby displaying the optimal performance in all the catalysts.In conclusion,evident support crystal structure effect is observed for Cu/REO catalysts,and a monoclinic phase REO is a better support than the respective cubic phase one.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 remova...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
Small Pt and Pt-Co nanoparticles（NPs） stabilized on La2 O2 CO3 nanorods（LOC） were prepared by wet impregnation method,and probed in liquid-phase chemoselective hydrogenation of crotonaldehyde（CRAL） to crotyl alc...Small Pt and Pt-Co nanoparticles（NPs） stabilized on La2 O2 CO3 nanorods（LOC） were prepared by wet impregnation method,and probed in liquid-phase chemoselective hydrogenation of crotonaldehyde（CRAL） to crotyl alcohol（CROL）.It is found that incorporation of Co atoms into Pt catalyst significantly improves the hydrogenation activity and desired selectivity to CROL as it destroys the Pt-lanthanum interfaces and results into the formation of Pt-Co particles.In addition,a close examination of catalyst surface and reactive performance suggests that the impregnation sequence of Pt and Co exerts great influence on the physicochemical property and the catalytic hydrogenation behavior of PtCo/LOC catalysts.As a result of the interaction between Pt and Co species,high alloying degree of Pt-Co NPs is obtained in the co-impregnated catalyst（Pt-Co/LOC）,thus achieving the highest hydrogenation activity.The selective deposit of Co atoms onto the low-coordinated Pt sites leads to the smallest metal particle size and high dispersion of Pt-Co NPs over the Pt/Co/LOC,giving rise to the highest selectivity and yield to CROL.展开更多
基金Project supported by the National Natural Science Foundation of China(22172071,22102069,22062013,22262021,21962009)Natural Science Foundation of Jiangxi Province,China(20202BAB203006,20212BAB203030)Key Laboratory Foundation of Jiangxi Province for Environment and Energy Catalysis,China(20181BCD40004).
文摘In this work,to study the phase structure effect,three groups of Cu/REO catalysts were prepared with cubic and monoclinic Gd_(2)O_(3),Eu_(2)O_(3)and Sm_(2)O_(3) supports for MSR reaction to produce H_(2).Based on CH3OH conversion and H_(2)yield,the reaction perfo rmance of the catalysts ranks as Cu/Sm_(2)O_(3)-M>Cu/Sm_(2)O_(3)-C>Cu/Gd_(2)O_(3)-M>Cu/Gd_(2)O_(3)-C>Cu/Eu_(2)O_(3)-M>Cu/Eu_(2)O_(3)-C.For the same kind of REO,Cu supported on the monoclinic support shows better performance than on the cubic one.Despite the phase structure difference,Sm_(2)O_(3) is the best support among all the three kinds of REOs.Compared with Cu/REO catalysts prepared with cubic supports,the corresponding catalysts prepared with monoclinic supports generally possess mo re surface oxygen vacancies,which can generate mo re surface active oxygen(O_(2)^(-)) and moderate basic sites.Moreover,the contents of Cu^(+) on the catalysts follow the same sequence.The reaction performance is positively related to the amount of these three types of surface sites.But metallic Cuo species is necessary to maintain the Cu^(+)■Cu^(0) redox cycle.Furthe rmore,on a catalyst with good perfo rmance,those vital surface reaction intermediates can be stabilized during the reaction.Cu/Sm_(2)O_(3)-M possesses the largest quantities of these surface sites,and has the appropriate amount of Cu^(+) and Cu^(0) after reduction,thereby displaying the optimal performance in all the catalysts.In conclusion,evident support crystal structure effect is observed for Cu/REO catalysts,and a monoclinic phase REO is a better support than the respective cubic phase one.
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.
基金Project supported by the National Natural Science Foundation of China(21401204,21773272)Science and Technology Project of Suzhou City(SYG201627)+1 种基金Innovation Promotion Association CAS(2017460)the Western Light Program of Chinese Academy of Sciences(2015)
文摘Small Pt and Pt-Co nanoparticles（NPs） stabilized on La2 O2 CO3 nanorods（LOC） were prepared by wet impregnation method,and probed in liquid-phase chemoselective hydrogenation of crotonaldehyde（CRAL） to crotyl alcohol（CROL）.It is found that incorporation of Co atoms into Pt catalyst significantly improves the hydrogenation activity and desired selectivity to CROL as it destroys the Pt-lanthanum interfaces and results into the formation of Pt-Co particles.In addition,a close examination of catalyst surface and reactive performance suggests that the impregnation sequence of Pt and Co exerts great influence on the physicochemical property and the catalytic hydrogenation behavior of PtCo/LOC catalysts.As a result of the interaction between Pt and Co species,high alloying degree of Pt-Co NPs is obtained in the co-impregnated catalyst（Pt-Co/LOC）,thus achieving the highest hydrogenation activity.The selective deposit of Co atoms onto the low-coordinated Pt sites leads to the smallest metal particle size and high dispersion of Pt-Co NPs over the Pt/Co/LOC,giving rise to the highest selectivity and yield to CROL.
