In order to explore the influence of modification sites of functional groups on landfill gas （CO2/CH4） separation performance of metal-organic frameworks （MOFs）, six types of or- ganic linkers and three types of f...In order to explore the influence of modification sites of functional groups on landfill gas （CO2/CH4） separation performance of metal-organic frameworks （MOFs）, six types of or- ganic linkers and three types of functional groups （i.e. -F, -NH2, -CH3） were used to construct 36 MOFs of pcu topology based on copper paddlewheel. Grand canonical Monte Carlo sim- ulations were performed in this work to evaluate the separation performance of MOFs at low （vacuum swing adsorption） and high （pressure swing adsorption） pressures, respectively. Simulation results demonstrated that CO2 working capacity of the unfunctionalized MOFs generally exhibits pore-size dependence at 1 bar, which increases with the decrease in pore sizes. It was also found that -NH2 funetionalized MOFs exhibit the highest CO2 uptake due to the enhanced Coulombic interactions between the polar -NH2 groups and the quadrupole moment of CO2 molecules, which is followed by -CH3 and -F functionalized ones. Moreover, positioning the functional groups -NH2 and -CH3 at sites far from the metal node （site b） exhibits more significant enhancement on CO2/CH4 separation performance compared to that adjacent to the metal node （site a）.展开更多
MCM-41 supporting CuO was prepared in the present research by immobilizing metal ions with organofunctionalized MCM-41 and subsequent ultrasonic washing and calcination.The coordination of Cu(II) with organic function...MCM-41 supporting CuO was prepared in the present research by immobilizing metal ions with organofunctionalized MCM-41 and subsequent ultrasonic washing and calcination.The coordination of Cu(II) with organic functionalized MCM-41 as well as the formation of CuO on the molecular sieve surface during the calcination process were investigated by FTIR and In-situ Drift FTIR.展开更多
Transition-metal-catalyzed C–H bond activation represents one of the most attractive research areas in organic synthesis.In contrast to the great developments made in directed C–H bond functionalization of arenes,th...Transition-metal-catalyzed C–H bond activation represents one of the most attractive research areas in organic synthesis.In contrast to the great developments made in directed C–H bond functionalization of arenes,the directing group-assisted activation of non-aromatic vinylic C–H bonds still remains challenging.During the recent years,significant progress has been made in this fascinating field with various functionalized alkenes,heterocycles and carbocycles being obtained.This article will focus on the recent achievements in the field of directing-group-assisted vinylic C–H bond functionalization.展开更多
Transition metal catalyzed C-H Functionalization is one of the most important and challenging research fields in or- ganic chemistry and has rapidly evolved in recent decades. Some recent achievements in the field inc...Transition metal catalyzed C-H Functionalization is one of the most important and challenging research fields in or- ganic chemistry and has rapidly evolved in recent decades. Some recent achievements in the field include i） minimizing the pre-activation procedures of substrates, ii） reducing waste production, and iii） shortening synthetic steps by de- veloping direct activations and straightforward transfor- mations of C-H bonds. With the rapid developments in chemistry and the continuous support of the Chinese gov- ernment, Chinese chemists have played important roles in this emerging field in the past two decades. To stimulate the continued success of Chinese chemists, this work provides an intensive account of the current status of this important field in China's Mainland.展开更多
Electrochemical oxidation of the carbon nanotube (CNT) polarizable electrodes of electric double layer capacitors (EDLCs) was studied. It indicated that electrochemical oxidation elevated the available surface area of...Electrochemical oxidation of the carbon nanotube (CNT) polarizable electrodes of electric double layer capacitors (EDLCs) was studied. It indicated that electrochemical oxidation elevated the available surface area of the electrodes and introduced some kinds of functional group on the CNT surfaces. The specific capacitances of the polarizable electrodes with organic electrolyte could be enhanced from 22.4 F g-1 to 78.2 F g-1 after electrolysis oxidization. The enhancement of the specific capacitance depends on the extent of electrochemical oxidation. Using acidic electrolyte for electrochemical oxidation has different effects on modifying the performances of the CNT polarizable electrodes compared to using basic electrolyte.展开更多
基金supported by the National Natural Science Foundation of China(No.51606081)the Basic Research Foundation of Shenzhen(No.JCYJ20160506170043770)
文摘In order to explore the influence of modification sites of functional groups on landfill gas （CO2/CH4） separation performance of metal-organic frameworks （MOFs）, six types of or- ganic linkers and three types of functional groups （i.e. -F, -NH2, -CH3） were used to construct 36 MOFs of pcu topology based on copper paddlewheel. Grand canonical Monte Carlo sim- ulations were performed in this work to evaluate the separation performance of MOFs at low （vacuum swing adsorption） and high （pressure swing adsorption） pressures, respectively. Simulation results demonstrated that CO2 working capacity of the unfunctionalized MOFs generally exhibits pore-size dependence at 1 bar, which increases with the decrease in pore sizes. It was also found that -NH2 funetionalized MOFs exhibit the highest CO2 uptake due to the enhanced Coulombic interactions between the polar -NH2 groups and the quadrupole moment of CO2 molecules, which is followed by -CH3 and -F functionalized ones. Moreover, positioning the functional groups -NH2 and -CH3 at sites far from the metal node （site b） exhibits more significant enhancement on CO2/CH4 separation performance compared to that adjacent to the metal node （site a）.
文摘MCM-41 supporting CuO was prepared in the present research by immobilizing metal ions with organofunctionalized MCM-41 and subsequent ultrasonic washing and calcination.The coordination of Cu(II) with organic functionalized MCM-41 as well as the formation of CuO on the molecular sieve surface during the calcination process were investigated by FTIR and In-situ Drift FTIR.
基金supported by the National Basic Research Program of China(2015CB856600)the National Natural Science Foundation of China(21332002,21272010)
文摘Transition-metal-catalyzed C–H bond activation represents one of the most attractive research areas in organic synthesis.In contrast to the great developments made in directed C–H bond functionalization of arenes,the directing group-assisted activation of non-aromatic vinylic C–H bonds still remains challenging.During the recent years,significant progress has been made in this fascinating field with various functionalized alkenes,heterocycles and carbocycles being obtained.This article will focus on the recent achievements in the field of directing-group-assisted vinylic C–H bond functionalization.
文摘Transition metal catalyzed C-H Functionalization is one of the most important and challenging research fields in or- ganic chemistry and has rapidly evolved in recent decades. Some recent achievements in the field include i） minimizing the pre-activation procedures of substrates, ii） reducing waste production, and iii） shortening synthetic steps by de- veloping direct activations and straightforward transfor- mations of C-H bonds. With the rapid developments in chemistry and the continuous support of the Chinese gov- ernment, Chinese chemists have played important roles in this emerging field in the past two decades. To stimulate the continued success of Chinese chemists, this work provides an intensive account of the current status of this important field in China's Mainland.
基金supported by the Major State Basic Research Development Program of China (Grant No. 10332020)
文摘Electrochemical oxidation of the carbon nanotube (CNT) polarizable electrodes of electric double layer capacitors (EDLCs) was studied. It indicated that electrochemical oxidation elevated the available surface area of the electrodes and introduced some kinds of functional group on the CNT surfaces. The specific capacitances of the polarizable electrodes with organic electrolyte could be enhanced from 22.4 F g-1 to 78.2 F g-1 after electrolysis oxidization. The enhancement of the specific capacitance depends on the extent of electrochemical oxidation. Using acidic electrolyte for electrochemical oxidation has different effects on modifying the performances of the CNT polarizable electrodes compared to using basic electrolyte.
