The permselectivity of H2/O2, H2/N2, H2/CO, and H2/CH4 mixtures passing a graphdiyne membrane is studied by molecular dynamics simulations. At pressure range of 0.047-4.5 GPa, H2 can pass the graphdiyen membrane quick...The permselectivity of H2/O2, H2/N2, H2/CO, and H2/CH4 mixtures passing a graphdiyne membrane is studied by molecular dynamics simulations. At pressure range of 0.047-4.5 GPa, H2 can pass the graphdiyen membrane quickly, while all the O2, N2, CO, and CH4 molecules are blocked. At pressure of 47 kPa, the hydrogen flow is 7 mol/m^2s. With increase of pressure, the hydrogen flow goes up, and reaches maximum of 6×10^5 mol/m^2s at 1.5 GPa. Compared to other known membranes, graphdiyne can be used for means of hydrogen purification with the best balance of high selectivity and high permeance.展开更多
To investigate the hydrogen permeability of calcium fluoride used for electroslag remelting （ESR） process, ＂Gas-slag- metal＂ osmosis process under argon atmosphere saturated with water vapor at 318 K was used to s...To investigate the hydrogen permeability of calcium fluoride used for electroslag remelting （ESR） process, ＂Gas-slag- metal＂ osmosis process under argon atmosphere saturated with water vapor at 318 K was used to study the hydrogen permeability of slag containing calcium fluoride. The results indicate that the conventional slag, consisting of 70% CaF2 and 30% A1203, has the lowest hydrogen permeability. A parameter EH was proposed for evaluation of the hydrogen permeability of slags containing calcium fluoride. The hydrogen permeability decreases with increasing EH to a certain extent. An appropriate choice of slag for the ESR process can be obtained. These results also suggest that the hydrogen pick-up in steel after remelting might be reduced when a slag with low hydrogen permeability is used.展开更多
Palladium membranes were prepared on an α-alumina support bymetal-organic compound chemical vapor deposition (MOCVD) method frompalladium (II) acetate precursor. Permeation properties of hydrogenand helium gas were s...Palladium membranes were prepared on an α-alumina support bymetal-organic compound chemical vapor deposition (MOCVD) method frompalladium (II) acetate precursor. Permeation properties of hydrogenand helium gas were studied as a function of the number of times ofdeposition of palladium on the peeling off phenomenon of palladium,which is common in electroless plated membrane, was observed. Silicawas introduced into the pores to prevent the palladium grain frompeeling off. The palladium-silica conjugated membrane does not showthe peeling off phenomenon and can withstand the high temperature upto 800 deg. C which is the upper limit of our apparatus.展开更多
基金V. ACKNOWLEDGMENTS This work was supported by the National Natu- ral Science Foundation of China （No.20603032 and 20733004）, the National Key Basic Research Program （No.2011CB921400）, the Foundation of National Excellent Doctoral Dissertation of China （No.200736）, the Fundamental Research Funds for the Central Universities （No.WK2340000006 and No.WK2060140005）, and the Shanghai Supercomputer Center, the USTC-HP HPC Project, and the SCCAS.
文摘The permselectivity of H2/O2, H2/N2, H2/CO, and H2/CH4 mixtures passing a graphdiyne membrane is studied by molecular dynamics simulations. At pressure range of 0.047-4.5 GPa, H2 can pass the graphdiyen membrane quickly, while all the O2, N2, CO, and CH4 molecules are blocked. At pressure of 47 kPa, the hydrogen flow is 7 mol/m^2s. With increase of pressure, the hydrogen flow goes up, and reaches maximum of 6×10^5 mol/m^2s at 1.5 GPa. Compared to other known membranes, graphdiyne can be used for means of hydrogen purification with the best balance of high selectivity and high permeance.
基金Project(50904015) supported by the National Natural Science Foundation of ChinaProject(N090402012) supported by the Fundamental Research Funds for Central Universities of China
文摘To investigate the hydrogen permeability of calcium fluoride used for electroslag remelting （ESR） process, ＂Gas-slag- metal＂ osmosis process under argon atmosphere saturated with water vapor at 318 K was used to study the hydrogen permeability of slag containing calcium fluoride. The results indicate that the conventional slag, consisting of 70% CaF2 and 30% A1203, has the lowest hydrogen permeability. A parameter EH was proposed for evaluation of the hydrogen permeability of slags containing calcium fluoride. The hydrogen permeability decreases with increasing EH to a certain extent. An appropriate choice of slag for the ESR process can be obtained. These results also suggest that the hydrogen pick-up in steel after remelting might be reduced when a slag with low hydrogen permeability is used.
文摘Palladium membranes were prepared on an α-alumina support bymetal-organic compound chemical vapor deposition (MOCVD) method frompalladium (II) acetate precursor. Permeation properties of hydrogenand helium gas were studied as a function of the number of times ofdeposition of palladium on the peeling off phenomenon of palladium,which is common in electroless plated membrane, was observed. Silicawas introduced into the pores to prevent the palladium grain frompeeling off. The palladium-silica conjugated membrane does not showthe peeling off phenomenon and can withstand the high temperature upto 800 deg. C which is the upper limit of our apparatus.
