Ni@Pd core-shell nanoparticles with a mean particle size of 8–9 nm were prepared by solvothermal reduction of bivalent nickel and palladium in oleylamine and trioctylphosphine.Subsequently,the first-ever deposition o...Ni@Pd core-shell nanoparticles with a mean particle size of 8–9 nm were prepared by solvothermal reduction of bivalent nickel and palladium in oleylamine and trioctylphosphine.Subsequently,the first-ever deposition of Ni@Pd core-shell nanoparticles having different compositions on a metal-organic framework（MIL-101）was accomplished by wet impregnation in n-hexane.The Ni@Pd/MIL-101 materials were characterized by powder X-ray diffraction,Fourier transform infrared spectroscopy,transmission electron microscopy,and energy-dispersive X-ray spectroscopy and also investigated as catalysts for the hydrogenation of nitrobenzene under mild reaction conditions.At 30 °C and 0.1 MPa of H2 pressure,the Ni@Pd/MIL-101 gives a TOF as high as 375 h–1 for the hydrogenation of nitrobenzene and is applicable to a wide range of substituted nitroarenes.The exceptional performance of this catalyst is believed to result from the significant Ni-Pd interaction in the core-shell structure,together with promotion of the conversions of aromatics by uncoordinated Lewis acidic Cr sites on the MIL-101 support.展开更多
This paper reports that the experimental excitation functions of reaction （p,n） are measured for ^106pd and ^110pd at proton energy Ep = 6.1 - 7.5 MeV and Ep = 6.0 - 7.7 MeV respectively. The off-resonance excitatio...This paper reports that the experimental excitation functions of reaction （p,n） are measured for ^106pd and ^110pd at proton energy Ep = 6.1 - 7.5 MeV and Ep = 6.0 - 7.7 MeV respectively. The off-resonance excitation functions were compared with calculation values of the statistical model. A new formula used to estimate the peak cross section of isobaric analogue resonance was tested and it was found that calculation values agree reasonably well with the present data within experimental error, which confirms that the excitation strength of isobaric analogue state in （p,n） reaction not only depends on its spin, but also proportionally increases with the projectile proton spatial transmission Tp and the spectroscopic factor S for reaction （d,p） on the same target.展开更多
Palladium（II） and chloride ions tend to form complexes in aqueous solution. Both theoretical and experimental （by UV spec- trum） results indicate that there are four complexes formed in aqueous solution containing...Palladium（II） and chloride ions tend to form complexes in aqueous solution. Both theoretical and experimental （by UV spec- trum） results indicate that there are four complexes formed in aqueous solution containing 3 mol/L hydrochloric acid and 20 mmol/L PdC12. This work evaluates the kinetics of electrochemical deposition of palladium on a Platinum electrode. For this purpose, palladium electrodeposition was investigated by means of cyclic voltammetry （CV）, potentiostatic current-time tran- sients （CTTs） and Tafel curve. By CTTs curves, the regions corresponding to the charge transfer control, mixed control and diffusion control were identified. In the diffusion control region, palladium electrodeposition mechanism was characterized as progressive nucleation with three-dimensional （3D） growth under diffusion control; as for the mixed control region, an adsorp- tion （1Ads）, ion transfer （liT）, and nucleation and growth （ING） model were proposed to analyze the current-time transients quan- titatively, which could separate the IAds, lit and IN~ perfectly.展开更多
基金supported by the National Natural Science Foundation of China(21322606 and 21436005)the Specialized Research Fund for the Doctoral Program of Higher Education(20120172110012)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Natural Science Foundation of Guangdong Province(S2011020002397 and 2013B090500027)~~
文摘Ni@Pd core-shell nanoparticles with a mean particle size of 8–9 nm were prepared by solvothermal reduction of bivalent nickel and palladium in oleylamine and trioctylphosphine.Subsequently,the first-ever deposition of Ni@Pd core-shell nanoparticles having different compositions on a metal-organic framework（MIL-101）was accomplished by wet impregnation in n-hexane.The Ni@Pd/MIL-101 materials were characterized by powder X-ray diffraction,Fourier transform infrared spectroscopy,transmission electron microscopy,and energy-dispersive X-ray spectroscopy and also investigated as catalysts for the hydrogenation of nitrobenzene under mild reaction conditions.At 30 °C and 0.1 MPa of H2 pressure,the Ni@Pd/MIL-101 gives a TOF as high as 375 h–1 for the hydrogenation of nitrobenzene and is applicable to a wide range of substituted nitroarenes.The exceptional performance of this catalyst is believed to result from the significant Ni-Pd interaction in the core-shell structure,together with promotion of the conversions of aromatics by uncoordinated Lewis acidic Cr sites on the MIL-101 support.
文摘This paper reports that the experimental excitation functions of reaction （p,n） are measured for ^106pd and ^110pd at proton energy Ep = 6.1 - 7.5 MeV and Ep = 6.0 - 7.7 MeV respectively. The off-resonance excitation functions were compared with calculation values of the statistical model. A new formula used to estimate the peak cross section of isobaric analogue resonance was tested and it was found that calculation values agree reasonably well with the present data within experimental error, which confirms that the excitation strength of isobaric analogue state in （p,n） reaction not only depends on its spin, but also proportionally increases with the projectile proton spatial transmission Tp and the spectroscopic factor S for reaction （d,p） on the same target.
基金supported by the National Natural Science Foundation of China(91026019,91126006)
文摘Palladium（II） and chloride ions tend to form complexes in aqueous solution. Both theoretical and experimental （by UV spec- trum） results indicate that there are four complexes formed in aqueous solution containing 3 mol/L hydrochloric acid and 20 mmol/L PdC12. This work evaluates the kinetics of electrochemical deposition of palladium on a Platinum electrode. For this purpose, palladium electrodeposition was investigated by means of cyclic voltammetry （CV）, potentiostatic current-time tran- sients （CTTs） and Tafel curve. By CTTs curves, the regions corresponding to the charge transfer control, mixed control and diffusion control were identified. In the diffusion control region, palladium electrodeposition mechanism was characterized as progressive nucleation with three-dimensional （3D） growth under diffusion control; as for the mixed control region, an adsorp- tion （1Ads）, ion transfer （liT）, and nucleation and growth （ING） model were proposed to analyze the current-time transients quan- titatively, which could separate the IAds, lit and IN~ perfectly.
