We used a dielectric barrier discharge(DBD)plasma technique to eliminate the protective ligand of ZnAl-hydrotalcite-supported gold nanoclusters.We used X-ray powder diffraction,ultraviolet-visible spectrophotometry,th...We used a dielectric barrier discharge(DBD)plasma technique to eliminate the protective ligand of ZnAl-hydrotalcite-supported gold nanoclusters.We used X-ray powder diffraction,ultraviolet-visible spectrophotometry,thermogravimetric analysis,and high angle annular dark-field-scanning transmission electron microscopy characterization to show that the samples pretreated with/without DBD-plasma displayed different performances in CO oxidation.The enhanced activity was obtained on the plasma-treated samples,implying that the protective ligand was effectively removed via the plasma technique.The crystal structure of the plasma-treated samples changed markedly,suggesting that the plasma treatment could not only break the chemical bond between the gold and the protective agent but could also decompose the interlayer ions over the hydrotalcite support.The particle sizes of the gold after DBD-plasma treatment implied that it was a good way to control the size of the gold nanoparticles under mild conditions.展开更多
The reactions of cationic zirconium oxide clusters （ZrxOy^＋） with ethylene （C2H4） were investigated by using a time-of-flight mass spectrometer coupled with a laser ablation/supersonic expansion cluster source. S...The reactions of cationic zirconium oxide clusters （ZrxOy^＋） with ethylene （C2H4） were investigated by using a time-of-flight mass spectrometer coupled with a laser ablation/supersonic expansion cluster source. Some hydrogen containing products （ZrO2）xH^＋（x=-1-4） were observed after the reaction. The density functional theory calculations indicate that apart from the common oxygen transfer reaction channel, the hydrogen abstraction channel can also occur in （ZrO2）x^＋＋C2H4, which supports that the observed （ZrO2）xH^＋ may be due to （ZrO2）x^＋＋C2H4→（ZrO2）xH^＋＋C2H3. The rate constants of different reaction channels were also calculated by Rice-Rarnsberger-Kassel-Marcus theory.展开更多
文摘We used a dielectric barrier discharge(DBD)plasma technique to eliminate the protective ligand of ZnAl-hydrotalcite-supported gold nanoclusters.We used X-ray powder diffraction,ultraviolet-visible spectrophotometry,thermogravimetric analysis,and high angle annular dark-field-scanning transmission electron microscopy characterization to show that the samples pretreated with/without DBD-plasma displayed different performances in CO oxidation.The enhanced activity was obtained on the plasma-treated samples,implying that the protective ligand was effectively removed via the plasma technique.The crystal structure of the plasma-treated samples changed markedly,suggesting that the plasma treatment could not only break the chemical bond between the gold and the protective agent but could also decompose the interlayer ions over the hydrotalcite support.The particle sizes of the gold after DBD-plasma treatment implied that it was a good way to control the size of the gold nanoparticles under mild conditions.
基金VI. ACKNOWLEDGEMENTS This work was supported by the Hundred Talents fund of The Chinese Academy of Sciences, the National Natural Science Foundation of China （No.20703048, No.20803083, and No.20933008）, the Center for Molecular Science Foundation of Institute of Chemistry, Chinese Academy of Sciences （No.CMS-CX200803）, and the National Basic Research Programs of China （No.2006CB932100 and No.2006CB806200）.
文摘The reactions of cationic zirconium oxide clusters （ZrxOy^＋） with ethylene （C2H4） were investigated by using a time-of-flight mass spectrometer coupled with a laser ablation/supersonic expansion cluster source. Some hydrogen containing products （ZrO2）xH^＋（x=-1-4） were observed after the reaction. The density functional theory calculations indicate that apart from the common oxygen transfer reaction channel, the hydrogen abstraction channel can also occur in （ZrO2）x^＋＋C2H4, which supports that the observed （ZrO2）xH^＋ may be due to （ZrO2）x^＋＋C2H4→（ZrO2）xH^＋＋C2H3. The rate constants of different reaction channels were also calculated by Rice-Rarnsberger-Kassel-Marcus theory.
