For dispersed ceria-zirconia-based solid solutions prepared via the polymerized complex method and annealed at 700 ℃, effects of bulk doping by Ca, Mn, Co, Bi or Nb cations and surface modification by Mn and Pt on th...For dispersed ceria-zirconia-based solid solutions prepared via the polymerized complex method and annealed at 700 ℃, effects of bulk doping by Ca, Mn, Co, Bi or Nb cations and surface modification by Mn and Pt on their structural features, surface/bulk oxygen reactivity and catalytic activity in methane combustion are considered. With up to 20 mol% doping, a structural type of homogeneous solid solutions of anion-deficient fluorite with disordered anion vacancies is formed. Doping by transition metal cations or Pt increases the mobility and reactivity of the surface/bulk oxygen. A broad variation in specific rates of methane combustion for the studied systems was observed, suggesting structural sensitivity of this reaction. In general, there is no universal relationship between the oxygen mobility, the reactivity and the catalytic activity in methane combustion, which is explained by the factor of specific methane activation on surface active sites. For the Pt-promoted samples, Pt efficiency in methane activation depends on the Pt-support interaction, and the most favorable ones being mixed Pt/MnOx and Pt/NbOx clusters on the surface of the supports that exhibit high lattice oxygen mobilities.展开更多
The properties of 2,4 bis(2 allylphenoxy) 6 N,N dialkylamino 1,3,5 triazine(alkyl=CH 3(BAPDMT),C 2H 5(BAPDET)) and bis(4 maleimidodiphenyl)methane(BMDPM) copolymers were stu died . The results showed that the triazine...The properties of 2,4 bis(2 allylphenoxy) 6 N,N dialkylamino 1,3,5 triazine(alkyl=CH 3(BAPDMT),C 2H 5(BAPDET)) and bis(4 maleimidodiphenyl)methane(BMDPM) copolymers were stu died . The results showed that the triazine monomers could improve the impact strength and shear strength of BMDPM homopolymer without strongly decreasing the heat resistance of the resin. The better results were obtained when the molar ratio of BMDPM to triazine was 4∶1.展开更多
通过简单的机械研磨,在x(氨基磺酸)=10%催化作用下,室温将吲哚与一系列醛类物质转化为二吲哚基甲烷类衍生物.共合成得到15个化合物,其结构经1 H NMR,13 C NMR及元素分析确定.同时,对催化剂的最佳用量和重复使用性能进行了探究.结果表明...通过简单的机械研磨,在x(氨基磺酸)=10%催化作用下,室温将吲哚与一系列醛类物质转化为二吲哚基甲烷类衍生物.共合成得到15个化合物,其结构经1 H NMR,13 C NMR及元素分析确定.同时,对催化剂的最佳用量和重复使用性能进行了探究.结果表明,催化剂的最佳用量为x(氨基磺酸)=10%,并在重复使用6次后依然保持较高的催化活性.展开更多
文摘For dispersed ceria-zirconia-based solid solutions prepared via the polymerized complex method and annealed at 700 ℃, effects of bulk doping by Ca, Mn, Co, Bi or Nb cations and surface modification by Mn and Pt on their structural features, surface/bulk oxygen reactivity and catalytic activity in methane combustion are considered. With up to 20 mol% doping, a structural type of homogeneous solid solutions of anion-deficient fluorite with disordered anion vacancies is formed. Doping by transition metal cations or Pt increases the mobility and reactivity of the surface/bulk oxygen. A broad variation in specific rates of methane combustion for the studied systems was observed, suggesting structural sensitivity of this reaction. In general, there is no universal relationship between the oxygen mobility, the reactivity and the catalytic activity in methane combustion, which is explained by the factor of specific methane activation on surface active sites. For the Pt-promoted samples, Pt efficiency in methane activation depends on the Pt-support interaction, and the most favorable ones being mixed Pt/MnOx and Pt/NbOx clusters on the surface of the supports that exhibit high lattice oxygen mobilities.
文摘The properties of 2,4 bis(2 allylphenoxy) 6 N,N dialkylamino 1,3,5 triazine(alkyl=CH 3(BAPDMT),C 2H 5(BAPDET)) and bis(4 maleimidodiphenyl)methane(BMDPM) copolymers were stu died . The results showed that the triazine monomers could improve the impact strength and shear strength of BMDPM homopolymer without strongly decreasing the heat resistance of the resin. The better results were obtained when the molar ratio of BMDPM to triazine was 4∶1.
文摘通过简单的机械研磨,在x(氨基磺酸)=10%催化作用下,室温将吲哚与一系列醛类物质转化为二吲哚基甲烷类衍生物.共合成得到15个化合物,其结构经1 H NMR,13 C NMR及元素分析确定.同时,对催化剂的最佳用量和重复使用性能进行了探究.结果表明,催化剂的最佳用量为x(氨基磺酸)=10%,并在重复使用6次后依然保持较高的催化活性.
