The surface tension and cenductivity of tetracthylarnmomum perfluorooctanesulfonate (TEPFOS) solu-tions in mixed solvents were determined The criticsl micelle concentrations (cmc) and surface adsorption of TEPFOS in v...The surface tension and cenductivity of tetracthylarnmomum perfluorooctanesulfonate (TEPFOS) solu-tions in mixed solvents were determined The criticsl micelle concentrations (cmc) and surface adsorption of TEPFOS in various solvents (Dimetbylsulfoxlde and DMSO, formamide and FA, and DMSO-H2O and FA H2O mixtures) were calculated from the above experimental date. The results show that the surface activity of TEPFOS is much higher than that of typical hydrocarbon surfactant, sodium dodecylsulfate (SDS); the melecalar interaction (in terms of colubility araneter or surface tension) of solvent is the decisive factor in sffecting the cmc of TEPFOS , in the apretic solvent DMSO, the value of entropy change during micelliza-tion of TEPFOS may beecme subsantially negative; the surfaof adsorption amount of TEPFOS is the largest in H2O, smaller in FA , and the smallest in DMSO.展开更多
The synthesis,crystal structure and properties of the first Mn(III)-disulfide complex(Et_4N)[Mn(mp-mp)_2]were reported with the Mn(III) ion in a S_2O_4 octahedron distorted due to Jahn-Teller effect.Spectroscopic data...The synthesis,crystal structure and properties of the first Mn(III)-disulfide complex(Et_4N)[Mn(mp-mp)_2]were reported with the Mn(III) ion in a S_2O_4 octahedron distorted due to Jahn-Teller effect.Spectroscopic data revealed its paramagnetic properties.展开更多
作为一种具有广泛应用前景的高效电合成技术,耦合电溶解的铪醇盐合成(EHS)基于铪溶解/乙醇脱氢的同时非均相反应以及溶液中Hf^(4+)阳离子和烷氧阴离子的自发结合反应。为了阐明EHS过程的机制和动力学,通过电化学测试、扫描电镜、气相色...作为一种具有广泛应用前景的高效电合成技术,耦合电溶解的铪醇盐合成(EHS)基于铪溶解/乙醇脱氢的同时非均相反应以及溶液中Hf^(4+)阳离子和烷氧阴离子的自发结合反应。为了阐明EHS过程的机制和动力学,通过电化学测试、扫描电镜、气相色谱和微观动力学模拟等手段,探究阳极铪溶解和阴极乙醇脱氢的电化学行为。结果表明,优选的支持电解质四乙基氯化铵(Et_(4)NCl)展现了钝化膜击穿与铪溶解协同的剧烈点蚀机制以及两段脱氢机制。为量化钝化膜击穿和铪点蚀的动力学参数,提取与钝化速率、钝化膜击穿敏感性和点蚀速率相关的3个指标,并通过建立微观动力学模型评估基于Et_(4)NCl体系的EHS工艺,其电能消耗为1.53~1.83 k W·h/kg Hf(OC_(2)H_(5))_(4)。展开更多
We presented a strategy to prepare spherical tungsten powder by the combination of hydrothermal method and H2reduction process.In hydrothermal process,the micelle of tetraethylammonium bromide(TEAB)act as spherical te...We presented a strategy to prepare spherical tungsten powder by the combination of hydrothermal method and H2reduction process.In hydrothermal process,the micelle of tetraethylammonium bromide(TEAB)act as spherical templates for the deposition of tungsten oxide,whereas the excessive TEAB inhibit the formation of spherical tungsten oxide due to the dense molecular layer of TEAB on the tungsten oxide particles.Citric acid(CA)can control the formation rate and structure of the tungsten oxide when its concentration is more than 0.2 mol/L,because of its ability to coordinate with tungsten atoms.The synergistic effect of TEAB and CA facilitates the formation of spherical tungsten oxide with nanorod crown.After being treated by H_(2)at 600 and 650℃,the tungsten oxide particles are reduced to tungsten particles,which maintain the spherical structure of tungsten oxide and have porous structure.展开更多
The present study reports a novel strategy to fabricate nanocrystal-assembled hierarchical MOR zeolites. This is the first demonstration of hierarchical MOR without preferential growth along the c-axis, which facilita...The present study reports a novel strategy to fabricate nanocrystal-assembled hierarchical MOR zeolites. This is the first demonstration of hierarchical MOR without preferential growth along the c-axis, which facilitates mass transfer in the 12-membered ring channels of MOR zeolite for the conversions involving bulky molecules. The facile method involves the combined use of tetraethylammonium hydroxide （TEAOH） and commercial surfactants, in which TEAOH is essential for the construction of nanocrystal assemblies. The surfactant serves as a crystal growth-inhibiting agent to further inhibit nanocrystalline particle growth, resulting in enhanced mesoporosity. The hierarchical MOR assembled particles, constructed of 20-50-nm crystallites, exhibit superior catalytic properties in the alkylation of benzene with benzyl alcohol compared with the control sample, as the hierarchical MOR possesses a larger external surface area and longer c-axis dimension. More importantly, the material shows improved activity and stability in the dimethyl ether carbonylation to methyl acetate reaction, which is a novel route to produce ethanol from syngas.展开更多
文摘The surface tension and cenductivity of tetracthylarnmomum perfluorooctanesulfonate (TEPFOS) solu-tions in mixed solvents were determined The criticsl micelle concentrations (cmc) and surface adsorption of TEPFOS in various solvents (Dimetbylsulfoxlde and DMSO, formamide and FA, and DMSO-H2O and FA H2O mixtures) were calculated from the above experimental date. The results show that the surface activity of TEPFOS is much higher than that of typical hydrocarbon surfactant, sodium dodecylsulfate (SDS); the melecalar interaction (in terms of colubility araneter or surface tension) of solvent is the decisive factor in sffecting the cmc of TEPFOS , in the apretic solvent DMSO, the value of entropy change during micelliza-tion of TEPFOS may beecme subsantially negative; the surfaof adsorption amount of TEPFOS is the largest in H2O, smaller in FA , and the smallest in DMSO.
文摘The synthesis,crystal structure and properties of the first Mn(III)-disulfide complex(Et_4N)[Mn(mp-mp)_2]were reported with the Mn(III) ion in a S_2O_4 octahedron distorted due to Jahn-Teller effect.Spectroscopic data revealed its paramagnetic properties.
基金Science and Technology Innovation Program of Hunan Province,China(No.2021RC2002)Yangfan Plan,China(No.2017YT05C107)。
文摘作为一种具有广泛应用前景的高效电合成技术,耦合电溶解的铪醇盐合成(EHS)基于铪溶解/乙醇脱氢的同时非均相反应以及溶液中Hf^(4+)阳离子和烷氧阴离子的自发结合反应。为了阐明EHS过程的机制和动力学,通过电化学测试、扫描电镜、气相色谱和微观动力学模拟等手段,探究阳极铪溶解和阴极乙醇脱氢的电化学行为。结果表明,优选的支持电解质四乙基氯化铵(Et_(4)NCl)展现了钝化膜击穿与铪溶解协同的剧烈点蚀机制以及两段脱氢机制。为量化钝化膜击穿和铪点蚀的动力学参数,提取与钝化速率、钝化膜击穿敏感性和点蚀速率相关的3个指标,并通过建立微观动力学模型评估基于Et_(4)NCl体系的EHS工艺,其电能消耗为1.53~1.83 k W·h/kg Hf(OC_(2)H_(5))_(4)。
基金Funded by the Key Program of Jiangxi Province on Development and Research(No.20203BBE53058)the Key Program of Ganzhou City on Development and Research(No.202101125003)。
文摘We presented a strategy to prepare spherical tungsten powder by the combination of hydrothermal method and H2reduction process.In hydrothermal process,the micelle of tetraethylammonium bromide(TEAB)act as spherical templates for the deposition of tungsten oxide,whereas the excessive TEAB inhibit the formation of spherical tungsten oxide due to the dense molecular layer of TEAB on the tungsten oxide particles.Citric acid(CA)can control the formation rate and structure of the tungsten oxide when its concentration is more than 0.2 mol/L,because of its ability to coordinate with tungsten atoms.The synergistic effect of TEAB and CA facilitates the formation of spherical tungsten oxide with nanorod crown.After being treated by H_(2)at 600 and 650℃,the tungsten oxide particles are reduced to tungsten particles,which maintain the spherical structure of tungsten oxide and have porous structure.
基金supported by the National Natural Science Foundation of China(21101150,21476228,21473182)~~
文摘The present study reports a novel strategy to fabricate nanocrystal-assembled hierarchical MOR zeolites. This is the first demonstration of hierarchical MOR without preferential growth along the c-axis, which facilitates mass transfer in the 12-membered ring channels of MOR zeolite for the conversions involving bulky molecules. The facile method involves the combined use of tetraethylammonium hydroxide （TEAOH） and commercial surfactants, in which TEAOH is essential for the construction of nanocrystal assemblies. The surfactant serves as a crystal growth-inhibiting agent to further inhibit nanocrystalline particle growth, resulting in enhanced mesoporosity. The hierarchical MOR assembled particles, constructed of 20-50-nm crystallites, exhibit superior catalytic properties in the alkylation of benzene with benzyl alcohol compared with the control sample, as the hierarchical MOR possesses a larger external surface area and longer c-axis dimension. More importantly, the material shows improved activity and stability in the dimethyl ether carbonylation to methyl acetate reaction, which is a novel route to produce ethanol from syngas.
