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
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
采用NaOH溶液对Hβ沸石进行脱硅处理,制备了一系列不同硅铝比的脱硅Hβ沸石,考察了模板剂氧氧化四乙基铵(TEAOH)对脱硅过程的影响及脱硅Hβ沸石在甲苯与叔丁醇烷基化反应中的催化性能。采用ICP、XRD、NH_3-TPD、FTIR、N_2吸附和^(29)Si ...采用NaOH溶液对Hβ沸石进行脱硅处理,制备了一系列不同硅铝比的脱硅Hβ沸石,考察了模板剂氧氧化四乙基铵(TEAOH)对脱硅过程的影响及脱硅Hβ沸石在甲苯与叔丁醇烷基化反应中的催化性能。采用ICP、XRD、NH_3-TPD、FTIR、N_2吸附和^(29)Si MAS NMR等手段对脱硅Hβ沸石进行了表征。表征结果显示,脱硅Hβ沸石存在部分介孔结构;TEAOH的存在能有效保护Hβ沸石的骨架结构,提高Hβ沸石晶体的结晶度。当c(NaOH)=0.03 mol/L时,对含TEAOH的Hβ沸石进行处理制备的Hβ0(0.03)沸石的酸量最大,催化活性最高。以Hβ0(0.03)沸石为催化剂,在反应温度180℃、反应时间4h、n(甲苯):n(叔丁醇):n(正己烷)=1:3:10、m(甲苯):m(催化剂)=8时,甲苯转化率为65.7%,叔丁基甲苯选择性为98.4%,对叔丁基甲苯选择性为75.8%。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.
文摘采用NaOH溶液对Hβ沸石进行脱硅处理,制备了一系列不同硅铝比的脱硅Hβ沸石,考察了模板剂氧氧化四乙基铵(TEAOH)对脱硅过程的影响及脱硅Hβ沸石在甲苯与叔丁醇烷基化反应中的催化性能。采用ICP、XRD、NH_3-TPD、FTIR、N_2吸附和^(29)Si MAS NMR等手段对脱硅Hβ沸石进行了表征。表征结果显示,脱硅Hβ沸石存在部分介孔结构;TEAOH的存在能有效保护Hβ沸石的骨架结构,提高Hβ沸石晶体的结晶度。当c(NaOH)=0.03 mol/L时,对含TEAOH的Hβ沸石进行处理制备的Hβ0(0.03)沸石的酸量最大,催化活性最高。以Hβ0(0.03)沸石为催化剂,在反应温度180℃、反应时间4h、n(甲苯):n(叔丁醇):n(正己烷)=1:3:10、m(甲苯):m(催化剂)=8时,甲苯转化率为65.7%,叔丁基甲苯选择性为98.4%,对叔丁基甲苯选择性为75.8%。
