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1.
采用等温蒸发法研究五元体系Li+,Na+//CO32-,SO42-,B4O72--H2O 288 K介稳相平衡关系,测定在288 K条件下的介稳平衡溶液中各组分的溶解度和溶液密度,根据实验数据绘制相应的介稳平衡相图及密度组成图。研究结果表明该五元体系介稳相平衡中有复盐Na3Li(SO4)2·6H2O生成,其介稳相图中有4个共饱点,9条单变量曲线,6个Li2CO3饱和的结晶区分别为LiBO2·8H2O,Na2B4O7·10H2O,Na2CO3·10H2O,Na2SO4,Li2SO4·H2O和复盐Na3Li(SO4)2·6H2O。  相似文献   

2.
共沉淀法制备了Ru-Zn催化剂,考察了反应修饰剂ZnSO4和预处理对苯选择加氢制环己烯Ru-Zn催化剂性能的影响。结果表明,反应修饰剂ZnSO4可以与Ru-Zn催化剂中助剂ZnO反应生成(Zn(OH)23(ZnSO4)(H2O)盐。随反应修饰剂ZnSO4浓度增加,(Zn(OH)23(ZnSO4)(H2O)盐量的逐渐增加,Ru-Zn催化剂活性逐渐降低,环己烯选择性逐渐升高。因为(Zn(OH)23(ZnSO4)(H2O)盐中的Zn2+可以使Ru变为有利环己烯生成的缺电子的Ruδ+物种,而且还可以占据不适宜环己烯生成的强Ru活性位。但当反应修饰剂ZnSO4浓度高于0.41 mol·L-1后,继续增加ZnSO4浓度,由于Zn2+水解浆液酸性太强,可以溶解部分(Zn(OH)23(ZnSO4)(H2O)盐,Ru-Zn催化剂活性升高,环己烯选择性降低。但环己烯选择性却略微降低,这是由于ZnSO4溶液中大量的Zn2+可以与生成的环己烯形成配合物,稳定生成的环己烯,抑制生成的环己烯再吸附到催化剂表面并加氢生成环己烷。在ZnSO4最佳浓度0.61 mol·L-1下对Ru-Zn催化剂预处理15 h,Ru-Zn催化剂中助剂ZnO可以与ZnSO4完全反应生成(Zn(OH)23(ZnSO4)(H2O)盐,在该催化剂上25 min苯转化68.2%时环己烯选择性和收率分别为80.2%和54.7%。而且该催化剂具有良好的稳定性和重复使用性能。  相似文献   

3.
Li+,Na+//SO42-,B4O72--H2O交互四元体系288 K介稳相平衡研究   总被引:3,自引:0,他引:3  
采用等温蒸发法研究了四元体系Li+,Na+//SO42-,B4O72--H2O 288 K介稳相平衡及平衡液相物化性质(密度、电导率、折光率、粘度和pH值),测定了该四元体系288 K条件下介稳平衡溶液溶解度及物化性质。根据实验数据绘制了相应的介稳相图及物化性质组成图。研究发现:该体系介稳平衡中有复盐Li2SO4·Na2SO4形成。其介稳相图中有3个共饱和点,7条单变量曲线,平衡固相为:Li2SO4·H2O,Na2SO4,Li2SO4·Na2SO4,Li2B4O7·3H2O,Na2B4O7·10H2O。复盐Li2SO4·Na2SO4和一水硫酸锂(Li2SO4·H2O)有较小的结晶区,而Li2B4O7·3H2O和Na2B4O7·10H2O有较大的结晶区;该四元体系介稳平衡条件下未发现Na2SO4·10H2O的结晶区。  相似文献   

4.
采用等温溶解平衡法研究了四元体系Na+,K+//Br-,SO42--H2O在323 K的相平衡关系,测定了该体系323 K的溶解度及平衡液相的密度,绘制了该体系的相图。研究发现:平衡体系存在复盐钾芒硝Na2SO4·3K2SO4的结晶区。其相图由3个共饱和点,7条单变量曲线和5个结晶区组成。相区分别对应NaBr·2H2O、Na2SO4、K2SO4、KBr和Na2SO4·3K2SO4结晶区。其中复盐钾芒硝Na2SO4·3K2SO4,Na2SO4和K2SO4有较大结晶区,而NaBr·2H2O和KBr有较小结晶区。对比了等温条件下四元体系Na+,K+//Cl-,SO42--H2O相平衡结果。实验结果表明溴化物对硫酸盐有较强盐析作用。  相似文献   

5.
利用沉淀法制备了纳米Ru催化剂,在ZnSO4存在下考察了Na2SiO3·9H2O和二乙醇胺作反应修饰剂对Ru催化剂催化苯选择加氢制环己烯性能的影响,并用X-射线衍射(XRD)、X-射线荧光光谱(XRF)和透射电镜-能量散射谱(TEM-EDS)等物理化学手段对加氢前后Ru催化剂进行了表征。结果表明,在水溶液中Na2SiO3与ZnSO4可以反应生成Zn4Si2O7(OH)2H2O盐、H2SO4和Na2SO4,化学吸附在Ru催化剂表面上的Zn4Si2O7(OH)2H2O盐起着提高Ru催化剂环己烯选择性的关键作用。Na2SiO3·9H2O量的增加,生成的Zn4Si2O7(OH)2H2O盐逐渐增加,Ru催化剂的活性降低,环己烯选择性逐渐升高。向反应体系中加入二乙醇胺,它可以中和Na2SiO3与ZnSO4反应生成的硫酸,使化学平衡向生成更多的Zn4Si2O7(OH)2H2O盐的方向移动,导致Ru催化剂环己烯选择性增加。当Ru催化剂与ZnSO4·7H2O、Na2SiO3·9H2O和二乙醇胺、分散剂ZrO2的质量比为1.0:24.6:0.4:0.2:5.0时,2 g Ru催化剂上苯转化73%时环己烯选择性和收率分别为75%和55%,而且该催化剂体系具有良好的重复使用性和稳定性。  相似文献   

6.
利用沉淀法制备了纳米Ru催化剂, 在ZnSO4存在下考察了Na2SiO3·9H2O和二乙醇胺作反应修饰剂对Ru催化剂催化苯选择加氢制环己烯性能的影响, 并用X-射线衍射(XRD)、X-射线荧光光谱(XRF)和透射电镜-能量散射谱(TEM-EDS)等物理化学手段对加氢前后Ru催化剂进行了表征。结果表明, 在水溶液中Na2SiO3与ZnSO4可以反应生成Zn4Si2O7(OH)2H2O盐、H2SO4和Na2SO4, 化学吸附在Ru催化剂表面上的Zn4Si2O7(OH)2H2O盐起着提高Ru催化剂环己烯选择性的关键作用。Na2SiO3·9H2O量的增加, 生成的Zn4Si2O7(OH)2H2O盐逐渐增加, Ru催化剂的活性降低, 环己烯选择性逐渐升高。向反应体系中加入二乙醇胺, 它可以中和Na2SiO3与ZnSO4反应生成的硫酸, 使化学平衡向生成更多的Zn4Si2O7(OH)2H2O盐的方向移动, 导致Ru催化剂环己烯选择性增加。当Ru催化剂与ZnSO4·7H2O、Na2SiO3·9H2O和二乙醇胺、分散剂ZrO2的质量比为1.0:24.6:0.4:0.2:5.0时, 2 g Ru催化剂上苯转化73%时环己烯选择性和收率分别为75%和55%, 而且该催化剂体系具有良好的重复使用性和稳定性。  相似文献   

7.
桑世华  殷辉安  曾英  刘凤英 《化学学报》2006,64(22):2247-2253
采用等温蒸发法研究了四元体系Li, Na// SO42-, CO32--H2O 288 K介稳相平衡及平衡液相的密度、电导率、折光率、粘度和pH值, 测定了该四元体系288 K条件下介稳平衡溶液溶解度及物化性质. 根据实验数据绘制了相应的介稳相图. 研究发现: 该体系介稳平衡中有复盐Na3Li(SO4)2•6H2O形成. 其介稳相图中有3个共饱点, 7条单变量曲线, 平衡固相为: Li2SO4•H2O, Na2SO4, Na3Li(SO4)2•6H2O, Li2CO3, Na2CO3•10H2O. 复盐Na3Li(SO4)2•6H2O和一水硫酸锂(Li2SO4•H2O)的结晶区较小, 而Li2CO3的结晶区最大; 该四元体系介稳平衡条件下未发现Na2SO4•10H2O的结晶区.  相似文献   

8.
复盐K2Zn(IO3)4·2H2O的热化学研究   总被引:3,自引:0,他引:3  
The standard enthalpy of formation (ΔfH?m[K2Zn(IO3)4·2H2O,s,298.2K]=-2210.68 kJ·mol-1) of a double salt K2Zn(IO3)4·2H相似文献   

9.
使Zn(OAc)2·2H2O或Cd(OAc)2·2H2O与邻羧基苯甲酰二茂铁钠(o-OOCC6H4COFcNa;Fc=(η5-C5H5)Fe(η5-C5H4))和1,10-邻菲咯啉(phen)在甲醇中反应,合成了含有混合配体的单核配合物[Zn(o-OOCC6H4COFc)2(phen)(H2O)]·CH3OH (1)和双核配合物{[Cd(η2-o-OOCC6H4COFc)( μ2-o-OOCC6H4COFc)(phen)]·CH3OH2·H2O}2 (2)。晶体结构表明:在1中,单核的结构单元通过分子间氢键形成了一维的长链结构;在2中,o-FcCOC6H4COO-以及phen均双齿螯合中心Cd(II)离子,随后在o-FcCOC6H4COO-的双齿桥联下,形成一个双核结构。研究了这2个配合物在DMF溶液中的电化学性能。  相似文献   

10.
在pH≈7.5的水溶液中,Na2WO4·2H2O,SbCl3·6H2O, 咪唑与 NiCl2·6H2O (或MnSO4·H2O,Co(NO3)2·6H2O, ZnSO4·7H2O)反应得到了四种咪唑配位的夹心型锑钨多氧酸盐Na9[{Na(H2O)2}3{M(C3H4N2)}3(SbW9O33)2]·xH2O(M=NiII, x = 32, CoII, x = 32,ZnII, x = 33, MnII, x = 34)。用X射线单晶衍射法确定了Na9[{Na(H2O)2}3{Ni(C3H4N2)}3(SbW9O33)2]·32H2O的结构,聚阴离子{Na(H2O)2}3{Ni(C3H4N2)}3(SbW9O33)2]9-具有近似C3v对称性,3个咪唑环垂直于中心带上六个金属离子(Na-Ni-Na-Ni-Na-Ni)所形成的平面。晶体结构中相邻的阴离子间存在着π-π相互作用,相邻咪唑的二面角为60º。用IR, UV-vis, TG 和DSC,对这些化合物的性质进行了表征,推测了它们的热分解过程。  相似文献   

11.
Chirai sodium zincophosphate nanocrystalline has been prepared and characterized. The standard molar enthaipy of the following reaction 12Na3PO4·12H2O(s)+ 12ZnSO4·7H2O(s)= Na12(Zn12P12O48)·12H2O(s)+ 12Na2SO4(s)+216H2O(1) was determined by solution reaction calorimetric at 298.15 K, and calculated to be 33.666±0.195 kl/mol. From the results and other auxiliary quantities, the standard enthalpy of formation for sodium zincophosphate nanocrystalline was derived to be △fHm^⊙ [Na12(Zn12P12O48)·12H2O(s), 298.15 K] =- 24268.494 ± 0.815 kJ/mol.  相似文献   

12.
Liao  Sen  Liu  Gang  Tian  Xiaozhen  Chen  Xia  Wu  Wenwei  Liang  Yugui 《中国化学》2010,28(1):50-54
A simple and novel route was provided for the preparation of the hexagonal Co(II)‐substituted sodium zincophosphate (CoZnPO‐HEX), which was obtained with ZnSO4·7H2O, CoCl2·6H2O and Na3PO4·12H2O as raw materials and polyethylene glycol‐400 (PEG‐400) as a surfactant via a one‐step solid‐state reaction at low heating temperature (60°C), and characterized with X‐ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectra, thermogravimetric analysis and the 1st derivative of thermogravimetric analysis (TG/DTG) and transmission electron microscopy (TEM). The experimental results showed that the CoZnPO‐HEX was selectively formed via this reaction at ambient temperature in the presence of PEG‐400.  相似文献   

13.
A platinum-lined, flowing autoclave facility is used to investigate the solubility/phase behavior of zinc(II) oxide in aqueous sodium phosphate solutions at temperatures between 17 and 287°C. ZnO solubilities are observed to increase continuously with temperature and phosphate concentration. At higher phosphate concentrations, a solid phase transformation to NaZnPO4 is observed. NaZnPO4 solubilities are retrograde with temperature. The measured solubility behavior is examined via a Zn(II) ion hydrolysis/complexing model and thermodynamic functions for the hydrolysis/complexing reaction equilibria are obtained from a least-squares analysis of the data. The existence of two new zinc(II) ion complexes, Zn(OH)2(HPO4)2– and Zn(OH)3(H2PO4)2–, is reported for the first time. A summary of thermochemical properties for species in the systems ZnO–H2O and ZnO–Na2O–P2O5–H2O is also provided.  相似文献   

14.
Phase formation in the ZrO(NO3)2-NaF(HF)-H3PO4-H2O system was studied at 20°C and 2.0–14.5 wt % ZrO2 in the initial solution along sections with molar ratios PO 4 3? /Zr = 0.5 and 1.5 and also in the presence of hydrogen fluoride at Na/Zr = 1 and PO 4 3? /Zr = 0.5, 1.0, and 1.5. Crystalline zirconium hydrophosphate Zr(HPO4)2 · H2O, fluorozirconates Na5Zr2F13 and Na7Zr6F31 · 12H2O, fluorophosphatozirconates NaH2Zr3F3(PO4)4 · 3H2O and NaZr2F6(PO4) · 4H2O, and amorphous NaZrO0.5F(PO4) · 4H2O (provisional composition) were separated at room temperature. NaH2Zr3F3(PO4)4 · 3H2O and NaZr2F6(PO4) · 4H2O were prepared for the first time and were studied by crystal-optical, elemental, and thermal analyses, X-ray powder diffraction, IR spectroscopy, scanning electron microscopy (SEM), and X-ray microanalysis. Na7Hf6F31 · 12H2O was found to exist in a mixture with the hydrophosphate.  相似文献   

15.
The title compound, [Zn(C8H5O4)2(C10H8N2)2], was obtained by the hydro­thermal reaction of ZnSO4·7H2O with phthalic acid (H2pht) and 4,4′‐bi­pyridine (4,4′‐bipy). Crystallographic analysis shows that it has a one‐dimensional double‐chain structure via hydrogen‐bonding interactions. Each ZnII atom, adopting a distorted tetrahedral geometry, is coordinated by two N atoms from two 4,4′‐bipy ligands, with Zn—N distances of 2.054 (4) and 2.104 (4) Å, and by two O atoms from symmetry‐related Hpht ligands, with Zn—O distances of 1.921 (4) and 2.019 (4) Å.  相似文献   

16.
The single phase ??-LiZnPO4·H2O was directly synthesized via solid-state reaction at room temperature using LiH2PO4·H2O, ZnSO4·7H2O, and Na2CO3 as raw materials. XRD analysis showed that ??-LiZnPO4·H2O was a compound with orthorhombic structure. The thermal process of ??-LiZnPO4·H2O experienced two steps, which involved the dehydration of one crystal water molecule at first, and then the crystallization of LiZnPO4. The DTA curve had the one endothermic peak and one exothermic peak, respectively, corresponding to dehydration of ??-LiZnPO4·H2O and crystallization of LiZnPO4. Based on the iterative iso-conversional procedure, the average values of the activation energies associated with the thermal dehydration of ??-LiZnPO4·H2O, was determined to be 86.59?kJ?mol?1. Dehydration of the crystal water molecule of ??-LiZnPO4·H2O is single-step reaction mechanism. A method of multiple rate iso-temperature was used to define the most probable mechanism g(??) of the dehydration step. The dehydration step is contracting cylinder model (g(??)?=?1?(1???)1/2) and is controlled by phase boundary reaction mechanism. The pre-exponential factor A was obtained on the basis of E a and g(??). Besides, the thermodynamic parameters (??S ??, ??H ??, and ??G ??) of the dehydration reaction of ??-LiZnPO4·H2O were determined.  相似文献   

17.
In this study, the synthesis of bis-(2-ethylhexyl) terephthalate, via the transesterification reaction of dimethyl terephthalate (DMT) by 2-ethylhexanol in the presence of different heterogeneous catalysts, such as Pb(OAc)2·3H2O, Cd(OAc)2·2H2O, Zn(OAc)2·2H2O, Hg(OAc)2·Ca(OAc)2·H2O, Cu(OAc)2·H2O, NaOAc, CaCO3, CaO, ZnSO4·7H2O, and sulfated zirconia, has been investigated. The reactivity of the catalysts in the reaction progress has been studied and compared. It was found that, hydrated cadmium acetate and sulfated zirconia were reactive catalysts to this reaction. The extent of transesterification of methyl ester groups reached up to 93% and 85.6% using these catalysts, respectively.  相似文献   

18.
廖森  田晓珍  吴文伟  陈霞  王天顺  李江涛 《中国化学》2008,26(10):1837-1842
对合成层状磷酸锌氢钠(NaH(ZnPO4)2)的新路线进行了研究,用Na2HPO4·12H2O及Zn(NO3)2·6H2O作为起始原料,聚乙二醇-400(PEG-400)为表面活性剂,通过一步固相反应于60 ℃下陈化得到了层状磷酸锌氢钠。用XRD, TG/DTG 及 FTIR表征了产物。实验结果表明,NaH(ZnPO4)2在500 ℃附近有一个主要的失重峰,归属为HPO42-脱水变成P2O74- 离子。因此,作为有机反应的非均相催化剂时,该化合物具有足够的热稳定性。对照实验的结果显示陈化温度调控着反应产物的生成。即,当反应混合物在60 ℃陈化时,生成的是NaH(ZnPO4)2,当反应混合物在室温陈化时,生成的则是α-Zn3(PO4)2·4H2O。  相似文献   

19.
Zusammenfassung Durch Zerreiben von Na2SO4·10 H2O, MgSO4·7 H2O, MnSO4·5 H2O, NiSO4·7 H2O, CoSO4-7H2O, ZnSO4·7H2O CuSO4·5 H2O, CdSO4·8— H2O, HgSO4 und (UO2)·SO4·3 H2O mit FeCl3·6 H2O werden ferromagnetische Gele erhalten. Durch Autoklavbehandlung dieser Gele entstehen Niederschl?ge, die in ihrem Aussehen weder H?matit noch Magnetit ?hnlich erscheinen. Es wird ein Demonstrationsversuch beschrieben, mit dem der Unterschied der magnetischen Eigenschaft von Eisenhydroxyden je nach der Herstellungsart veranschaulicht wird. Die beim Mischen von Ferro- und Ferril?sungen entstehenden Farb?nderungen werden photometrisch gemessen und diskutiert.  相似文献   

20.
The study of homogeneous distribution coefficients in determining the transition temperatures of isomorphologically analogous components and in predicting the existences of some new unstable compounds has been carried out in detail with special references to vitriols of nickel, manganese, zinc, copper and magnesium. In the course of the investigation with NiSO4·7H2O as host and54Mn as guest, the transition temperature of orthorhombic NiSO4·7H2O was shown to be 26.5 °C, and with orthorhombic ZnSO4·7H2O and MgSO4·7H2O as host and copper sulphate as guest, the limits of existences of orthorhombic CuSO4·7H2O and newly predicted CuSO4·6H2O were found to be 13.5° to 44 °C and 44° to 51 °C, respectively. In addition, the transition temperatures of orthorhombic MnSO4·7H2O (10 °C), stable NiSO4·7H2O (30.5±5 °C) and orthorhombic ZnSO4·7H2O (39 °C) were verified. The new method of approach is very simple, reproducible and easily adaptable.  相似文献   

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