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A solid ternary mixture consisting of NaF,silicon and one metal oxide such as La2O3,CeO2,Pr6O11,Nd2O3,and Y2O3 was prepared and usedas de-fluorinated reagent for CF4 decomposition.The results show that 90% conversion of CF4 can be reached initially over NaF-Si-La2O3,NaF-Si-CeO2,NaF-Si-Nd2O3,and NaF-Si-Y2O3 at 850 C.The fresh and used reagents were characterized using XRD and XPS techniques.It was found that the active components of NaF and metal oxides in NaF-Si-CeO2,NaF-Si-Pr6O11,NaF-Si-Nd2O3,and NaF-Si-Y2O3 weretransformed into inert phases of mixed metal fluorides and silicates,respectively,resulting in an ineffective utilization of these de-fluorinatedreagents,whereas no inert phases from NaF and La2O3 can be observed in the used NaF-Si-La2O3,indicating the NaF-Si-La2O3 reagent couldbe utilized more efficiently than the other reagents in CF4 decomposition.  相似文献   

3.
张霞  黄雪莉 《化学通报》2015,78(4):337-341
采用等温溶解平衡法研究了四元体系Na+//Cl-,SO42-,NO-3-H2O在5、0、-5与-15℃下的相平衡关系。结果表明,4个温度下体系无复盐形成,平衡相图的构型基本一致;平衡相图均由3个结晶区(Na2SO4·10H2O、Na Cl和Na NO3)、3条单变量曲线(Na Cl-Na2SO4·10H2O、Na Cl-Na NO3、Na NO3-Na2SO4·10H2O)及1个共饱点(Na Cl-Na NO3-Na2SO4·10H2O)组成;4个温度下的平衡相图相比,随着温度的下降Na2SO4·10H2O结晶区不断扩大,Na Cl和Na NO3结晶区相对缩小;与该体系常温下的平衡相图相比,由于无复盐形成,低温下的相图大为简化。  相似文献   

4.
刘春丽  周利  林瑞森 《化学学报》2007,65(10):998-1001
利用Anton Paar DMA 55精密数字密度计测定了L-丙氨酸在LiNO3, NaNO3, KNO3和NaClO4水溶液中的密度, 计算了L-丙氨酸的表观摩尔体积、极限偏摩尔体积、迁移偏摩尔体积、理论水化数和体积作用系数. 根据静电相互作用和结构水合作用模型讨论了阴离子和阳离子对迁移偏摩尔体积的影响. 结果表明, L-丙氨酸在四种含氧酸盐水溶液中的迁移体积均为正值, 并且随着盐浓度的增大而增大. L-丙氨酸两性离子端基和阴阳离子间的静电作用对迁移体积的贡献是主要的. 静电作用削弱了两性离子带电中心对周围水分子的电致收缩效应, 造成了理论水化数随溶液浓度的增加而减小. L-丙氨酸在NaNO3, KNO3和NaClO4水溶液中迁移体积的不同主要是由于静电作用的不同引起的, 在LiNO3水溶液中迁移体积的“反常”是由于结构相互作用的影响较大所致.  相似文献   

5.
廖玲  黄雪莉 《化学通报》2016,79(1):62-65,61
新疆盐湖资源丰富,冬季寒冷漫长,已有研究表明利用冬季冷能可以实现卤水浓淡分离。本文采用等温溶解平衡法针对新疆含硝酸盐卤水开发过程中涉及的Na~+,K~+//Cl~-,SO_4~(2-),NO_3~-H_2O及Na~+,K~+//Cl~-,NO_3~-H_2O体系273.15K下的相平衡关系进行了研究。通过查找文献及实验获得两个体系各盐的溶解度及溶液密度,并绘制相图。研究表明,上述四元体系的干盐相图有2个零变量点、5条单变量溶解度曲线、4个单盐结晶区分别对应于NaNO_3、NaCl、KNO_3和KCl,与该体系在298.15K下的相图相比,硝酸钾结晶区扩大很多;上述五元体系干盐相图(NaCl饱和)有2个零变量点、5条单变量溶解度曲线、4个两盐结晶区分别对应于NaCl+NaNO_3,NaCl+Na_2SO_4·10H_2O,NaCl+KNO_3,NaCl+KCl,与该体系298.15K下的相图相比,复盐钾芒硝和钠硝矾结晶区消失,芒硝结晶区扩大,相图大为简化。  相似文献   

6.
运用量子化学密度泛函理论UB3LYP/6-311+G*和高级电子相关校正的偶合簇(CCSD(T)/6-311+G*)方法,对CH3CH2,CH3CHCl和CH3CCl2自由基与NO2反应的机理和动力学进行了理论研究,得到了体系的势能面信息和可能的反应机理.根据计算得到的各反应热力学参数及反应能垒,采用传统过渡态理论计算了各反应在温度T=298 K和T=700 K时的速率常数.研究结果表明,该类反应均通过1个中间体和1个过渡态生成产物,产物分别为CH3CHO+HNO,CH3CHO+ClNO和CH3CClO+ClNO.  相似文献   

7.
The Michael addition of nitromethane to 3-buten-2-one has been carried out in the absence of solvent, using potassium fluoride supported on Al2O3, ZnO, SnO2, sepiolite, AlPO4, AlPO4–Al2O3 and AlPO4–ZnO catalysts. We found that KF/ZnO easily performed the Michael addition and thus, ZnO is a better support for the basic reagent than Al2O3. Besides, the Michael addition was not successful with AlPO4 or AlPO4-metal oxide acidic supports.
3--2- , , Al2O3, ZnO, SnO2, , AlPO4, AlPO4–Al2O3 AlPO4–ZnO. , KF/ZnO .. ZnO, , , Al2O3. , , AlPO4 AlPO4- .
  相似文献   

8.
研究了复合物Mg-NCSCH3在230~440 nm波段和Ca-NCSCH3在320~560 nm波段的光解离光谱. 复合物Mg-NCSCH3, Ca-NCSCH3光诱导反应的产物质谱表明有非反应猝灭产物Mg(Ca), C—S键断裂产物Mg(Ca)NC 和Mg(Ca)NCS以及重排反应产物Mg(Ca)-CHSH通道. 在原子跃迁谱线(32S→32P, 对于Mg; 42S?42P, 对于Ca)的红和蓝两边, Mg-NCSCH3的光解离光谱由两个宽峰组成; 而对于Ca-NCSCH3, 则是由三个谱峰构成. CIS/6-311++G**等级上, 对应于基态构型的Mg-NCSCH3电子态跃迁能量和振子强度与实验光谱较为一致; 而Ca-NCSCH3有较大的差别. 这是因为CIS方法忽略电子相关效应, 而Ca-based的跃迁中3d和4s轨道间存在较强的混合所致.  相似文献   

9.
Reaction of tin tetrachloride with the appropriate Grignard reagent gave Sn[C6H4-CH(OCH2)2]4 (2), which was transformed to Sn[C6H4-CHO]4 (3) and its hydrazido and amino derivatives Sn[C6H4-CHN-NH-C6H3-2,4-(NO2)2]4 (5) and Sn{C6H4-CH[N(C2H4)2O]2}4 (8). Oxidation of (3) produced Sn[C6H4-COOH]4 (4) while reduction of (3) gave Sn[C6H4-CH2-OH]4 (6). From the acid 4, an amino acid Sn[C6H4-CO-NH-CH2-CO-OCH3]4 (7) could be obtained by reaction with the methyl ester of glycine. All compounds were isolated in pure form with yields of 40-64% and were characterised by spectroscopic means (heteronuclear NMR) or by X-ray structure determination (3).  相似文献   

10.
研究了AlCl3(ZnCl2、MgCl2)对Sm2O3的氯化效果以及Sm2O3在LiCl-KCl-AlCl3(ZnCl2、MgCl2)熔盐体系中的电化学行为。在LiCl-KCl-Sm2O3熔盐中加入AlCl3(ZnCl2、MgCl2)后,ICP测量结果表明,AlCl3体系中Sm(Ⅲ)离子的浓度最高,并且在923 K时达到最大值;固相反应表明,AlCl3氯化Sm2O3生成SmCl3,而Sm2O3和ZnCl2(MgCl2)反应生成SmOCl。电化学行为表明,AlCl3体系中观察到了两种Al-Sm的合金峰,而ZnCl2体系中只观察到Zn-Sm金属间化合物的形成峰,MgCl2体系中没有形成合金。在-6.25 A·cm-2下,W电极上恒电流电解2 h获得了Al-Li-Sm合金,经XRD分析,合金为Al2Sm相。  相似文献   

11.
研究了AlCl_3(ZnCl_2、MgCl_2)对Sm_2O_3的氯化效果以及Sm_2O_3在Li Cl-KCl-AlCl_3(ZnCl_2、MgCl_2)熔盐体系中的电化学行为。在Li Cl-KCl-Sm_2O_3熔盐中加入AlCl_3(ZnCl_2、MgCl_2)后,ICP测量结果表明,AlCl_3体系中Sm(Ⅲ)离子的浓度最高,并且在923 K时达到最大值;固相反应表明,AlCl_3氯化Sm_2O_3生成SmCl_3,而Sm_2O_3和ZnCl_2(MgCl_2)反应生成Sm OCl。电化学行为表明,AlCl_3体系中观察到了两种Al-Sm的合金峰,而ZnCl_2体系中只观察到Zn-Sm金属间化合物的形成峰,MgCl_2体系中没有形成合金。在-6.25 A·cm~(-2)下,W电极上恒电流电解2 h获得了Al-Li-Sm合金,经XRD分析,合金为Al_2Sm相。  相似文献   

12.
研究了复合物Mg-NCSCH3在230~440 nm波段和Ca-NCSCH3在320~560 nm波段的光解离光谱. 复合物Mg-NCSCH3, Ca-NCSCH3光诱导反应的产物质谱表明有非反应猝灭产物Mg(Ca), C—S键断裂产物Mg(Ca)NC 和Mg(Ca)NCS以及重排反应产物Mg(Ca)-CHSH通道. 在原子跃迁谱线(32S→32P, 对于Mg; 42S?42P, 对于Ca)的红和蓝两边, Mg-NCSCH3的光解离光谱由两个宽峰组成; 而对于Ca-NCSCH3, 则是由三个谱峰构成. CIS/6-311++G**等级上, 对应于基态构型的Mg-NCSCH3电子态跃迁能量和振子强度与实验光谱较为一致; 而Ca-NCSCH3有较大的差别. 这是因为CIS方法忽略电子相关效应, 而Ca-based的跃迁中3d和4s轨道间存在较强的混合所致.  相似文献   

13.
The kinetics of the peroxy radicals RHFO2 reactions with NO has been studied by using pulse radiolysis and UV absorption spectroscopy. The rate constants of interaction of oxygen atoms with NO − k 2 = 2.2±0.2·10−12 cm3·s−1 and NO2k 3 = 2.1±0.2·10−11 cm3·s−1 were found in agreement with the literature values. The bath gases (SF6 or CO2) have got minor effect on the rate constants of RHFO2+NO→NO2+prod. reactions; RHFO2 = CH3CH2O2, CH3CHFO2, CH3CF2O2, CF3CH2O2, CF3CHFO2. The obtained rate coefficients are in the scope of the literature values, although they are lower than those recommended in NIST database. The reasons are discussed.  相似文献   

14.
Quantitative IR investigation of solid-state [Co(NH3)5ONO]XY[Co(NH3)5NO2]XY (XY=Cl2, Br2, I2, (NO3)2 Cl; NO3) linkage isomerization in KBr pellets has shown the kinetics to depend upon the outer-sphere anion. The red shift of the 5(ONO) band during isomerization is a linear function of transformation degree.  相似文献   

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Electrochemical nitrogen reduction reaction(NRR)is one of the most promising alternatives to the traditional Haber-Bosch process.Designing efficient electrocatalysts is still challenging.Inspired by the recent experimental and theoretical advances on single-cluster catalysts(SCCs),we systematically investigated the catalytic performance of various triple-transition-metal-atom clusters anchored on nitrogen-doped graphene for NRR through density functional theory(DFT)calculation.Among them,Mn3-N4,Fe3-N4,Co3-N4,and Mo3-N4 were screened out as electrocatalysis systems composed of non-noble metal with high activity,selectivity,stability,and feasibility.Particularly,the Co3-N4 possesses the highest activity with a limiting potential of-0.41 V through the enzymatic mechanism.The outstanding performance of Co3-N4 can be attributed to the unique electronic structure leading to strong π backdonation,which is crucial in effective N2 activation.This work not only predicts four efficient non-noble metal electrocatalysts for NRR,but also suggest the SCCs can serve as potential candidates for other important electrochemical reactions.  相似文献   

17.
Preparation of the following new m-SF5CF2CF2C6H4X derivatives has been achieved: X=N3(2), Br(3), OC(O)CHCH2(4), CHCH2(5). The compounds were characterized by their respective IR, NMR, mass spectra (MS) and high resolution mass spectrometry (HRMS). An improved yield of SF5(CF2)2C6H5 (1) is also reported along with the synthesis of the polyacrylate (6) and polystyrene (7) from their respective monomers.  相似文献   

18.
The following ions [UO2(NO3)3], [UO2(ClO4)3], [UO2(CH3COO)3] were generated from respective salts (UO2(NO3)2, UO2(ClO4)3, UO2(CH3COO)2) by laser desorption/ionization (LDI). Collision induced dissociation of the ions has led, among others, to the formation of UO4 ion (m/z 302). The undertaken quantum mechanical calculations showed this ion is most likely to possess square planar geometry as suggested by MP2 results or strongly deformed geometry in between tetrahedral and square planar as indicated by DFT results. Interestingly, geometrical parameters and analysis of electron density suggest it is an UVI compound, in which oxygen atoms bear unpaired electron and negative charge.  相似文献   

19.
The electrical resistivity and Hall factor in n-CdAs2, p-ZnAs2, and n-Cd x Zn1 − x As2 were measured at hydrostatic pressures up to 9 GPa and quasi-hydrostatic pressures up to 50 GPa at room temperature. For n-CdAs2, a phase transition was discovered at p = 5.5 GPa; for p-ZnAs2, two phase transitions were discovered: one at P = 10–15 GPa and the other at p = 35–40 GPa. No anomalies were found on ρ(p) and R(p) curves for Cd x Zn1 − x As2 when p ≤ 9 GPa. Original Russian Text ? A.Yu. Mollaev, I.K. Kamilov, R.K. Arslanov, L.A. Saipulaeva, R.G. Dzhamamedov, S.F. Marenkin, A.N. Babushkin, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 1, pp. 122–125.  相似文献   

20.
Keeping of MVO(XO4)2 under saturated vapor pressure at room temperature resulted in the synthesis of a number of isostructural complexes M[VO2(XO4)(H2O)2] · H2O, where X = S, M = K, Rb, NH4, Tl and X = Se, M = K, Rb, NH4. The conclusion about the isostructural nature of the synthesized sulfate and selenate compounds was based on X-ray diffraction and vibrational spectroscopy data. Characteristic features of the thermal decomposition of M[VO2(XO4)(H2O)2] · H2O on heating in air were identified. It was shown that K[VO2(SeO4)(H2O)2] · H2O tends to undergo spontaneous dehydration under ambient conditions to give the monohydrate K[VO2(SeO4)(H2O)].  相似文献   

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