酒石酸法合成的LiCoO_2的结构及其二次锂电池行为研究

采用Ｘ射线衍射,光电子能谱,库仑滴定,循环伏安等方法研究酒石酸法合成的ＬｉＣｏＯ＿２的结构及其二次锂电池行为。结果表明ＬｉＣｏＯ＿２具有六方晶系空间群结构,相应晶胞参数ａ＝０．２８１０ｎｍ,ｃ＝１．４０８８ｎｍ;其中Ｃｏ￣（３＋）为低自旋;且其表面存在Ｌｉ＿２Ｏ。同时,其二次锂电池电容量可达１２０ｍＡ·ｈ·ｇ￣（－１）,半容量工作电压达３．８ｖ,当正极中Ｌｉ￣＋含量（Ｘ）为０．４５１≤ｘ≤０．９３４时,该电池开路电压（Ｅ）符合：Ｅ＝４．３１８－０．４５０Ｘ￣（２／３）。     

钙－亚硫酰氯电池的研究

应用交流阻抗、恒电流、ＳＥＭ等方法,研究了Ｃａ－ＳＯＣｌ２电池中ＣａＣｌ２（ＳＥＩ）膜的性质;不同电解质和添加剂对电极性能的影响．结果表明,ＣａＣｌ２ＳＥＩ膜在阳极反应时电阻下降。ＣｕＣｌ２、ＣｕＢｒ２可改变ＣａＣｌ２沉积形态,提高阴极性能．组装的Ｃａ－ＳＯＣｌ２电池可高速率放电,在５０ｍＡ·ｃｍ－２的条件下,达到１７．５ｍＡｈ·ｃｍ－２。     

钙—亚硫酰氯电池的研究

应用交流阻抗，恒电流，ＳＥＭ等方法，研究了Ｃａ－ＳＯＣｌ２电池中ＣａＣｌ２（ＳＥＩ）膜的性质，不同电解质和添加剂对电极性的影响，结果表明，ＣａＣｌ２ＳＥＩ膜在阳极反应电阻下降，ＣｕＣｌ２，ＣｕＢｒ２可改变ＣａＣｌ２沉积形态，提高阴极性能，组装的Ｃａ－ＳＯＣｌ２电池可高速率放电，在５０ｍＡ．ｃｍ＾－２的条件下，达到了１７．５ｍＡｈ．ｃｍ＾－２。     

析氯钛基RuO_2－Co_3O_4－TiO_2（60）涂层的研究

用稳定极化、Ｘ射线衍射、透射电镜和扫描电镜的方法研究了钛基ＲｕＯ_２－Ｃｏ_３Ｏ_４－ＴｉＯ_２（６０）涂层的析氯活性、导电性、使用寿命、微观结构和表面形貌。并对其活性表面积进行了评价。详细讨论了涂层成份、微观结构和表面形貌对涂层析氯活性和活性表面积的影响。发现在０～１０ｍ／ｏＣｏ_３Ｏ_４和６０ｍ／ｏＴｉＯ_２成份范围内ＲｕＯ_２、Ｃｏ_３Ｏ_４和ＴｉＯ_２可形成单一金红石型固溶体,且有优异的析氯活性、电导率和使用寿命。以此研究为基础可改进氯碱工业广泛使用的传统ＲｕＯ_２－ＴｉＯ_２阳极,降低阳极涂层中贵金属含量,提高阳极的电化学性能．     

α,ω-双(4-(4′-甲基)-偶氮苯基)苯氧甲基-1,1,3,3-四甲基二硅氧烷的合成和结构

合成了（ＣＨ３（Ｃ６Ｈ４）Ｎ２（Ｃ６Ｈ４）ＯＣＨ２Ｓｉ（ＣＨ３）２２Ｏ,对其晶体结构及分子偶极矩进行了研究．结果表明,晶体属单斜晶系,Ｉ２Ａ空间群,晶胞参数如下：ａ＝２．１７８３４ｎｍ,ｂ＝０．８０３２５ｎｍ,ｃ＝２．０８８９５ｎｍ,β＝１１９．１９１°,Ｖ＝３１８２６ｎｍ３,Ｚ＝４,Ｄｃ＝１．２１６ｋｇ／ｍ３．分子偶极矩μ＝８．９３２×１０－３０Ｃ·ｍ．通过对分子结构和矩值的分析,说明了由刚性基团和柔性基团组成的端介晶基四甲基二硅氧烷的性能与结构之间的关系．     

钕, 铈掺杂的正极材料尖晶石型LiMn2O4的制备及性能

通过掺杂不同含量的Ｎｄ,Ｃｅ制备ＬｉＭｎ２－ｘＲＥｘＯ４（ＲＥ＝Ｃｅ,Ｎｄ;ｘ＝０,０．０５,０．１,０．１５,０．２）锂离子电池正极材料,研究稀土元素拓杂对尖晶石ＬｉＭｎ２Ｏ４正极材料电化学性质的影响。掺杂Ｎｄ,Ｃｅ后ＬｉＭｎ２Ｏ４正极材料更适合于锂离子的嵌入和脱出,电池的循环性能提高,但充放电容量随掺杂量的增加而下降。Ｘ射线光电子能谱分析表明掺杂Ｎｄ,Ｃｅ的ＬｉＭｎ２Ｏ４正极材料,其Ｍｎ＾４＋     

二次Li／LiNi0.3Co0.7O2电池反应研究

利用循环伏安，库仑滴定，Ｘ射线衍射，恒电流阶跃等方法研究了Ｌｉ／ＬｉＮｉ０．２Ｃｏ０．７Ｏ２电池反应。结果表明该电池在４．３０－３．００Ｖ间放电容量可达１２０－１４０ｍＡ．ｈ．ｇ＾－１，充，放电机理为Ｌｉ＾＋在ＬｉＮｉ０．３Ｃｏ０．７Ｏ２中进行两步脱嵌与嵌入反应。     

MCFC隔膜用γ—LiAlO2组细匹配料制备研究

用高温反应法制得的γ－ＬｉＡｌＯ２粗料，另用氯化物法先制得α－ＬｉＡｌＯ２细料，此细料在９００℃焙烧几小时，它首先转化为中间过渡型（无定型），进而再转化为γ－ＬｉＡｌＯ２超细料，其粒度〈０．１８μｍ，ＢＥＴ比表面积〉４３ｍ＾２／ｇ。用带铸法把以上γ－ＬｉＡｌＯ２粗细匹配料制得ＭＣＦＣ隔膜。用此膜组装的电池性能较高，在２００和３００ｍＡ／ｃｍ＾２放电时，电池输出电压分别为０．８５Ｖ和０．７５Ｖ时，功     

参考答案

参考答案单元练习一参考答案及提示一、二、三、选择题四、２８．Ｏ２＋２ＫＩ＋Ｈ２Ｏ→２ＫＯＨ＋Ｉ２＋Ｏ２;Ｉ２,ＫＯＨ２９．１０００ｍ／１６ａ;１４．Ｚａ／ｂ;３０．ＣＨ４;Ｈ２;１：２;因为Ｃ：Ｈ＝３／１２：１＝１：４,ＣＨ４分子里Ｃ与Ｈ的质量比为３...     

微量贵金属对Co／γ-Al_2O_3的作用及其结构表征Ⅰ．Co－M／γ－Al_2O_3催化剂的活性及其XRD和XPS表征

催化剂采用等量浸渍法，先后将Ｃｏ与贵金属组分浸于γ－Ａｌ２Ｏ３上，经５００℃焙烧，４５０℃氢气还原制得（ｍＣｏ３Ｏ４／ｍＡｌ２Ｏ３＝０．０８，ｍ贵金属／ｍ催化剂＝１／１０００）．ＣＯ氧化活性的测定结果表明，贵金属Ｐｔ和Ｐｄ与Ｃｏ之间具有明显的协同催化作用，而Ｒｈ与Ｃｏ的协同作用较差．在Ｃｏ－Ｐｔ／γ－Ａｌ２Ｏ３和Ｃｏ－Ｐｄ／γ－Ａｌ２Ｏ３上，ＣＯ１００％转化的温度较在Ｃｏ／γ－Ａｌ２Ｏ３上下降了约６０℃，而在Ｃｏ－Ｒｈ／γ－Ａｌ２Ｏ３上仅下降了２５℃左右．ＸＲＤ和ＸＰＳ的表征结果表明，Ｃｏ／γ－Ａｌ２Ｏ３中Ｃｏ以高分散的金属Ｃｏ相和类似ＣｏＡｌ２Ｏ４的尖晶石相存在，而Ｃｏ－Ｍ／γ－Ａｌ２Ｏ３（Ｍ＝Ｐｔ，Ｐｄ，Ｒｈ）催化剂中，Ｃｏ相已完全被还原为零价．高分散的金属钴相和贵金属相的协同作用，可能与氧从贵金属至Ｃｏ相上的溢流效应有关．     

Interaction of Al2O3 and CeO2 surfaces with SO2 and SO2 + O2 studied by X-ray photoelectron spectroscopy

The interaction of Al2O3 and CeO2 thin films with sulfur dioxide (2.5 mbar) or with mixtures of SO2 with O2 (5 mbar) at various temperatures (30-400 degrees C) was studied by X-ray photoelectron spectroscopy (XPS). The analysis of temperature-induced transformations of S2p spectra allowed us to identify sulfite and sulfate species and determine the conditions of their formation on the oxide surfaces. Sulfite ions, SO3(2-), which are characterized by the S2p(3/2) binding energy (BE) of approximately 167.5 eV, were shown to be formed during the interaction of the oxide films with pure SO2 at temperatures < or =200 degrees C, whereas sulfate ions, SO4(2-), with BE (S2p(3/2)) approximately 169 eV were produced at temperatures > or =300 degrees C. The formation of both the sulfite and sulfate species proceeds more efficiently in the case of CeO2. The addition of oxygen to SO2 suppresses the formation of the sulfite species on both oxides and facilitates the formation of the sulfate species. Again, this enhancement is more significant for the CeO2 film than for the Al2O3 one. The sulfation of the CeO2 film is accompanied by a reduction of Ce(IV) ions to Ce(III) ones, both in the absence and in the presence of oxygen. It has been concluded that the amount of the sulfates on the CeO2 surface treated with the SO2 + O2 mixture at > or =300 degrees C corresponds to the formation of a 3D phase of the Ce(III) sulfate. The sulfation of Al2O3 is limited by the surface of the oxide film.     

氧化铈作为阴极催化剂在直接硼氢化物燃料电池中的应用

研究以氧化铈(CeO2)作为直接硼氢化物燃料电池(DBFC)阴极催化剂的性能.结果表明:氧化铈对氧还原具有良好的催化效能,但对BH4-离子水解没有明显的促进作用,而且还能抑制它在正极的氧化.以氧化铈为阴极催化剂组装成的模拟单室燃料电池在常温下的最高功率密度为67.8mW·cm-2,运行稳定.     

CeO2-MOx (M=La3+, Ca2+)改性Pd/γ-Al2O3催化甲烷燃烧性能

采用沉积-沉淀法制备了固溶体CeO2-MOx(M=La3+, Ca2+)改性的Pd/γ-Al2O3催化剂, 利用XRD、Raman和XPS对催化剂进行了表征. 结果表明, 金属(M)离子进入CeO2的晶格, 形成CeO2-MOx固溶体, Raman谱上463 cm-1处对应于Ce—O键的F2g对称伸缩振动强度降低. 其中, 样品Pd/γ-Al2O3-CeO2-CaO在615 cm-1处出现一小峰, 样品Pd/γ-Al2O3-CeO2-La2O3在320 cm-1处出现的肩峰, 都表明固溶体CeO2-MOx的形成使O2-亚晶格结构对称性降低. XPS分析表明, 固溶体改性的Pd/γ-Al2O3催化剂中Pd 的3d5/2结合能比正常价态的PdO的结合能高出0.5-0.6 eV, 形成了一种高度离子化的, 与载体具有强相互作用的Pd物种. 催化甲烷燃烧实验证明, 固溶体CeO2-MOx(M=La3+, Ca2+)改性的Pd/γ-Al2O3催化剂的低温活性和稳定性均高于未经改性的Pd/γ-Al2O3催化剂和仅用CeO2改性的Pd/γ-Al2O3催化剂, 在空速为50000 h-1时, 可使1%CH4-99%空气(体积分数)混合气中甲烷的10%转化温度降至254 ℃, 转化率100%时的转化温度降至340 ℃.     

Cu-CeO2基阳极直接甲烷SOFC的制备及其性能

采用干压法制备了NiO-YSZ(氧化钇稳定氧化锆)/(ZrO2)0.89(Sc2O3)0.1(CeO2)0.01(10ScSZ-1CeO2)半电池, 经还原-酸溶法除去NiO制备了多孔YSZ负载致密10ScSZ-1CeO2双层结构, 通过浸渍法在多孔YSZ阳极基体中引入Ce、Cu的硝酸盐制备Cu-CeO2-YSZ复合阳极, 结合La0.6Sr0.4Co0.2Fe0.8O3-δ(LSCF)阴极构建了Cu-CeO2-YSZ/10ScSZ-1CeO2/LSCF单元电池. 通过X射线衍射(XRD)和场发射扫描电镜(FESEM)等手段对电池单元的物相、微观结构进行表征. 结果表明: 还原-酸溶法制备的YSZ/10ScSZ-1CeO2双层结构的YSZ基体具有孔隙率高(>64%)、孔洞连通性好的微观结构, 有助于采用浸渍法引入Ce、Cu硝酸盐; 10ScSZ-1CeO2电解质薄膜致密无缺陷, 厚约30 μm. 电性能测试表明所构建单元固体氧化物燃料电池(SOFC)具有良好的电性能输出, 在650 ℃以湿H2和CH4为燃料时的最大功率密度分别为0.29和0.09 W·cm-2; 在700 ℃以湿H2和CH4为燃料时的最大功率密度分别达到0.48 和0.21 W·cm-2. 优良的电性能主要归功于小的电解质内阻和阴极极化电阻以及良好的阳极微观结构.     

CeO2-MOx（M=La^3＋,Ca^2＋）改性Pd/γ-Al2O3催化甲烷燃烧性能

采用沉积-沉淀法制备了固溶体CeO2-MOx=(M=La3+,Ca2+)改性的Pd/γ-Al2O3催化剂,利用XRD、Raman和XPS对催化剂进行了表征.结果表明,金属(M)离子进入CeO2的晶格,形成CeO2-MOx固溶体,Raman谱上463cm-1处对应于Ce-O键的F2g对称伸缩振动强度降低.其中,样品Pd/γ-Al2O3CeO2-CaO在615 cm-1处出现一小峰,样品Pd/γ-Al2O3-CeO2-La2O3在320cm-1处出现的肩峰,都表明固溶体CeO2-MOx的形成使O2-亚晶格结构对称性降低.XPS分析表明,固溶体改性的Pd/γ-Al2O3催化剂中Pd的3d5/2结合能比正常价态的PdO的结合能高出0.5-0.6 eV,形成了一种高度离子化的.与载体具有强相互作用的Pd物种.催化甲烷燃烧实验证明,固溶体CeO2-MOx(M=La3+,Ca2+)改性的Pd/γ-Al2O3催化剂的低温活性和稳定性均高于未经改性的Pd/γ-Al2O3催化剂和仅用CeO2改性的Pd/γAl2O3催化剂,在空速为50000 h-1时,可使1%CH4-99%空气(体积分数)混合气中甲烷的10%转化温度降至254℃,转化率100%时的转化温度降至340℃.     

Ga2O3薄膜的光致发光及激光烧蚀产物的分布

采用脉冲激光沉积技术在氧气氛中制备了Ga2O3薄膜。X射线衍射表明薄膜属于β单斜晶系,薄膜的颗粒在纳米量级;原子力显微镜显示随着氧气压强的增加,薄膜颗粒增大。测定了薄膜的光致发光,发现沉积时氧气压强的增加可以提高 纯Ga2O3薄膜的发光强度,且峰位红移。Ga2O3靶物质中掺杂少量的CeO2后所得到的薄膜,其发光强度可以明显地增加。此外,还利用发光光谱技术研究了由激光 烧蚀所产生的羽状物中Ga原子或离子的氧化反应。     

CeO2基固溶体氧缺位拉曼光谱表征的研究进展

总结了拉曼光谱表征CeO2基固溶体中氧缺位的研究成果,评述了氧缺位的生成和影响氧缺位浓度观察值的因素,并提出了亟待解决的问题.CeO2基固溶体的拉曼谱图中出现三个重要的特征拉曼峰(465、560、600cm-1),一般分别归属于CeO2的F2g振动模式、氧缺位和MO8型缺陷物种.研究发现氧缺位的产生与掺杂金属离子价态有关,而MO8型缺陷物种的产生与掺杂金属离子半径有关.CeO2基固溶体中氧缺位浓度观察值(AD/AF2g)与样品吸光度和表面富集有关.原位拉曼光谱研究表明:气氛及温度影响CeO2基固溶体的吸光度变化,从而影响拉曼光谱采样深度,导致氧缺位浓度观察值的变化.     

HIGHLY SENSITIVE CATALASE ELECTRODE BASED ON POLYPYRROLE FILMS WITH MICROCONTAINERS

Highly sensitive catalase electrodes for sensing hydrogen peroxide have been fabricated based on polypyrrole films with microcontainers. The microcontainers have a cup-like morphology and are arranged in a density of 4000 units cm^-2. Catalase was immobilized into the polypyrrole films with microcontainers （Ppy-mc）, which were coated on a Pt substrate electrode. The catalase/Ppy-mc/Pt electrode showed linear response to hydrogen peroxide in the range of 0-18 mmol/L at a potential of-0.3 V （versus SCE）. Its sensitivity was measured to be approximately 3.64 μA （mmol/L） ^-1 cm^- 2, which is about two times that of the electrode fabricated from a flat Ppy film （catalase/Ppy-flat/Pt electrode）. The electrode is highly selective for hydrogen peroxide and its sensitivity is interfered by potential interferents such as ascorbic acid, urea and fructose. Furthermore, such catalase electrodes showed long-term storage stability of 15 days under dry conditions at 4℃.     

Boundary effects on the electrical conductivity of pure and doped cerium oxide thin films

Thin films of CeO(2) (both nominally pure and 10 mol% gadolinium-doped) grown via pulsed-laser deposition were studied. The electrical conductivity of the samples was measured as a function of thickness, temperature and oxygen partial pressure (pO(2)) using impedance spectroscopy. As expected, undoped CeO(2) exhibits electronic conductivity (with activation energy between 1.4 and 1.6 eV) whereas the highly doped samples are oxygen vacancy conductors (activation energy around 0.7 eV for epitaxial films). In order to investigate the influence of the nature of the substrate the thin films were grown on two different substrates, Al(2)O(3) (0001) and SiO(2) (0001), and compared. While the films grown on SiO(2) exhibit a microstructure characterized by columnar grains, the films grown on Al(2)O(3) are epitaxial. Notably, for films on both substrates the conductivity and activation energy vary with film thickness and exhibit remarkable differences when the films on different substrates are compared. In the case of the polycrystalline films (SiO(2) substrate), the space charge layer effects of the grain boundaries dominate over the substrate-film interface effect. In the case of the epitaxial films (Al(2)O(3) substrate), a small interface effect, probably due to a space charge layer or structural strain, is observed.     

添加碱土金属化合物对CeO2甲烷氧化偶联催化性能的影响

天然气中甲烷的利用,特别是氧化偶联(OCM)制乙烯过程近年来成为多相催化研究的热点之一.自从1982年Keller和Bhasin提出该课题以来许多学者已进行了大量催化剂的研制工作.尽管在这方面已取得重要进展,但催化剂的性能距工业化要求还有较大差距.