CATALYTIC BEHAVIOR OF DOPED MTiO_3 CATALYSTS FOR OXIDATIVE DEHYDROGENATION OF ETHANE

用Ｌｉ＋部分替代ＭＴｉＯ３（Ｍ＝Ｃａ、Ｓｒ）催化剂中的Ｔｉ４＋，明显地提高了乙烷氧化脱氢（ＯＤＨＥ）反应中乙烯的选择性。在ＣａＴｉ０．９Ｌｉ０．１Ｏ３－δ催化剂上，反应温度为８５０℃时，乙烯选择性为７７．４％，乙烷转化率为８１．７％。Ｌｉ掺杂的作用是增加了催化剂的Ｐ型半导性和未充分还原的氧物种数目。     

硼掺杂还原态氧化石墨烯催化剂的制备及其蒽催化加氢性能的研究

制备了一系列硼掺杂的还原氧化态石墨烯催化剂并应用于蒽加氢反应。结果表明，随着催化剂处理温度的升高，催化剂中有序碳结构会发生变化，硼会取代材料骨架中的碳，进而影响蒽和氢气的吸附活化。经硼改性后，催化剂对蒽加氢反应表现出了很高的加氢活性，蒽的最高转化率可达97%，深度加氢产物八氢蒽的最高选择性可达19%。     

Selective Electroanalytical Assay for Cysteine at a Boron Doped Diamond Electrode

The electrochemical oxidation of the cysteine‐quinone adduct has been examined as a means of providing an electroanalytical cysteine specific detection protocol. The appliance of square‐wave voltammetry allowed 0.5 μM as a limit of detection. The effects of various biologically relevant interferences including other thiols were studied and found to present no change in the voltammetric profile. The practical applicability and efficiency of the methodology was probed through the determination of cysteine concentration in growth tissue medium.     

A Theoretical Study on the Conductivity of Carbon Doped BNNT

From the changes in energy band, density of state (DOS) and electronic structure calculated by the DFT/B3LYP method, the conductivity of carbon doped boron‐nitride nanotube (BNNT), which is formed by C‐C bond substituting B‐N bond, was discussed. The results indicate that the substitution will strengthen the conductivity of the tube, and its semi‐conductivity might be adjusted by controlling the substitution.     

An In Situ Copper Plated Boron‐Doped Diamond Microelectrode Array for the Sensitive Electrochemical Detection of Nitrate

The first example of using a copper microelectrode array for use in electroanalysis is explored and exemplified with the electroanalytical quantification of nitrate. The analytical approach is based upon the in situ deposition of copper at a boron‐doped diamond (BDD) microelectrode array. The immobilized copper layer is electrocatalytic for nitrate reduction and exhibits an analytically useful range from 1.2 to 124 μM with a marked selectivity for nitrate ion over nitrate, with a limit of detection of 0.76 μM. The analytical applicability was examined through standard addition determinations of nitrate in drinking and river water samples.     

DEHYDROGENATION AND AROMATIZATION OF METHANE IN THE ABSENCE OF OXYGEN OVER DOPED Mo/HZSM-5 CATALYSTS

研究了在Ｍｏ／ＨＺＳＭ－５催化剂上添加助剂以及不同的反应预处理温度对甲烷无氧脱氢芳构化反应的影响。实验结果表明，由于第二组分的添加，Ｍｏ／ＨＺＳＭ－５催化剂的活性和选择性都得到了较大程度的改善。预处理温度是影响催化剂反应性能的关键因素。Ｍｏ－Ｒｕ／ＨＺＳＭ－５催化剂经过８７３Ｋ空气预处理后，甲烷在９７３Ｋ的转化率约为１０％，催化剂的稳定性也得到较大程度的提高。ＴＰＳＲ实验结果表明，Ｒｕ的加入降低了芳烃生成的温度。ＴＰＯ和ＤＴＡ实验结果表明，在Ｍｏ－Ｒｕ／ＨＺＳＭ－５催化剂上可生成较多的碳物种，结合反应结果，可以认为反应过程中生成的碳物种对甲烷的无氧脱氢芳构化反应是起积极作用的     

纳米Eu0.10Y1.90-xNdxO3-δ的光致发光特性及浓度猝灭研究

使用超声波作用下的均匀沉淀法,制备了Eu0.10Y1.90-xNdxO3-δ纳米晶荧光粉,用X射线粉末衍射、荧光光谱等对其进行表征.研究了掺杂Nd3 离子对Y2O3∶Eu3 晶格常数、晶粒尺寸及室温光致发光特性的影响.由不同掺杂浓度x=0~0.18下样品的发射光谱强度变化曲线得到猝灭浓度值,探讨了掺杂Nd3 的样品荧光浓度猝灭的机理.发光强度与浓度的关系表明,掺杂离子之间存在的Eu3 -Nd3 或Nd3 -Nd3 间交换相互作用,是导致掺杂样品浓度猝灭的主要原因.     

溶胶—凝胶合成（Mg,Ca）O—SiO2：Eu^3＋,Bi^3＋发光体及其发光行为

以Ｍｇ（ＮＯ３）２，Ｃａ（ＮＯ３）２，Ｅｕ（ＮＯ３）３，Ｂｉ（ＮＯ３）３和Ｓｉ（ＯＣ２Ｈ５）４为反应物，采用溶胶－凝胶法，在比较低的温度，首次合成０．７０１ｍｏｌＭｇＯ－０．１７５ｍｏｌＣａＯ－１．２５ｍｏｌＳｉＯ２：０．０６ｍｏｌＥｕ＾３＋，０．００２ｍｏｌＢｉ＾３＋（加入Ｌｉ＾＋作为电荷补偿剂）发光体，得到了最佳合成条件，研究了由溶胶向凝胶转变和凝胶向发光晶体的转变过程，探讨了发光体在不同激光     

Vanadium Doped Sol-Gel TiO2 Coatings

A study of the experimental conditions required to obtain vanadium doped sol-gel TiO2 coatings is presented. Tetraethyl orthotitanate was employed as the TiO2 source and VCl3, VOSO4 · H2O and VOSO4 dissolved H2SO4 where employed as vanadium sources.Dip coating has been used to produce coatings on silicon wafers, spectral carbon electrodes and titanium electrodes. Both supported and unsupported films have been studied by UV-Vis spectra, IR spectroscopy and X-ray diffraction (XRD). The measurements have been made on samples as prepared and treated thermally at temperatures between 100°C and 300°C. The thermal treatment temperatures have been established from DTA/TGA measurements.The vanadium doped sol-gel TiO2 coatings have been tested as sensors for redox potential measurements in electrochemical processes. The influence of both the thickness of films and the nature of substrate has been investigated.     

Mo/Fe3O4(111)表面对燃煤烟气汞吸附的密度泛函研究

利用CASTEP软件包采用密度泛函理论计算研究了过渡金属Mo掺杂Fe_3O_4(111)Fe_(tet)表面对Hg~0、HgCl和HgCl_2的吸附特征,分析了Mo掺杂前后Fe_3O_4(111)Fe_(tet)表面上不同汞物种的吸附形态。结果表明,Mo掺杂Fe_3O_4(111)Fe_(tet)表面对HgCl和HgCl_2为化学吸附,而对Hg~0的吸附为物理吸附;与纯净表面相比,HgCl在Mo原子掺杂表面上的吸附能提高了40%-66%。HgCl_2在纯净Fe_3O_4(111)Fe_(tet)表面形成"M"形结构;而掺杂Mo原子后,由于Cl原子与Mo原子之间更强的相互作用,使得HgCl_2发生了完全解离,两个Cl原子分别与Mo原子和Fe原子成键吸附在表面,Hg脱附。相关研究结果可为脱除燃煤烟气中的汞提供一定的理论指导。