添加钇提高不锈钢耐蚀性能的AES研究

用俄歇能谱仪对比研究了添加０．２％Ｙ对高硅不锈钢在９３％Ｈ２ＳＯ４介质中所形成的钝化膜中各元素浓度分布的影响，添加０．２％Ｙ增大了ＳｉＯ２在不锈钢钝化膜中的比例，从而使合金中Ｓｉ可充分形成富ＳｉＯ２的钝化膜。     

ChemInform Abstract: YCa3(CrO)3(BO3)4: A Cr3+ Kagome Lattice Compound Showing No Magnetic Order Down to 2 K.

Polycrystalline gaudefroyite‐type YCa₃(CrO)₃(BO₃)₄ with Cr³⁺ ions (3d³, S = 3/2) forming an undistorted Kagome lattice is prepared by reaction of a stoichiometric mixture of Y₂O₃, CaCO₃, Cr₂O₃, H₃BO₃ in a KCl flux (Al₂O₃ crucible, 1000 °C, 1 d) followed by re‐grinding and further annealing (1000 °C, 2 d, 95% yield).     

Y修饰CuO/ZrO_2催化剂高效催化水煤气变换反应制氢

采用水热法制备了具有不同Y掺杂量的单分散ZrO_2纳米粒子(n(Y)/n(Y+Zr)=0-5%),并以其为载体采用沉积-沉淀法制得CuO/ZrO_2催化剂;考察了富氢气氛下上述催化剂的水煤气变换反应(WGS)催化性能。结果表明,掺杂Y后催化剂的活性明显提高,其中,载体掺杂2%Y的催化剂具有最佳的催化活性,在270℃时的CO转化率高达91.4%,明显高于研究较多的CuO/ZnO和CuO/CeO_2催化剂。X射线粉末衍射、N_2物理吸附-脱附、N_2O滴定、扫描电镜和CO程序升温还原等表征结果表明,Y~(3+)掺入了ZrO_2的晶格并对催化剂的结构和还原性能产生直接影响。Y助剂的引入一方面促进了CuO在ZrO_2表面的分散,提高了催化剂表面活性Cu-[O]-Zr物种的含量;另一方面,改善了催化剂的颗粒单分散性和织构性能。载体掺杂2%Y助剂的样品具有较高的Cu-[O]-Zr物种含量、较佳的颗粒单分散性和织构性能,且其表面的Cu-[O]-Zr物种和活性羟基具有较佳的还原性能,因而表现出较高的催化活性     

ChemInform Abstract: Crystal Structure and Properties of the Manganese Containing Swedenborgite YBaMn3AlO7.

Small crystals of the title compound are grown from BaAl₂O₄, Y₂BaO₄, and MnO in a floating‐zone mirror‐image furnace.     

不同形貌YF_3微米晶的水热合成及YF_3:Eu~(3+)荧光性质(英文)

水热条件下,Y(NO3)3·6H2O分别与K2SiF6、KPF6反应得到了不同形貌的YF3(八面体及椭球形)。以X射线光电子能谱(XPS)检测了产物的化学组成,表明产物中只含有Y和F。X射线衍射(XRD)结果表明所得的产物均为正交晶系。扫描电子显微镜(SEM)和透射电子显微镜(TEM)对产物的表征结果指明八面体形YF3棱长为200nm,而椭球形YF3是由小的纳米块自组装而成。还研究了Eu3+掺杂后YF3的荧光性质,并提出了可能的形成机理。     

铈酸钡和钇掺杂的铈酸钡复合氧化物的制备及其在钌基氨合成催化剂中的应用

 采用柠檬酸法合成了 BaCeO3 和掺杂 Y3+的 BaCe0.9Y0.1O3-δ 复合氧化物, 以 Ru3(CO)12 为前体, 利用浸渍法制备了 Ru/BaCeO3 和 Ru/BaCe0.9Y0.1O3-δ 催化剂. 通过 X 射线衍射、扫描电镜和透射电镜技术对样品进行了表征, 并在固定床反应器中考察了催化剂的氨合成反应活性. 结果表明, 载体 BaCeO3 的稳定性优于 BaCe0.9Y0.1O3-δ, 但 Ru/BaCe0.9Y0.1O3-δ 催化剂的氨合成活性明显高于 Ru/BaCeO3, 在 3.0 MPa, 15 000 h1, 425 oC 反应时, Ru/BaCe0.9Y0.1O3-δ 催化剂上氨合成反应速率达到 432.5 ml/(g•h), 是 Ru/BaCeO3 催化剂的 1.6 倍. 这种活性和稳定性的显著差异来自载体中 Ce4+ 与 Ru 纳米粒子间的电子作用.     

Synthesis,Crystal Structure,Vibrational Spectroscopy,and Thermal Behavior of Y[B_2O_3（OH）]_3

The hydroxy yttrium hexaborate,Y[B2O3(OH)]3,has been synthesized under mild hydrothermal conditions at 458 K.The crystal structure was solved and refined from single-crystal X-ray diffraction.It adopts a trigonal space group R3c(No.161) with a = 8.3942(4),c = 20.6484(12) ,V = 1260.03(12) 3,YB6H3O12,Mr = 348.79,Z = 6,Dc = 2.758 g/cm3,F(000) = 1008,μ = 7.015 mm-1,R = 0.0321 and wR = 0.0772.Its crystal structure is made up of six-membered rings,alternating three-connected [BO3(OH)] tetrahedra and planar [BO3] trigonal groups,which are interconnected with each other by sharing their common oxygen corners to form a three-dimensional framework structure with six-membered ring channels that are occupied by the yttrium atoms and run along the c axis.FT-IR,Raman,and TG-DTA results are also presented.     

Synthesis and characterization of doped apatite-type lanthanum silicates for SOFC applications

A series of iron- and/or aluminium-doped apatite-type lanthanum silicates (ATLS) La_9.83Si_{6 ‐ x ‐ y}Al_xFe_yO_26 ± δ (x = 0, 0.25, 0.75, and 1.5, y = 0, 0.25, 0.75, and 1.5) were synthesized using the mechanochemical activation (MA), solid state reaction (SSR), Pechini (Pe) and sol-gel (SG) methods. The total conductivity of the prepared materials was measured under air in the temperature range 600-850 °C using 4-probe AC impedance spectroscopy. Its dependence on composition, synthesis method, sintering conditions and powder particle size was investigated. It was found that for electrolytes of the same composition, those prepared via mechanochemical activation exhibited the highest total specific conductivity, which was improved with increasing Al- and decreasing Fe-content. The highest conductivity value at 700 °C, equal to 2.04 × 10^− 2 S cm^− 1, was observed for the La_9.83Si₅Al_0.75Fe_0.25O_26 ± δ electrolyte. La_9.83Si_4.5Fe_1.5O_26 ± δ electrolyte samples synthesized using the Pechini method exhibited higher conductivity when sintered conventionally than when spark-plasma sintering (SPS) was used.