REG: X-Ray Powder Diffractometer for Characterization of Ultrafine Materials and Novel Structures

中文摘要Ying CTS-9411901 将购买一台X射线粉末衍射仪，专门用于支持马萨诸塞州理工学院化学工程和化学系的几个研究项目。 这些项目包括通过纳米晶合成，溶胶-凝胶处理和层状结构的柱撑产生的超细材料的结构剪裁。 这些计划的共同主题在于纳米结构的设计，纳米结构由纳米尺寸的微晶或二维层状结构、高体积分数的表面和界面以及微孔网络组成。 X射线衍射法将用于鉴定晶相，以及表征微晶尺寸、晶格应变、膜厚度、层间距和热稳定性。 新型纳米结构的目标是以下应用：（1）用于SO2脱除的高活性催化剂，（2）用于部分氧化和加氢脱硫的微孔分子混合多组分催化剂，（3）低温可烧结的高强度Si 3 N4基结构复合材料，以及（4）用于氢气纯化和膜反应的高选择透过性致密金属膜。 前三个项目目前由NSF资助。 提出的衍射仪也将用于新的氮化物和氧离子导体的相鉴定和结构测定。 以固态氧化物为前驱体，通过氨解反应合成具有金属和磁性的三元氮化物。 这些多晶粉末的准确结构表征将与X射线Rietveld细化。 类似的结构测定也提出了新的层状氧化铋与本征氧空位。 它们作为低温超离子氧离子导体具有很大的潜力，在燃料电池和空气分离技术中具有重要的应用价值。 研究经费来自分部和美国化学学会石油研究基金的资助。*

ABSTRACT Jackie Y. Ying CTS-9411901 A X-ray powder diffractometer will be purchased and dedicated to support several research projects in the Departments of Chemical Engineering and Chemistry at Massachusetts Institute of Technology. The projects include structural tailoring of ultrafine materials generated through nanocrystalline synthesis, sol-gel processing, and pillaring of layered structures. The common theme of these programs lies in the design of nanoscale structure, which consists of nanometer-sized crystallites or two-dimensional layered structures, high volume fraction of surfaces and interfaces, and microporous network. X-ray diffractometry will be used in the identification of crystalline phases, and in the characterization of crystallite size, lattice strain, film thickness, interlayer spacing, and thermal stability. Novel nanostructures are targeted towards the following applications: (1) high activity catalysts for SO2 removal, (2) microporous molecularly mixed multicomponent catalysts for partial oxidation and hydrodesulfirization, (3) low-temperature sinterable, high strength Si3N4-based structural composites, ad (4) high permselectivity dense metallic membranes for hydrogen purification and membrane reaction. The first three projects are currently funded by NSF. The proposed diffractometer will be also used in the phase identification and structural determination of new nitrides and oxygen ion conductors. Ternary nitrides which have interesting metallic and magnetic properties will be synthesized via ammonolysis of solid state oxide precursors. Accurate structural characterization of these polycrystalline powders will be performed with X-ray Rietveld refinement. Similar structural determination is also proposed for novel layered bismuth oxides with intrinsic oxygen vacancies. They have great potential as low-temperature superionic oxygen ion conductors, which will be very useful in fuel cell and air separation technologies. Research is funded through gran ts from Division and American Chemical Society Petroleum Research Fund. ***