Spectroscopic studies of transition-metal oxides, silicates, and pnictides: developing materials capable of sequestering nunclear waste

过渡金属氧化物、硅酸盐和磷族化物的光谱研究：开发能够封存核废料的材料

• 批准号: 386347-2010
• 负责人: Grosvenor, Andrew
• 金额: $ 2.55万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=485291
• 关键词: Spectroscopic; studies; transition; metal; oxides

With governments considering phasing out fossil fuel based power generators because of environmental concerns, nuclear energy is once again a serious alternative. Although the power generated by nuclear reactors is "clean", hazardous radioactive waste is produced. Canada supplies >25% of the worlds' uranium (U) supply (production value >$2.5 billion), with much of it destined for nuclear power facilities. To increase Canada's position in the U market, it is important to develop materials for use in the storage of nuclear waste. This waste can be sequestered in compounds that are densely packed and retard outward diffusion of the radioactive elements. The long-term goal of this research program is the development of ordered compounds that can sequester U in the structure and resist radiation induced structure damage. To initiate this research, model compounds representing host materials will be examined in order to gain a clear understanding of the relationship between crystal structure composition, bonding, electronic structure, and surface reactivity to the sequestration of actinides like U. In this program, pyrochlore ceramics (A2B2X6X'; A=Ca, Mn, Fe, rare-earths (RE); B=Ti,Nb,Ta; X/X'=O, F, OH), materials adopting the zircon (ASiO4; A=Zr, Hf) and zirconolite (A2B2O7; A/B=Ca, V, Zr, Ti, Hf) structures, amorphous silicates ([AO2]x[A'O2]y[SiO2]1-x-y; A/A'=Ti, Zr, Hf), and skutterudites (REM4Pn12; RE=La, Ce, Eu, Gd; M = Fe, Co; Pn (pnictide)=P, As, Sb, Bi) will be synthesized. The electronic structure and ability of these materials to be oxidized will be investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy, utilizing synchrotron radiation. Studying crystalline and amorphous silicates will allow for an examination of how radiation induced structure damage affects a materials ability to sequester U. (Many of the above materials also have applications in semiconductor devices, power generation, and refrigeration.) This research program is dedicated to applying X-ray spectroscopy to the study of the oxidation behaviour and changes in electronic structure with elemental substitution of the systems described above, so as to develop materials capable of sequestering nuclear waste.

由于环境问题，各国政府正在考虑逐步淘汰化石燃料发电机，核能再次成为一种重要的替代能源。 虽然核反应堆产生的电力是“清洁的”，但会产生危险的放射性废物。 加拿大供应世界铀供应量的25%以上（产值> 25亿美元），其中大部分用于核电设施。 为了提高加拿大在美国市场的地位，重要的是开发用于储存核废料的材料。 这种废物可以被隔离在化合物中，这些化合物被密集地包装并阻碍放射性元素的向外扩散。该研究计划的长期目标是开发有序化合物，可以在结构中螯合U并抵抗辐射引起的结构损伤。 为了启动这项研究，代表主体材料的模型化合物将被检查，以获得晶体结构组成，键合，电子结构和表面反应性之间的关系，以螯合的锕系元素，如U。 在这个节目中，烧绿石陶瓷（A2 B2 X6 X '; A=Ca、Mn、Fe、稀土（RE）; B=Ti、Nb、Ta; X/X'= O、F、OH），采用该锆英石的材料（ASiO 4; A=Zr，Hf）和锆英石（A2 B2 O 7; A/B=Ca、V、Zr、Ti、Hf）结构，无定形硅酸盐（[AO 2]x[A 'O2]y[SiO2]1-x-y; A/A'= Ti，Zr，Hf）和方钴矿（REM_4Pn_（12）; RE=La，Ce，Eu，Gd; M = Fe，Co; Pn（磷属元素化物）=P，As，Sb，Bi）。 这些材料的电子结构和被氧化的能力将通过X射线衍射、X射线光电子能谱和X射线吸收光谱利用同步辐射进行研究。 研究结晶和无定形硅酸盐将允许检查辐射引起的结构损伤如何影响材料螯合铀的能力。 (Many上述材料中的一种还可用于半导体器件、发电和制冷。 该研究计划致力于将X射线光谱学应用于研究上述系统的氧化行为和电子结构随元素取代的变化，以开发能够隔离核废料的材料。