Engineering of spinels for catalysis

该研究计划的目标是开发利用磁性尖晶石进行多相气相反应的微波或感应场辅助催化技术。创新之处在于利用了这样一个事实，即只需要纳米颗粒上的反应部位处于较高的温度，就可以提高表面反应的效率和活性。这样的工艺可以快速加热到给定的再生温度，并最大限度地减少烧结。这项为期5年的研究计划旨在合成、表征和研究各种尖晶石铁氧体的纳米结构，即M=Ni、Co、Mn、Zn或其混合物的MxFe3-xO4。这些纳米材料具有磁性，对微波敏感，被认为是制造适用于辅助催化的杂化纳米结构的基石。 铁尖晶石将使用溶液喷雾热等离子体生产，这是我们实验室成熟的一项技术。已知铁尖晶石的催化性能与金属原子对尖晶石晶格特定位置的亲和力直接相关。这些金属-位置的相互作用将使用一系列互补的表征方法来研究，例如X射线衍射(X射线衍射)、X射线荧光和电子显微镜。 这些材料的热化学将使用操作员技术进行研究，使这些材料能够在工作条件下进行探测，以重现尖晶石在反应中的行为，并设计出适合所选反应的更好的尖晶石。利用气体流动池，铁尖晶石结构的变化将使用opando X射线衍射，X射线吸收光谱(XAS，在加拿大光源，萨斯卡通)和热重分析来探索。 由于所提出的金属尖晶石(锰、铁、钴、镍和锌)的原子序数如此接近，X射线衍射分析仍然隐藏着结构的更细微细节。然而，如果用中子而不是X射线探测，预计这些元素的对比度会更强。另一个目标是设计和建造一个适合加拿大中子散射研究所(CINS)束线的环境站，以全面了解这些复杂尖晶石在反应过程中的气体/固体和固体相互作用。 拟议的研究项目是该实验室长期目标的基石：开发基于新型混合材料的技术。该研究项目涵盖了整个创新周期，从新型纳米材料的设计和合成，到使能技术的概念验证。 这项研究的成果有望通过设计新型纳米材料来提高催化转化过程的能效，并在纳米材料科学、化学工程和材料物理的十字路口提供培训。

The goal of the research program is to develop the technology of microwave or induction field assisted catalysis using magnetic spinels for heterogeneous gas-phase reactions. The innovation is to take advantage of the fact that only the reaction site on the nanoparticles needs to be at higher temperature to improve the efficiency and activity of surface reactions. Such process would enable fast heating to a given regeneration temperature and minimize sintering. The proposed 5-year research project intends to synthesize, characterize and study nanostructures of various spinel ferrites, namely MxFe3-xO4, with M = Ni, Co, Mn, Zn or mixture thereof. Being magnetic and susceptible to microwave, these nanomaterials are being considered as building blocks for producing hybrid nanostructures adapted for assisted catalysis. The ferrospinels will be produced using solution-spray thermal plasma, a technique well-established in our lab. The catalytic properties of the ferrospinels are known to be directly related to the affinity of the metals atoms towards specific sites of the spinel crystalline lattice. These metal-site interactions will be investigated using an array of complementary characterization methods, such as X-ray diffraction (XRD), X-ray fluorescence and electron microscopy. The thermochemistry of these materials will be investigated using operando techniques, allowing the materials to be probed in working conditions to reproduce the behavior of spinels under reaction and design better spinels adapted to selected reactions. Using a gas flow cell, the change of the ferrospinels structure will be probed using operando XRD, X-ray absorption spectroscopy (XAS, at the Canada Light Source, Saskatoon), and thermogravimetry. With the proposed metal spinels (Mn, Fe, Co, Ni, and Zn) so close in atomic number, finer details of the structure remain hidden from XRD analysis. However, a stronger contrast for these elements is expected if probed with neutron rather than X-rays. Another objective is to design and build an ambient station adapted to the beam line of the Canadian Institute for Neutron Scattering (CINS) in order to gain a comprehensive understanding of the gas/solid and solid-state interactions of these complex spinels during reaction. The proposed research project is cornerstone to the long-term objective of the lab: the development of technologies based on novel hybrid materials. This research project covers the entire innovation cycle, from the design and synthesis of novel nanomaterials, to the proof of concept of an enabling technology. The outcome of this research is expected to improve the energy efficiency of catalytic conversion processes by engineering novel nanomaterials and provide training in fields at the crossroads of nanomaterials science, chemical engineering and materials physics.