Powders and Granules in reactive and non-reactive environments

拟议研究的总体目标是研究粉末和颗粒在以下情况下的行为：1。非均相催化剂的纳米形态，特别是三相边界长度（TPBL）与催化活性的关系。短期目标和主要新颖之处在于适应聚焦离子束（FIB）断层扫描/扫描电子显微镜（SEM）成像分析，直接计算TPBL并将其与催化剂活性联系起来。除了开发可用于工业应用的新型催化配方外，主要的挑战是开发一种方案，在不影响催化剂完整性的情况下，允许足够的图像对比度和随时间流动的采样。该方法依赖于对新鲜和使用过的配方的处理以及SEM/FIB，透射电子显微镜(TEM)/电子能量损失光谱（EELS）和TEM/能量色散x射线光谱（EDXS）分析。两个关键问题是(a)催化剂支撑相和含催化金属相必须具有明显不同的分子量，以便通过SEM容易区分；(b)能够穿透催化剂开放孔隙的树脂的选择和使用。一旦样品按照上述方法制备，从目标材料的fib蚀刻表面产生成堆的SEM图像；每个制造出来的表面都进行了SEM显微照相；然后，用一种算法读取图像堆栈，并根据所研究材料的数学三维重建估计TPBL。2. 研究从冶金尾矿中制备的新型尖晶石基纳米催化剂在需要最佳金属相分散的催化体系中的适用性。这些尖晶石基配方已被证明在高温和低压的各种重整和POX制度下是有效和稳健的。高压以及将该催化剂家族用于其他催化反应是该专业的首要目标

The general objective of the proposed research is to study the behaviour of powders and granules in the following contexts: 1. Link nanomorphology of heterogeneous catalysts and more particularly the triple phase boundary length (TPBL) with catalytic activity. The short-term objective and main novelty resides in the adaptation of focused ion beam (FIB) tomography/scanning electron microscopy (SEM) imaging analysis to calculate directly the TPBL and relate it to the catalysts activity. Besides the development of novel catalytic formulations, which could find industrial applications, the main challenge is to develop a protocol allowing for sufficient image contrast and sampling over time-on-stream without affecting catalysts integrity. The methodology relies on the handling of fresh and used formulations and SEM/FIB, transmission electron microscopy (TEM)/electron energy loss spectroscopy (EELS) and TEM/energy dispersive x-ray spectroscopy (EDXS) analyses. Two critical issues is (a) that the catalyst support and catalytic metal containing phases must have significantly different molecular weights to be easily diffentiated by SEM and (b) the choice and use of a resin able to penetrate the open porosity of the catalysts. Once the samples are prepared in accordance with the above, stacks of SEM images are produced from FIB-etched surfaces of the targeted material; each of the so-produced surfaces are SEM micrographed; then, the stack of images are read with an algorithm and the TPBL is estimated from a mathematical 3D reconstruction of the material studied.. 2. Investigate the applicability of a novel patent-pending family of spinel-based nanocatalysts formulated from metallurgical tailings, to catalytic systems requiring optimal metallic phase dispersion. These spinel-based formulations have been proven efficient and robust at various reforming and POX regimes at highretemperature and low pressures. High pressures as well as the use of this catalysts' family to other catalytic reactions are first objective of the pro