Powders and Granules in reactive and non-reactive environments

这项研究的总体目标是研究粉末和颗粒在以下背景下的行为：1.将多相催化剂的纳米形态，尤其是三相界面长度(TPBL)与催化活性联系起来。短期目标和主要创新在于采用聚焦离子束(FIB)层析/扫描电子显微镜(SEM)成像分析来直接计算TPBL并将其与催化剂活性相关联。除了开发可用于工业应用的新型催化配方外，主要挑战是开发一种协议，允许在不影响催化剂完整性的情况下，随着时间的推移实现足够的图像对比度和采样。该方法依赖于新鲜和二手配方的处理以及扫描电子显微镜/FIB、透射电子显微镜(TEM)/电子能量损失谱(EELS)和透射电子显微镜/能量色散X射线光谱(EDXS)分析。两个关键问题是(A)催化剂载体和催化金属相必须具有明显不同的分子质量，以便通过扫描电子显微镜进行区分；(B)能够穿透催化剂开口孔洞的树脂的选择和使用。一旦按照上述方法制备样品，就从目标材料的FIB蚀刻表面产生层叠的扫描电子显微镜图像；对每个如此产生的表面进行扫描电子显微镜显微照相；然后，用算法读取该层叠图像，并根据所研究材料的数学3D重建来估计TPBL。2.研究以冶金尾矿为原料合成的新型尖晶石基纳米催化剂是否适用于需要最佳金属相分散的催化体系。事实证明，这些基于尖晶石的配方在高温和低压下的各种重整和POX制度下都是有效和坚固的。高压以及将这种催化剂家族用于其他催化反应是PRO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