Powders and Granules in reactive and non-reactive environments

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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 proposed research. Three catalytic reactions are targeted: Oxidation, Reduction/Hydrogenation and Alkylation. The methodology is determined by an already advanced literature review and the previous experience of my group and includes the following: functionalization/doping of the UGSO metallurgical residue with the appropriate metal(s); study qualitatively and quantitatively the resulting oxide, spinel and metallic phases and understand the mechanisms of the reactions; relate the nature and the experimental conditions with conversions and selectivity and use them to model the process and propose scale-up criteria. A thermocatalytic scale-up building, equipped with high P and T kg-lab-scale fixed and fluidized bed reactors, is under construction at the Université de Sherbrooke (UdeS), to accommodate my projects, including the ones presented in this proposal and will be available before April 2019.