Design and in situ Characterization of High-Surface Area Metallic and Bimetallic Nanoscale Catalysts

本研究涉及材料化学的应用，以合理设计用于选择性氧化和加氢反应的纳米颗粒催化剂。催化剂设计将用于提高纳米颗粒催化剂的活性和稳定性，以及通过空间隔离催化位点或通过控制底物进入纳米颗粒表面来提高催化剂的选择性。此外，纳米颗粒设计和纳米颗粒催化的原位表征将通过x射线吸收光谱在附近的加拿大光源进行，使用专门为液相和气相工作开发的细胞。我们在该领域的长期目标是开发具有高催化活性，对特定底物具有优异选择性，以及优异的催化剂寿命和可回收性的催化剂。因此，我们将开发可持续的催化材料，以减少有害物质和溶剂的浪费，并实现昂贵的贵金属催化剂的高原子经济性。具体来说，三个方向将作为设计纳米颗粒催化剂的一种手段，针对特定的应用。这些方向包括a)用于稳定和选择性加氢和氧化催化剂的原子精密金属和双金属团簇的合成；B)将催化金属电还原到金属氧化物纳米颗粒载体上，c)通过对纳米颗粒进行脱合金处理，并利用纳米颗粒的内部空腔来加速催化反应，从而合成和表征多孔纳米颗粒催化剂。这项研究对加拿大来说非常重要，因为它将允许催化剂的设计，从而提高石化过程的效率，并将产生具有可持续化学和催化过程中纳米级材料的合成、表征和应用技能的HQP。纳米技术和可持续化学有望为加拿大的石油化工和材料工业等部门带来巨大的利益。

The proposed research involves the use of materials chemistry toward the rational design of nanoparticle catalysts for selective oxidation and hydrogenation reactions. Catalyst design will be undertaken to improve activity and stability of nanoparticle catalysts, as well as improving catalyst selectivity by spatially isolating catalytic sites or by control of substrate access to nanoparticle surfaces. In addition, in situ characterization of both nanoparticle design and nanoparticle catalysis will be carried out by X-ray absorption spectroscopy at the nearby Canadian Light Source using specialized cells which have been developed for liquid and gas phase work. Our long-term goal in this field is to develop catalysts which have high catalytic activity, excellent selectivity towards specific substrates, and excellent catalyst longevity and recyclability. Thus we will be developing sustainable catalytic materials which can minimize waste of hazardous materials and solvents, and attain a high atom economy for expensive noble metal catalysts. Specifically three directions will be pursued as a means of designing nanoparticle catalysts directed towards specific applications. These directions include a) the synthesis of atom-precise metallic and bimetallic clusters for stable and selective hydrogenation and oxidation catalysts; b) galvanic reductions of catalytic metals onto metal oxide nanoparticle supports, and c) the synthesis and characterization of porous nanoparticle catalysts via dealloying of nanoparticles and using the interior cavities of such nanoparticles to accelerate catalytic reactions. The proposed research is of importance to Canada as it will allow for the design of catalysts which can increase the efficiency of petrochemical processes and will lead to the generation of HQP who have skill-sets in the synthesis, characterization, and applications of nanoscale materials for sustainable chemistry and catalytic processes. Nanotechnology and sustainable chemistry promises to bring tremendous benefits to Canadian sectors such as the petrochemical and materials industry.