Reducible oxide materials: knowledge-driven design of novel low-temperature synthesis routes

在离子液体中低温合成可还原性氧化物纳米材料，有可能使具有定制结构和组成的新型材料成为可能。然而，基于知识的新合成路线设计需要对控制颗粒成核和生长的界面化学有深入的了解。该项目旨在提供这些知识，并将其应用于综合方法的合成，该方法结合了基础界面科学、原位光谱学和实际材料的制备。我们的战略是基于Wasserscheid集团在il相关材料的合成化学方面的专业知识，以及Libuda集团在表面科学和原位光谱方面的能力。此外，该项目将受益于SPP 1708内部的密切合作。在第一个资助期有条不紊地发展的基础上，第二个资助期的项目特别着眼于氧化钴纳米颗粒的合成，这种材料在催化和能源技术方面具有取代贵金属的巨大潜力。我们的目标是在近室温条件下形成具有明确定义的成分，形状和结构的纳米材料。纳米材料将由咪唑和吡咯烷基il中的分子前体使用非常规氧化剂（如臭氧）形成。我们将把IL/氧化物界面化学的基础研究与实际材料合成过程中的原位光谱结合起来。因此，我们将探索ILs，分子Co前体和氧化剂臭氧之间的相互作用，确定反应机制和中间体，使用时间分辨原位光谱提取动力学数据，并研究合成的实际方面，如优化溶解度。研究IL在明确的钴氧化物界面上的吸附、相互作用和反应的结构依赖性，我们将探索结构导向效应的起源。基于这些结果，我们的目标是通过利用il的结构多样性来调整氧化物- il的相互作用，例如通过改变阴离子、阳离子、取代和功能化。最后，我们将把力学、光谱和动力学数据与所获得的纳米材料的性质联系起来。这也将包括在合成过程中去除污染物和引入掺杂剂的策略，例如通过将il氧化转化为挥发性产物。按照这一策略，我们期望获得决定关键性质的因素的基本见解，如颗粒形状、结构、大小和组成，最终将有助于释放il中低温合成氧化物纳米颗粒的全部潜力。

The low-temperature synthesis of reducible oxide nanomaterials in ionic liquids (ILs) holds the potential to make novel materials with tailor-made structure and composition available. However, the knowledge-based design of new synthesis routes requires an in-depth understanding of the interfacial chemistry that controls particle nucleation and growth. The project aims at providing this knowledge and at applying it for synthesis in an integrated approach that combines fundamental interface science, in-situ spectroscopy and the preparation of real materials. Our strategy is based on the complementary expertise of the Wasserscheid Group with its know-how in synthetic bench chemistry with IL-related materials and of the Libuda Group bringing in its capabilities in surface science and in-situ spectroscopy. In addition, the project will benefit from intense cooperation within the SPP 1708. Based on the methodic developments of the first funding period, the project for the second funding period aims in particular at the synthesis of cobalt oxide nanoparticles, materials that offer great potential to replace noble metals in catalysis and energy technology. We will target the formation of nanomaterials with well-defined composition, shape and structure at near-room-temperature conditions. Nanomaterials will be formed from molecular precursors in imidazolium- and pyrrolidinium-based ILs using unconventional oxidizing agents such as ozone. We will combine fundamental studies of the IL/oxide interfacial chemistry with in-situ spectroscopy during synthesis of real materials. Thereby, we will explore the interactions between the ILs, molecular Co precursors and the oxidizing agent ozone, identify reaction mechanisms and intermediates, extract kinetic data using time-resolved in-situ spectroscopies and investigate practical aspects of synthesis such as optimized solubility properties. Investigating the structure dependence of IL adsorption, interaction and reaction at well-defined cobalt oxide interfaces, we will explore the origin of structure-directing effects. Based on these results, we aim to tune oxide-IL interactions by employing the structural diversity of ILs, e.g. by varying anions, cations, substitution and functionalization. Finally, we will correlate the mechanistic, spectroscopic and kinetic data to the properties of the nanomaterials obtained. This will also include strategies to remove contaminations and introduce dopants during synthesis, for instance by oxidative transformation of ILs into volatile products. Following this strategy, we expect to obtain fundamental insights into the factors that determine key properties such as particle shape, structure, size, and composition, which, eventually, will help to unleash the full potential of low-temperature synthesis of oxide nanoparticle in ILs.