Development of New Precursors and Processes for the Controlled Deposition of Platinum Groups Metals

铂族金属(PGm：Ru、Rh、Pd、Os、Ir和Pt)既可以以分子形式(均相催化)应用，也可以作为纳米材料(多相催化)应用，在有机化合物的化学合成或燃料电池应用中作为高效和有效的催化剂得到了广泛的应用。由于其丰度低，开采难度大，最近的研究往往集中在具有类似催化活性、更有效利用或环境友好型回收策略的不含PGM的替代品上。目前的建议将有助于通过了解潜在的化学和物理机制，通过化学气相沉积(CVD)更有效地制备纳米结构多相PGM催化剂。CVD方法可以实现无溶剂、稳定和均匀的材料沉积，即使在开孔衬底内也是如此，这对于高效的催化剂材料是必不可少的。因此，获得、理解和控制具有高挥发性和匹配的反应性轮廓的已定义的分子前体对于通过气相进行定向沉积至关重要。新的PGM前体文库的化学和物理性质将与现有的前体进行比较，以分别建立反应性和挥发性的分子结构-性质关系。除了前体化学外，针对每个前体使用匹配沉积策略的靶向材料合成对于深入分析潜在的反应路径至关重要。只有对材料加工有全面的了解和控制，才能产生确定的催化活性表面，这本身就构成了面向材料的结构-性能关系的基础，例如，在燃料电池应用中的催化活性。特别是，原位和原位表征方法(即气态PGM前体的红外光谱分析或CVD系统中空气中分解产物的质谱分析)揭示了在现实反应条件下的进一步洞察。该项目遵循“从分子到材料”的整体方法，强调了两个相互交织的研究重点--一个是前体化学，另一个是材料科学--的研究工作。这一综合办法被认为是必要的，以评估前体对作为非均相催化剂的所产生材料的技术应用的影响，并作为一项长期目标处理技术相关性。在PGM前体和催化剂材料的分子和材料化学方面的发现将通过与外部研究小组的合作进一步得到证实，这些研究小组对理论分子和材料建模以及以应用为中心的燃料电池研究做出了贡献。

The platinum group metals (PGM: Ru, Rh, Pd, Os, Ir and Pt), which can be applied in molecular form (homogeneous catalysis) or as nanostructured materials (heterogeneous catalysis), find widespread application as highly efficient and effective catalysts in chemical synthesis of organic compounds or in fuel cell applications. Due to their low abundance and challenging mining, recent research often focusses on PGM-free alternatives with comparable catalytic activity, more efficient utilization or environmentally friendly recycling strategies. The current proposal shall contribute to a more efficient preparation of nanostructured heterogeneous PGM catalysts via chemical vapor deposition (CVD), by understanding the underlying chemical and physical mechanisms. The CVD method allows to achieve solvent-free, stable and homogeneous deposition of materials even inside of open-porous substrates, which is essential for efficient catalyst materials. Therefore, the availability, understanding and control over defined molecular precursors with high volatility and matching reactivity profile is essential for a targeted deposition via the gas phase. The chemical and physical properties of new PGM precursor libraries will be compared with existing precursors, to establish molecular structure-property relations of reactivity and volatility, respectively. Besides precursor chemistry, a target-oriented materials synthesis using a matching deposition strategy for each precursor is crucial for in-depth analysis of underlying reaction pathways. Only a comprehensive understanding and control of material processing, yields defined catalytically active surfaces, which in itself forms the foundation of materials-oriented structure-property relations for the catalytic activity in fuel cell applications, for example. In particular, in-situ and in-operando characterization methods (i.e. IR spectroscopic analysis of gaseous PGM precursors or mass spectrometric characterization of air-borne decomposition products in CVD systems) unlock further insights under realistic reaction conditions. This project follows the holistic approach "from molecules to materials", which is underlined by structuring the research efforts in two intertwined research foci - one precursor chemistry and the other materials science centered. This integrated approach is considered necessary to assess the precursor influence on the technological application of the resulting materials as heterogeneous catalysts and addressing the technological relevance as a long-term objective. The findings on the molecular and materials chemistry of PGM precursors and catalyst materials will be further corroborated by collaborations with external research groups contributing with theoretical molecular and materials modelling and application centered fuel cell research.