Supported ionic liquid phase (SILP) catalysis

近年来，离子液体作为过渡金属均相催化的替代反应介质引起了人们极大的关注。除了不挥发性的工程优势外，许多研究小组已经展示了开发新的液-液两相反应体系的巨大潜力。然而，在某些情况下，当化学动力学快速时，反应可能发生在离子液体的表面或扩散层中，而不是在本体溶剂中。在这些情况下，普通的液-液两相催化因此可能不是用离子催化剂层实现催化反应的理想方式，因为在反应中仅有效地使用相对昂贵的离子液体和溶解在其中的催化剂的小部分。在本项目中，将研究在多孔载体表面上固定含有活性过渡金属催化剂的中性弱配位离子液体薄层。当过渡金属催化剂通过溶解的配体配位时，离子液体通过物理吸附分布在载体上。这一概念将被评估为至少两个连续的气相过程：铑催化烯烃加氢和镍催化乙烯齐聚。对于这两个反应，新的“负载型离子液相（SILP）催化剂”的催化性能将与液-液两相催化的结果进行比较。详细的光谱研究的支持和模型系统中的活性催化物种将是我们的研究的一个组成部分，以了解活性，选择性和寿命的差异。拟议的项目旨在创建改进的催化系统，以一种新的，令人兴奋的方式弥合均相和多相催化之间的传统差距。参与的两个小组将把他们互补的专业知识带入联合项目：埃尔兰根小组以其在使用离子液体的均相催化方面的专业知识而闻名，而哥本哈根小组在连续支撑液相（SLP）和多相催化以及通过光谱方法进行催化剂表征方面拥有长期经验。这些小组之间的合作创造了科学的协同作用，在这个多学科领域进行创新和高效研究的潜力巨大。

In the last years, ionic liquids have attracted significant attention as an alternative reaction medium for transition metal homogeneous catalysis. Besides the engineering advantage of their non-volatile nature, the great potential to develop new liquid-liquid biphasic reaction systems has been demonstrated by many research groups. However, in some cases when the chemical kinetics are fast the reaction may take place at the surface or in the diffusion layer of the ionic liquid rather than in the bulk solvent. In these cases, the ordinary liquid-liquid biphasic catalysis may therefore not be the ideal way to realise a catalytic reaction with an ionic catalyst layer, since only a minor part of the - relatively expensive - ionic liquid and of the catalyst dissolved therein is effectively used in the reaction. In this project, the immobilisation of a thin layer of a neutral, weakly-coordinating ionic liquid containing an active transition metal catalyst on the surface of a porous support will be investigated. While the transition metal catalyst is coordinated by dissolved ligands, the ionic liquid is distributed by physisorption on the support. This concept will be evaluated for at least two continuous gas phase processes: The Rh-catalysed hydroformylation of olefins and the Ni-catalyzed oligomerization of ethylene. For both reactions the catalytic performance of the new "supported ionic liquid phase (SILP) catalysts" will be compared to results for liquid-liquid biphasic catalysis. Detailed spectroscopic investigations of the active catalytic species on the support and in model systems will be an integral part of our studies to understand differences in activity, selectivity and lifetime. The proposed project aims to create improved catalytic systems in bridging the traditional gap between homogeneous and heterogeneous catalysis in a new, exciting manner. Both groups involved will bring their complementary expertise into the joint project: The Erlangen group is well-known for its expertise in homogeneous catalysis using ionic liquids, while the Copenhagen group has a long experience in continuous supported liquid phase (SLP) and heterogeneous catalysis and catalyst characterization by spectroscopic methods. The collaboration between the groups creates a scientific synergy with a great potential for innovative and efficient research in this multidisciplinary field.