Solid State NMR studies on the mechanisms of immobilized organic-inorganic metal containing heterogeneous catalysts

多核固体核磁共振和其他物理化学技术被用来研究固定化催化剂、金属簇合物、金属纳米粒子及其与底物的相互作用。固定化催化剂是通过有机连接剂将含金属催化剂共价键合到不同形貌(多孔或纳米)的纳米二氧化硅材料表面。考察了负载型催化剂在载体材料上的结构、与底物的相互作用以及温度等宏观参数对其性能的影响。通过模型反应，特别是加氢反应对催化剂的催化活性进行了测试。最初采用了简单的反应，如氢的同位素扰乱或乙烯的加氢作为催化剂的模型反应。为了揭示载体的大小和形态的影响，我们研究了较大的底物分子和对映体选择性的固定化催化剂。在进行这些研究的同时，我们希望继续与Chaudret和Poteau小组合作，研究分子氢与具有催化活性的过渡金属化合物和纳米粒子之间的相互作用。在这里，我们想要使用第一阶段建立的2H核磁共振数据库来研究氢在过渡金属纳米颗粒(Ru、Pd、Pd)上的吸附。最后，我们想要研究H_4Ru_4(CO)_(12)团簇的氢动力学，揭示这个动力学过程的本质和它的能量参数。

Multi nuclear solid state NMR and other physico-chemical techniques are employed for the study of immobilized catalysts, metal-clusters, metal-nanoparticles and their interactions with substrates. The immobilized catalysts are made by covalently binding metal-containing catalysts to the surface of nano-structured silica materials with different morphologies(porous or nanoparticles) via organic linkers. The structure of the immobilized catalysts on the support material, its interactions with substrates and the influence of macroscopic parameters such as temperature on its properties are investigated. The catalytic activity of the catalysts is tested by model reactions, in particular hydrogenations. Initially simple reactions like the isotope scrambling of hydrogen or the hydrogenation of ethylene as model reactions for the catalysts are employed. To reveal effects of the size and morphology of the support, larger substrate molecules and enantio-selective immobilized catalysts are studied. In parallel to these studies we wish to continue our collaboration with the Chaudret and Poteau groups on the study of molecular hydrogen interacting with catalytically active transition metal compounds and nano-particles. Here we want to employ the 2H NMR data-base built in the first period for the study of hydrogen adsorbed on transition-metal nanoparticles (ruthenium, palladium, platinum). Finally we want to study the hydrogen dynamics of the H4Ru4(CO)12 cluster and reveal the nature of the dynamic process and its energetic parameters.