非稀有过渡金属簇合物对氢气的活化机理和储氢性能的研究

Mixed metal polynuclear cluster complexes has a variety of critical applications in catalysis and other areas. For example, transition metal carbonyl clusters may serve as good homogeneous and heterogenous catalysts. The objective of this proposal is to prepare new carbonyl complexes from non-precious transition metals, for applications in hydrogen absorption, homogeneous and heterogeneous catalysis, and preparation of nano-structured materials. It has been proved that mixed-metal heterogeneous catalysts containing platinum, ruthenium, rhodium, and other transition metals show high reactivity and selectivity in many industrial applications such as petroleum refining. It has also been proved that some bi-metallic carbonyl cluster complexes could reversibly absorb hydrogen under mild conditions. However, due to their precious nature, large-scale usage is limited and costly. According the the "surface-cluster analogy", it is proposed in this article to use elements from the early transition metals and from the first row in place of the second and third row of the transition series to prepare new heteroneuclear complexes. Electronic unsaturation plays a critical role for metal complexes to absorb small molecules like hydrogen, and previous research has shown that a variety of sterically bulky ligands can be applied to the synthesis of new mixed-metal carbonyl complexes for the purpose of stabilization and in the meanwhile to bring about unsaturation. This proposal will focus on the chemical absorption and activation mechanism of small molucles on metal clusters and their applications as hydrogen storage metarial. The prorposed new mixed metal systems will serve as platforms that will enhance understanding on how hydrogen, as well as other small molecules, undergo activation and are then utilized in ensuing catalytic cycles.

过渡金属簇合物的中心原子呈现较低的氧化态，其大多服从有效原子序数规则，因此无论是在理论研究还是在均相及多相催化中都占据非常重要的地位，特别是在开发新型催化剂和能源转化，如石油精炼和新能源的开发方面意义重大。前期的结果表明，有一些混合金属的原子簇合物可以在室温下迅速加合多个氢原子，并可在温和条件下可逆地释放氢气，从而成为一种值得研究的储氢材料，和其它的储氢材料，如硼、铝的氢化物、纳米碳管、过渡金属合金等相比有独特的优点。但目前这一类簇合物中都含有一种或多种稀有的过渡金属如铂、铑、锇等，我们研究的中心课题将围绕开发新型的非稀有金属簇合物以降低成本，采用新型的配体以增加分子整体的不饱和度，达到提高载氢量的目的。课题着重研究对小分子气体的吸附活化机理和在储能材料方面的应用。氢气在金属上的的活化是加氢脱氢反应的重要步骤，其机理的研究不仅有助于储氢材料的开发，也对工业的催化剂的设计具有指导意义。

项目执行的两年中集中进行了四个方面的研究（1）铁铜双金属簇合物和大配体之间的反应机理研究（2）铁锡双金属之间的协同效应的研究及其对氢气活化的效果检测（3）新型大空阻配体的合成及其与羰基配合物的反应。（4）在催化方面的其它成果。目前在本项目的支持下取得SCI论文成果已发表5篇，