[Fe]-氢化酶的化学模拟研究

Hydrogen (H2) is an clean energy, however, more than 99% of the world's hydrogen is still produced by steam reforming of fossil fuels. It not only consumes a lot of non-renewable resources, but also produces a lot of carbon dioxide. Thus, it is very urgent to develop other sustainable methods to produce hydrogen. Electrolysis of H2O to produce H2 is an ideal method because H2O is very abundant on the earth. However, currently it is not an economic method. One of the reasons is that it requires an elctrocatalyst based on platinum or certain of its alloys. The sustainability of platium is very doubtful. Thus, to replace Pt by Fe or Ni catalyst, understanding the chemistry of the hydrogenases by the design of artificial enzymes is highly important. The project will focus on the research of the third hydrogenase: [Fe]-hydrogenase. [Fe]-hydrogenase has a unique mono-Fe-containing active site. It is a recent discovery and the model chemistry is in its infancy. We will design and synthesize more faithful structural mimics of [Fe]-hydrogenase, and study the reactivities of the model complexes. Besides, the effects of the models as catalysts for hydrogenation and hydrosilation would also be explored. The research should not only result in a better understanding of hydrogenases, but also lead to discoveries of better H2 processing catalysts that would benefit the industry and society.

氢气是一种理想的清洁能源，但是现今超过99%的氢气是通过消耗天然气等非可再生资源而制备的，并且同时产生大量的二氧化碳。因此，探索新的可持续的制备方法显得非常迫切。而电解水制备氢气是一种比较理想的方法，但是现今仍然面临很多问题，其中之一就是此方法一般需要用Pt等贵金属作为电催化剂。化学模拟氢化酶就是为了用Fe、Ni等便宜催化剂代替Pt。本项目致力于研究化学模拟第三种氢化酶：[Fe]-氢化酶。通过设计合成与[Fe]-氢化酶活性中心类似的化合物，推测[Fe]-氢化酶活性中心的具体结构；通过研究模拟物的反应性，推测[Fe]-氢化酶的作用机理，从而制备功能性人工[Fe]-氢化酶，并且研究这些模拟物在催化氢化、催化硅氢化等领域的催化效果。本项目研究有助于进一步认识氢化酶作用机理，从而制备更加高效的人工氢化酶。这不仅仅有助于解决氢气的绿色制备问题，也有助于发展出可应用于氢化反应的便宜高效的催化剂。

本项目利用核磁、红外、X-射线单晶衍射以及元素分析等手段分析鉴定了一系列含有“吡啶亚甲基酰基”或“吡啶酮亚甲基酰基”配体的[Fe]-氢化酶模拟物。.（1）制备了一系列含“吡啶亚甲基酰基”配体的Fe-芳基巯基化合物，并发现此类化合物存在“单核-双核”平衡。.（2）首次制备了含“吡啶亚甲基酰基”配体的Fe-烷基巯基化合物。.（3）首次制备了一系列含“吡啶酮亚甲基酰基”配体的单核Fe-巯基化合物，此类化合物更加精确地模拟了[Fe]-氢化酶活性中心结构。.（4）将乙酸基或2-巯基乙醇配体成功引入含“吡啶酮亚甲基酰基”配体的Fe中心，从而精确模拟并间接证明了[Fe]-氢化酶辅因子的结构。. 上述成果对于研究[Fe]-氢化酶的反应性、确定[Fe]-氢化酶辅因子的结构、以及制备下一代功能型[Fe]-氢化酶模拟物具有重要的意义。. 相关成果共发表SCI论文3篇，两篇发表在《Chem. Eur. J.》上(其中一篇为封面），一篇发表在《Chem. Asian J.》 上。