Hydrogenation of Carbon Dioxide by Combining Ruthenium Hydrido Complexes with Protic Ligands and Protic Metal Oxide Sites

如果所需的二氢可以通过光伏发电产生，二氧化碳加氢生成甲醇在能量上是有益的。在未来，这一过程将是维持一定生活水平和减缓即将到来的气候变化的少数几种选择之一。在初步实验中，W. R. Thiel小组可以通过量子化学计算和模型系统上的催化反应来证明，氢化钌（II）与螯合吡唑配体含有至少一个质子NH位点是这种转化的有希望的候选物。由于质子（在配体上）和水合氢原子（在金属位点上）的存在，这些体系可以将H2转移到极化的E=C双键上。该项目分为四个任务，将在凯泽斯劳滕和里昂的团队密切合作下完成。-新型氢钌催化剂的合成：氢钌配合物的有机金属化学性质将得到扩展，并将基于含吡唑配合物的模块化生成，研究其对二氧化碳还原序列中涉及的小底物的反应性。-催化活性评价：将参与CO2还原的小底物的催化加氢与氮给体配体对催化性能影响的实验和计算研究相结合。-催化剂的固定化：为了增加催化剂的稳定性，活性位点将被隔离在大表面积的氧化物表面上。为此，将适当的官能团引入配体的主链，从而使配合物在惰性载体上的接枝得到控制。此外，将开发具有完美分布功能的材料，以获得表面物种的明确位点隔离。-评价多相催化剂的催化性能：在较大的温度范围内评价催化剂的活性和稳定性。

Hydrogenation of CO2 to give methanol is energetically beneficial if the required dihydrogen can be generated by photovoltaics. This process will in the future be one of only a few alternatives for the maintenance of a certain standard of life and the slowdown of the coming climate change. In preliminary experiments, the group of W. R. Thiel could prove by means of quantumchemical calculations as well as catalytic reactions on model systems, that hydrido ruthenium(II) with chelating pyrazole ligands containing at least one protic NH site are promising candidates for this transformation. Due to the presence of a protic (at the ligand) as well as a hydridic (at the metal site) hydrogen atom, these systems can transfer H2 to polarized E=C double bonds.The project is split into four tasks which will be worked out in close collaboration between the groups in Kaiserslautern and Lyon.- Synthesis of novel hydridoruthenium catalysts: The organometallic chemistry of the hydridoruthenium complexes will be extended and the reactivity against small substrates involved in the CO2 reduction sequence will be investigated based on the modular generation of pyrazole containing complexes.- Evaluation of the catalytic activity: The catalytic hydrogenation of small substrates involved in the CO2 reduction will be combined with an experimental and computational investigation on the influence of the nitrogen donor ligand on the catalytic performance. - Immobilization of the catalysts: To increase the stability of the catalyst, active sites will be isolated on large surface area oxide surfaces. For this, appropriate functionalities will be introduced into the backbone of the ligands allowing a controlled grafting of complexes onto inert supports. In addition, materials with perfectly distributed functionalities will be developed to obtain a defined site isolation of surface species. - Evaluation of the catalytic performances of heterogeneous catalysts: The activity and the stability of the catalysts will be evaluated over a large range of temperature.