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

如果所需的氢气可以通过光伏产生，二氧化碳加氢生成甲醇在能量上是有益的。未来，这一进程将是维持一定生活标准和减缓即将到来的气候变化的为数不多的替代办法之一。在初步的实验中，W.R.Thiel小组可以通过量子化学计算和模型体系上的催化反应证明，氢化Ru(II)与至少含有一个质子化NH位的吡唑配体的络合是这种转化的有希望的候选者。由于质子(在配位体)以及氢化氢(在金属位置)的存在，这些系统可以将氢转移到极化的E=C双键。该项目分为四项任务，将在凯泽斯劳滕和里昂的基团之间密切合作完成。-新型氢化物催化剂的合成：氢化物的有机金属化学将得到扩展，并将基于含有吡唑的络合物的模块化生成来研究与二氧化碳还原序列中涉及的小底物的反应活性。-催化活性评估：将结合参与二氧化碳还原的小底物的催化氢化，以及氮给体配体对催化性能的影响的实验和计算研究。-催化剂的固定化：为了提高催化剂的稳定性，活性中心将被隔离在大表面积的氧化物表面。为此，将在配体的主链上引入适当的官能团，允许将络合物受控地接枝到惰性载体上。此外，还将开发具有完美分布功能的材料，以获得明确的表面物种隔离位置。-多相催化剂催化性能的评估：将在大范围的温度范围内评估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.