Development of hybrid photocatalysts with metal complexes and semiconductor for CO2 reduction

整个光化学CO2还原过程的反应谱表明，超分子催化剂具有较高的tof。因此，有可能证明一种高效的超分子Ru(II)-Mn(I)催化剂，超过了它的单单元垂坠。同时，Ru(II)-Mn(I)催化剂在1小时后开始快速降解，降低了其相对于混合体系的优越性能。在Ru(II)-Mn(I)的情况下，发现在第一个小时的过程中，Ru- oers在反应中积累。最后，假设甲酸锰中间体的配位对于mn单元周围的有限空间来说可能太大。研究发现，强碱性酸能以相当正的还原电位促进CO的形成。因此，选择三氟乙醇（TFE）作为Bronsted酸。我们很高兴地发现，在6小时的时间里，不能检测到典型的Ru-OERS积累。此外，该催化剂被证明具有更高的稳定性。在相同的条件下，相应的混合体系被证明效率较低，表明了超分子结构的优势。为了更详细地研究反应，记录了紫外可见光谱。结果表明，Ru(II)-Mn(I)形成了一个吸收在450 nm范围内的新物质。筛选较强的光源，在20小时的反应时间内获得具有代表性的吨。获得了稳定的CO-formation，最终TONCO为250。没有HCOOH或大量的氢可以检测到。

The reaction profile over the entire course of the photochemical CO2 reduction proved higher TOFs for the supramolecular catalysts. It was therefore possible to demonstrate a highly potent supramolecular Ru(II)-Mn(I) catalyst, exceeding its single-unit pendant. At the same time, the Ru(II)-Mn(I) catalyst revealed a rapid degradation initiating after 1 hour diminishing its superior performance relative to the mixed system.In the case of the Ru(II)-Mn(I), it was found that over the course of the first hour, Ru-OERS accumulated in the reaction. Eventually, it was hypothesized that coordination of the Mn-formate intermediate might be too large for the confined space around the Mn-unit. Strong Brønsted acids were found to promote CO formation at fairly positive reduction potentials. Therefore, trifluoroethanol (TFE) was applied as Bronsted acid of choice.We were pleased to find that over the cause of 6 hrs the typical accumulation of Ru-OERS could not be detected. Moreover, the catalyst proved to show a much higher stability. Under identical conditions, the corresponding mixed system proved to be less efficient, demonstrating the advantage of supramolecular architectures.To investigate the reaction in more detail, UV-Vis spectra were recorded. It was found that in the case of Ru(II)-Mn(I), a new species with an absorption in the range of 450 nm was formed.Stronger light sources were screened to obtain representable TONs over 20 hrs reaction time. A stable CO-formation was obtained with a final TONCO of 250. No HCOOH or significant amounts of hydrogen could be detected.