Intelligent Polymer Research Institute and ARC Centre of Excellence for Electromaterials Science, University of Wollongong, Wollongong, NSW 2522, Australia.
Molecules. 2023 Jul 3;28(13):5179. doi: 10.3390/molecules28135179.
Cu complexes facilitate the reduction of CO to valuable chemicals. The catalytic conversion likely involves the binding of CO and/or reduction intermediates to Cu, which in turn could be influenced by the electron density on the Cu ion. Herein we investigated whether modulating the redox potential of Cu complexes by changing their ligand structures influenced their CO reduction performance significantly. We synthesised new heteroleptic Cu complexes, and for the first time, studied a (Cu-bis(8-quinolinolato) complex, covering a Cu redox potential range of 1.3 V. We have found that the redox potential influenced the Faradaic efficiency of CO reduction to CO. However, no correlation between the redox potential and the Faradaic efficiency for methane was found. The lack of correlation could be attributed to the presence of a Cu-complex-derived catalyst deposited on the electrodes leading to a heterogeneous catalytic mechanism, which is controlled by the structure of the in situ deposited catalyst and not the redox potential of the pre-cursor Cu complexes.
Cu 配合物促进了 CO 向有价值的化学品的还原。这种催化转化可能涉及 CO 和/或还原中间体与 Cu 的结合，而 Cu 的电子密度反过来又可能受到影响。在此，我们研究了通过改变配体结构来调节 Cu 配合物的氧化还原电位是否会显著影响其 CO 还原性能。我们合成了新的杂配 Cu 配合物，并首次研究了 Cu 氧化还原电位范围为 1.3 V 的（Cu-双（8-喹啉醇）配合物。我们发现氧化还原电位影响 CO 还原为 CO 的法拉第效率。然而，没有发现氧化还原电位与甲烷的法拉第效率之间存在相关性。这种不相关可能归因于存在沉积在电极上的源自 Cu 配合物的催化剂，导致了非均相催化机制，该机制由原位沉积催化剂的结构控制，而不是前体 Cu 配合物的氧化还原电位控制。
