State Key Laboratory of Fine Chemicals, DUT-KTH Joint Education and Research Centre on Molecular Devices, Dalian University of Technology (DUT), Dalian, 116024, PR China.
School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, PR China.
ChemSusChem. 2017 Nov 23;10(22):4581-4588. doi: 10.1002/cssc.201701458. Epub 2017 Oct 10.
Two copper complexes, (L1)Cu(OH ) [1; L1=N,N'-dimethyl-N,N'-bis(pyridin-2-ylmethyl)-1,2-diaminoethane] and (L2)Cu(OH ) [2, L2=2,7-bis(2-pyridyl)-3,6-diaza-2,6-octadiene], were prepared as molecular water oxidation catalysts. Complex 1 displayed an overpotential (η) of 1.07 V at 1 mA cm and an observed rate constant (k ) of 13.5 s at η 1.0 V in pH 9.0 phosphate buffer solution, whereas 2 exhibited a significantly smaller η (0.70 V) to reach 1 mA cm and a higher k (50.4 s ) than 1 under identical test conditions. Additionally, 2 displayed better stability than 1 in controlled potential electrolysis experiments with a faradaic efficiency of 94 % for O evolution at 1.58 V, when a casing tube was used for the Pt cathode. A possible mechanism for 1- and 2-catalyzed O evolution reactions is discussed based on the experimental evidence. These comparative results indicate that fine-tuning the structures of tetradentate N ligands can bring about significant change in the performance of copper complexes for electrochemical water oxidation.
两种铜配合物(L1)Cu(OH) [1; L1=N,N'-dimethyl-N,N'-bis(pyridin-2-ylmethyl)-1,2-diaminoethane]和(L2)Cu(OH) [2，L2=2,7-bis(2-pyridyl)-3,6-diaza-2,6-octadiene]被制备为分子水氧化催化剂。配合物 1 在 pH 9.0 磷酸盐缓冲溶液中在 1.07 V 的过电位(η)下显示出 1 mA cm 的电流密度和 13.5 s 的观察到的速率常数(k )，而 2 在相同的测试条件下，以达到 1 mA cm 的 η 1.0 V 和高于 1 的 k (50.4 s )显示出更小的 η(0.70 V)。此外，在使用套管管作为 Pt 阴极的恒电位电解实验中，2 的稳定性优于 1，O 演化的法拉第效率为 94%，当在 1.58 V 时。基于实验证据，讨论了 1 和 2 催化的 O 演化反应的可能机制。这些比较结果表明，精细调整四齿 N 配体的结构可以使铜配合物在电化学水氧化中的性能发生显著变化。
