用五牙多胺复合物的催化H2演变的电子和固体调节
Ping Wang1, Guangchao Liang2, M Ramana Reddy1
1Department of Chemistry , The University of Memphis , Memphis , Tennessee 38152 , United States.
Journal of the American Chemical Society
|June 28, 2018
概括
在催化剂中用异类替代,可显著增强演化反应 (HER) 的活性. 这种结构修改降低了过量的潜能,并提高了H2生产的催化效率,为催化剂设计提供了洞察力.
科学领域:
- 协调化学
- 催化剂
- 电化学
- 摄影化学
- 演化反应 (HER)
背景情况:
- 分子催化剂对于理解演化反应 (HER) 中的结构功能关系至关重要.
- 之前的研究表明,修改配体结构可以调整催化剂的H2生产性能.
- 在HER催化过程中,五酸复合物的轴性组的作用需要进一步研究.
研究的目的:
- 研究五酸复合体中轴性异类组对HER的电子和硬质影响.
- 合成和描述两种新的复合物与修饰的配体:DPA-1-MPI和DPA-3-MPI.
- 评估这些复合物的电气和光化学性能,以生产气.
主要方法:
- 两种新型五酸复合物的合成和表征,Co ((DPA-1-MPI)) ((H2O)) ((PF6) 3) 和Co ((DPA-3-MPI)) ((H2O)) ((PF6) 3).
- 电化学测量以确定氧化还原潜力 (CoII/CoI和CoIII-H/CoII-H对).
- 在水溶液中进行光催化生产实验.
- 密度函数理论 (DFT) 计算以阐明反应机制和能量.
主要成果:
- 与类同类相比,复合物与异类同类具有显著改变的电化学特性.
- [Co ((DPA-1-MPI) ((H2O)) ](PF6) 3显示了氧化还原潜力的积极转移,并且在光催化H2产生中比[Co ((DPA-3-MPI) ((H2O)) ](PF6) 3活跃大约32倍.
- DFT计算表明,CoI到CoIII-H的质子化对DPA-1-MPI复合物更有利,并确定平双单元和电子捐赠轴群是稳定低价值物种和促进质子结合的关键.
结论:
- 通过结合异类组对五联体的结构修饰对HER的复合物的催化活性和电化学特性产生显著影响.
- 轴联体的电子和硬质性在稳定关键中间体和促进催化循环中的质子转移步骤方面发挥着关键作用.
- 该研究提出了用于催化H2进化的改性电子转移-质子转移-电子转移-质子转移 (mod-ECEC) 途径,强调了联体设计在开发高效分子生产催化剂中的重要性.
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