Zhang Wendy, Gu Chaoxuan, Wang Yi, Ware Skyler D, Lu Lingxiang, Lin Song, Qi Yue, See Kimberly A
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States.
School of Engineering, Brown University, Providence, Rhode Island 02912, United States.
JACS Au. 2023 Jul 28;3(8):2280-2290. doi: 10.1021/jacsau.3c00305. eCollection 2023 Aug 28.
Mg is commonly used as a sacrificial anode in reductive electrosynthesis. While numerous methodologies using a Mg sacrificial anode have been successfully developed, the optimization of the electrochemistry at the anode, i.e., Mg stripping, remains empirical. In practice, electrolytes and organic substrates often passivate the Mg electrode surface, which leads to high overall cell potential causing poor energy efficiency and limiting reaction scale-up. In this study, we seek to understand and manipulate the Mg metal interfaces for a more effective counter electrode in tetrahydrofuran. Our results suggest that the ionic interactions between the cation and the anion of a supporting electrolyte can influence the electrical double layer, which impacts the Mg stripping efficiency. We find halide salt additives can prevent passivation on the Mg electrode by influencing the composition of the solid electrolyte interphase. This study demonstrates that, by tailoring the electrolyte composition, we can modify the Mg stripping process and enable a streamlined optimization process for the development of new electrosynthetic methodologies.
镁通常用作还原电合成中的牺牲阳极。虽然已经成功开发了许多使用镁牺牲阳极的方法，但阳极电化学（即镁剥离）的优化仍基于经验。在实际应用中，电解质和有机底物常常会使镁电极表面钝化，这会导致电池整体电位升高，从而造成能源效率低下，并限制反应规模扩大。在本研究中，我们试图了解并操控镁金属界面，以便在四氢呋喃中获得更有效的对电极。我们的结果表明，支持电解质中阳离子和阴离子之间的离子相互作用会影响双电层，进而影响镁的剥离效率。我们发现卤化物盐添加剂可以通过影响固体电解质界面的组成来防止镁电极钝化。这项研究表明，通过调整电解质组成，我们可以改变镁的剥离过程，并为开发新的电合成方法实现简化的优化过程。
