Laboratory of Nanochemistry for Energy Research, Institute of Chemical Sciences and Engineering, Ecole Politechnique Fédérale de Lausanne, Sion, CH-1950, Switzerland.
Swiss-Norwegian Beamlines, European Synchrotron Radiation Facility, 38000 Grenoble, France.
J Am Chem Soc. 2022 Jun 8;144(22):10053-10063. doi: 10.1021/jacs.2c03698. Epub 2022 May 26.
Liquid metals (LMs) have been used in electrochemistry since the 19th century, but it is only recently that they have emerged as electrocatalysts with unique properties, such as inherent resistance to coke poisoning, which derives from the dynamic nature of their surface. The use of LM nanoparticles (NPs) as electrocatalysts is highly desirable to enhance any surface-related phenomena. However, LM NPs are expected to rapidly coalesce, similarly to liquid drops, which makes their implementation in electrocatalysis hard to envision. Herein, we demonstrate that liquid Ga NPs (18 nm, 26 nm, 39 nm) drive the electrochemical CO reduction reaction (CORR) while remaining well-separated from each other. CO is generated with a maximum faradaic efficiency of around 30% at -0.7 V, which is similar to that of bulk Ga. The combination of electrochemical, microscopic, and spectroscopic techniques, including X-ray absorption, indicates that the native oxide skin of the Ga NPs is still present during CORR and provides a barrier to coalescence during operation. This discovery provides an avenue for future development of Ga-based LM NPs as a new class of electrocatalysts.
液态金属（LM）自 19 世纪以来就在电化学中得到应用，但直到最近，它们才作为具有独特性质的电催化剂出现，例如固有的抗焦中毒能力，这源于其表面的动态性质。使用 LM 纳米颗粒（NPs）作为电催化剂是增强任何表面相关现象的理想选择。然而，LM NPs 预计会像液滴一样迅速聚结，这使得它们在电催化中的应用难以想象。在此，我们证明液态 Ga NPs（18nm、26nm、39nm）在彼此之间保持良好分离的情况下，驱动电化学 CO 还原反应（CORR）。在-0.7V 时，CO 的最大法拉第效率约为 30%，与块状 Ga 相似。电化学、微观和光谱技术（包括 X 射线吸收）的结合表明，Ga NPs 的天然氧化物外壳在 CORR 期间仍然存在，并在操作过程中提供了聚结的障碍。这一发现为开发基于 Ga 的 LM NPs 作为一类新型电催化剂提供了途径。
