Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute & Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, People's Republic of China.
ACS Nano. 2023 May 23;17(10):9338-9346. doi: 10.1021/acsnano.3c01059. Epub 2023 May 4.
Main group indium materials have been known as promising electrocatalysts for two-electron-involved carbon dioxide reduction to produce formate, which is a key energy vector in many industrial reactions. However, the synthesis of two-dimensional (2D) monometallic nonlayered indium remains a great challenge. Here, we present a facile electrochemical reduction strategy to transform 2D indium coordination polymer into elemental indium nanosheets. In a customized flow cell, the reconstructed metallic indium exhibits a high Faradaic efficiency (FE) of 96.3% for formate with a maximum partial current density exceeding 360 mA cm and negligible degradation after 140 h operation in 1 M KOH solution, outperforming the state-of-the-art indium-based electrocatalysts. Moreover, and electrochemical analysis and characterizations demonstrate that the enhanced exposure of active sites and mass/charge transport at the CO gas-catalyst-electrolyte triple-phase interface and the restrained electrolyte flooding are contributing to producing and stabilizing carbon dioxide radical anion intermediates, thus leading to superior catalytic performance.
主族铟材料已被证明是一种很有前途的电催化剂，可用于将两电子参与的二氧化碳还原为甲酸盐，甲酸盐是许多工业反应中的关键能量载体。然而，二维（2D）单金属非层状铟的合成仍然是一个巨大的挑战。在这里，我们提出了一种简便的电化学还原策略，可将二维铟配合物聚合物转化为元素铟纳米片。在定制的流动池中，重构的金属铟对甲酸盐表现出高达 96.3%的法拉第效率（FE），最大局部电流密度超过 360 mA cm，在 1 M KOH 溶液中运行 140 小时后几乎没有降解，优于最先进的基于铟的电催化剂。此外，和电化学分析和表征表明，在 CO 气体-催化剂-电解质三相界面处活性位点的增强暴露和质量/电荷传输以及对电解质泛滥的抑制有助于生成和稳定二氧化碳自由基阴离子中间体，从而导致优异的催化性能。
