Amphipathic Surfactant on Reconstructed Bismuth Enables Industrial-Level Electroreduction of CO<sub>2</sub> to Formate
Yiqun Chen, Yan Zhang, Zhen Li, Mengjie Liu, Qiang Wu, Tsz Woon Benedict Lo, Zheng Hu, Lawrence Yoon Suk Lee
Abstract
Developing efficient electrocatalysts for selective formate production via the electrochemical CO 2 reduction reaction (CO 2 RR) is challenged by high overpotential, a narrow potential window of high Faradaic efficiency (FE formate ), and limited current density ( J formate ). Herein, we report a hierarchical BiOBr (CT/h-BiOBr) with surface-anchored cetyltrimethylammonium bromide (CTAB) for formate-selective large-scale CO 2 RR electrocatalysis. CT/h-BiOBr achieves over 90% FE formate across a wide potential range (−0.5 to −1.1 V) and an industrial-level J formate surpassing 100 mA·cm –2 at −0.7 V. In situ investigations uncover the reconstructed Bi(110) surface as the active phase, with CTAB playing a dual role: its hydrophobic alkyl chains create a CO 2 -enriching microenvironment, while its polar head groups fine-tune the electronic structure, fostering a highly active phase. This work provides valuable insights into the role of surfactants in electrocatalysis and guides the design of electrocatalysts for the large-scale CO 2 RR.