Extrinsic hydrophobicity-controlled silver nanoparticles as efficient and stable catalysts for CO2 electrolysis
Young‐Jin Ko, Chulwan Lim, Junyoung Jin, Min Gyu Kim, Ji Yeong Lee, Tae‐Yeon Seong, Kwan‐Young Lee, Byoung Koun Min, Jae‐Young Choi, Taegeun Noh, Gyu Weon Hwang, Woong Hee Lee, Hyung‐Suk Oh
Abstract
Abstract To realize economically feasible electrochemical CO 2 conversion, achieving a high partial current density for value-added products is particularly vital. However, acceleration of the hydrogen evolution reaction due to cathode flooding in a high-current-density region makes this challenging. Herein, we find that partially ligand-derived Ag nanoparticles (Ag-NPs) could prevent electrolyte flooding while maintaining catalytic activity for CO 2 electroreduction. This results in a high Faradaic efficiency for CO (>90%) and high partial current density (298.39 mA cm ‒2 ), even under harsh stability test conditions (3.4 V). The suppressed splitting/detachment of Ag particles, due to the lipid ligand, enhance the uniform hydrophobicity retention of the Ag-NP electrode at high cathodic overpotentials and prevent flooding and current fluctuations. The mass transfer of gaseous CO 2 is maintained in the catalytic region of several hundred nanometers, with the smooth formation of a triple phase boundary, which facilitate the occurrence of CO 2 RR instead of HER. We analyze catalyst degradation and cathode flooding during CO 2 electrolysis through identical-location transmission electron microscopy and operando synchrotron-based X-ray computed tomography. This study develops an efficient strategy for designing active and durable electrocatalysts for CO 2 electrolysis.