Voltage-driven surface reconstruction of ternary liquid metals for enhanced electrocatalytic CO2 conversion

Abstract

The development of high-performance catalysts holds great importance for advancing electrocatalytic CO₂ hydrogenation to value-added products. Herein, a ternary GaInBi liquid-alloy catalyst was engineered, which demonstrated a superior reactivity for CO₂ electrocatalytic conversion to formate, with a formate Faraday efficiency (FE_formate) of 95.3% at −1.2 V (vs. RHE), and excellent stability during a 12 hours test. The remarkable performance could be attributed to the dynamic structure reconstruction, which led to active-site-enrichment on the surface of GaInBi during the reaction, enhancing CO₂ adsorption and activation. Meanwhile, the reconstructed catalyst surface lowered the energy barrier for the transformation of *OCHO to formate and suppressed the hydrogen evolution reaction (HER) by hindering the H-intermediate adsorption. Furthermore, 3D-printed GaInBi microcavity arrays were constructed to optimize mass-transfer efficiency, demonstrating morphological stability of the liquid metal electrode and controllable regulation of electrocatalytic performance. This work provides new insights into the dynamic surface modulation of ternary liquid alloys for advancing their applications in CO₂ reduction reactions.