Quasi-Operando Liquid-Phase Electron Imaging of Metallic Copper Nanocubes Reveals Step-by-Step Subtle Dissolution,...

Area of Science:

• Electrochemistry
• Materials Science
• Nanotechnology

Background:

• Metallic copper nanocubes are utilized for carbon dioxide electroreduction (CO2ER), showing moderate intermediate binding and ethylene selectivity.
• The restructuring mechanisms and deactivation pathways of copper nanocubes during CO2ER are not fully understood.

Purpose of the Study:

• To observe the real-time evolution of copper nanocubes during CO2ER at the nanoscale.
• To elucidate the restructuring mechanisms and their impact on catalyst stability and selectivity.

Main Methods:

• Electrochemical liquid-phase transmission electron microscopy (EC-LTEM) was employed for in-situ observation.
• Statistical analysis was performed on the observed nanocube evolution.

Main Results:

• Dissolution/redeposition was identified as the primary mechanism driving nanocube evolution.
• Thermodynamically active edges of copper cubes attracted redeposited aggregates, moderating the surface-to-volume ratio.
• Nanocube fragmentation was observed, potentially linked to highly defective sites.

Conclusions:

• The study highlights the synergistic effects of high-energy sites and kinetic barriers in Cu nanocube dynamics during CO2ER.
• Understanding these evolution dynamics is crucial for improving the long-term stability and selectivity of copper-based CO2ER catalysts.