Morphology Dependent N₂ Reduction on Cu₂O: Combined Experimental and Computational Study for Efficient Ammonia...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalytic nitrogen reduction reaction (NRR) is crucial for sustainable ammonia synthesis.
• Catalyst morphology plays a key role in optimizing electrocatalytic performance.
• Copper oxide (Cu2O) nanocrystals are promising electrocatalysts for NRR.

Purpose of the Study:

• To investigate the structure-dependent performance of Cu2O nanocrystals with cubic and octahedral morphologies for NRR.
• To elucidate the mechanistic insights governing the enhanced activity of specific Cu2O morphologies.
• To provide guidance for designing efficient Cu2O-based catalysts for ammonia electrosynthesis.

Main Methods:

• Synthesis of Cu2O nanocrystals with distinct cubic and octahedral morphologies.
• Electrocatalytic performance evaluation for the nitrogen reduction reaction (NRR).
• Density functional theory (DFT + U) calculations for mechanistic studies.

Main Results:

• Nanooctahedral Cu2O exhibited enhanced NRR performance (182.1 µg h⁻¹ mg⁻¹ NH₃ yield, 35.8% FE at -0.5 V vs RHE) compared to cubic Cu2O.
• DFT + U calculations revealed thermodynamically favorable NRR pathways on the (111) facets of Cu2O.
• Charge transfer analysis provided insights into electron density redistribution during NRR.

Conclusions:

• Morphological tuning of Cu2O nanocrystals significantly impacts electrocatalytic NRR performance.
• The exposed (111) facets of nanooctahedral Cu2O are key to its enhanced activity.
• Synergistic experimental and theoretical findings highlight the importance of morphology in designing efficient ammonia electrosynthesis catalysts.