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

Tailoring morphology to alter catalyst performance offers a promising approach to enhance electrocatalytic nitrogen reduction reaction (NRR) for ammonia electrosynthesis. In this work, the structure-dependent performance of Cu₂O nanocrystals with distinct cubic and octahedral morphologies is investigated. Experimental results demonstrate the structure-dependent activity, wherein Cu₂O with nanooctahedral morphology shows enhanced NRR performance achieving NH₃ yield of 182.1 µg h^-1 mg_cat ^-1 and Faradaic efficiency (FE) of 35.8% at -0.5 V versus RHE, surpassing its cubic counterpart. To gain mechanistic insights, density functional theory calculations are performed with Hubbard correction (DFT + U). The results indicate thermodynamically favorable nitrogen reduction pathway on the exposed (111) facets of Cu₂O. Furthermore, charge transfer analysis provides insights into the redistribution of electron density during NRR. The synergy between experimental results and theoretical insights highlights the importance of morphological tuning in designing efficient Cu₂O-based catalysts for electrocatalytic ammonia synthesis.