Cu doping in CeO₂ to form multiple oxygen vacancies for dramatically enhanced ambient N₂ reduction performance

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Developing efficient electrocatalysts for the nitrogen reduction reaction (NRR) is crucial for sustainable ammonia synthesis.
• Pure cerium oxide (CeO2) nanostructures have shown limited activity for NRR.

Purpose of the Study:

• To synthesize and investigate the electrocatalytic performance of copper-doped cerium oxide (Cu-CeO2) nanorods for the nitrogen reduction reaction (NRR).
• To understand the role of copper doping in enhancing the NRR activity of CeO2.

Main Methods:

• Synthesis of Cu-doped CeO2 nanorods via a facile hydrothermal method.
• Post-synthesis thermal treatment in a H2/Ar atmosphere.
• Electrochemical evaluation of the synthesized materials for NRR in a neutral electrolyte.

Main Results:

• Cu-CeO2-3.9 exhibited a high surface area (95.2 m2 g-1) and mesoporous structure.
• Achieved an NH3 yield rate of 5.3 × 10-10 mol s-1 cm-2 and a Faradaic efficiency of 19.1% at -0.45 V (vs. RHE).
• Cu doping significantly enhanced NRR activity compared to pure CeO2 nanorods.

Conclusions:

• Copper doping effectively tunes oxygen vacancy concentration in CeO2, leading to improved NRR performance.
• Cu-CeO2 nanorods are promising electrocatalysts for efficient and selective ammonia production via NRR.