Optimizing oxygen vacancies through grain boundary engineering to enhance electrocatalytic nitrogen reduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalytic nitrogen reduction to ammonia faces challenges in achieving high yield and efficiency.
• Developing advanced catalysts is crucial for sustainable ammonia synthesis.

Purpose of the Study:

• To develop an efficient catalyst for electrocatalytic nitrogen reduction.
• To investigate the role of grain boundaries and oxygen vacancies in catalyst performance.

Main Methods:

• In situ anchoring of ultrafine MoO2 nanograins on N-doped carbon fibers.
• Optimization of thermal treatment to generate grain boundaries and oxygen vacancies.
• Electrochemical measurements and in situ characterization (XPS, DFT calculations).

Main Results:

• The optimal catalyst (MoO2/C700) achieved an NH3 yield of 173.7 μg h−1 mg−1cat and 27.6% Faradaic efficiency.
• Engineered grain boundaries and oxygen vacancies enhanced electron transfer and nitrogen adsorption.
• The catalyst demonstrated excellent stability over 60 hours of continuous operation.

Conclusions:

• Engineering grain boundaries to promote oxygen vacancies is an effective strategy for enhancing electrocatalytic nitrogen reduction.
• The developed catalyst shows significant potential for practical and sustainable ammonia production.
• Interfacial effects and electronic structure modifications are key to catalyst performance.