Single-Atom Bismuth Catalyst with Sulfur Modulation: Toward Efficient Electrochemical Ammonia Synthesis via NRR-EGOR...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Nitrogen reduction reaction (NRR) is crucial for sustainable ammonia synthesis.
• Developing efficient and environmentally benign electrocatalysts for NRR remains a challenge.
• Single-atom electrocatalysts offer unique advantages for catalytic applications.

Purpose of the Study:

• To develop a novel sulfur-doped single-atom bismuth-based nitride catalyst (S-BiNSPC) for efficient electrochemical ammonia synthesis.
• To investigate the structural and electronic properties of S-BiNSPC and their influence on NRR performance.
• To explore the potential of S-BiNSPC in coupled reaction systems, such as NRR with ethylene glycol oxidation reaction (EGOR).

Main Methods:

• Synthesis of S-BiNSPC via a molecular engineering strategy.
• Characterization using X-ray photoelectron spectroscopy (XPS) and extended X-ray absorption fine structure (EXAFS).
• Electrochemical evaluation of NRR performance in KOH electrolyte and DFT calculations.

Main Results:

• S-BiNSPC demonstrated excellent NRR performance with an ammonia yield of 77.71 µg.h⁻¹ mgcat⁻¹ and a Faraday efficiency of 37.03%.
• Sulfur incorporation optimized the electronic structure and local geometry of bismuth, enhancing NRR activity.
• DFT calculations confirmed that sulfur doping facilitates nitrogen activation and reduces the energy barrier for the initial hydrogenation step.

Conclusions:

• The developed S-BiNSPC is a highly efficient and environmentally benign electrocatalyst for ammonia synthesis via NRR.
• Sulfur doping is an effective strategy to enhance the performance of single-atom bismuth catalysts for NRR.
• The catalyst shows potential for practical applications, including coupled reaction systems for value-added product generation.