Efficient electrocatalytic nitrogen reduction to ammonia with aqueous silver nanodots

Area of Science:

• Electrocatalysis
• Materials Science
• Electrochemistry

Background:

• Electrocatalytic nitrogen reduction reaction (NRR) is crucial for ammonia synthesis.
• Development of efficient electrocatalysts and systems is essential for NRR.
• Current NRR systems often rely on loading catalysts onto electrode substrates.

Purpose of the Study:

• To develop a non-loading electrocatalysis system for enhanced NRR.
• To investigate the use of aqueous silver nanodots (AgNDs) as catalysts.
• To explore the role of current collectors in improving NRR performance.

Main Methods:

• Dispersing AgNDs in aqueous solution as a non-loading catalyst.
• Utilizing metallic titanium (Ti) mesh as a current collector.
• Employing Ti mesh modified with TiO2 nanosheets to enhance performance.
• Developing a flow-type electrochemical reactor for continuous ammonia production.

Main Results:

• Aqueous AgNDs achieved an NH3 yield rate of 600.4 μg h−1 mgAg−1 with 10.1% FE at -0.25 V.
• Using TiO2 nanosheet-modified Ti mesh improved FE to 20.1% at -0.25 V.
• The flow-type reactor demonstrated an NH3 yield rate of 804.5 μg h−1 mgAg−1 with 8.2% FE at -1.8 V.

Conclusions:

• The non-loading system effectively utilizes AgNDs for N2 adsorption and activation.
• Theoretical calculations suggest an alternative hydrogenation mechanism.
• This approach offers a new strategy for designing efficient electrocatalytic NRR systems.