Active hydrogen boosts electrochemical nitrate reduction to ammonia

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical nitrate reduction to ammonia is an alternative to the Haber-Bosch process.
• Current methods face challenges with low Faradaic efficiency and ammonia yield due to complex reaction steps.

Purpose of the Study:

• To develop a highly efficient electrocatalyst for nitrate reduction to ammonia.
• To investigate the mechanism behind enhanced ammonia production.
• To explore potential applications in large-scale ammonia synthesis and carbon dioxide capture.

Main Methods:

• Synthesis of hollow cobalt phosphide nanospheres on carbon nanosheet arrays using a confinement strategy.
• Electrochemical evaluation of the catalyst's performance for nitrate reduction.
• In situ experiments and theoretical calculations to elucidate the reaction mechanism.

Main Results:

• The catalyst achieved an exceptionally high ammonia yield rate of 8.47 mmol h⁻¹ cm⁻².
• High Faradaic efficiency was observed for ammonia production.
• Mechanism revealed a dynamic equilibrium between active hydrogen generation and consumption.

Conclusions:

• The cobalt phosphide catalyst significantly advances electrochemical ammonia synthesis.
• Active hydrogen equilibrium is key to achieving high yields and efficiencies.
• The findings offer a new pathway for sustainable ammonia production and CO2 capture.