Nitrate-to-Ammonia Conversion at an InSn-Enriched Liquid-Metal Electrode

Area of Science:

• Electrochemistry
• Materials Science
• Renewable Energy

Background:

• Electrochemical conversion of nitrates to ammonia is a promising route for hydrogen carrier production.
• Developing stable and efficient electrocatalysts remains a significant challenge.

Purpose of the Study:

• To investigate the use of room-temperature liquid metal Galinstan as an electrocatalyst for nitrate-to-ammonia conversion.
• To understand the mechanism behind its high efficiency and stability.

Main Methods:

• Electrochemical experiments were conducted using Galinstan as the electrocatalyst.
• Density Functional Theory (DFT) calculations were employed to study the reaction mechanism.
• Experimental observations were used to validate theoretical findings.

Main Results:

• Galinstan demonstrated high efficiency and stability for nitrate conversion to ammonia, achieving rates up to 2335 μg h⁻¹ cm⁻² with 100% Faradaic efficiency.
• InSn alloy enrichment on the liquid metal surface was identified as the active site.
• The In₃Sn active site effectively suppressed the competing hydrogen evolution reaction.

Conclusions:

• Room-temperature liquid metal Galinstan is a highly efficient and stable electrocatalyst for ammonia synthesis from nitrates.
• The findings highlight the potential of gallium-based liquid metals in clean energy applications.
• This study advances the development of novel electrocatalytic materials for sustainable chemical production.