Governing Interlayer Strain in Bismuth Nanocrystals for Efficient Ammonia Electrosynthesis from Nitrate Reduction

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical ammonia synthesis from nitrate offers sustainable production and denitrification.
• Complex reaction pathways and intermediates hinder efficiency and selectivity.

Purpose of the Study:

• To investigate the effect of interlayer strain compression in bismuth nanocrystals on ammonia electrosynthesis from nitrate.
• To improve the activity and selectivity of nitrate reduction to ammonia.

Main Methods:

• Utilized bismuth nanocrystals with controlled interlayer strain compression.
• Employed comprehensive spectroscopic studies and theoretical calculations.
• Evaluated electrochemical performance including Faradaic efficiency and generation rate.

Main Results:

• Interlayer lattice compression in bismuth shortens Bi-Bi bonds, broadening the 6p bandwidth for electron delocalization.
• Enhanced chemical affinities for nitrogen intermediates facilitate nitrate activation and reduce energy barriers.
• Suppressed nitrite generation by alleviating nitrite desorption.
• Achieved a maximal Faradaic efficiency of 90.6% and a generation rate of 46.5 g h⁻¹ gcat⁻¹.
• Demonstrated industrially scalable partial current density up to 300 mA cm⁻².

Conclusions:

• Interlayer strain compression in bismuth nanocrystals is a viable strategy to enhance electrochemical ammonia synthesis from nitrate.
• The approach improves both catalytic activity and selectivity, offering a promising route for sustainable ammonia production and environmental remediation.