Electrochemical surface reconstruction of amorphous Co-based boride for nitrate reduction process

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Sustainable nitrogen cycle management requires efficient catalysts for nitrate reduction to ammonia.
• Electrochemical reduction of nitrate offers a promising pathway for ammonia synthesis.

Purpose of the Study:

• To develop and characterize an amorphous multimetal borides (CoFeNiB) catalyst for efficient electrochemical nitrate reduction to ammonia.
• To investigate the catalytic mechanism and stability of the CoFeNiB catalyst.

Main Methods:

• Synthesis of amorphous multimetal borides (CoFeNiB) catalyst.
• Electrochemical characterization including cyclic voltammetry and chronoamperometry.
• Surface analysis using X-ray photoelectron spectroscopy (XPS) and in-situ Raman spectroscopy.

Main Results:

• The CoFeNiB catalyst demonstrated exceptional performance in nitrate reduction to ammonia.
• Surface reconstruction to CoOOH with active Co³⁺ sites was observed, enhancing nitrate and hydrogen adsorption.
• Achieved a stable Faradaic efficiency >90% over a wide voltage range and a high ammonia yield of 3961.4 mmol g_cat⁻¹ h⁻¹.

Conclusions:

• The CoFeNiB catalyst exhibits enhanced activity and stability due to synergistic effects of Ni and Fe.
• This catalyst presents a viable solution for efficient and stable ammonia synthesis from nitrate, contributing to environmental sustainability.