Support effect-induced electronic modulation facilitates ammonia desorption on Co₃O₄/NF for enhanced nitrate...

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Ammonia synthesis is crucial for agriculture and industry.
• Nitrate reduction reaction (NRR) offers a sustainable pathway for ammonia production.
• Developing efficient catalysts for NRR remains a significant challenge.

Purpose of the Study:

• To synthesize and characterize a novel cobalt oxide catalyst supported on nickel foam for nitrate reduction.
• To evaluate the electrocatalytic performance of the Co3O4/Ni foam catalyst for ammonia synthesis.
• To elucidate the mechanism underlying the enhanced catalytic activity.

Main Methods:

• Synthesis of uniformly dispersed Co3O4 catalyst on nickel foam via flame combustion.
• Electrochemical characterization including linear sweep voltammetry and chronoamperometry.
• Ammonia yield and faradaic efficiency measurements.
• Density Functional Theory (DFT) calculations to investigate reaction mechanisms.

Main Results:

• The Co3O4/Ni foam catalyst exhibited a high ammonia production rate of 2.96 mmol h⁻¹cm⁻² at -0.7 V vs. RHE.
• Achieved a faradaic efficiency approaching 100% for ammonia production during nitrate reduction.
• Theoretical calculations confirmed electron transfer from Ni to Co, lowering the NH3 desorption energy barrier.

Conclusions:

• The Co3O4/Ni foam composite is a highly effective electrocatalyst for ammonia synthesis from nitrate.
• The nickel support plays a critical role in enhancing catalytic activity by facilitating ammonia desorption.
• This study presents a promising strategy for efficient and sustainable ammonia production.