Atomic-Scale Homogeneous RuCu Alloy Nanoparticles for Highly Efficient Electrocatalytic Nitrogen Reduction.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Ruthenium (Ru) is a key electrocatalyst for nitrogen (N2) reduction reaction (NRR) due to its N2 adsorption properties.
• Homogeneous Ru-based alloys (e.g., Ru-Rh, Ru-Pt, Ru-Co) enhance ammonia (NH3) selectivity and formation rates.
• The potential of immiscible metal combinations with Ru for NRR remains largely unexplored.

Purpose of the Study:

• To investigate the performance of an immiscible Ru-Cu alloy for NRR.
• To fabricate homogeneous Ru-Cu alloy nanoparticles (Ru-Cu NPs) using the carbothermal shock method.
• To evaluate the selectivity and NH3 formation rate of Ru-Cu NPs on a cellulose/carbon nanotube sponge support.

Main Methods:

• Fabrication of homogeneous Ru-Cu alloy nanoparticles (Ru-Cu NPs) via the carbothermal shock method.
• Immobilization of Ru-Cu NPs onto a cellulose/carbon nanotube sponge.
• Electrocatalytic testing for nitrogen reduction reaction (NRR) to quantify ammonia (NH3) production.

Main Results:

• The Ru-Cu homogeneous NP alloys demonstrated high selectivity for NH3 formation (≈31%).
• The NH3 formation rate achieved was approximately -73 μmol h⁻¹ cm⁻².
• These performance metrics represent the highest values reported for Ru-based alloy combinations in NRR.

Conclusions:

• Immiscible Ru-Cu alloy nanoparticles show significant promise for efficient electrocatalytic NRR.
• The carbothermal shock method is effective for fabricating high-performance Ru-Cu alloy catalysts.
• This work expands the scope of metal combinations for NRR catalysts, achieving state-of-the-art performance.