Pd₁Cu Single-Atom Alloys for High-Current-Density and Durable NO-to-NH₃ Electroreduction

Area of Science:

• Electrochemistry
• Materials Science
• Catalysis

Background:

• Electrochemical reduction of nitric oxide to ammonia (NORR) is a promising route for ammonia electrosynthesis.
• Developing efficient and robust catalysts is crucial for industrial-scale applications.

Purpose of the Study:

• To design and investigate a single-atom Pd-alloyed Cu (Pd1Cu) catalyst for NORR.
• To understand the catalytic mechanism and optimize performance at industrial current densities.

Main Methods:

• Synthesis of single-atom Pd-alloyed Cu catalyst.
• Operando spectroscopic characterizations.
• Theoretical computations (e.g., DFT).
• Electrochemical testing in a flow cell setup.

Main Results:

• Pd1Cu demonstrates high catalytic activity and selectivity for NORR at industrial current densities (>0.2 A cm-2).
• Operando studies and computations reveal electronic coupling between Pd1 and Cu atoms enhances NO activation and protonation, suppressing hydrogen evolution.
• Achieved an NH3 yield rate of 1341.3 μmol h-1 cm-2 and 85.5% Faradaic efficiency at 210.3 mA cm-2.
• Exhibited excellent long-term durability over 200 hours of electrolysis.

Conclusions:

• Single-atom Pd-alloyed Cu is an efficient and robust catalyst for NORR.
• The catalyst design enables high-performance ammonia electrosynthesis.
• Represents a significant advancement in NORR technology with potential for industrial implementation.