N-Heterocyclic Carbene-Ligated Mixed-Valent Linear Cu₃ Cluster for Enhanced Electrocatalytic Nitrite Reduction.

Area of Science:

• Inorganic chemistry
• Catalysis
• Electrochemistry

Background:

• Multinuclear copper centers are vital for biological electron transfer.
• Mimicking biological copper systems for multielectron catalysis, like nitrite reduction, is challenging.
• The CuA site exemplifies efficient mixed-valence copper cycling.

Purpose of the Study:

• To design and synthesize a stable, mixed-valent linear copper (Cu3) cluster.
• To investigate its catalytic activity for nitrite reduction.
• To explore the role of N-heterocyclic carbene ligands in stabilizing copper clusters.

Main Methods:

• Synthesis of a linear Cu3 cluster coordinated by an N-heterocyclic carbene (NHC) ligand.
• Structural and electronic characterizations (e.g., temperature-dependent studies).
• Electrochemical reduction of nitrite to ammonia.

Main Results:

• A stable, mixed-valent linear Cu3 cluster was successfully synthesized.
• The NHC ligand effectively stabilized the Cu3 core and facilitated electron transfer.
• Temperature-dependent electron delocalization was observed.
• The Cu3 cluster demonstrated efficient and selective electrochemical reduction of nitrite to ammonia under mild conditions.

Conclusions:

• The synthesized Cu3 cluster is a promising catalyst for sustainable nitrite reduction.
• Mixed-valence copper clusters play a significant role in catalysis.
• This work provides insights into designing efficient copper-based catalysts.