Stepwise structural evolution toward robust carboranealkynyl-protected copper nanocluster catalysts for nitrate...

Area of Science:

• Catalysis
• Nanomaterials Science
• Electrochemistry

Background:

• Atomically precise metal nanoclusters (NCs) offer ideal models for understanding structure-activity relationships in catalysis.
• Synthesizing robust NCs with accessible active sites presents a significant challenge.

Purpose of the Study:

• To develop novel copper nanoclusters (NCs) with enhanced stability and accessible catalytic sites.
• To investigate the catalytic performance of these NCs in electrocatalytic nitrate reduction.
• To elucidate the reaction mechanism through computational and experimental methods.

Main Methods:

• Stepwise synthesis of bulky carboranealkynyl-protected copper NCs (monomer Cu_x·3PF₆ and dimer Cu_x·4PF₆) via ligand shell modification and metal-core evolution.
• Electrocatalytic nitrate reduction to ammonia reaction studies.
• Theoretical computations and in situ FTIR spectroscopy for mechanistic elucidation.

Main Results:

• Successful synthesis of stable monomer and dimer copper NCs with accessible open metal sites.
• Both NCs exhibited remarkable catalytic activity and selectivity for nitrate reduction to ammonia.
• The dimer copper NC (Cu_x·4PF₆) demonstrated superior catalytic performance compared to the monomer.

Conclusions:

• The study presents effective strategies for synthesizing tailored copper NC catalysts.
• The developed copper NCs serve as a platform for exploring structure-activity relationships in catalysis.
• This work advances the field of NC catalysis for important chemical transformations like ammonia synthesis from nitrate.