Construction of Atomic-Scale Compressive Strain for Oxime Electrosynthesis

Area of Science:

• Nanomaterials Science
• Catalysis
• Electrochemistry

Background:

• Tuning surface strain in metal nanocatalysts is crucial for enhancing catalytic activity.
• Atomically precise catalysts with controlled intramolecular strain are needed to understand strain-structure-activity relationships.
• Electrosynthesis of valuable organic molecules like cyclohexanone oxime requires efficient catalytic systems.

Purpose of the Study:

• To synthesize and characterize an atomically precise bimetallic nanocluster with intramolecular strain.
• To investigate the catalytic performance of the nanocluster for cyclohexanone oxime electrosynthesis.
• To elucidate the atomic-level mechanism underlying the catalyst's activity and selectivity.

Main Methods:

• Synthesis of the Ag16Cu18 nanocluster with a central Cu6 ring.
• Single-crystal X-ray diffraction for structural analysis, revealing a short Cu-Cu bond.
• Electrochemical measurements and in-situ attenuated total reflection surface-enhanced infrared spectroscopy (ATR-SEIRAS) for catalytic performance and mechanism studies.
• Density functional theory (DFT) calculations to confirm strain effects and reaction pathways.

Main Results:

• An atomically precise Ag16Cu18 nanocluster was synthesized, featuring a central Cu6 ring with the shortest Cu-Cu bond (1.616 Å) reported for Cu nanomaterials.
• The nanocluster exhibited significant intramolecular compressive strain, even after immobilization on carbon paper.
• The Ag16Cu18 catalyst achieved excellent performance in cyclohexanone oxime electrosynthesis, with a maximal Faradaic efficiency of 47.4% and yield of 95.4% at -0.35 V.
• Mechanistic studies indicated that strained Cu sites facilitate H* formation and cyclohexanone adsorption, crucial for oxime generation.

Conclusions:

• The study reports a novel atomically precise nanocluster with intrinsic compressive strain, offering a platform for studying strain effects at the atomic level.
• The Ag16Cu18 nanocluster demonstrates superior catalytic activity for cyclohexanone oxime electrosynthesis, driven by its unique structural and electronic properties.
• This work provides fundamental insights into the design of bimetallic nanocluster catalysts for efficient electrosynthesis of valuable organic compounds.