Single-Atom Based Metal-Organic Frameworks for Efficient C-S Cross-Coupling.

Area of Science:

• Heterogeneous catalysis
• Materials science
• Nanotechnology

Background:

• Single-atom catalysts (SACs) offer high atom utilization and selectivity in catalysis.
• Metal-Organic Frameworks (MOFs) provide stable, high-surface-area platforms for catalyst immobilization.
• Defect engineering in MOFs can enhance catalytic activity and create unique active sites.

Purpose of the Study:

• To develop a novel nickel single-atom catalyst (SAC) integrated into a defect-engineered Metal-Organic Framework (MOF).
• To evaluate the catalytic performance of the developed SAC in C-S coupling reactions.
• To elucidate the reaction mechanism using computational methods.

Main Methods:

• Synthesis of a nickel single-atom catalyst (UiO-66/Ni) via solution impregnation.
• Characterization of the catalyst's structure and composition.
• Testing catalytic activity and selectivity in C-S coupling reactions at room temperature.
• Density functional theory (DFT) calculations to study the reaction mechanism.

Main Results:

• Uniform distribution of nickel single atoms covalently attached to defect-engineered Zr-oxide clusters within the UiO-66 framework.
• Exceptional catalytic activity and selectivity in C-S coupling of aryl thiols and aryl halides, irrespective of electronic substituents.
• Robust catalytic stability, maintaining performance over six reaction cycles.
• DFT calculations revealed the synergistic role of Ni single atoms and MOF defects in facilitating C-S bond formation.

Conclusions:

• The developed UiO-66/Ni catalyst demonstrates superior performance for C-S coupling reactions.
• The catalyst's stability and efficiency highlight the potential of single-atom catalysts in defect-engineered MOFs.
• This work provides a mechanistic understanding and a pathway for designing advanced hybrid catalytic systems.