Metal-Support Interactions in Molecular Single-Site Cluster Catalysts

Area of Science:

• Heterogeneous catalysis
• Materials science
• Organometallic chemistry

Background:

• Understanding single-site catalyst-support interactions is crucial for optimizing catalytic performance.
• Transition metal chalcogenides offer unique electronic properties for catalytic applications.

Purpose of the Study:

• To investigate the atomistic interface between single-site catalysts and transition metal chalcogenide supports.
• To elucidate the relationship between electronic structure and catalytic activity.
• To design and synthesize a molecular platform for probing these interactions.

Main Methods:

• Synthesis of a molecular platform MCo6Se8(PEt3)4(L)2 (1-M) with varying active metals (M = Cr, Mn, Fe, Co, Cu, Zn).
• Characterization using single crystal X-ray diffraction, NMR, electronic absorption spectroscopy, and cyclic voltammetry.
• Computational methods to analyze electronic and structural properties.

Main Results:

• All 3d transition metal 1-M clusters showed remarkable catalytic activity for coupling tosyl azide and tert-butyl isocyanide.
• Mn and Co derivatives exhibited the fastest catalytic turnover rates.
• Catalytic activity correlated with the degree of electronic interaction and redox cooperativity between the active metal site and the support.

Conclusions:

• Peak catalytic activity is achieved when edge/support redox cooperativity is maximized.
• The transition metal chalcogenide support can deliver electrons to the catalytic site, enhancing reactivity.
• This work provides a molecular platform for designing highly active single-site catalysts.