Stable Mg Single-Atom Solid Base Catalysts Anchored on Metal-Organic Framework-Derived Nitrogen-Doped Carbon

Area of Science:

• Materials Science
• Catalysis
• Nanotechnology

Background:

• Solid base catalysts offer environmental and separation benefits but suffer from site aggregation and instability.
• Developing robust and highly active solid base catalysts remains a key challenge in chemical synthesis.

Purpose of the Study:

• To prepare highly active and stable magnesium single-atom catalysts (Mg1/NC) for base-catalyzed reactions.
• To investigate the catalytic performance and stability of Mg1/NC compared to conventional counterparts.

Main Methods:

• A sublimation-trapping strategy was employed, involving Mg vapor sublimation and subsequent trapping on nitrogen-doped carbon derived from ZIF-8.
• The Knoevenagel condensation of benzaldehyde with malononitrile was used as a model reaction to evaluate catalytic activity.

Main Results:

• The synthesized Mg1/NC catalyst, featuring atomically dispersed Mg sites, demonstrated high catalytic activity with a turnover frequency of 49.6 h⁻¹.
• Mg1/NC exhibited superior stability, with no loss of activity after five catalytic cycles, unlike the unstable MgO/NC.
• The Mg1/NC catalyst significantly outperformed the traditional MgO/NC catalyst (7.7 h⁻¹).

Conclusions:

• The sublimation-trapping strategy effectively produces stable and highly active magnesium single-atom catalysts.
• Atomically dispersed Mg sites on nitrogen-doped carbon are crucial for enhanced catalytic performance and stability in base-catalyzed reactions.
• Mg1/NC represents a promising alternative to conventional solid base catalysts for industrial applications.