Tailored Metalloporphyrin-Based Three-Dimensional Covalent Organic Frameworks for Enhanced Photocatalytic CO₂...

Area of Science:

• Materials Science
• Catalysis
• Renewable Energy

Background:

• Efficient photocatalysts are crucial for addressing climate change and energy demands.
• Three-dimensional covalent organic frameworks (3D COFs) show promise for CO2 reduction but face synthesis and design challenges.
• Metalloporphyrin-based 3D COFs offer a tunable platform for photocatalysis.

Purpose of the Study:

• To design and synthesize novel metalloporphyrin-based 3D COFs (3D-MPor-COF) with a 5-fold pts topology.
• To investigate the impact of metal centers (Co, Ni, Pt) on photocatalytic CO2 reduction efficiency.
• To optimize COF structure, specifically pore size, for enhanced performance.

Main Methods:

• Synthesis of highly crystalline metalloporphyrin-based 3D COFs with specific topology.
• Photocatalytic experiments to evaluate CO2 reduction rates and selectivity.
• Structural modification (pore enlargement) to create isoreticular COFs.

Main Results:

• The metal center significantly influences photocatalytic activity; 3D-CoPor-COF demonstrated high performance.
• 3D-CoPor-COF achieved a CO production rate of ~11.3 mmol g⁻¹ h⁻¹ with 91.9% selectivity.
• Isoreticular 3D-CoPor-Ph-COF, with enlarged pores, showed enhanced rates (~20.7 mmol g⁻¹ h⁻¹) and selectivity (95.4%).

Conclusions:

• Tailoring pore environments, including catalytic site identity and pore size, is critical for optimizing 3D COFs for CO2 reduction.
• These findings provide molecular-level insights for developing high-performance COF-based photocatalysts.
• The study advances sustainable energy applications through improved CO2 utilization.