Iron-Complex-Based Supramolecular Framework Catalyst for Visible-Light-Driven CO2Reduction

Molecule-based heterogeneous photocatalysts without noble metals are one of the most attractive systems for visible-light-driven CO₂ reduction. However, reports on this class of photocatalysts are still limited, and their activities are quite low compared to those containing noble metals. Herein, we report an iron-complex-based heterogeneous photocatalyst for CO₂ reduction with high activity. The key to our success is the use of a supramolecular framework composed of iron porphyrin complexes bearing pyrene moieties at meso positions. The catalyst exhibited high activity for CO₂ reduction under visible-light irradiation (29100 μmol g^-1 h^-1 for CO production, selectivity 99.9%), which is the highest among relevant systems. The performance of this catalyst is also excellent in terms of apparent quantum yield for CO production (0.298% at 400 nm) and stability (up to 96 h). This study provides a facile strategy to create a highly active, selective, and stable photocatalyst for CO₂ reduction without utilizing noble metals.