Internal Electric Field‐Regulated Dual‐Site Fe–Re Supramolecular Assembly for Photocatalytic CO 2 Reduction Toward Multicarbon Products

ABSTRACT Photocatalytic CO 2 reduction to multicarbon products remains challenging because C–C coupling is kinetically demanding and often limited by inefficient charge separation and poor control over reaction intermediates. Herein, a heterobimetallic supramolecular catalyst (Fe–Re SA) is constructed via electrostatic self‐assembly between a porphyrinic FeTCPP unit and a molecular Rebpy complex. Structural and spectroscopic analyses confirm that the Fe–N 4 and Re(I) carbonyl coordination environments remain preserved after assembly, while density functional theory (DFT)‐supported interfacial charge redistribution induces an internal electric field that promotes directional charge transfer and suppresses carrier recombination. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) reveals * CO‐related and C–C coupling‐related features, supporting a tandem catalytic mechanism in which the Re site catalyzes CO generation and the Fe‐centered porphyrin promotes subsequent C–C coupling. As a result, Fe–Re SA exhibits enhanced photocatalytic CO 2 reduction toward multicarbon products, achieving a C 2 H 4 formation rate of 4967 µmol g −1 h −1 with a total C 2 selectivity of 57.2% (C 2 H 4 selectivity of 47.5%) among carbon‐containing products. The catalyst also maintains decent activity under low CO 2 concentration (3% CO 2 in Ar) and under natural sunlight irradiation, highlighting its potential for practical solar‐driven CO 2 conversion.