An Efficient Intercalation Supramolecular Structure for Photocatalytic CO₂ Reduction to Ethylene Under Visible Light

Abstract

Abstract Photocatalytic CO 2 reduction (CO 2 PR) into multi‐carbon products (especially C 2 H 4 ) is a highly attractive route for global carbon cycle, however, which is seriously limited by sluggish C‐C coupling kinetics and competitive hydrogen evolution reaction (HER) and so on. Herein, the fabrication of a novel supramolecular assembly of NiAl‐Fe‐TCPP is reported by intercalating iron porphyrin (Fe‐TCPP) into NiAl‐layered double hydroxide (NiAl‐LDH), and the resultant NiAl‐Fe‐TCPP exhibit superior catalytic performance on CO 2 PR to C 2 H 4 under visible light irradiation in presence of photosensitizer. A high C 2 H 4 selectivity up to 93.4% in the carbon‐containing products with the production rate as high as 24.7 µmol h −1 can be achieved over NiAl‐Fe‐TCPP. The ex/in situ X–ray absorption spectoscopy (XAS) indicates that the electron transfer between NiAl‐LDH and Fe‐TCPP can promote the generation of low‐valence of Fe sites, resulting in the efficient production of C 2 H 4 . The spin‐polarized density functional theory (DFT) calculations find that the synergistic mechanism that CO 2 molecules are activated to CO on NiAl‐LDH and then spilled to Fe‐TCPP and coupled to COCHO # , which is further reduced to C 2 H 4 , are feasible in the perspective of Gibbs free energy. Moreover, the strong host‐guest interactions between NiAl‐LDH and Fe‐TCPP lead to the promoted photocatalytic activity and superior cycle stability.