Electron‐Rich Pincer Ligand‐Coupled Cobalt Porphyrin Polymer with Single‐Atom Sites for Efficient (Photo)Electrocatalytic CO₂ Reduction at Ultralow Overpotential

Abstract

Porphyrin and phthalocyanine complexes bearing single‐atom catalytic sites (M‐N4) have been explored as promising electrocatalysts for CO2 reduction reaction (CO2RR), whose activity can be improved by regulating the ligands and/or the metal centers. Moreover, their photosensitive features also provide the possibility for highly efficient photoelectrocatalytic CO2RR. Herein, a novel N′NN′‐pincer‐ligand (N3)‐coupled cobalt porphyrin (CoPor‐N3) polymer is developed for realizing efficient (photo)electrocatalytic CO2RR. The unraveled electronic structure and (photo)electrocatalytic features suggest that a synergistic effect between the electron‐rich N3 ligands and the Co‐N4 single‐atom sites in the CoPor‐N3 polymer results in the Co centers attaining more electrons, which is beneficial to facilitating the electron transfer to CO2 for the activation and reduction processes. As expected, the resultant CoPor‐N3 polymer delivers a good long‐term durability and high CO faradaic efficiency (96%) at an ultralow overpotential (0.39 V), which outperforms the CoPor alone and most porphyrin‐/phthalocyanine‐based electrocatalysts reported so far. Moreover, the photosensitivity of CoPor units can further reduce the overpotential to 0.34 V with a CO faradaic efficiency over 90% under light illumination. The present findings offer a new approach to constructing porphyrin‐based photosensitive electrocatalysts with high‐efficiency photoelectrocatalytic CO2RR.

Emerging Single-Atom Catalysts and Nanomaterials for Photoelectrochemical Reduction of Carbon Dioxide to Value-Added Products: A Review of the Current State-of-the-Art and Future Perspectives

“…Conductive polymers have also been incorporated to effectively enhance the PEC reduction. During the reduction reaction, the organic molecules play the role of mediators, which effectively transfer photogenerated charge carriers to active metal centers. , Numerous functional groups have been attached to the polymeric chain of the conductive polymer to effectively tune the CO 2 reduction for achieving higher selectivity by bonding the functional group and reaction intermediates.…”

“…157,158 Numerous functional groups have been attached to the polymeric chain of the conductive polymer to effectively tune the CO 2 reduction for achieving higher selectivity by bonding the functional group and reaction intermediates. Seta-wiaderek et al synthesized a hybrid photocathode consisting of poly(4-vinylpyridine) (P4VP) modified with Cu 2 O along with Pd NPs to form HCOOH 159.…”

Single-atom-based catalysts for photoelectrocatalysis: challenges and opportunities

“…SACs can also be utilized for PEC reduction reactions. [71][72][73] As shown in Fig. 6a and b, the Cu 2 O nanowire (NW) photocathode has been retrotted with Pt 1 /N-Ni (Pt SAs supported by a porous nickel framework on nickel foam) as a co-catalyst for hydrogen production.…”

Advances for CO2 Photocatalytic Reduction in Porous Ti-Based Photocatalysts

“…Until now, multiple energy production technical routes based on CO 2 conversion have been developed, including thermocatalysis, photocatalysis, electrocatalysis, photo-electrocatalysis, and biocatalysis. − Among them, solar light-driven CO 2 conversion used inexhaustible and cost-free solar energy as the only energy input. It can be performed under mild conditions, which is highly deserving for investigation.…”