2D Covalent Organic Frameworks as Intrinsic Photocatalysts for Visible Light-Driven CO₂ Reduction

Abstract

Covalent organic framework (COF) represents an emerging class of porous materials that have exhibited great potential in various applications, particularly in catalysis. In this work, we report a newly designed 2D COF with incorporated Re complex, which exhibits intrinsic light absorption and charge separation (CS) properties. We show that this hybrid catalyst can efficiently reduce CO 2 to form CO under visible light illumination with high electivity (98%) and better activity than its homogeneous Re counterpart. More importantly, using advanced transient optical and X-ray absorption spectroscopy and in situ diffuse reflectance spectroscopy, we unraveled three key intermediates that are responsible for CS, the induction period, and rate limiting step in catalysis. This work not only demonstrates the potential of COFs as next generation photocatalysts for solar fuel conversion but also provide unprecedented insight into the mechanistic origins for light-driven CO 2 reduction.

Imidazolium‐Salt‐Functionalized Covalent Organic Frameworks for Highly Efficient Catalysis of CO2 Conversion

“…[4][5][6] In particular, the cycloaddition of epoxidesw ith CO 2 to form cyclic carbonates is an important and atom-economic reaction, and the resultant products are important heterocyclic compounds widely used in organic synthesis. [10,11] For example, metal-organic frameworks (MOFs) have served as excellent heterogeneousc atalysts for this reaction. Recently,s ome crystalline porousm aterials have shown promising applications in gas adsorptiona nd catalysis because of the predictable control over their structure.…”

Bismuth‐Based Photocatalysts for Solar Photocatalytic Carbon Dioxide Conversion

“…(1)], [125][126][127][128] DRM [Eq. (3)], [132][133][134][135][136][137][138][139][140] were reported. (3)], [132][133][134][135][136][137][138][139][140] were reported.…”

“…Many photocatalytic materials, such as traditional TiO 2based materials, [132,133] new non-metallicg raphite-like carbon nitride materials, [134,135] metal-organic framework (MOF)c ompounds, [136,137] and even covalento rganic framework (COF) compounds, [138][139][140] have been used for this reaction. The main products are H 2 ,C O, CH 4 , and other hydrocarbons, and the most advantageous characteristics of this reaction are the use of solar heat andl ight energy.I np reviousy ears, research into the photocatalytic CDC reactiona sar educing process has received extensive attention.…”

Kovalente organische Gerüstverbindungen: chemische Ansätze für Designerstrukturen und integrierte Funktionen

“…Unter sichtbarem Licht reduziert Re‐COF CO 2 zu CO mit einer Selektivität von 98 %. Dieses Ergebnis wird der erleichterten Elektronenübertragung vom Gerüst auf den Re‐Komplex zugeschrieben …”