Highly Perfluorinated Covalent Triazine Frameworks Derived from a Low‐Temperature Ionothermal Approach Towards Enhanced CO₂ Electroreduction

Abstract

Perfluorinated covalent triazine frameworks (F-CTFs) have shown unique features and attractive performance in separation and catalysis. However, state-of-the-art F-CTFs synthesized via the ZnCl 2 -promoted procedure have quite low fluorine contents due to C À F bond cleavage induced by chloride (a Lewis base) and the harsh conditions deployed (400-700 8C). Fabricating F-CTFs with high fluorine contents (> 30 wt %) remains challenging. Herein, we present a lowtemperature ionothermal approach (275 8C) to prepare F-CTFs, which is achieved via polymerization of tetrafluoroterephthalonitrile (TFPN) over the Lewis superacids, e.g., zinc triflimide [Zn(NTf 2 ) 2 ] without side reactions. With low catalyst loading (equimolar), F-CTFs are afforded with high fluorine content (31 wt %), surface area up to 367 m 2 g À1 , and micropores around 1.1 nm. The highly hydrophobic F-CTF-1 exhibits good capability to boost electroreduction of CO 2 to CO, with faradaic efficiency of 95.7 % at À0.8 V and high current density (À141 mA cm À2 ) surpassing most of the metal-free electrocatalysts.

Fluorinated porous frameworks enable robust anode-less sodium metal batteries

“…Meanwhile, the F 1s spectrum shows a strong peak at 687.8 eV (fig. S7C), and the corresponding F content of FCTF is estimated to be 8.17 atomic % from XPS (table S2), slightly lower than the theoretical value (43,44). Upon increasing the ratio of DCFB, the F peak in XPS and the C-F peak in FTIR are gradually strengthened (figs.…”

Fluorine‐Containing Covalent Organic Frameworks: Synthesis and Application

“…It is also proposed that the fluorine in fCOFs can stabilize the key intermediates during the CO 2 conversion. [ 54 ] Consequently, fCOFs have been employed as catalysts for photocatalysis and electrocatalysis.…”

“…Dai and coworkers synthesized a fluorinated covalent triazine framework (F‐CTF‐1) through a low‐temperature ionothermal method by using 2,3,5,6‐tetrafluoroterephthalonitrile as the monomer. [ 54 ] F‐CTF‐1 affords a fluorine content of 31 wt.% and a BET specific surface area of 367 m 2 g −1 . The introduction of fluorine enhances the hydrophobic nature and CO 2 ‐philic property of F‐CTF‐1, improving the interaction between F‐CTF‐1 and CO 2 molecules.…”

Imidazole linker‐induced covalent triazine framework–ZIF hybrids for confined hollow carbon super‐heterostructures toward a long‐life supercapacitor

“…Among the various MOFs/COFs, 2D carbon materials based on covalent triazine frameworks (CTFs) 25–27 are extensively investigated in energy storage applications thanks to their high specific surface area, ordered structure, unique triazine moiety with 2D sheet‐like structures, good thermal stability, high carbon yield, high nitrogen content, and increased electrical conductivity 25,28 . To date, many ordered CTFs have been synthesized via the ionothermal and low‐temperature (<100°C) superacid (triflic acid) trimerization of nitrile monomers 29–31 . Following these two pioneering synthetic strategies, many alternative approaches (e.g., acid‐catalyzed microwave chemistry, polycondensation, and mechanochemistry) have been applied to synthesize ordered, defect‐free CTF‐based porous materials 26,32,33 .…”

“…25,28 To date, many ordered CTFs have been synthesized via the ionothermal and lowtemperature (<100°C) superacid (triflic acid) trimerization of nitrile monomers. [29][30][31] Following these two pioneering synthetic strategies, many alternative approaches (e.g., acid-catalyzed microwave chemistry, polycondensation, and mechanochemistry) have been applied to synthesize ordered, defect-free CTF-based porous materials. 26,32,33 However, reports of the synthesis of linker-defective disordered 2D CTFs (d-CTFs) and their site-specific hybrid materials are still scarce.…”