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

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 ZnCl2‐promoted procedure have quite low fluorine contents due to C−F bond cleavage induced by chloride (a Lewis base) and the harsh conditions deployed (400–700 °C). Fabricating F‐CTFs with high fluorine contents (>30 wt %) remains challenging. Herein, we present a low‐temperature ionothermal approach (275 °C) to prepare F‐CTFs, which is achieved via polymerization of tetrafluoroterephthalonitrile (TFPN) over the Lewis superacids, e.g., zinc triflimide [Zn(NTf2)2] without side reactions. With low catalyst loading (equimolar), F‐CTFs are afforded with high fluorine content (31 wt %), surface area up to 367 m2 g−1, and micropores around 1.1 nm. The highly hydrophobic F‐CTF‐1 exhibits good capability to boost electroreduction of CO2 to CO, with faradaic efficiency of 95.7 % at −0.8 V and high current density (−141 mA cm−2) surpassing most of the metal‐free electrocatalysts. [ABSTRACT FROM AUTHOR]