美国橡树岭国家实验室Sheng Dai团队报道了基于基于低温离子热方法制备高全氟共价三嗪骨架增强CO2电还原。相关研究成果发表在2021年9月28日出版的《德国应用化学》。

全氟共价三嗪骨架（F-CTF）在分离和催化方面显示出独特的特性和诱人的性能。然而，由于氯化物（一种路易斯碱）诱导的C-F键断裂和恶劣条件（400-700℃），通过ZnCl₂促进程序合成的最先进的F-CTF具有相当低的氟含量。制备高氟含量（>30 wt%）的F-CTF仍然具有挑战性。

该文中，研究人员提出了一种低温离子热方法（275°C）来制备F-CTF，该方法是通过在Lewis超强酸（例如三氟酰亚胺锌[Zn（NTf 2）2]）上聚合四氟对苯二甲酸（TFPN）实现的，无副反应。在低催化剂负载量（等摩尔）下，F-CTF具有高氟含量（31 wt%），表面积高达367 m² g^-1，微孔约为1.1 nm。高疏水性F-CTF-1表现出良好的促进CO ₂电还原为CO的能力，在0.8 V下法拉第效率为95.7%，电流密度（141 mA cm^-2）高，超过大多数无金属电催化剂。

附：英文原文

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

Author: Xian Suo, Fengtao Zhang, Zhenzhen Yang, Hao Chen, Tao Wang, Zongyu Wang, Takeshi Kobayashi, Chi-Linh Do-Thanh, Dmitry Maltsev, Zhimin Liu, Sheng Dai

Issue&Volume: 2021-09-28

Abstract: Perfluorinated covalent triazine frameworks (F-CTFs) have shown unique features and attractive performance in separation and catalysis. However, state-of-art F-CTFs synthesized via the ZnCl  2  -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(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  -1  , 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 0.8 V and high current density (141 mA cm  -2  ) surpassing most of the metal-free electrocatalysts.

DOI: 10.1002/anie.202109342

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202109342