Hydrogen Bond Activation by Pyridinic Nitrogen for the High Proton Conductivity of Covalent Triazine Framework Loaded with H3PO4

Abstract Under high temperature anhydrous conditions, it is still a formidable challenge to improve the performance of proton‐conducting materials based on H 3 PO 4 and elucidate its proton conduction mechanism. Herein, a highly stable covalent triazine frameworks (CTFs) based on H 3 PO 4 is reported. The more pyridinic nitrogen CTFs contain, the higher proton conductivity is. Compared with H 3 PO 4 @CTF−L with less pyridinic nitrogen, H 3 PO 4 @CTF−H has a higher proton conductivity of 1.6×10 −1 S cm −1 at 150 °C under anhydrous conditions, which does not decay after about 18 months exposure in air. The high proton conductivity is associated with the formation and breaking of the activated N triazine ⋯H + ⋯H 2 PO 4 − pairs by pyridinic nitrogen of CTFs. The outstanding long‐term stability is mainly attributed to the ultra‐strong triazine skeleton structure of CTFs.