A General Strategy for Kilogram-Scale Preparation of Highly Crystal-line Covalent Triazine Frameworks

Scalable and eco-friendly synthesis of crystalline porous covalent triazine frameworks (CTFs) is essential to realize their broad industrial applications but remains a great challenge, which requires the fundamental understanding of the two-dimensional polymerization mechanism. Herein, we report a universal polyphosphoric acid (H6P4O13)-catalyzed nitrile trimerization route to synthesize a series of highly crystalline CTFs with high specific surface areas. This new strategy enables the cost-effective large-scale fabrication of crystalline CTFs at kilogram level for the first time. Through density functional theory calculation and detailed controlled experiments, we reveal that the polyphosphate acid show much higher catalytic activity for trimerization reaction than its analogues such as P2O5 and H3PO4. Furthermore, the crystalline CTFs with regular porosity and abundant triazine groups exhibit ultrahigh removal efficiency of micropollutants, indicating its great potential in environment remediation.

Automated summary

A universal polyphosphoric acid catalyzed nitrile trimerization route for synthesizing highly crystalline CTFs at large scale is reported. The study reveals the high catalytic activity of polyphosphate acid and the high removal efficiency of micropollutants by CTFs.