Evolution of the formation of a covalent triazine-based framework catalyzed by p-toluenesulfonic acid monohydrate

Abstract

A porous covalent triazine-based framework (CTF) was prepared by a two-step strategy, where p-toluenesulfonic acid monohydrate (TsOH·H₂O) was used as a catalyst. The porosity and gas storage capacity of the as-obtained framework was evaluated. In addition, the evolution of the chemical structure during the two stages was studied. Crystallite size was calculated to study the formation of the framework; the evolution of internal porosity has been discussed based on the results obtained. In the first step, a triazine-based polymer was formed at relatively low temperatures, and limited crystallites were developed. However, in the second step, a treatment at higher temperatures performed in an open system resulted in the purification of the chemical structure; furthermore, CTF lamellae with an improved ordered stacking developed, resulting in a dramatic increase in internal porosity.