Viciazites: Carbon materials with adjacent nitrogen functionalities for advanced CO2 capture

Abstract

Nitrogen-doped carbon materials are promising candidates for CO2 capture. However, establishing precise structure-property relationships remains challenging due to the difficulty in identifying optimal nitrogen functionalities and controlling their atomic positions without using catalysts. This study successfully synthesized three types of “Viciazites” carbon materials with controlled structures and adjacent nitrogen sites, such as primary amines (NH2), pyrrolic nitrogen, and pyridinic nitrogen without using catalysts to determine the most effective configurations for CO2 capture and desorption. A novel three-step process involving carbonization (973 K), bromination, and amination of coronene yielded adjacent primary amines with 76% selectivity at 723 K. Furthermore, pyrrolic nitrogen (82% selectivity) and pyridinic nitrogen (60% selectivity) were prepared via simple carbonization of 11,12-dihydroindolo[2,3- a ]carbazole (873 K) and 1,10-phenanthroline (673 K), respectively. Comparative experimental studies supported by calculations demonstrated that specific adjacent functionalities dictate CO2 interactions. Most notably, materials with adjacent NH2 and adjacent pyrrolic nitrogen exhibited superior energy efficiency, enabling CO2 desorption below 333 and 363 K, respectively. The desorption temperature of 333 K for adjacent NH2 is significantly lower than conventional requirements (373 K). Consequently, this work provides validated pathways to synthesize designer nitrogen-doped carbon materials, offering the molecular-level control essential for developing next-generation, cost-effective, and advanced CO2 capture technologies.