One-pot synthesis of melamine-based porous polyamides for CO2 capture

Abstract

Porous organic polymers (POPs) with high Brunauer-Emmett-Teller (BET) surface area ( S BET ) and plentiful heteroatoms are promising for CO 2 capture and separation. Herein a series of melamine-based porous polyamides were synthesized from melamine and binary/ternary benzoic acid by one-pot polycondensation strategy. These polymers have considerably high S BET (up to 521 m 2 /g) and enriched nitrogen (13.8–44.9 wt%). Importantly, they possess noteworthy CO 2 uptake (0.53–2.9 mmol/g at 273 K and 1 bar), the synergistic effect of predominant microporosity and abundant nitrogen are beneficial. Moreover, they have moderate isosteric heats ( Q st ) (29.5–43.7 kJ/mol) and acceptable CO 2 /N 2 selectivity (IAST: 31.6–277.8), which are highly relevant to the micropore volume, micropore area, and nitrogen content. • A series of melamine-based porous polyamides were facilely prepared by one-pot synthesis without catalyst. • These polyamides with abundant nitrogen content had much higher surface areas compared to previous polyamides. • Their porosity and nitrogen content were carefully controlled via a simple and effective approach. • The well-defined microporosity and abundant nitrogen give them outstanding CO 2 capture. • The CO 2 adsorption was highly dependent on the V micro /V total .